Socioeconomic status, diabetes, and gestation length in Native American and White women.

OBJECTIVE: "Diminishing returns" of socioeconomic status (SES) suggests that higher SES may not confer equivalent health benefits for ethnic minority individuals as compared to White individuals. Little research has tested whether diminishing returns also affects Native Americans. The objective of this study was to determine whether higher SES is associated with lower diabetes risk and longer gestational length in both Native American and White women, and whether SES predicts gestational length indirectly via diabetes risk.

METHOD: A sample of 674,014 Native American and White women was drawn from a population-based California cohort of singleton births (2007-2012). Education, public health insurance status, gestational length, and diabetes diagnosis were extracted from a state-maintained birth cohort database. Covariates were age, health behaviors, pregnancy variables, residence rurality, and prepregnancy body mass index.

RESULTS: In logistic regression models, the race by SES interaction (both education and insurance status) was associated with diabetes risk. Compared to high-SES White women, high- and low-SES Native American women had highest and equivalent diabetes risk. In path analyses, the race by SES interaction indirectly predicted gestational length through diabetes, ps < .001. For White women, an indirect effect of diabetes was detected, ps < .001, such that higher SES was associated with reduced risk for diabetes and thus longer gestational length. For Native American women, no indirect effect was detected, ps > .067.

CONCLUSIONS: Among Native American women, higher SES did not confer protection against diabetes or shorter gestational length. These findings are consistent with the diminishing returns of SES phenomenon. (PsycInfo Database Record (c) 2021 APA, all rights reserved).