Active ghrelin and the postpartum

PURPOSE: Postpartum depression (PPD) occurs in 10%–15% of women. The appetite hormone ghrelin, which fluctuates during pregnancy, is associated with depression in nonpregnant samples. Here, we examine the association between PPD and active ghrelin from pregnancy to postpartum. We additionally examine whether ghrelin changes from pregnancy to postpartum and differs between breastfeeding and non-breastfeeding women. METHODS: Sixty women participated in a survey examining PPD and had information in regard to ghrelin concentrations were included in the study. The Edinburgh Postnatal Depression Scale was used to assess symptoms of PPD. Raw ghrelin levels and ghrelin levels adjusted for creatinine were included as outcomes. RESULTS: Women screening positive for PPD at 12-weeks postpartum had higher pregnancy ghrelin concentrations. Ghrelin concentrations significantly decreased from pregnancy to 6-weeks postpartum and this change differed based on pregnancy depression status. Finally, ghrelin levels were lower in women who breastfed compared with women who were bottle-feeding. No significant findings remained once ghrelin levels were adjusted for creatinine. CONCLUSIONS: Although results do not suggest an association between PPD and ghrelin after adjusting for creatinine, future research should continue to explore this possibility extending further across the postpartum period with larger sample sizes

Ghrelin plays a role in various physiological and pathophysiological brain functions

The ghrelin receptor is now known to play an important role in regulating physiological responses to stress. In particular, ghrelin acting at the growth hormone secretagogue receptor (ghrelin receptor) may promote anxious behaviours under non-stressed conditions, and attenuate anxiety under conditions of stress. Dysregulation of the ghrelin system therefore has significant consequences for stress-related mood disorders such as anxiety and depression; disorders that pose a substantial problem for human health. These effects of the ghrelin system on mood are of particular concern in obese populations, where the likelihood of a mood disorder is higher and the ghrelin system disrupted. Studies in humans are still revealing conflicting roles for ghrelin and the ghrelin receptor in anxiety and depression, but these, and studies in animal models, offer evidence that ghrelin may influence its receptor at extra-hypothalamic brain regions to exert indirect control over central responses to stress and over brain pathways related to anxiety and depression. In this chapter, I discuss the background and potential mechanisms for ghrelin and ghrelin receptor's role in regulating stress and stress-related mood disorders