Inflammatory biomarker pentraxin 3 (PTX3) in relation to obesity, body fat depots and weight loss

OBJECTIVE: The relation between inflammatory markers, adiposity and disease is under extensive study. Here we tested the hypothesis that the immunomodulatory protein pentraxin 3 (PTX3) is associated with adiposity in the general population. METHODS: Serum PTX3 concentrations, body mass index (BMI), waist circumference (WC) and fat depots, as quantified by dual-energy X-ray absorptiometry and magnetic resonance imaging, were assessed in three community-based cohorts: ULSAM, n = 790, mean age 78 years; PIVUS, n = 1003, mean age 70 years, women 50%; and the NORDIET-trial, n = 86, mean age 53 years, women 63%. Participants were re-examined after 5 years (PIVUS, n = 804) or following a 6-week randomized controlled dietary intervention (NORDIET). RESULTS: PTX3 levels were inversely associated with BMI and WC as well as with total and visceral fat (P < 0.05 for all; adjusted for age, inflammatory biomarkers and cardiovascular risk factors). The association between PTX3 and BMI appeared even stronger in nonobese individuals. A decrease in BMI over 5 years as well as weight loss following the NORDIET intervention were associated with increased serum PTX3 concentrations (P < 0.001). CONCLUSIONS: These consistent data support an inverse association between circulating PTX3 and anthropometrical measures, calling for further mechanistic studies of the link between PTX3 and fat.