Insulin Sensitivity and Insulin Secretion Determined by the Homeostasis Model Assessment (HOMA) and Risk of Diabetes Mellitus in a Multi-Ethnic Cohort of Women: The Women's Health Initiative Observational Study
- Yiqing Song, MD, ScD1,
- JoAnn E. Manson, MD, DrPH1,,2,
- Lesley Tinker, PhD, RD3,
- Barbara V. Howard, PhD4,
- Lewis H. Kuller, MD, DrPH5,
- Lauren Nathan, MD6,
- Nader Rifai, PhD7 and
- Simin Liu, MD, ScD (siminliu{at}ucla.edu)1,,2,,8,,9
- 1Division of Preventive Medicine, Medicine, Brigham and Women's Hospital, Boston, Massachusetts
- 2Epidemiology, Harvard School of Public Health, Boston, Massachusetts
- 3Public Health Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
- 4MedStar Research Institute, Washington, D.C
- 5Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania
- 6Obstetrics and Gynecology, University of California, Los Angeles, California
- 7Children's Hospital, Boston, Massachusetts
- 8Epidemiology, and
- 9David Geffen School of Medicine, University of California, Los Angeles, California
Abstract
OBJECTIVE The homeostasis model assessment (HOMA) based on plasma levels of fasting glucose and insulin has been widely validated and applied for quantifying insulin resistance and β-cell function. However, prospective data regarding its relation to diabetes risk in ethnically diverse populations are limited.
RESEARCH DESIGN AND METHODS Among 82,069 women aged 50 to 79 years free of cardiovascular disease or diabetes participating in the Women's Health Initiative Observational Study (WHI-OS), we conducted a nested case-control study to prospectively examine the relations of HOMA-insulin resistance (HOMA-IR) and β-cell function (HOMA-%B) with diabetes risk. During a median follow-up period of 5.9 years, 1,584 diabetes patients were matched with 2,198 controls by age, ethnicity, clinical center, time of blood draw, and follow-up time.
RESULTS Baseline levels of fasting glucose, insulin, and HOMA-IR were each significantly higher among cases than controls while HOMA-%B was lower (all P values<0.0001). After adjustment for matching factors and diabetes risk factors, all four markers were significantly associated with diabetes risk; the estimated relative risks (RRs) per standard deviation increment were 3.54 (95% CI, 3.02-4.13) for fasting glucose, 2.25 (1.99-2.54) for fasting insulin, 3.40 (2.95-3.92) for HOMA-IR, and 0.57(0.51-0.63) for HOMA-%B. While no statistically significant multiplicative interactions were observed between these markers and ethnicity, the associations of both HOMA-IR and HOMA-%B with diabetes risk remained significant and robust in each ethnic group including Whites, Blacks, Hispanics, and Asians/Pacific Islanders. When evaluated jointly, the relations of HOMA-IR and HOMA-%B with diabetes risk appeared to be independent and additive. HOMA-IR was more strongly associated with an increased risk than were other markers after we excluded those with a fasting glucose ≥ 126 mg/dl at baseline.
CONCLUSIONS High HOMA-IR and low HOMA%B were independently and consistently associated with an increased diabetes risk in a multi-ethnic cohort of US postmenopausal women. These data suggest the values of HOMA indices for diabetes risk in epidemiologic studies.
Footnotes
-
- Received February 20, 2007.
- Accepted April 14, 2007.
- Copyright © American Diabetes Association
