Diabetes, Fasting Glucose Levels, and Risk of Ischemic Stroke and Vascular Events: Findings from the Northern Manhattan Study (NOMAS)

doi:10.2337/dc07-0797

Diabetes, Fasting Glucose Levels, and Risk of Ischemic Stroke and Vascular Events: Findings from the Northern Manhattan Study (NOMAS)

Bernadette Boden-Albala, MPH, DrPH (bb87{at}columbia.edu)^1,,²,
Sam Cammack, MS¹,
Ji Chong, MD¹,
Culing Wang, PhD³,
Clinton Wright, MD, MS¹,
Tatjana Rundek, MD⁴,
Mitchell S.V. Elkind, MD, MS¹,
Myunghee C Paik, PhD³ and
Ralph L Sacco, MD, MS⁴

¹Columbia University College of Physicians and Surgeons, the Mailman School of Public Health, Department of Neurology, New York, NY 10032
²Columbia University College of Physicians and Surgeons, the Mailman School of Public Health, Dept of Sociomedical Science
³Columbia University College of Physicians and Surgeons, the Mailman School of Public Health, Dept of Biostatistics
⁴University of Miami, Department of Neurology, Miami, Fl

Abstract

Background: There is insufficient randomized trial data to support evidence-based recommendations for tight control of fasting blood glucose (FBG) among diabetics in primary stroke prevention. We explored the relationship between FBG among diabetics and risk of ischemic stroke in a multi-ethnic prospective cohort.

Methods: Medical/social data and FBG were collected on 3298 stroke-free community residents: mean age was 69 years ±10 yrs; 63% were women; 21% white, 24% black, 53% Hispanic; 6.5 yrs follow-up. Baseline FBG levels were categorized: 1) Elevated FBG, history of diabetes and FBG ≥ 126 mg/dl (7.0 mmol/l); 2) Target FBG, history of diabetes and FBG < 126 mg/dl (7.0mmol/l); or, 3) no diabetes/reference group. Cox models calculated hazard ratios (HR) and 95% confidence intervals (95% CI) for ischemic stroke and vascular events.

Results: In NOMAS, 572 reported a history of diabetes and 59% (n=338) had elevated FBG. Elevated FBG among diabetics was associated with female gender (p 0.04), Medicaid (p = 0.01) or no insurance (p=0.03). We detected 190 ischemic strokes and 585 vascular events. Diabetics with elevated FBG [HR 2.7, 95% CI 2.0 – 3.8] were at increased risk of stroke, but those with target FBG levels[HR 1.2, 95% CI 0.7 – 2.1] were not, even after adjustment. A similar relationship existed for vascular events: elevated FBG [HR 2.0, 95% CI 1.6 – 2.5]; target FBG [HR 1.3, 95% CI 0.9 – 1.8].

Conclusions: This prospective cohort study provides evidence for the benefits of tighter glucose control for primary stroke prevention.