High‐density lipoprotein‐cholesterol and incident type 2 diabetes mellitus among African Americans: The Jackson Heart Study

AIMS: Accruing evidence suggests an association between high‐density lipoprotein cholesterol (HDL‐C) and incident diabetes. However, there is a paucity of data on the link between HDL‐C and diabetes, especially among African Americans (AAs). We aimed to assess the association of HDL‐C and its fractions with incident type 2 diabetes among AAs. METHODS: We included Jackson Heart Study participants who attended visit 1 (2001–2004), were free from diabetes and were not treated with lipid‐modifying medications. Incident diabetes was assessed at two subsequent‐yearly visits (2 and 3). We cross‐sectionally assessed the association of HDL‐C and insulin resistance (IR) using multivariable linear models. We prospectively assessed the association of HDL‐C and its fractions with incident diabetes using multivariable Cox regression models. RESULTS: Among 2829 participants (mean age: 51.9 ± 12.4 years, 63.9% female), 487 participants (17%) developed new‐onset diabetes, over a median follow‐up of 8 years. In adjusted models, a higher HDL‐C concentration was associated with a lower odds of IR (odds ratio [OR] per standard deviation [SD] increment: OR 0.56 [95% confidence interval, CI 0.50–0.63], p < 0.001). In adjusted models, a higher HDL‐C concentration was associated with a lower risk of diabetes (HR per SD increment: 0.78 [95% CI 0.71, 0.87], p < 0.001; HR for highest vs. the lowest tertile of HDL‐C was 0.56 [95% CI: 0.44, 0.71], p < 0.001). CONCLUSION: In a sample of African‐American adults not on any lipid‐modifying therapy, high HDL‐C concentrations were inversely associated with the risk of new‐onset diabetes. These findings suggest a strong link between HDL‐C metabolism and glucose regulation.