Little information exists about the relationship of nutritional status and motor performance conditional on asymptomatic parasitemia in rural African children.

The aims of this study were to (1) determine if malnourished youths from rural African areas have lower levels of physical fitness (PF) and physical activity (PA) compared to normal weight youths, (2) verify the biological relevance of anthropometric criteria used to classify nutritional status in youth, and (3) determine the prevalence of parasitological indicators, and its association with nutritional status and PF.

The sample comprised 794 youths (6–17 years) from Calanga, a rural community in Mozambique. PF tests were selected from standardized test batteries, and PA was estimated by accelerometry. Nutritional status was defined according to WHO recommendations for stunting, wasting and normal weight. Parasitological indicators were determined based on stool specimens' analysis.

In general terms the normal group out-performed the other nutritional groups (stunted and wasted) for PF. However, no significant differences were found for PA among nutritional groups. There were also no significant differences in prevalence of intestinal parasites.

Nutritional status was not associated with PA levels or the prevalence of parasitological indicators in youth, but was related to physical performance. Am. J. Hum. Biol., 2013. © 2013 Wiley Periodicals, Inc.

The paper tests the thrifty phenotype hypothesis, according to which nonharmonious growth trajectories are costly for adult health.

The American surge in the prevalence of type 2 diabetes is concentrated in the South, a region characterized by a long history of poverty followed by rapid economic growth beginning in the 1960s. Civil rights legislation further accelerated income growth for African-Americans in the region. The paper investigates the hypothesis by using per capita income at the state level as a proxy for net nutritional conditions.

Regressions at the state level explain 56% of the variation in the prevalence rate of type 2 diabetes in 2009 using two explanatory variables: the ratio of per capita income in 1980 to that in 1950 and the share of the population that was African-American. The paper discusses ways that rapid economic growth may have translated into weight gain and type 2 diabetes.

If the thrifty phenotype hypothesis is correct, future rates in the prevalence of type 2 diabetes are predictable based on income history. The forecast for rapidly developing countries such as India and China are ominous. Am. J. Hum. Biol., 2013. © 2013 Wiley Periodicals, Inc.

We measured height, weight, body mass index (BMI), upper arm circumference, and triceps skinfolds of 186 children and adolescents aged 2 to 18 years from seven communities. Anthropometric z-scores were calculated based on the National Health and Nutritional Examination Survey. Comparisons were made with this US reference group, along with between community differences to contextually explore the impacts of varying degrees of market integration.

We found a high prevalence of stunting in both boys (40%) and girls (34%). Adiposity increased with age and 40% of girls between 15 and 18 years old were overweight. There were large sex differences in body composition with higher BMI, arm circumference, and triceps skinfolds in adolescent girls. The Kichwa demonstrated the poorest growth outcomes and nutritional stress followed by the Huaorani and Shuar; yet distinctions in under- and over-nutrition were evident within groups.

Market integration is a major factor influencing the developmental and lifestyle mismatch associated with the epidemiologic and nutrition transition in general, and the dual burden pattern of high rates of stunting yet adequate to above average short-term nutritional status indicators found among indigenous Amazonian populations. Am. J. Hum. Biol., 2013. © 2013 Wiley Periodicals, Inc.

Studies of the placenta in pregnancies complicated by pre-eclampsia have led to the suggestion that tissue along the length and breadth of its surface has different functions. A recent study in Saudi Arabia showed that the body size of newborn babies was related to the breadth of the surface at birth but not to its length. We have now examined whether the association between placental breadth and body size reflects large size of the baby from an early stage of gestation or rapid growth between early and late gestation.

We studied 230 women who gave birth to singleton babies in King Khalid Hospital, Riyadh, Saudi Arabia. In total, 176 had ultrasound measurements both before 28 weeks and at 28 weeks or later, which we define as early and late gestation. We used these to calculate growth velocities between early and late gestation, which we expressed as the change in standard deviation scores over a 10-week period.

The breadth of the placental surface was correlated with fetal growth velocity. The correlation coefficients were 0.24 (P = 0.002) for the head circumference, 0.24 (P = 0.001) for the biparietal diameter and 0.34 (P < 0.001) for the abdominal circumference. The length of the surface was not related to fetal growth velocity.

Tissue along the breadth of the placental surface may be more important than tissue along the length in the transfer of nutrients from mother to baby. This may be part of a wider phenomenon of regional differences in function across the placental surface. Am. J. Hum. Biol., 2013. © 2013 Wiley Periodicals, Inc.

