Abstract MP021: Glycated Hemoglobin and Risk of Incident Hypertension in the Atherosclerosis Risk in Communities (ARIC) Study

Abstract

Introduction: Diabetes and hypertension often co-occur and have shared risk factors. While hypertension is known to predict diabetes, hyperglycemia may also be independently associated with incident hypertension. We investigated glycated hemoglobin (HbA1c) as a predictor of incident hypertension in individuals in the Atherosclerosis Risk in Communities (ARIC) cohort. Methods: We conducted a prospective analysis of 9,603 middle-aged participants in the ARIC Study without hypertension at baseline. Using Cox proportional hazards models, we estimated the association between HbA1c at baseline and incident hypertension by two definitions: (1) self-reported hypertension during a maximum of 18 years of follow-up; and (2) measured blood pressure or hypertension medication use recorded at clinic visits for a maximum of 9 years of follow-up. Results: We observed 4,800 self-reported hypertension cases and 1,670 visit-based cases. Higher baseline HbA1c was associated with increased risk of hypertension and was robust to adjustment for a comprehensive list of confounders that included two measures of adiposity (body mass index and waist-hip ratio). Compared to nondiabetic adults with HbA1c <5.7%, HbA1c in the pre-diabetic range (5.7–6.4%) was independently associated with incident self-reported hypertension (HR 1.25, 95% CI: 1.16–1.34) and visit-detected hypertension (HR 1.18, 95% CI: 1.04–1.34). The HR per 1-% point higher HbA1c was 1.11 (1.06–1.16) among those with no history of diabetes and 1.06 (1.01–1.11) among those with diagnosed diabetes; the continuous associations between HbA1c and incidence of self-reported hypertension for individuals without diabetes are illustrated in the Figure. Conclusions: The association of HbA1c with incident hypertension suggests that elevated levels of circulating glucose may independently contribute to cardiovascular risk through higher blood pressure. Persons with elevated HbA1c, even without a prior diabetes diagnosis, are at increased risk of developing hypertension.