Prolactin in obese children: A bridge between inflammation and metabolic-endocrine dysfunction

Objective Adipocytes, regulated by insulin, represent the major peripheral source of prolactin (PRL), which play a pivotal role in energy balance, acting on adipogenesis and lipolysis. The aim of this study was to investigate whether PRLwas associated with obesity-related inflammatory status and metabolic parameters. The diagnostic and prognostic role of PRLfor metabolic syndrome (MS) was assessed. The effects of short-term lifestyle therapy on PRLlevels were evaluated.Subjects Prolactin was assessed in 94 obese patients and compared with 40 healthy children (HS).Patients were followed up for 1year. Receiver operating characteristics (ROC) analysis was employed to find the best cut-off values capable of identifying MSin obese children for PRL, IL-6 and TNF-. Kaplan-Meier curves were also generated. Adjusted risk estimates for MSwere calculated using Cox proportional hazard regression analysis. An obesity intervention programme was administered for 12months.Results Prolactin levels were lower in obese patients than controls (P < 0.0001). PRLwas found to be inversely correlated with BMI, IL-6 and HOMA-IR, whereas a direct correlation was found with HDLvalues. At ROCanalysis, PRLshowed higher sensitivity and specificity than IL-6 and TNF- in identifying MSin obese children. Cox proportional hazard regression analysis showed that PRLpredicted MSindependently of other potential confounders. The lifestyle intervention improved PRLand metabolic parameters.Conclusions Prolactin represents a prognostic marker for obese children and a predictive factor for progression to MS. PRLmeasurement may be useful as part of the endocrine work-up of obese children.