A longitudinal cohort of Finnish twin pairs (FinnTwin12) was analyzed using self-reported height at 11–12, 14, 17 years and measured stature at adult age (21–24 years). Data were available for 719 individual twins including 298 complete pairs. Serum lipids and lipoprotein subclasses were measured by proton nuclear magnetic resonance spectroscopy. Multivariate variance component models for twin data were fitted. Cholesky decomposition was used to partition the phenotypic covariation among traits into additive genetic and unique environmental correlations.

In men, the strongest associations for both adult height and puberty were observed with total cholesterol, low-density lipoprotein cholesterol, intermediate-density lipoprotein cholesterol, and low-density lipoprotein particle subclasses (max. r = −0.19). In women, the magnitude of the correlations was weaker (max. r = −0.13). Few associations were detected between height during adolescence and adult lipid profile. Early onset of puberty was related to an adverse lipid profile, but delayed pubertal development in girls was associated with an unfavorable profile, as well. All associations were mediated mainly by additive genetic factors, but unique environmental effects cannot be disregarded.

Early puberty and shorter adult height relate to higher concentrations of atherogenic lipids and lipoprotein particles in early adulthood. Common genetic effects behind these phenotypes substantially contribute to the observed associations. Am. J. Hum. Biol., 2013. © 2013 Wiley Periodicals, Inc.

We conducted an in-home intervention study in which fathers (n = 44) played with their toddlers. Subjects provided saliva samples before interacting with their children, with additional collections 40 and 70 min later.

E2 did not significantly change over the study period (P > 0.4). P4 declined significantly from baseline to 40 min (P < 0.05) and 70 min (P < 0.001). Men reporting that the interaction made them feel very happy/relaxed had greater P4 exposure from baseline through 70 min (area under the curve) compared with men reporting less positive post-interaction mood (P < 0.05). This relationship persisted after controlling for cortisol. Men's % decrease in P4 (baseline to 40 min) was significantly greater if they had an infant (P < 0.05), while fathers' % decline in E2 (baseline to 70 min) was larger if they had more children (P < 0.05).

These results require replication but could indicate that grouping fathers with different levels of experience obscures meaningful variation in hormonal responses to child interaction. Our findings appear consistent with the effects of P4 as a mood enhancer and suggest future research should explore the possible role of P4 as hormonal mechanism that could reinforce or facilitate paternal investment. Am. J. Hum. Biol., 2013. © 2013 Wiley Periodicals, Inc.

The subjects were 37 men (age = 40.9 ± 10.7 years) and 42 women (age = 35.8 ± 10.4 years) who were employed as hotel workers in Hawaii. Each wore an ABP monitor for one midweek workday and had pressures averaged in three daily microenvironments (work, home, and during sleep). They also had fasting blood samples taken for lipid profiling.

Multivariate analysis of covariance shows that there was a strong inverse relationship between HDL and both systolic (P < 0.006) and diastolic (P < 0.006) BP, overall and in each microenvironment, but no statistically significant relationships with other lipid measures.

These results suggest lipids and BP do not act as a group in healthy adults but that higher HDL is associated with lower BP. This latter finding is consistent with research that shows that HDL promotes vasodilation via its effect on endothelial nitric oxide synthase. Am. J. Hum. Biol., 2013. © 2013 Wiley Periodicals, Inc.

On each of 217 policemen, 18 saliva specimens were obtained for cortisol. Statistical models examined the associations of within-subjects (W-S) cortisol standard deviation (SD) and W-S cortisol mean with waist circumference and four body composition indexes: BMI, and three derived from DEXA: fat-mass, and trunk and extremities lean-mass. Explained variance and the functional nature of associations are reported.

Associations of anthropometrics with W-S cortisol mean were not statistically significant at P < 0.05; all associations with W-S cortisol SD were significant. The association of trunk lean mass index (LMI_t) with W-S cortisol SD dominated all models. Associations of W-S cortisol SD with other indexes vanished when models contained LMI_t ; when any other index was included in models predicting LMI_t, associations with W-S cortisol SD remained significant. The functional association between LMI_t and W-S cortisol SD is progressively “hockey stick,” monotonic increasing, and flattens at joint high values.

Results support inferences that LMI_t measures visceral adiposity and W-S cortisol variability appears to be an appropriate construct to measure in association with visceral adiposity. The “hockey stick” character of the association is consistent with other investigations suggesting obesity is associated with less W-S cortisol variation; however, the monotonic increase and flattening of association at increasing W-ScortisolSD values suggests a more complex association, potentially interpretable by allostasis models of causation. Am. J. Hum. Biol., 2013. © 2013 Wiley Periodicals, Inc.

