Diabetes-Specific Food Insecurity Is Associated with Impaired Heart Rate Variability Independent of Glycemic Control: Exploratory Findings among Latinos with Type 2 Diabetes.

Background: Food insecurity (FI), diabetes prevalence, and poor diabetes outcomes all disproportionately affect Latinos in the United States. Heart rate variability (HRV) reflects autonomic tone, is associated with glycemic control, and predicts mortality in type 2 diabetes. It is unknown whether FI is related to HRV and, if so, whether glycemic control accounts for this association. Objective: This exploratory cross-sectional study examined FI and HRV among US Latinos with type 2 diabetes. Methods: Participants reported demographic characteristics, socioeconomic status, and FI, including the 6-item USDA food security module and a 1-item measure of diabetes-specific food security. Participants wore an ambulatory electrocardiogram monitor for 24 h. In the time domain, HRV was assessed with the SD of the R-R interval (SDNN). In the frequency domain, the power spectrum was integrated over 3 frequency bands-very low frequency (VLF), low frequency (LF), and high frequency (HF)-and then natural log transformed. Unadjusted ANOVA and ANCOVA adjusted for age, sex, glycated hemoglobin (HbA1c), and indicators of socioeconomic status compared food security groups on HRV. Results: Participants' mean ± SD age was 59.7 ± 10.9 y, and 73% were women. Of the 94 participants, 63 reported FI according to the USDA food security module and 46 reported FI according to the diabetes-specific measure. Mean ± SD HbA1c was 8.6% ± 1.7% and was marginally higher among those reporting diabetes-specific FI than those reporting diabetes-specific food security. Participants who reported diabetes-specific FI had lower SDNN, VLF, LF, and HF HRV with effect sizes in the small-to-medium range. Differences remained significant even after controlling for age, sex, socioeconomic hardship, and HbA1c. The 6-item USDA food security module was not associated with HRV. Conclusions: Diabetes-specific FI may be a unique risk factor for poor health outcomes among US Latinos. Efforts to address FI could benefit diabetes outcomes.