# SIRT1 Serum Concentrations in Lipodystrophic Syndromes

## TL;DR

The study found that SIRT1 levels are higher in people with lipodystrophy compared to those with obesity or normal weight, but not linked to body fat amount.

## Contribution

The novel contribution is the observation of elevated SIRT1 levels in lipodystrophy patients and lack of correlation with body fat.

## Key findings

- SIRT1 serum levels were higher in lipodystrophy patients compared to normal weight and obese subjects.
- SIRT1 levels in lipodystrophy were similar to those in anorexia nervosa patients.
- No relationship was found between SIRT1 levels and body fat amount in lipodystrophy patients.

## Abstract

Lipodystrophies (LDs) are rare, complex disorders of the adipose tissue characterized by selective fat loss, altered adipokine profile and metabolic impairment. Sirtuins (SIRTs) are class III NAD+-dependent histone deacetylases linked to fat metabolism. SIRT1 plays a critical role in metabolic health by deacetylating target proteins in tissue types including liver, muscle, and adipose. Circulating SIRT1 levels have been found to be reduced in obesity and increased in anorexia nervosa and patients experiencing weight loss. We evaluated circulating SIRT1 levels in relation to fat levels in 32 lipodystrophic patients affected by congenital or acquired LDs compared to non-LD subjects (24 with anorexia nervosa, 22 normal weight, and 24 with obesity). SIRT1 serum levels were higher in LDs than normal weight subjects (mean ± SEM 4.18 ± 0.48 vs. 2.59 ± 0.20 ng/mL) and subjects with obesity (1.7 ± 0.39 ng/mL), whereas they were close to those measured in anorexia nervosa (3.44 ± 0.46 ng/mL). Our findings show that within the LD group, there was no relationship between SIRT1 levels and the amount of body fat. The mechanisms responsible for secretion and regulation of SIRT1 in LD deserve further investigation.