The sample included 382 White and African American 5–18-year-olds. Body mass index (BMI), waist circumference (WC) and sexual maturity status (breast/genital and pubic hair stage) were assessed in a clinical setting. Total body fat (TBF) was measured by dual-energy X-ray absorptiometry and abdominal subcutaneous (SAT) and visceral adipose tissue (VAT) were measured by magnetic resonance imaging. Analysis of covariance adjusted for age was used to examine the association between sexual maturity status and adiposity, and linear regression adjusted for age was used to examine the influence of sexual maturation on ethnic differences in adiposity. Analysis of VAT also controlled for TBF. Significance was accepted at P < 0.05.

Breast/genital stage was significantly associated with BMI, WC, TBF, and SAT in girls of both ethnic groups and in White boys. Breast stage was associated with VAT. Stage of pubic hair was significantly associated with TBF and VAT in White girls only. In girls, sexual maturation attenuated the ethnic effects on BMI and WC, but the ethnic effect in VAT persisted. In boys, sexual maturation did not attenuate ethnic differences on VAT and did not predict WC or SAT. Sexual maturity status independently explained variance in adiposity in girls only.

Sexual maturity status is an important determinant of pediatric adiposity and attenuates ethnic differences in girls' adiposity. Am. J. Hum. Biol., 2013. © 2013 Wiley Periodicals, Inc.

We examined mtDNA sequence variation from the hypervariable region 1 (HVS-1) and NRY genetic variation using short tandem repeat (STR) loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, and DYS439) and NRY haplogroups (Q1a3a, Q1a3*, C3b, R1b1b2, E1b1, G2a2, and I) identified through single-nucleotide polymorphisms. Phylogenetic analysis included multidimensional scaling (MDS), heterozygosity versus r_ii, and analysis of molecular variance (AMOVA).

Eighteen mtDNA haplotypes were characterized in 131 participants with 94.6% of these assigned to the Amerindian mtDNA subclades, A2 and B2. The Amerindian NRY haplogroup, Q1a3a, was present in all five groups and ranged from 85% (Zapatón-Huetar) to 35% (Chorotega). Four populations (Rama, Chorotega, Zapatón-Huetar, and Abrojo-Guaymí) were also characterized by the presence of NRY haplogroup R1b1b2 indicative of western European admixture. Seventy NRY STR haplotypes were identified of which 69 (97%) were population specific. MDS plots demonstrated genetic similarities between Mesoamericans and northern Chibchan Amerindian populations, absent in mtDNA analyses, which is further supported by heterozygosity versus r_ii results.

We conclude that although these linguistically related populations in geographic proximity demonstrate a high degree of paternal genetic differentiation, recent demographic events have dramatically altered the paternal genetic structure of the regions Amerindian populations. Am. J. Hum. Biol., 2013. © 2013 Wiley Periodicals, Inc.

One hundred women of Yoruba ethnicity from southwest Nigeria and 94 African American women from metropolitan Chicago were recruited and compared using a standardized survey protocol and the same laboratory assay for 25(OH)D.

Mean 25(OH)D levels were 64 nmol/l among the Nigerians and 29 nmol/l among the AA. Only 10% of the values were shared in common between the groups, and 76% of the Nigerians were above the currently defined threshold for adequate circulating 25(OH)D compared to 5% of the AA. Modest associations were seen between 25(OH)D and measures of obesity, although adjustment for these traits did not materially affect the group differences.

These data support the presumption that skin color is an adaptive trait which has evolved in part to regulate 25(OH)D. It remains undetermined, however, whether lower values observed in AA have negative health consequences. Am. J. Hum. Biol., 2013. © 2013 Wiley Periodicals, Inc.

The main purpose of this study was to explore changes in body weight and height, BMI, body fat, and AR timing in girls from Krakow within the last 3 decades.

1,970 girls were measured in 2010. Using the results of body height, weight and skin folds measurements, the BMI and %BF was calculated. The LMS method was used to constructed BMI and %BF centiles. Three fractions were distinguished in individual age groups of the subjects—below the 15th percentile (underweight girls), 50th percentile and above 85th percentile (overweight girls). These data were compared with the results from previous survey series (1983 and 2000). The mean age of the menarche onset were calculated by means of the probit method.

The girls from last series are taller and heavier than girls measured in 1983. Before the time of AR, girls from last series have lowest BMI and %BF than girls from the first series. In spite of this, all girls measured in 2010 have the time of AR earlier than girls measured in 1983. The girls from the last series of measurements showed also acceleration of sexual maturation and the average menarche age was the earliest in them and equalled 12.68 years.

