Dysglycemia and incident heart failure among blacks: The jackson heart study

Background: We aimed to investigate the associations of glycemic markers (hemoglobin A_1C [HbA_1C], fasting plasma glucose [FPG] and glycemic status [normoglycemia, prediabetes and diabetes]) with incident heart failure (HF) and its subtypes, among Blacks. Methods: We included 2,290 community-dwelling Blacks (64% women, mean age 58 years) without prevalent HF from the Jackson Heart Study who attended the second exam (2005 – 2008). The associations between glycemic markers and incident HF (and subtypes including HF with preserved ejection fraction [HFpEF] and reduced ejection fraction [HFrEF]) were evaluated using Cox proportional hazards regression models, adjusting for risk factors and coronary heart disease. Results: There were 119 incident HF events (48 HFpEF, 58 HFrEF, and 13 unclassified HF events) over a median follow-up of 10.5 years. Higher levels of HbA_1C (HR per SD increment, 1.30; 95% CI 1.12, 1.51) and FPG (HR per SD increment FPG: 1.32; 95% CI: 1.17, 1.48) were associated with a higher risk of incident HF. Compared to normal glycemia, diabetes status was associated with a higher risk of incident HF (HR: 1.24; 95%CI: 1.02, 2.05). HbA_1C was significantly associated with higher risks of HFpEF (HR per SD increment: 1.41, 95% CI: 1.18, 1.69) and HFrEF (HR per SD increment: 1.32; 95% CI: 1.12, 1.56). FPG was significantly associated with higher risk of HFpEF (HR per SD increment: 1.35, 95% CI: 1.14, 1.62) but not HFrEF (HR per SD increment: 1.12; 95% CI: 0.53, 2.35). Conclusions: Among community-dwelling Blacks, higher levels of glycemic markers were associated with higher risk of HF subtypes.