Lactation and maternal risk of type 2 diabetes: a population-based study.
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 > or =1 month. In fully adjusted models, the risk of type 2 diabetes among women who consistently breastfed all of their children for > or =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 1.93; 95% CI, 1.14-3.27) [corrected]. 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.
Schwarz
Eleanor Bimla
EB
Department of Medicine, University of Pittsburgh, PA, USA. schwarzeb@upmc.edu
Brown
Jeanette S
JS
Creasman
Jennifer M
JM
Stuebe
Alison
A
McClure
Candace K
CK
Van Den Eeden
Stephen K
SK
Thom
David
D
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism*; D015992:Body Mass Index; D001942:Breast Feeding; D002140:California / Q000453:epidemiology; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000378:metabolism / Q000517:prevention & control*; D005260:Female; D006801:Humans; D007774:Lactation / Q000378:metabolism*; D016015:Logistic Models; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011247:Pregnancy; D013997:Time Factors
D001786:Blood Glucose
J Clin Endocrinol Metab. 1998 Jan;83(1):103-6
9435424
Obstet Gynecol. 2009 May;113(5):974-982
19384111
MMWR Morb Mortal Wkly Rep. 2007 Aug 3;56(30):760-3
17673896
Nature. 2001 Dec 13;414(6865):782-7
11742409
Obstet Gynecol. 1993 Sep;82(3):451-5
8355952
J Clin Endocrinol Metab. 2004 Dec;89(12):6239-43
15579783
MMWR Morb Mortal Wkly Rep. 2008 Jun 13;57(23):621-5
18551096
Pediatrics. 2008 Oct;122 Suppl 2:S56-62
18829832
Pediatrics. 2005 Feb;115(2):496-506
15687461
JAMA. 2005 Nov 23;294(20):2601-10
16304074
J Womens Health Gend Based Med. 2001 Sep;10(7):681-7
11571098
Diabetes Care. 1999 Sep;22(9):1471-8
10480511
FEBS Lett. 1986 Jan 6;194(2):292-6
3079710
Gynecol Obstet Invest. 2006;61(2):115-8
16272815
BMJ. 2001 Nov 24;323(7323):1213-7
11719411
Am J Physiol. 1986 Nov;251(5 Pt 1):E537-41
3535531
Metabolism. 2001 Jun;50(6):715-9
11398150
Diabetes Care. 2009 Feb;32(2):287-94
19017771
Evid Rep Technol Assess (Full Rep). 2007 Apr;(153):1-186
17764214
Biochem J. 1984 Jun 1;220(2):455-60
6146315
J Urol. 2006 Jan;175(1):259-64
16406923
Am J Epidemiol. 2005 Feb 1;161(3):289-96
15671261
Diabetes Care. 1995 Jul;18(7):1050-64
7555542
J Nutr. 2001 Nov;131(11):3009S-11S
11694637
Diabetologia. 2008 Feb;51(2):258-66
18040660