AR cannot be explained only by changes in body adiposity. Early AR could be a marker of acceleration of development already in an early postnatal ontogenesis. Am. J. Hum. Biol. 25:300–306, 2013. © 2013 Wiley Periodicals, Inc.

Thirty men aged 19–37 were recorded using motion-capture technology as they danced to a standard rhythm. Participants also completed a vascular fitness test, assessments of upper- and lower-body strength, and biomechanical indices were extracted from their dance movements. Dance clips were converted into virtual humanoid characters (avatars) and rated by 27 women and 21 men on perceived dance quality.

General linear mixed modeling revealed that both handgrip strength and arm movements of the dancer were statistically significant predictors of dance quality ratings; stronger males who displayed larger, more variable, and faster movements of their arms being rated as better dancers. There was no effect of the sex of the observer in predicting dance quality ratings, indicating that male and female observers rated dance quality equivalently. Physical fitness was not associated with perceived dance quality.

Men and women are able to derive certain quality cues from observing male dance movements in the form of controlled stimuli. Thus, male dancing may form a condition-dependent ornament of certain aspects of mate quality. Am. J. Hum. Biol. 25:307–312, 2013. © 2013 Wiley Periodicals, Inc.

The frequencies for five Y-chromosome linked microsatellites (DYS19, DYS390, DYS391, DYS392, and DYS393) were characterized in four Amerindian tribes from Brazilian Amazon (Tikúna, Baníwa, Kashinawa, and Kanamarí), and in four quilombo remnants (Mimbó, Sítio Velho, Gaucinha, and São Gonçalo) and two urban populations (Teresina and Jequié) from Northeastern Brazil. We then estimated the male genetic ancestry in each admixed population. Moreover, we performed analysis of molecular variance (AMOVA), F_ST, haplotype diversity, and principal component analysis.

Lower haplotype diversity (h) values were observed for Tikúna compared with other tribes. Quilombo remnants exhibited higher h levels ranging from 0.893 ± 0.027 in Sítio Velho to 0.963 ± 0.033 in São Gonçalo. African ancestry estimates ranged from 0.529 ± 0.027 in Mimbó to 0.602 ± 0.086 in Sítio Velho. Conversely, European contribution was 0.795 ± 0.045 in Teresina and 0.826 ± 0.040 in Jequié.

F_ST and principal component analysis indicate homogeneity in the male genetic constitution among the quilombo remnants analyzed. Data on Amerindians allowed accurate ancestry estimates, which indicated a higher African contribution, followed by a considerable European contribution for these quilombo remnants. Am. J. Hum. Biol. 25:313–317, 2013. © 2013 Wiley Periodicals, Inc.

We use the large urban-rural mortality differential to capture the predicted/perceived mortality environment. We categorize children into different groups by their migration status: conceived and living in the same environment (urban or rural); conceived in one but born in another environment (urban-to-rural or rural-to-urban); and born in one but migrating to another environment. We use Kaplan-Meier survival curves and fixed effect survival models to estimate to what extent child survival up to the age of 15 depends on migration status.

Child mortality within families that moved from urban to rural areas does not depend on the child's migration status. Within families that moved to urban areas, children who were conceived and born in the rural areas exhibit the lowest mortality. This contradicts a phenotype-environment-mismatch scenario, which would result in higher rather than lower mortality.

We do not find evidence for functional (adaptive) epigenetic inheritance. Migration into an environment with lower or higher extrinsic mortality affects child mortality within the families differently than predicted by the concept of epigenetic inheritance. The results suggest that epigenetic inheritance may not be important for child mortality among migrants. Am. J. Hum. Biol. 25:318–328, 2013. © 2013 Wiley Periodicals, Inc.

This investigation aimed to evaluate the secular trend exhibited by developing permanent teeth in 5 to 6 years old southern Chinese children.

Four hundred radiographs of children born in the years 1981 (n=200) and 2001 (n=200) were randomly selected, and then age and gender matched. Maxillary and mandibular teeth on the left side were scored. The number of tooth developmental stages (n-tds) for each stage of development and total n-tds in crown and root development was calculated. Logistic regression, X² test for occurrence of trend and Fisher's exact test were used to evaluate the variations in n-tds between crown and root maturation and also maturation among different teeth. Dental maturation between boys and girls was also compared.

In the maxillary dentition, children born in 2001 showed advanced dental maturation (odds ratio, 1.29; P=0.001), and girls exhibited earlier maturation than boys (odds ratio, 1.43; P=0.001). In the mandibular dentition, no significant difference between the years was observed (odds ratio, 0.97; P=0.761), however, girls showed accelerated development than boys (odds ratio, 1.26; P=0.002). Variations in maturation were also observed between individual tooth in the same arch and between the arches.

