Homeostasis model assessment of insulin resistance in relation to the incidence of cardiovascular disease: the San Antonio Heart Study.
OBJECTIVE
The prospective association between insulin levels and risk of cardiovascular disease (CVD) is controversial. The objective of the present study was to investigate the relationship of the homeostasis model assessment of insulin resistance (HOMA-IR), as well as insulin levels, with risk of nonfatal and fatal CVD over the 8-year follow-up of the San Antonio Heart Study.


METHODS
Between 1984 and 1988, randomly selected Mexican-American and non-Hispanic white residents of San Antonio participated in baseline examinations that included fasting blood samples for glucose, insulin, and lipids, a glucose tolerance test, anthropometric measurements, and a lifestyle questionnaire. Between 1991 and 1996, 2,569 subjects who were free of diabetes at baseline were reexamined using the same protocol.


RESULTS
Over the follow-up period, 187 subjects experienced an incident cardiovascular event (heart attack, stroke, heart surgery, angina, or CVD death). Logistic regression analysis indicated that risk of a CVD event increased across quintiles of HOMA-IR after adjustment for age, sex, and ethnicity (P for trend <0.0001; quintile 5 vs. quintile 1, odds ratio [OR] 2.52, 95% CI 1.46-4.36). Additional adjustment for LDL, triglyceride, HDL, systolic blood pressure, smoking, alcohol consumption, exercise, and waist circumference only modestly reduced the magnitude of these associations (P for trend 0.02; quintile 5 vs. quintile 1, OR 1.94, 95% CI 1.05-3.59). Furthermore, there were no significant interactions between HOMA-IR and ethnicity, sex, hypertension, dyslipidemia, glucose tolerance (impaired glucose tolerance versus normal glucose tolerance), or obesity. The magnitude and direction of the relationship between insulin concentration and incident CVD were similar.


CONCLUSIONS
We found a significant association between HOMA-IR and risk of CVD after adjustment for multiple covariates. The topic remains controversial, however, and additional studies are required, particularly among women and minority populations.
Hanley
Anthony J G
AJ
Division of Clinical Epidemiology, University of Texas Health Sciences Center at San Antonio, San Antonio, Texas 78229-3900, USA.
Williams
Ken
K
Stern
Michael P
MP
Haffner
Steven M
SM
D000328:Adult; D000428:Alcohol Drinking; D001786:Blood Glucose / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000097:blood / Q000453:epidemiology* / Q000378:metabolism; D015444:Exercise; D005260:Female; D005500:Follow-Up Studies; D005951:Glucose Tolerance Test; D006630:Hispanic or Latino; D006706:Homeostasis; D006801:Humans; D015994:Incidence; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008055:Lipids / Q000097:blood; D008297:Male; D008954:Models, Biological; D016017:Odds Ratio; D044469:Racial Groups; D012307:Risk Factors; D013781:Texas / Q000453:epidemiology; D013997:Time Factors
D001786:Blood Glucose; D007328:Insulin; D008055:Lipids