Inflammation and Stress Biomarkers Mediate the Association between Household Food Insecurity and Insulin Resistance among Latinos with Type 2 Diabetes

Household food insecurity (HFI) is a stressor that is associated with type 2 diabetes (T2D). However, little is known about HFI and the insulin resistance (IR) underlying T2D, and the mechanisms involved. We examined the cross-sectional association between HFI and IR among low-income Latinos with T2D and tested whether inflammation and stress hormones mediated this association. HFI was measured with the 6-item US Household Food Security Survey module. IR was calculated from fasting plasma blood glucose and serum insulin. Inflammation was indicated by high-sensitivity C-reactive protein (hsCRP), and stress hormones included urinary cortisol, metanephrine, and normetanephrine. To test for an indirect effect of HFI on homeostasis model assessment of IR, a parallel multiple mediation model was run with biological markers that significantly differed between food security status—entered as mediators in the model. We used 95% bias-corrected bootstrap CIs, with 10,000 bootstrap samples, to assess the significance of the indirect effects. The 121 participants with T2D were primarily Puerto Rican (85.8%), aged mean = 60.7 y, and 74% were female. Eighty-two (68%) were classified as food insecure. Compared with food-secure individuals, food-insecure individuals had a significantly higher IR [mean difference (Δ) = 7.21, P = 0.001], insulin (Δ = 9.7, P = 0.019), glucose (Δ = 41, P