Children born in 2001 demonstrated accelerated dental development only in the maxillary dentition. Girls born in 1981 and 2001 exhibited advanced maturation than boys. Variations in development among different teeth in the year groups indicate the need for inclusion of all developing teeth to establish a secular change. Am. J. Hum. Biol. 25:329–334, 2013. © 2013 Wiley Periodicals, Inc.

Data (N = 5,123) were collected in cross-sectional health surveys among the Inuit in Greenland in 1993–1994, 1999–2001, and 2005–2010. Sociodemographic information was obtained by interview. Information on obesity (body mass index (BMI) and waist circumference) was obtained by clinical examination and in 1993–1994 by interview. Statistics included multiple linear regression and Univariate General Linear Models.

Among men the prevalence of overweight (BMI 25–29.9) decreased while general obesity (BMI ≥ 30) did not change. Central obesity increased from 16.0% in 1993–1994 to 25.4% in 2005–2010 (P < 0.001). Among women general and central obesity increased. Central obesity increased from 31.3% in 1993–1994 to 54.2% in 2005–2010 (P < 0.001). In 2005–2010 both general and central obesity showed significantly increasing trends with social position (general obesity: P < 0.001 for men, P = 0.04 for women; central obesity: P < 0.001 for both men and women). The social trend was absent in the earlier surveys.

General and central obesity is increasing among the Inuit in Greenland. There is an increasing positive association of obesity with social position for both men and women. The high prevalence of obesity is a serious public health problem that is expected to affect the already high prevalence of Type 2 diabetes and its complications. Am. J. Hum. Biol. 25:335–340, 2013. © 2013 Wiley Periodicals, Inc.

We have reported that changes in the lifestyle of pregnant women during Ramadan affect more than one generation. In a series of newborn babies in Saudi Arabia, those whose mothers had been in utero during Ramadan differed from those whose mothers had not been in utero during Ramadan. These were unexpected findings and require replication.

We examined body size at birth in 1,321 babies (682 boys and 639 girls) born in Gafsa, a small city in Tunisia.

Babies whose mothers had been in utero during Ramadan were smaller and thinner, and had smaller placentas, than those whose mothers had not been in utero during Ramadan. After adjustment for sex, the babies were 93 g lighter (95% confidence interval, 32–153, P=0.003) than those whose mother had not been in utero during Ramadan, their mean ponderal index was 0.52 kg/m³ lower (0.24–0.79, P<0.001) and their placental weight was 21 g lower (5–37, P=0.01). The findings did not differ by trimester of maternal exposure to Ramadan. They were similar in boys and girls and in primiparous and multiparous mothers

This study provides further evidence that changes in lifestyle during Ramadan have intergenerational effects. Am. J. Hum. Biol. 25:341–343, 2013. © 2013 Wiley Periodicals, Inc.

A total of 381 pregnant women were enrolled. Blood lead and cadmium were measured using electrothermal atomic absorption spectrometry, and dietary intake was assessed using 24-h recall questionnaire.

Lead levels in the first trimester were negatively correlated with cadmium levels in the two trimesters, and levels of both metals correlated positively in the third trimester. Zinc and calcium intakes were negatively associated with blood lead during third trimester. Thiamine and folic acid intakes were negatively and positively associated (respectively) with blood lead at third trimester with marginal significance. Fat, niacin, and vitamin B12 intakes were significantly and positively associated with blood cadmium at first trimester. Folic acid and zinc intakes showed positive and marginally significant associations with blood cadmium without adjustments. At third trimester, blood cadmium was negatively associated to ascorbic acid intake, and positively associated with iron intake with a marginal significance.

Possible acute and late effects of nutrients intake in blood lead and cadmium levels could be related with associations exclusively observed in the first and third trimester. This study represents the first exploration of relationships among a wide range of nutrients intake in the first trimester of pregnancy with blood lead and cadmium in first and third trimester of gestation. Further studies are required to confirm the findings mentioned herein. Am. J. Hum. Biol. 25:344–350, 2013. © 2013 Wiley Periodicals, Inc.

Cortisol is one of the most frequently used stress biomarkers in humans. Urine and saliva are the matrices of choice to longitudinally monitor cortisol levels. Salivary and urinary cortisol are often discussed as though they provide similar information. However, the relationship between “free” cortisol levels in urine (nonconjugated) and saliva (non-protein-bound) has yet to be properly evaluated using naturalistic designs.

To investigate the longitudinal relationship between salivary cortisol (SC) and first morning urinary cortisol (FMUC), and to compare the advantages and disadvantages of these matrices in assessing longitudinal changes in cortisol secretion using naturalistic designs.

