Association of Food Insecurity With Allostatic Load Among Older Adults in the US.

Importance: Allostatic overload, a biomarker of wear and tear, could be the potential pathway through which food insecurity leads to increased morbidity risk. Objective: To assess the association of food insecurity with allostatic load (AL) among US adults aged 50 years or older. Design, Setting, and Participants: A multiwave longitudinal cohort study was conducted using data from the 2006 to 2014 waves of the Health and Retirement Study in a national cohort study setting. The data comprise 26 509 person-years observations from 14 394 noninstitutionalized individuals aged 50 years or older during the study period. Data were analyzed from September 1 to December 14, 2020. Exposures: Moderate food insecurity (not enough money to buy the food needed) and severe food insecurity (reduced food intake due to financial constraints) measured at the household level. Main Outcomes and Measures: The AL score (0-9, with higher scores indicating a greater risk of physiologic dysregulation) and binary indicators of dysregulated inflammatory (C-reactive protein), cardiovascular (systolic and diastolic blood pressure, pulse rate, and cystatin C), and metabolic (hemoglobin A1c, body mass index, waist-to-height ratio, total cholesterol to high-density lipoprotein cholesterol ratio) systems. Results: Of 14 394 participants included in the analysis, the median age was 60 (IQR, 56-69) years, 8143 (56.6%) were women, 517 (3.6%) were moderately food insecure, and 804 (5.6%) were severely food insecure. In adjusted models, the incidence rate of AL was 1.05 (95% CI, 1.00-1.09) times higher for the participants with moderate food insecurity and 1.11 (95% CI, 1.07-1.15) times higher for the participants with severe food insecurity, compared with those who were food secure. The increased incidence rate of AL among participants with severe food insecurity was associated with C-reactive protein level (odds ratio [OR], 1.22; 95% CI, 1.04-1.44), cystatin C level (OR, 1.23; 95% CI, 1.01-1.51), hemoglobin A1c level (OR, 1.27; 95% CI, 1.01-1.59), body mass index (OR, 1.84; 95% CI, 1.41-2.40), waist-to-height ratio (OR, 1.54; 95% CI, 1.26-1.88), and total to high-density lipoprotein cholesterol ratio (OR, 1.32; 95% CI, 1.10-1.59) inflated to the high-risk range. The interaction between moderate food insecurity and Supplemental Nutrition Assistance Program (SNAP) enrollment (β = -0.18; P = .001) and the interaction between severe food insecurity and SNAP enrollment (β = -0.09; P = .02) were associated with a reduction in AL. Conclusions and Relevance: In this national cohort study of US adults aged 50 years or older, food insecurity was associated with higher AL, mainly through dysregulation of the inflammatory and metabolic systems. SNAP enrollment may modify this association between food insecurity and AL.