D Aune1, T Norat2, P Romundstad3, L J Vatten3. 1. Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway; Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, United Kingdom. Electronic address: d.aune@imperial.ac.uk. 2. Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, United Kingdom. 3. Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway.
Abstract
BACKGROUND AND AIMS: Breastfeeding has been associated with reduced risk of maternal type 2 diabetes in some cohort studies, but the evidence from published studies have differed with regard to the strength of the association. To clarify this association we conducted a systematic review and dose-response meta-analysis of breastfeeding and maternal risk of type 2 diabetes. METHODS AND RESULTS: We conducted a systematic review and dose-response meta-analysis of prospective studies of breastfeeding and maternal risk of type 2 diabetes. We searched the PubMed, Embase and Ovid databases up to September 19th 2013. Summary relative risks were estimated using a random effects model. Six cohort studies including 10,842 cases among 273,961 participants were included in the meta-analysis. The summary RR for the highest duration of breastfeeding vs. the lowest was 0.68 (95% CI: 0.57-0.82, I(2) = 75%, p heterogeneity = 0.001, n = 6). The summary RR for a three month increase in the duration of breastfeeding per child was 0.89 (95% CI: 0.77-1.04, I(2) = 93%, p heterogeneity < 0.0001, n = 3) and the summary RR for a one year increase in the total duration of breastfeeding was 0.91 (95% CI: 0.86-0.96, I(2) = 81%, p heterogeneity = 0.001, n = 4). There was little difference in the summary estimates whether or not BMI had been adjusted for. The inverse associations appeared to be nonlinear, p nonlinearity < 0.0001 for both analyses, and in both analyses the reduction in risk was steeper when increasing breastfeeding from low levels. CONCLUSION: This meta-analysis suggests that there is a statistically significant inverse association between breastfeeding and maternal risk of type 2 diabetes.
BACKGROUND AND AIMS: Breastfeeding has been associated with reduced risk of maternal type 2 diabetes in some cohort studies, but the evidence from published studies have differed with regard to the strength of the association. To clarify this association we conducted a systematic review and dose-response meta-analysis of breastfeeding and maternal risk of type 2 diabetes. METHODS AND RESULTS: We conducted a systematic review and dose-response meta-analysis of prospective studies of breastfeeding and maternal risk of type 2 diabetes. We searched the PubMed, Embase and Ovid databases up to September 19th 2013. Summary relative risks were estimated using a random effects model. Six cohort studies including 10,842 cases among 273,961 participants were included in the meta-analysis. The summary RR for the highest duration of breastfeeding vs. the lowest was 0.68 (95% CI: 0.57-0.82, I(2) = 75%, p heterogeneity = 0.001, n = 6). The summary RR for a three month increase in the duration of breastfeeding per child was 0.89 (95% CI: 0.77-1.04, I(2) = 93%, p heterogeneity < 0.0001, n = 3) and the summary RR for a one year increase in the total duration of breastfeeding was 0.91 (95% CI: 0.86-0.96, I(2) = 81%, p heterogeneity = 0.001, n = 4). There was little difference in the summary estimates whether or not BMI had been adjusted for. The inverse associations appeared to be nonlinear, p nonlinearity < 0.0001 for both analyses, and in both analyses the reduction in risk was steeper when increasing breastfeeding from low levels. CONCLUSION: This meta-analysis suggests that there is a statistically significant inverse association between breastfeeding and maternal risk of type 2 diabetes.
Authors: Erica P Gunderson; Cora E Lewis; Ying Lin; Mike Sorel; Myron Gross; Stephen Sidney; David R Jacobs; James M Shikany; Charles P Quesenberry Journal: JAMA Intern Med Date: 2018-03-01 Impact factor: 21.873