Cortisol levels from 31 healthy, Kakchiquel Mayan women in Guatemala were compared in one first morning urine (FMU) and four saliva specimens collected daily across three alternate days. Linear mixed-effect regression models including fixed and random effects were used to analyze the repeated-measures data.

FMUC levels (16.04–242.18 ng/ml) were higher than SC levels (0.21–5.16 ng/ml). A small but statistically significant relationship was found between FMUC and SC (each 1 ng/ml increase in FMUC predicted a 0.1% increase in SC; P < 0.05).

Nonconjugated FMUC levels are related to non-protein-bound SC levels collected throughout the day. FMU presents several advantages over saliva for the longitudinal assessment of cortisol in naturalistic studies. Cortisol levels are about 53-fold higher in FMU than in saliva, which makes between- and within-individual variation easier to detect, and FMUC levels are less likely to be affected by confounders than diurnal SC levels. Am. J. Hum. Biol. 25:351–358, 2013. © 2013 Wiley Periodicals, Inc.

Five MHC-Alu elements (AluMicB, AluTF, AluHJ, AluHG, and AluHF) were typed in samples from Jujuy (N = 108) and Waorani (N = 36). Allele and haplotype frequency data on worldwide populations were compiled to explore spatial structuring of the MHC-Alu diversity through AMOVA tests. We utilized the median-joining network approach to illustrate the continental distribution of the MHC-Alu haplotypes and their phylogenetic relationships.

Allele and haplotype distributions differed significantly between Jujuy and Waorani. The Waorani featured a low average heterozygosity attributable to strong population isolation. Overall, Alu markers showed great genetic heterogeneity both within and among populations. The haplotype distribution was distinctive of each continental ancestry group. Contrary to expectations, Africans showed the lowest MHC-Alu diversity.

Genetic drift mainly associated to population bottlenecks seems to be reflected in the low MHC-Alu diversity of the Amerindians, mainly in Waorani. Geographical structuring of the haplotype distribution supports the efficiency of the MHC-Alu loci as lineage (ancestry) markers. The markedly low Alu diversity of African populations relative to other continental clusters suggests that these MHC-Alus might have arisen after the anatomically modern humans expanded out of Africa. Am. J. Hum. Biol. 25:359–365, 2013. © 2013 Wiley Periodicals, Inc.

An online sample of 954 women reported on their childhood living circumstances, their age of menarche, first coitus, first pregnancy, and first birth.

Cox regression and Kaplan–Meier plots showed an increased risk of becoming a parent for father absent women in their 20s, but no overall greater likelihood of parenthood.

These data support the suggestion that father absence is associated with an acceleration of reproductive behavior in Western samples, rather than a simple increase in likelihood of reproduction. Am. J. Hum. Biol. 25:366–369, 2013. © 2013 Wiley Periodicals, Inc.

This study examines cross-sectional associations of indices of adiposity, lean body mass, and physical activity, with heart rate variability (HRV), a marker for parasympathetic cardiac vagal control.

The study population consists of 360 officers from the Buffalo New York Police Department. Indices of adiposity include body mass index, waist circumference, and a fat-mass index taken from dual-energy X-ray absorptiometry (DEXA) measurements. Lean body mass indices were derived from DEXA measurements of trunk mass and extremity lean mass. Physical activity was measured using a 7-day self-report questionnaire. HRV was obtained from 5-min electrocardiogram measurements by means of parametric spectral analysis resulting in estimates for high-frequency (HF) and low-frequency (LF) HRV.

Both HF and LF HRV were significantly associated with markers for adiposity, two components of lean mass and physical activity with all associations being in the expected direction except that for trunk lean mass. This unexpected result is explained by the possibility that trunk mass is a marker for visceral adiposity rather than lean mass. Body mass index did not explain any additional variance in HRV above and beyond waist circumference and the DEXA indices.

Higher levels of physical activity, lower levels of markers for central adiposity and higher lean mass in the extremities predict higher levels of HRV in this population of police officers. This association between modifiable risk factors and markers for autonomic function suggest possible interventions that may improve health and performance. Am. J. Hum. Biol. 25:370–377, 2013. © 2013 Wiley Periodicals, Inc.

BMI-for-age curves were produced for 747 non-Hispanic, white Fels Longitudinal Study participants, from which individual age (Age_Peak) and BMI (BMI_Peak) at maximum infant BMI were estimated. Multivariable general linear regression was used to examine the effects of sex and birth year cohort (1929–1950, 1951–1970, and 1971–2010) on Age_Peak and BMI_Peak, with associations between BMI_Peak and concurrent sum of four skinfold thicknesses assessed in a subsample (N = 155). Heritability (h²) of Age_Peak and BMI_Peak was estimated using maximum-likelihood variance components analysis.

