Community‐level socioeconomic distress is associated with nutritional status in adults with sickle cell anemia

Abstract Sickle cell anemia (SCA) negatively impacts the ability to achieve educational and occupational goals increasing vulnerability to socioeconomic challenges. In a cross‐sectional analysis of 332 SCA adults, we investigated whether the distressed community index (DCI) was associated with SCA‐related complications and nutritional status. More patients with higher DCI had Medicaid insurance. A higher DCI was independently associated with tobacco use and lower body mass index, serum albumin, and vitamin D 25‐OH levels after adjusting for insurance status but was not associated with SCA‐related complications. Future studies investigating access to healthy foods may help improve health equity in patients with SCA.


INTRODUCTION
Sickle cell anemia (SCA) is among the most common inherited red blood cell disorders affecting approximately one in 500 African Americans and 25 million people worldwide [1]. Hallmark features of SCA include vaso-occlusion and intravascular hemolysis, which lead to a myriad of acute and chronic complications, including vaso-occlusive pain episodes (VOE), acute chest syndrome, and stroke. These complications negatively impact the ability of people with SCA to achieve educational and occupational goals [2,3]. In addition, African Ameri- The Distressed Communities Index (DCI) is a tool that was developed to compare the economic well-being of US communities by zip code. The components of the DCI score include measures of educational level, housing vacancy, unemployment, poverty rate, and median income. A study which assessed the impact of community-level socioeconomic well-being using the DCI found that Medicare beneficiaries living in distressed communities were at greater risk for lower health care quality, including annual wellness checks and receiving recommended annual tests, and experienced a higher rate of potentially avoidable hospital admissions, 30-day hospital readmissions, and higher overall mortality [4]. Community-level socioeconomic distress can also reduce access to healthy foods and increase metabolic risk factors for morbidity and early mortality [5].

F I G U R E 1
Adults with sickle cell anemia and Medicare or Medicaid/self-pay insurance had progressively higher rates of (A) vaso-occlusive episodes (VOE) and (B) acute chest syndrome history as well as a trend for (C) more stroke history compared to those with private insurance. A higher Distressed Community Index (DCI) was associated with lower (D) body mass index, (E) serum albumin concentration, and (F) vitamin D 25-OH levels in adults with sickle cell anemia.
The impact of community level socioeconomic distress in patients with SCA is less clear. In one cohort from the United Kingdom, people with SCA living in disadvantaged neighborhoods had higher rates of emergency room readmissions and inpatient mortality compared to those living in less disadvantaged neighborhoods [6]. In another study, children with SCA living in socioeconomically deprived neighborhoods had less episodes of recurrent acute chest syndrome compared to those living in more affluent neighborhoods [7].
The purpose of this cross-sectional study was to determine (1) the prevalence of community level socioeconomic distress, as determined by the DCI, and (2) its association with SCA-related complications and markers of nutritional status in adults with SCA.

METHODS
The study was approved by the University of Illinois Chicago Institu-

RESULTS
The median age of the cohort was 31 years (IQR, 24-41 years), 55% were female, 98.5% were African American, and 53% were on hydroxyurea therapy. The median DCI in this cohort was 87 (IQR, 61-96) with 61% of SCA patients living in a distressed tier (DCI ≥ 80) and only 5% living in a prosperous tier (DCI < 20). Fifty percent of the cohort had Medicaid insurance (n = 165) or were categorized as self-pay (n = 1), 26% had Medicare insurance, and 24% had private insurance listed as their primary insurance. VOE frequency and acute chest syndrome his-tory were progressively higher while a trend for higher stroke history was observed in SCA patients with Medicare and with Medicaid/selfpay compared to those with private insurance (Figure 1A-C). The proportion of SCA patients with Medicaid insurance progressively increased with higher DCI tertile (Table 1). SCA patients in progressively higher DCI tertiles were more frequently African American, being treated with hydroxyurea, used tobacco, and had higher serum ferritin concentrations and lower serum vitamin D 25-OH levels (p < 0.05).
We did not observe an association between DCI scores and SCArelated complications, such as VOE frequency, history of acute chest syndrome, or stroke history, on univariate analysis or after adjusting for age, sex, hydroxyurea use, and insurance status (P ≥ 0.07) (Supplementary Table 1

DISCUSSION
We demonstrate that socioeconomic distress at the community level was associated with tobacco use and with several markers of nutritional status in patients with SCA. Distressed communities are neighborhoods with reduced socio-economic well-being which can lead to reduced access to health-related community resources, such as health care facilities, healthy foods, and recreational activities, as well as an increased risk of exposure to environmental toxins and unhealthy behaviors [9,10]. In our cohort, 61% of patients with SCA lived in a distressed tier (DCI ≥ 80). This is similar to what has been reported in a cohort of patients with sickle cell disease from England, where 58% lived in the most socio-economically deprived areas [6]. In another pediatric cohort from Alabama, 45% of children with sickle cell disease lived in the most deprived area [7]. In our study, SCA-related complications were associated with insurance status but not with DCI. The association of SCA-related complications with insurance status has been observed in other cohorts of patients with sickle cell disease [11,12] and our findings suggest that individual-level indicators of socio-economic well-being may be a stronger predictor of these complications than community-level indicators [13]. A higher DCI score was independently associated with a greater proportion of SCA patients smoking tobacco, which may represent a modifiable risk factor for cardiovascular disease in the general population and for acute chest syndrome in adults with sickle cell disease [14].
We found that a higher DCI score was independently associated with several markers of poor nutrition, including lower body mass index, serum albumin, and vitamin D 25-OH concentration. Potential reasons for this might include food insecurity and low access to healthy foods. Food insecurity is increased in people with reduced income, low employment, or disability [15]. Risk factors for food insecurity in people with SCA, reported in 30%-46% of other sickle cell disease cohorts [16,17], are less clear. Although we did not measure food insecurity, our results suggest that community-level barriers, such as access to healthy foods, may play an important role in the nutritional status of adults with SCA.
Limitations of our study include being cross-sectional in nature, the narrow distribution of DCI, and lacking additional measures of individual socioeconomic status, such as household income and educational level. Future studies prospectively investigating the effects of socioeconomic distress at an individual and community level will help us better understand the impact of social determinants of health in people with SCA and guide public health strategies to improve health equity for this population.

AUTHOR CONTRIBUTIONS
SAA, JH, RS, REM, VRG, and JPL designed and performed research and wrote the paper. SLS designed and performed research, analyzed the data, and wrote the paper.