High serum oxytocin is associated with metabolic syndrome in older men - The MINOS study.

ABSTRACT

AIM: Oxytocin regulates food intake, carbohydrate and lipid metabolism, and urinary sodium excretion. We assessed the association between serum oxytocin levels and presence of metabolic syndrome (MetS) in older men. METHODS: Cross-sectional study was performed in 540 volunteer men aged 50-85yrs from the MINOS cohort. Oxytocin was measured in fasting serum by radioimmunoassay (Oxytocin RIA, Phoenix Pharmaceuticals). MetS was diagnosed using the harmonized definition. RESULTS: Serum oxytocin was higher in 166 men with MetS vs. controls (p<0.005). After adjustment for confounders including leptin, higher oxytocin was associated with higher odds of MetS (OR=1.38 per SD, 95%CI 1.10-1.71, p<0.005). Men with serum oxytocin >0.74pg/mL (median) had higher odds of MetS vs. men with oxytocin ⩽0.74pg/mL (OR=2.06, 95%CI 1.33-3.18, p<0.005). Higher oxytocin levels and low testosterone levels (total or free) were significantly associated with higher odds of MetS jointly and independently of each other. Men having oxytocin >0.74pg/mL and total testosterone <300ng/dL (<10.4nmol/L) had higher odds of MetS vs. men without these characteristics (OR=3.95, 95%CI 1.65-9.46, p<0.005). Men having 25-hydroxycholecalciferol levels <30ng/mL and oxytocin >0.74pg/mL had higher odds of MetS vs. men without these characteristics (OR=2.86, 95%CI 1.47-5.58, p<0.01). Men having oxytocin >0.74pg/mL and osteocalcin levels <14.6ng/mL (lowest quartile) had higher odds of MetS vs. men without these characteristics (OR=4.12, 95%CI 2.07-8.20, p<0.001). CONCLUSION: In older men, higher serum oxytocin levels are associated with higher odds of MetS regardless of potential confounders.