Age_Peak occurred at 9 months of age in both sexes, but BMI_Peak was 0.4 kg/m² higher for boys than for girls (P-value < 0.001). Infants born between 1971 and 2010 experienced a 1.5 month earlier Age_Peak and a 0.35 kg/m² lower BMI_Peak than infants born between 1929 and 1950 (P-values < 0.001). Skinfold thickness explained 37% of the variance in BMI_Peak in boys and 20% of the variance in girls (p-values < 0.001). Age_Peak and BMI_Peak were significantly heritable (h² = 0.54 and 0.75, respectively).

Both Age_Peak and BMI_Peak decreased over successive birth year cohorts in the Fels Longitudinal Study. Despite a positive association of BMI_Peak with concurrent adiposity, Age_Peak appears to occur later than does the well-documented peak in infant fat mass and BMI_Peak does not capture known sex differences in infant adiposity. Strong heritability of these infant BMI traits suggests investigation of genetic control, and validation of their relationship to body composition is greatly needed. Am. J. Hum. Biol. 25:378–388, 2013. © 2013 Wiley Periodicals, Inc.

Urinary CRP, salivary progesterone, and estradiol were measured over one menstrual cycle from rural Polish women (n = 25), representing a natural fertility sample. Age of menarche was assessed through interview recall methods. We used minimum second-order Akaike Information Criteria as a means of multiple regression model selection, and repeated measures ANOVA to test cycle-dependent hypotheses.

Comparisons of individuals in high and low CRP tertiles revealed that those with high CRP had significantly lower progesterone (luteal P = 0.03, mid luteal P = 0.007) but not estradiol (follicular P = 0.21, luteal P = 0.15) concentrations through the menstrual cycle. However, when the age at menarche was included in the analysis, both age at menarche and urinary CRP were negatively associated with estradiol (R² = 0.44, P = 0.0007). Age at menarche and estradiol were the strongest negative predictors of CRP (R² = 0.52, P = 0.0001).

Inflammation itself may suppress ovarian function, or indicate immune challenges that lead to ovarian suppression. The timing of menarche may also influence adult inflammatory sensitivity and ovarian hormone concentrations. This lends support to existing models of trade-offs between maintenance and reproduction in women. Am. J. Hum. Biol. 25:389–398, 2013. © 2013 Wiley Periodicals, Inc.

We measured Secretory IgA (SIgA) levels in the human milk of 91 postpartum mothers (after vaginal delivery) by using an enzyme immunoassay, in postpartum day 3, and weeks 1, 2, 3, 4, 8, and 12.

The SIgA concentration gradually declined over the 12-week period, with the highest level recorded in day 3. At week 4, the SIgA levels decreased to half the initial levels. Although the difference in concentration from one week to the next was remarkable, the decrease in concentration was rapid in the first 4 weeks but gradual from week 4 to week 12.

The SIgA levels gradually decreased up to week 12. However, the concentration of SIgA in breast milk did not change constantly. It changed relatively rapid until 4 weeks after childbirth, and because the concentration from the third day to the eighth week became 50%, it was understood that the change was temporal. Am. J. Hum. Biol. 25:399–403, 2013. © 2013 Wiley Periodicals, Inc.

In a cross-sectional study, 691 German children aged 6–10 years were investigated. BMI, % body fat, Frame-Index, total steps p.w., sports club rate p.w., training time p.d., and TV-time p.d. were determined.

Total steps (P < 0.001), BMI (P < 0.001), and % body fat (P = 0.024) are positively linked to Frame-Index. Total steps (P < 0.001), sports club rate (P = 0.001), and training time (P < 0.001) are negatively associated with % body fat. Total steps (P = 0.017) are negatively linked to BMI. TV-time is positively related to BMI (P < 0.001) and % body fat (P < 0.001). % Body fat is affected by age (P < 0.001), sex (P = 0.028), and total steps (P = 0.002). BMI is influenced by age (P < 0.001), and Frame-Index by sex (P < 0.001) and total steps (P = 0.029). Principal component analysis indicates an association between BMI and TV-time and Frame-Index and total steps.

We demonstrate an association between external skeletal robustness and physical activity, which is not captured by in BMI measurements. Children should be physically active in order to maintain skeletal robustness. Am. J. Hum. Biol. 25:404–410, 2013. © 2013 Wiley Periodicals, Inc.

