Abstract 2184: Glycemic Level and Future Stroke in Type 2 Diabetes Mellitus: The Strong Heart Study.
Although glycemic level has been associated with increased macrovascular events in patients with diabetes, few studies have specifically addressed the relationship between degree of hyperglycemia and stroke. To date, glycemic control has not been demonstrated to reduce stroke risk, leaving open whether diabetes is indeed a modifiable risk factor for this outcome. We investigated the relationship between glycohemoglobin (HbA1c) and incident stroke in a cohort of 1691 American Indians with diabetes and no prevalent cardiovascular disease participating in the population-based Strong Heart Study. Diabetes was defined by ADA criteria. Cox models adjusted for age, sex, BMI, HTN, cholesterol/HDL, smoking, alcohol, creatinine, and albuminuria. Median HbA1c was 8.6% (range 3.3–17.9%). During median follow-up of 9.2 yrs, there were 117 incident strokes. When evaluated by quartiles of its distribution, HbA1c was significantly associated with future stroke risk after adjustment for covariates (Q2 vs Q1: RR 1.20, 95% CI 0.68–2.14; Q3 vs Q1: RR 1.25, 95% CI 0.70–2.21, Q4 vs Q1: RR 1.99, 95% CI 1.15–3.44; P trend 0.015). A significant relationship persisted when HbA1c was examined continuously (adjusted RR 1.14 per 1% increase, 95% CI 1.06–1.24). These relationships were not meaningfully changed after adjustment for diabetes duration or insulin therapy. In this large cohort with type 2 diabetes, baseline glycemic levels were independently predictive of stroke risk, even when strong predictors like albuminuria were taken into account. These findings suggest that glycemic control may indeed yield cerebrovascular benefits in diabetics, but this proposition will require further study.