Association of Parity With Risk of Type 2 Diabetes and Related Metabolic Disorders
- Anthony J.G. Hanley, PHD12,
- Gail McKeown-Eyssen, PHD1,
- Stewart B. Harris, MD3,
- Robert A. Hegele, MD4,
- Thomas M.S. Wolever, MD5,
- Jeremy Kwan, MSC6 and
- Bernard Zinman, MD2
- 1Department of Public Health Sciences, University of Toronto, Toronto, Canada
- 2Samuel Lunenfeld Research Institute, Mt. Sinai Hospital, Toronto, Canada
- 3Centre for Studies in Family Medicine, University of Western Ontario, London, Canada
- 4Robarts Research Institute, London, Canada
- 5Department of Nutritional Sciences, University of Toronto, Toronto, Canada
- 6Banting and Best Diabetes Centre, University of Toronto, Toronto, Canada
Abstract
OBJECTIVE—The relationship between parity and risk of diabetes is controversial, and little information is available regarding associations between parity and measures of insulin resistance and β-cell function. The objective of this study was to investigate the association between parity and risk of glucose intolerance and related metabolic disorders using data from a population-based study in a Native Canadian community.
RESEARCH DESIGN AND METHODS—Female participants (n = 383, aged 12–79 years) provided fasting blood samples for the determination of glucose, insulin, C-peptide, and proinsulin concentrations. A 75-g oral glucose tolerance test was administered, and diabetes and impaired glucose tolerance were diagnosed according to World Health Organization criteria. Waist circumference and percent body fat were determined. Information regarding occurrence of live births and previously diagnosed diabetes was obtained from interviewer-administered questionnaires.
RESULTS—Parity was associated with a significantly reduced risk of diabetes (nulliparous vs. ≥1 birth, odds ratio 0.43, 95% CI 0.19– 0.94, P < 0.05) after adjustment for age and waist circumference. In addition, nondiabetic nulliparous women had significantly elevated concentrations of fasting insulin and proinsulin relative to nondiabetic parous women (all P < 0.05) in analyses adjusted for age and waist circumference.
CONCLUSIONS—Our results are consistent with those from other populations experiencing high rates of diabetes and suggest the presence of a diabetes-prone phenotype within the nulliparous subcohort of this population, which may contribute to infertility.
- CV, coefficient of variation
- GDM, gestational diabetes mellitus
- HOMAIR, homeostasis model assessment index of insulin resistance
- IGT, impaired glucose tolerance
- OC, oral contraceptive
- OGTT, oral glucose tolerance test
- OR, odds ratio
- PCOS, polycystic ovary syndrome
- SLHDP, Sandy Lake Health and Diabetes Project
Footnotes
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Address correspondence and reprint requests to Dr. A. Hanley, Division of Epidemiology and Biostatistics, Samuel Lunenfeld Research Institute, Mt. Sinai Hospital, 843-600 University Ave., Toronto, ON, M5G 1X5, Canada. E-mail: hanley{at}mshri.on.ca.
Received for publication 31 October 2001 and accepted in revised form 20 December 2001.
A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.
- DIABETES CARE
