Neighborhood Segregation May Be Linked to Glycemic Control in T1D

Among Black youth with type 1 diabetes (T1D), racial residential segregation (RRS) was associated with glycemic control, according to a study published in Pediatrics.

The researchers employed several methods to investigate the relationship between RRS and T1D management among Black youth. First, they recruited 148 total participants from 7 pediatric diabetes clinics in 2 US cities—3 in Detroit, Michigan, and 4 in Chicago, Illinois. RRS was then computed at the census block group level using US Census data. Additionally, T1D management was assessed through a self-report questionnaire, whereas hemoglobin A_1c (HbA_1c) data were collected from participants during home-based data collection.

T1D self-management was measured using the Diabetes Management Scale (DMS). In bivariate analyses, RRS was significantly associated with HbA_1c (r = 0.28; P = .001), but not with youth-reported diabetes management according to DMS (r = –0.08; P = .311).

Because of this, DMS was not included in multivariate analyses. Neighborhood Adversity Index score was also significantly associated with RRS (r = 0.55; P = .001), but the authors added that this association was moderate, saying these variables measured different aspects of neighborhoods as expected.

The mean yearly family income in the sample was $34,236—equivalent to roughly 125% of the US 2020 poverty line for a family of 4—and the median family income was $25,000. Mean HbA_1c level was 11.5% or 102 mmol/mol, suggesting that the sample had suboptimal glycemic control based on American Diabetes Association guidelines, which recommend maintaining HbA_1c at or below 7.0% in adolescents.

RRS was evaluated based on the concentration-evenness dimension of segregation using the location quotient (LQ). Mean (SD) LQ was 3.04 (1.49), indicating that the participants lived in highly segregated neighborhoods. Additionally, over 80% of families lived in neighborhoods with an LQ greater than or equal to 1.20, indicating high concentrations of Black families in these areas compared with the rest of the metropolitan area.

To determine the effects of RRS on T1D management, the researchers also used hierarchical linear regression—consisting of 2 models—and controlled for factors such as family income, youth age, insulin delivery method, and neighborhood adversity.

“The inclusion of variables such as composite measures of neighborhood adversity or disadvantage in models predicting health outcomes could help to clarify the specific effects of segregation on the health of Black youth with T1D,” the authors wrote.

In the hierarchical regression analyses, model 1 showed that family income, youth age, and insulin delivery method were all significantly associated with HbA_1c. However, model 2 showed that RRS, age, and insulin delivery method showed significant association with HbA_1c. Model 2 also explained 25% of the variance in HbA_1c (P < .001).

“Although not measured in the current study, RRS could affect glycemic control via pathways such as exposure to psychosocial stressors such as racism, as such stressors can have a direct effect on glycemic control via dysregulated cortisol,” the authors noted.

This study also did not measure other neighborhood-level factors that have been found to be associated with RRS, such as health care access. Prior research has shown that Black adults that live in more segregated neighborhoods have to travel longer distances to access health care, and that fewer visits to pediatric diabetes specialty clinics are linked to suboptimal glycemic control.

According to the authors, these findings suggest that in a sample of Black youth living in urban areas, the degree of segregation within the youth’s neighborhood was a better predictor of glycemic control than family income or neighborhood conditions, such as high rates of neighborhood poverty, unemployment, vacant homes, or renter-occupied homes.

“Policies to reduce residential segregation, along with improved screening for neighborhood-level risk, hold the potential to improve the health of a vulnerable population of youth,” the authors said.

Reference

Ellis DA, Cutchin MP, Carcone AI, et al. Racial residential segregation and the health of Black youth with type 1 diabetes. Pediatrics. 2023;e2022058856. doi:10.1542/peds.2022-058856