The skeletal sample used in this study comes from Lisbon, Portugal, and individuals in the sample were born between 1806 and 1935. This represents a period during which Lisbon was beginning to undergo the modern health transition, in which mortality from infectious disease began to decline while mortality from degenerative diseases began to increase. Approximately equal numbers of individuals in the sample died from infectious diseases, such as tuberculosis, and from degenerative diseases. Fluctuating asymmetry is examined using three-dimensional landmark data collected from 392 individuals with documented causes of death. Landmark data may provide a more robust measure of fluctuating asymmetry, although it has not often been used in studies of fluctuating asymmetry in human skeletal samples.

The results of the study show that individuals who died from degenerative diseases have higher rates of fluctuating asymmetry compared to individuals who died from infectious diseases. Males also exhibit higher rates of fluctuating asymmetry compared to females.

The results of this study confirm earlier findings that early development has a significant impact on adult health outcomes. Furthermore, the results suggest that fluctuating asymmetry in skeletal samples may offer a means of testing the Developmental Origins of Health and Disease hypothesis. Am. J. Hum. Biol. 25:411–417, 2013. © 2013 Wiley Periodicals, Inc.

We used microarrays to determine age-related patterns of mRNA expression in human cerebral cortical samples ranging from infancy to adulthood. In contrast to previous developmental gene expression studies of human neocortex that relied on postmortem tissue, we measured mRNA expression from the nondiseased margins of surgically resected tissue. We used regression models designed to identify transcripts that followed significant linear or curvilinear functions of age and used population genetics techniques to examine the evolution of these genes.

We identified 40 transcripts with significant age-related trajectories in expression. Ten genes have documented roles in nervous system development and energy metabolism, others are novel candidates in brain development. Sixteen transcripts showed similar patterns of expression, characterized by decreasing expression during childhood. Comparative genomic analyses revealed that the regulatory regions of three genes have evidence of adaptive evolution in recent human evolution.

These findings provide evidence that a subset of genes expressed in the human cerebral cortex broadly mirror developmental patterns of cortical glucose consumption. Whether there is a causal relationship between gene expression and glucose utilization remains to be determined. Am. J. Hum. Biol. 25:418–430, 2013. © 2013 Wiley Periodicals, Inc.

The subjects included 31 FA and 27 EA nurses and nurses aides and eight FA and 19 EA hotel workers from Hawaii who wore an ambulatory BP monitor and collected timed urine specimens (4 h at work, approx.4 h at home and approx. 8 h overnight) for assay of EPI and NE. Proportional changes in systolic and diastolic BP from sleep to work and sleep to home were examined using ANCOVA models including fixed effect-covariate interactions, with ethnicity as a fixed factor, and BMI and the appropriate proportional change in EPI or NE as covariates.

The results show that there was no association between changes in EPI and BP, either overall or by ethnic group; however, overall changes in diastolic BP from sleep to work tended to be smaller among the FAs (P < 0.06). There was also an interactive effect of NE and ethnic group on diastolic BP such that among FAs, as diastolic BP increased, the corresponding NE change decreased (P < 0.039).

The relationships between diurnal BP and catecholamine variations differ by ethnicity. Further research is needed to better understand the mechanisms behind the differences and to evaluate whether this vascular tonic relationship has been the focus of natural selective processes. Am. J. Hum. Biol. 25:431–433, 2013. © 2013 Wiley Periodicals, Inc.

A sample of 1,885 Portuguese children, aged 3–10 years, living in Coimbra, Portugal, was observed. Weight and height were measured and obesity was defined by age-and sex-specific, BMI cut-off points. Questionnaires included variables on SA levels, SES and parental neighborhood perceptions were done. A CATPCA was performed and two neighborhood dimensions were achieved. The independent associations of SES with obesity, SA and perceived neighborhood dimensions was analyzed using ordered logistic regressions.

Children of low [odds ratio (OR) = 1.76; confidence interval (CI) = 1.25–1.99] and medium SES (OR = 1.57; CI = 1.34–2.33) were more likely to be obese than their high-SES peers, less likely to participate in SA (low SES OR = 0.177; CI = 0.12–0.26; medium SES OR = 0.357; CI = 0.24–0.53), and their parents were less likely to have positive perceptions of their built environment (low SES OR = 0.516; CI = 0.38–0.70; medium SES OR = 0.565; CI = 0.37–0.86).

Obesity increases and SA decreases among children with the lowest SES and these living in neighborhoods with higher perceived risk. This finding suggests a model of environmental injustice, whereby differential access to the neighborhood's resources overlaps with familial socioeconomic disadvantage. Am. J. Hum. Biol. 25:434–436, 2013. © 2013 Wiley Periodicals, Inc.