Associations of Circulating PYY3-36 Concentrations with Metabolic Syndrome in Extremely Obese Subjects

Abstract

Background: The gut hormone peptide YY3-36 (PYY3-36) plays major roles in regulation of appetite and energy metabolism, mediates beneficial effects of bariatric surgery, and may be a potential weight-reducing and glucose-modulating therapy. Obesity may influence the metabolic expression of circulating PYY3-36 and metabolic markers. We studied the relationship of PYY3-36 concentrations with metabolic syndrome (MetSyn) components, lipids, insulin resistance, and inflammatory biomarkers in subjects with extreme obesity. Methods: We measured MetSyn components and PYY3-36, lipids, hormones, homeostasis model assessment (HOMA) index, and inflammatory biomarkers in consecutively referred patients (180 women and 111 men) aged 18-78 years with body mass index (BMI) ≥40 kg/m2. Associations of PYY3-36 to components, insulin resistance, and biomarkers were examined with partial correlations and linear regression. Results: PYY3-36 concentrations were not related to MetSyn components, HOMA index, or to inflammatory biomarker or leptin concentrations. PYY3-36 concentrations correlated with systolic blood pressure (r = 0.21; P < 0.0001) after adjustment for age and gender. In linear regression analysis, PYY3-36 concentrations were associated with systolic blood pressure after adjustment for age, gender, and central obesity in the entire sample (Beta 0.21; 95% CI 0.09-0.34) as well as in subjects not taking blood pressure-lowering medication (Beta 0.19; 95% CI 0.04-0.36). These associations were not statistically significant in the small subset of participants (22%) with type 2 diabetes. Conclusions: In extremely obese patients, fasting PYY3-36 concentrations were linked to systolic blood pressure, but not to other components of MetSyn, suggesting divergence between pathways of blood pressure and glucose/body weight regulation. However, this finding will need to be further investigated.