AUTHOR=Mariani Stefania , di Giorgio Maria R. , Martini Paolo , Persichetti Agnese , Barbaro Giuseppe , Basciani Sabrina , Contini Savina , Poggiogalle Eleonora , Sarnicola Antonio , Genco Alfredo , Lubrano Carla , Rosano Aldo , Donini Lorenzo M. , Lenzi Andrea , Gnessi Lucio 

TITLE=Inverse Association of Circulating SIRT1 and Adiposity: A Study on Underweight, Normal Weight, and Obese Patients

JOURNAL=Frontiers in Endocrinology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2018.00449

DOI=10.3389/fendo.2018.00449

ISSN=1664-2392

ABSTRACT=<p><bold>Context:</bold> Sirtuins (SIRTs) are NAD+-dependent deacetylases, cellular sensors to detect energy availability, and modulate metabolic processes. SIRT1, the most studied family member, influences a number of tissues including adipose tissue. Expression and activity of SIRT1 reduce with weight gain and increase in conditions of starvation.</p><p><bold>Objective:</bold> To focus on SIRT1 plasma concentrations in different conditions of adiposity and to correlate SIRT1 with fat content and distribution, energy homeostasis and inflammation in under-weight, normal-weight, and obese individuals.</p><p><bold>Materials and Methods:</bold> 21 patients with anorexia nervosa, 26 normal-weight and 75 patients with obesity were evaluated. Body fat composition by dual-energy X-ray absorptiometry, ultrasound liver adiposity, echocardiographic epicardial fat thickness (EFT), inflammatory (ESR, CRP, and fibrinogen), and metabolic (FPG, insulin, LDL- and HDL-cholesterol, triglycerides) parameters, calculated basal metabolic rate (BMR) and plasma SIRT1 (ELISA) were measured.</p><p><bold>Results:</bold> SIRT1 was significantly higher in anorexic patients compared to normal-weight and obese patients (3.27 ± 2.98, 2.27 ± 1.13, and 1.36 ± 1.31 ng/ml, respectively). Linear regression models for each predictor variable adjusted for age and sex showed that SIRT1 concentration was inversely and significantly correlated with EFT, fat mass %, liver fat content, BMR, weight, BMI, WC, LDL-cholesterol, insulin, ESR. Stepwise multiple regression analysis revealed that age and EFT were the best independent correlates of SIRT1 (β = −0.026 ± 0.011, <italic>p</italic> = 0.025, and β = −0.516 ± 0.083, <italic>p</italic> &lt; 0.001, respectively).</p><p><bold>Conclusions:</bold> Plasma SIRT1 shows a continuous pattern that inversely follows the whole spectrum of adiposity. SIRT1 significantly associates with EFT, a strong index of visceral fat phenotype, better than other indexes of adiposity studied here.</p>