Frontiers in Endocrinology (Aug 2018)

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

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

DOI
https://doi.org/10.3389/fendo.2018.00449
Journal volume & issue
Vol. 9

Abstract

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Context: 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.Objective: 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.Materials and Methods: 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.Results: 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, p = 0.025, and β = −0.516 ± 0.083, p < 0.001, respectively).Conclusions: 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.

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