Association Between Rental Assistance Programs and Hemoglobin A1c Levels Among US Adults.

Importance: Programs that provide affordable and stable housing, such as federal rental assistance, may be associated with improved mean blood glucose levels and related diabetes outcomes. Objective: To assess whether 2 different types of federal rental assistance programs are associated with glycated hemoglobin A1c (HbA1c) levels among middle-aged and older US adults. Design, Setting, and Participants: This cohort study used data from the National Health and Nutrition Examination Survey (NHANES) linked with US Department of Housing and Urban Development records of rental assistance participation. Adults aged 45 years or older who were receiving 2 types of rental assistance (project-based housing or housing vouchers) at the time of the NHANES interview and those who would receive rental assistance within the subsequent 2 years (waitlist group) were included. Data were collected from January 1999 to December 2016 and analyzed in October 2021. Exposures: Rental assistance participation, including project-based housing (subsidized housing developments including public housing) and housing vouchers (tenant-based subsidies for private market housing). Main Outcomes and Measures: The primary outcome was continuous HbA1c level, a common measure of blood glucose reflecting diabetes control. Linear regression was used to estimate the association between the 2 rental assistance programs and HbA1c level. Logistic regression was used to assess the association between rental assistance programs and HbA1c cut points (prediabetes: 5.7% to ≤6.5%; diabetes: >6.5%; uncontrolled diabetes: ≥9% [to convert to proportion of total Hb, multiply by 0.01]). Analyses used weights created by the National Center for Health Statistics that adjust for linkage eligibility. Results: Among 1050 adults in the study (41.6% aged ≥65 years; 70.1% female), 795 were receiving rental assistance at time of the NHANES interview (450 lived in project-based housing, and 345 had housing vouchers), and 255 received rental assistance within 2 years after the interview. Participants in project-based housing had lower HbA1c levels compared with individuals in the waitlist group (β, -0.290; 95% CI, -0.599 to 0.020), but the difference was not significant. No significant differences in HbA1c levels were found between those receiving housing vouchers and those in the waitlist group (β, 0.051; 95% CI, -0.182 to 0.284). Receiving project-based housing was associated with a reduced likelihood of uncontrolled diabetes (-3.7 percentage points; 95% CI, -7.0 to -0.0 percentage points) compared with being in the waitlist group. Conclusions and Relevance: In this cohort study of a nationally representative sample of US adults, living in project-based, federally subsidized housing was associated with a reduced likelihood of uncontrolled diabetes. The findings suggest that affordable housing programs may be associated with improved diabetes outcomes.