Plasma metabolomic signature of breastfeeding and risk of cardiometabolic diseases.

Breastfeeding is inversely associated with cardiometabolic disease incidence in prospective studies; however, the metabolic pathways underlying these associations remain largely unknown. Here, we derive a plasma metabolomic score of lifetime total duration of breastfeeding using elastic net regularized regression in Nurses' Health Studies (n = 4349) and replicate in the Women's Health Initiative (n = 2088). Data include 181 untargeted plasma metabolites profiled by liquid chromatography mass spectrometry using blood samples collected in mid-life, and self-reported lifetime total duration of breastfeeding. We then examine the associations between the metabolite-based breastfeeding score and risk of T2D and CVD using multivariable Cox regression models and replicated in two external cohorts. The metabolite-based breastfeeding score comprised of 5 metabolites (i.e., C54:2 triglyceride, C56:2 triglyceride, C56:3 triglyceride, cotinine, indole-3-propionate), which show a modest but statistically significant correlation with lifetime total duration of breastfeeding. The metabolite-based breastfeeding score significantly inversely associate with T2D incidence (HR = 0.76, 95%CI = 0.71-0.82) and with CVD incidence (HR = 0.88, 95%CI = 0.84-0.93) independent of T2D and CVD risk factors. We identify plasma metabolite profiles in mid-life associated with breastfeeding duration, which is also linked to CVD and T2D risk.