The relationship between endogenous oxytocin and vasopressin levels and the Prader-Willi syndrome behaviour phenotype

Abstract

BackgroundOxytocin and vasopressin systems are altered in Prader Willi syndrome (PWS). However, investigations into endogenous oxytocin and vasopressin levels as well as clinical trials evaluating the effect of exogenous oxytocin on PWS symptoms have had mixed results. It is also unknown whether endogenous oxytocin and vasopressin levels are associated with certain PWS behaviours.MethodWe compared plasma oxytocin and vasopressin and saliva oxytocin levels in 30 adolescents and adults with PWS to 30 typically developing age-matched controls. We also compared neuropeptide levels between gender and genetic subtypes within the PWS cohort and examined the relationship between neuropeptide levels and PWS behaviours.ResultsWhile we did not measure a group difference in plasma or saliva oxytocin levels, plasma vasopressin was significantly lower in individuals with PWS compared to controls. Within the PWS cohort, saliva oxytocin levels were higher in females compared to males and individuals with the mUPD compared to the deletion genetic subtype. We also found the neuropeptides correlated with different PWS behaviours for males and females and for genetic subtypes. For the deletion group, higher plasma and saliva oxytocin levels were related to fewer behaviour problems. For the mUPD group, higher plasma vasopressin levels were related to more behaviour problems.ConclusionThese findings support existing evidence of a vasopressin system defect in PWS and for the first time identify potential differences in the oxytocin and vasopressin systems across PWS genetic subtypes.

Hormonal Imbalances in Prader–Willi and Schaaf–Yang Syndromes Imply the Evolution of Specific Regulation of Hypothalamic Neuroendocrine Function in Mammals

“…Besides oxytocin, researchers have identified decreases in several other neuropeptides relevant to PWS (Table 1). Lower levels of AVP, which regulates the tonicity of body fluids and affects behaviors related to social interactions, have been reported in Magel2null mice and PWS patients [65,73,202]. Orexin/hypocretin, which is important for sleep regulation, food intake, and energy balance, is also altered in PWS patients and mouse models (Table 1) [153,203].…”

Intranasal Oxytocin in Pediatric Populations: Exploring the Potential for Reducing Irritability and Modulating Neural Responses: A Mini Review

“…Common symptoms of PWS include cognitive, endocrine and behavioral dysfunction, including irritability, which often manifests itself as temper tantrums [ 55 ]. Rice et al [ 56 ] found that, in patients with the 15q11-q13 PWS subtype, salivary OXT levels were inversely correlated with symptom severity, suggesting that OXT deficiency may play a role in the PWS symptomatology. Further studies have connected OXT deficiency with aberrant behaviors observed in patients with PWS [ 57 ].…”