In This Issue

Regional differences in subcutaneous adipose tissue

inline image Visceral adipose tissue is known to be functionally different from subcutaneous adipose tissue, but the various regions of subcutaneous tissue are considered homogeneous. To investigate possible differences, Charles Rehrer and colleagues compared gene expression in adipose tissue in the upper abdomen, lower abdomen, flank, and hip in healthy women of normal weight. They found no differences when the hip and flank or the upper and lower abdomen were compared. However, there were several differentially expressed genes between the hip and flank and the abdomen. These differences could influence the pathophysiology of obesity-related metabolic diseases. See page 2168

Endurance training preferable for men's health

inline image To investigate whether the health benefits of physical activity come from the activity itself or from the consequent weight loss, Pernille Nordby and team conducted a 12-week intervention program that compared diet-induced weight loss with endurance training, with or without a reduced-calorie diet, in 48 sedentary, moderately overweight men. The results showed that endurance training had a beneficial health effect on body composition, cardiovascular fitness, and insulin sensitivity, regardless of weight loss. Loss of fat mass through diet or training improved hepatic insulin sensitivity, and there were no effects on blood glucose or blood pressure. The authors conclude that endurance training should be included in interventions for improving metabolic health in moderately overweight men. See page 2202

Comparison of infant body-composition measures

inline image Infancy can be a critical period for establishing risk of obesity development, and many standard measures do not take into account the composition of weight gained. David Fields and colleagues investigated two ways of measuring fat mass and fat-free mass in 84 6-month-olds: dual-energy X-ray absorptiometry (DXA) and air-displacement plethysmography (ADP). Both methods are relatively fast, noninvasive, and inexpensive, but each has limitations. DXA involves low radiation exposure and the subject needs to be kept still, and ADP is unable to measure infants weighing more than 8kg. The authors found that the two methods gave highly correlated estimates of body composition, but DXA estimates of fat percentage were significantly higher, warranting further investigation. See page 2302

Microbiota differences in preschool children

inline image Obese children have a higher risk of health problems in adulthood. To continue recent research on the connection between obesity and the bacterial flora of the gut, Caroline Karlsson and team investigated the gut microbiota of 40 preschool children who were either overweight or of normal weight. In the overweight children, they found significantly higher levels of Enterobacteriaceae and significantly lower levels of Desulfovibrio and Akkermansia muciniphila—like bacteria than in the normal-weight children. Further studies will be needed to determine the relationship—causal or otherwise—between gut microbiota and body weight. See page 2257