Breast-Feeding and Childhood-Onset Type 1 Diabetes: A Pooled Analysis of Individual

Participant Data from 43 Observational Studies

Featured Article:

Chris R. Cardwell, Ph.D., Lars C. Stene, Ph.D., Johnny Ludvigsson, M.D., Ph.D., Joachim Rosenbauer, M.D., D.I.P.L. M.A.T.H., Ondrej Cinek, M.D., Ph.D., Jannet Svensson, Ph.D., Francisco Perez-Bravo, Ph.D., Anjum Memon, M.B.B.S., D.P.H.I.L., Suely G. Gimeno, DP.h., Emma J.K. Wadsworth, Ph.D., Elsa S. Strotmeyer, Ph.D., Michael J. Goldacre, F.F.P.H.M., Katja Radon, Ph.D., Lee-Ming Chuang, M.D., Ph.D., Roger C. Parslow, Ph.D., Amanda Chetwynd, Ph.D., Kyriaki Karavanaki, M.D., Ph.D., Girts Brigis, M.D., Ph.D., Paolo Pozzilli, M.B.B.S., M.D., Brone Urbonaité, M.D., Ph.D., Edith Schober, M.D., Gabriele Devoti, M.D., Sandra Sipetic, M.D., Ph.D., Geir Joner, M.D., Ph.D., Constantin Ionescu-Tirgoviste, M.D., Ph.D., Carine E. De Beaufort, M.D., Ph.D., Kirsten Harrild, M.S.C., Victoria Benson, Ph.D., Erkki Savilahti, M.D., Ph.D., Anne-Louise Ponsonby, M.B.B.S., Ph.D., Mona Salem, M.D., Samira Rabiei, M.S.C., Chris C. Patterson, Ph.D.

Diabetes Care Volume 35: 2215-2225

November, 2012

STUDY OBJECTIVE 

• To investigate if there is reduced risk of type 1 diabetes in breastfed children

Cardwell C et al. Diabetes Care 2012;35:2215-2225

STUDY DESIGN AND METHODS

• Relevant studies identified from literature searches

• Authors of relevant studies asked to provide individual participant data or conduct prespecified analyses

• Meta-analysis techniques used to combine odds ratios (ORs) and investigate heterogeneity between studies

Cardwell C et al. Diabetes Care 2012;35:2215-2225

RESULTS

• Data from 43 studies including 9,874 patients with type 1 diabetes

• Reduction in the risk of diabetes was seen after exclusive breast-feeding for >2 weeks (20 studies; OR 0.75, 95% CI 0.64–0.88)

• Association after exclusive breast-feeding for >3 months was weaker (30 studies; 0.87, 0.75–1.00)

Cardwell C et al. Diabetes Care 2012;35:2215-2225

RESULTS

• No association was observed after (nonexclusive) breast-feeding for >2 weeks (28 studies; 0.93, 0.81–1.07) or >3 months (29 studies; 0.88, 0.78–1.00)

• Associations were all subject to marked heterogeneity (I2 = 58, 76, 54, and 68%, respectively)

• In studies with lower risk of bias, reduced risk remained after exclusive breast-feeding for >2 weeks (12 studies; 0.86, 0.75–0.99) and heterogeneity was reduced (I2 = 0%)

Cardwell C et al. Diabetes Care 2012;35:2215-2225

Cardwell C et al. Diabetes Care 2012;35:2215-2225

Cardwell C et al. Diabetes Care 2012;35:2215-2225

Cardwell C et al. Diabetes Care 2012;35:2215-2225

Cardwell C et al. Diabetes Care 2012;35:2215-2225

Cardwell C et al. Diabetes Care 2012;35:2215-2225

Cardwell C et al. Diabetes Care 2012;35:2215-2225

CONCLUSIONS

• Pooled analysis suggests weak protective associations between exclusive breast-feeding and type 1 diabetes risk

Cardwell C et al. Diabetes Care 2012;35:2215-2225