Prospective associations of fasting insulin, body fat distribution, and diabetes with risk of ischemic stroke. The Atherosclerosis Risk in Communities (ARIC) Study Investigators.
OBJECTIVE
We tested the hypothesis that diabetes, body fat distribution, and (in nondiabetic subjects) fasting insulin levels are positively associated with ischemic stroke incidence in the general population.


METHODS
As part of the Atherosclerosis Risk in Communities (ARIC) Study, we measured diabetes by using fasting glucose criteria, waist and hip circumferences, and fasting insulin levels with a radioimmunoassay in > 12,000 adults aged 45-64 years who had no cardiovascular disease at baseline. We followed them for 6-8 years for ischemic stroke occurrence (n = 191).


RESULTS
After adjustment for age, sex, race, ARIC community, smoking, and education level, the relative risk of ischemic stroke was 3.70 (95% CI 2.7-5.1) for diabetes, 1.74 (1.4-2.2) for a 0.11 increment of waist-to-hip ratio, and 1.19 (1.1-1.3) for a 50-pmol/l increment of fasting insulin among nondiabetic subjects. Ischemic stroke incidence was not statistically significantly associated with BMI (comparably adjusted relative risk = 1.15, 95% CI 0.97-1.36). With adjustment for other stroke risk factors (some of which may mediate the effects of diabetes, fat distribution, and hyperinsulinemia), the relative risks for diabetes, waist-to-hip ratio, and fasting insulin level were 2.22 (95% CI 1.5-3.2), 1.08 (0.8-1.4), and 1.14 (1.01-1.3), respectively.


CONCLUSIONS
Diabetes is a strong risk factor for ischemic stroke. Aspects of insulin resistance, as reflected by elevated waist-to-hip ratios and elevated fasting insulin levels, may also contribute to a greater risk of ischemic stroke.
Folsom
A R
AR
Division of Epidemiology, School of Public Health, University of Minnesota, Minneapolis 55454-1015, USA. folsom@epi.umn.edu
Rasmussen
M L
ML
Chambless
L E
LE
Howard
G
G
Cooper
L S
LS
Schmidt
M I
MI
Heiss
G
G
D000273:Adipose Tissue / Q000033:anatomy & histology*; D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D001824:Body Constitution; D015992:Body Mass Index; D002545:Brain Ischemia / Q000453:epidemiology*; D015331:Cohort Studies; D003920:Diabetes Mellitus / Q000453:epidemiology* / Q000503:physiopathology; D005215:Fasting; D005260:Female; D006801:Humans; D015994:Incidence; D007328:Insulin / Q000097:blood*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012306:Risk; D012307:Risk Factors; D014481:United States / Q000453:epidemiology
D001786:Blood Glucose; D007328:Insulin