Higher Community Climate Vulnerability Index Predicts Increased T2D Incidence: JAMA
Researchers have found in a cohort study of 1,003,526 adults that a higher community Climate Vulnerability Index is linked to an increased risk of developing type 2 diabetes, independent of traditional risk factors. Integrating the geocoded Climate Vulnerability Index (CVI) with electronic health records may help improve targeted prevention, risk stratification, and population health planning. The study was published in JAMA Network Open by Jad A. and colleagues.
This was a retrospective cohort study that analyzed data from the Houston Methodist Learning Health System Registry, an integrated health system serving Greater Houston in Texas. Inclusion criteria included adults aged 18 years or older without type 2 diabetes at baseline with at least 1 outpatient encounter and 1 subsequent health care encounter between June 2016 and August 2023. Data analysis was completed in September 2025. Census tract–level Climate Vulnerability Index values were geocoded and linked to electronic health records.
The sample for this analysis included 1,003,526 participants, who had a mean (SD) age of 50.9 (18.4) years. Women made up 605,829 participants (60.4%). The breakdown across race and ethnicity was 132,451 (13.2%) African American or Black, 71,408 (7.1%) Asian, 156,989 (15.6%) Hispanic or Latinx, 566,632 (56.5%) White, 35,565 (3.5%) other races, and 42,942 (4.3%) unknown or not reported. Participants contributed 2.1 million person-years of follow-up.
In this study, exposure was defined as residence in a census tract grouped by CVI quartiles, which ranged from Q1 (lowest vulnerability) to Q4 (highest vulnerability). The main outcome was incident type 2 diabetes identified using ICD-10 diagnostic codes, antihyperglycemic medication prescriptions, or hemoglobin A1c ≥6.5%. Calculation of incidence rates per 100 person-years and adjusted hazard ratios with their 95% CIs, considering demographics, insurance type, cardiometabolic risk factors, and baseline hemoglobin A1c, was done by Cox proportional hazards models.
Key Findings
During follow-up, 40,152 participants developed type 2 diabetes, corresponding to an overall incidence rate of 1.88 cases per 100 person-years.
Participants residing in the highest CVI quartile experienced markedly higher diabetes incidence compared with those in the lowest quartile (2.66 vs 1.48 cases per 100 person-years).
The 7-year cumulative risk of developing diabetes was 14.1% among residents in Q4 areas compared with 8.6% among those in Q1 areas.
After full adjustment, residence in Q4 vs Q1 CVI areas was associated with a 23% higher risk of developing type 2 diabetes (hazard ratio, 1.23; 95% CI, 1.11–1.36), representing a statistically significant association.
In this cohort study, residence in areas with higher Climate Vulnerability Index scores was independently associated with a significantly increased risk of incident type 2 diabetes. These findings emphasize the need to consider environmental and social determinants of health in diabetes prevention strategies and provide a rationale for the use of metrics of climate vulnerability to inform population-level health interventions.
Reference:
Ardakani J, Shahid I, Gullapelli R, et al. Climate Vulnerability Index and Incident Type 2 Diabetes in a Large Integrated Health Care System. JAMA Netw Open. 2025;8(12):e2547119. doi:10.1001/jamanetworkopen.2025.47119
