Lactation and Maternal Risk of Type 2 Diabetes: A Population-based Study

Schwarz, Eleanor Bimla; Brown, Jeanette S.; Creasman, Jennifer M.; Stuebe, Alison; McClure, Candace K.; Van Den Eeden, Stephen K.; Thom, David

doi:10.1016/j.amjmed.2010.03.016

« Previous Next »The American Journal of Medicine
Volume 123, Issue 9 , Pages 863.e1-863.e6, September 2010

Lactation and Maternal Risk of Type 2 Diabetes: A Population-based Study

Eleanor Bimla Schwarz, MD, MS
- Department of Medicine, University of Pittsburgh, Pa
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh, Pa
- Department of Epidemiology, University of Pittsburgh, Pa
- Requests for reprints should be addressed to Eleanor Bimla Schwarz, MD, MS, Department of Medicine, University of Pittsburgh Center for Research on Health Care, 230 McKee Place, Suite 600, Pittsburgh, PA 15213
Jeanette S. Brown, MD
- Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco
- Department of Urology, University of California, San Francisco
- Department of Epidemiology, University of California, San Francisco
Jennifer M. Creasman, MPH
- Women's Health Clinical Research Center, University of California, San Francisco
Alison Stuebe, MD, MSc
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, University of North Carolina, Chapel Hill
Candace K. McClure, PhD
- Department of Epidemiology, University of Pittsburgh, Pa
Stephen K. Van Den Eeden, PhD
- Division of Research, Kaiser Permanente, Northern California, Oakland
David Thom, MD, PhD
- Department of Family and Community Medicine, University of California, San Francisco

Abstract

Background

Lactation has been associated with improvements in maternal glucose metabolism.

Methods

We explored the relationships between lactation and risk of type 2 diabetes in a well-characterized, population-representative cohort of women, aged 40-78 years, who were members of a large integrated health care delivery organization in California and enrolled in the Reproductive Risk factors for Incontinence Study at Kaiser (RRISK), between 2003 and 2008. Multivariable logistic regression was used to control for age, parity, race, education, hysterectomy, physical activity, tobacco and alcohol use, family history of diabetes, and body mass index while examining the impact of duration, exclusivity, and consistency of lactation on risk of having developed type 2 diabetes.

Results

Of 2233 women studied, 1828 were mothers; 56% had breastfed an infant for ≥1 month. In fully adjusted models, the risk of type 2 diabetes among women who consistently breastfed all of their children for ≥1 month remained similar to that of women who had never given birth (odds ratio [OR] 1.01; 95% confidence interval [CI], 0.56-1.81). In contrast, mothers who had never breastfed an infant were more likely to have developed type 2 diabetes than nulliparous women (OR 1.92; 95% CI, 1.14-3.27). Mothers who never exclusively breastfed were more likely to have developed type 2 diabetes than mothers who exclusively breastfed for 1-3 months (OR 1.52; 95% CI, 1.11-2.10).

Conclusions

Risk of type 2 diabetes increases when term pregnancy is followed by <1 month of lactation, independent of physical activity and body mass index in later life. Mothers should be encouraged to exclusively breastfeed all of their infants for at least 1 month.

Keywords: Breastfeeding, Lactation, Pregnancy, Type 2 diabetes, Women

Funding: The Reproductive Risk factors for Incontinence Study at Kaiser (RRISK) was funded by the National Institute of Diabetes and Digestive and Kidney Diseases/Office of Research on Women's Health Specialized Center of Research Grant #P50 DK064538. Dr Schwarz was supported by National Institute of Child Health and Development grant #K23 HD051585-01.

Conflict of Interest: None of the authors have any conflicts of interest.

Authorship: All authors had access to the data and an active role in writing this manuscript.

PII: S0002-9343(10)00385-2

doi:10.1016/j.amjmed.2010.03.016