The Association between Blood SIRT1 and Ghrelin, Leptin, and Antibody Anti-Hypothalamus: A Comparison in Normal Weight and Anorexia Nervosa

Abstract

Sirtuin 1 (SIRT1) is a sensor of cell energy availability, regulating metabolic homeostasis as well as leptin and ghrelin, and it could be considered as a potential plasmatic marker. The aim of this study was to assess whether circulating SIRT1 varies consistently with leptin, ghrelin, body mass index (BMI), and IgG reactive to hypothalamic antigens in anorexia nervosa (AN). Fifty-four subjects were evaluated: 32 with AN and 22 normal-weight control subjects. Serum levels of SIRT1, leptin, ghrelin, and IgG reactive to hypothalamic antigens were evaluated by ELISA. Results showed that serum SIRT1 is increased in patients with AN, and the amount is decreased in relation to the duration of the illness. SIRT1 concentration approaches the values obtained for the control group, although the difference is still statistically significant. A negative correlation between serum SIRT1 values and leptin or BMI values has been found. On the contrary, a positive correlation between SIRT1 and ghrelin or IgG specific for hypothalamic antigens is reported. These findings suggest that a peripheral evaluation of SIRT1 could be a possible clinical/biochemical parameter related to AN. In addition, we can assume that SIRT1 is related to autoantibody production and may correlate with the intensity/severity of AN. Thus, reducing the production of autoantibodies specific for hypothalamic cells could be a sign of improvement of the clinical condition.

Sirtuin 1 serum concentration in healthy children - dependence on sex, age, stage of puberty, body weight and diet

“…It was proven that, SIRT1 play an important role in detection of cellular energy levels and regulation of energy metabolism and increase in response to fasting, caloric restriction and malnutrition (3). Several reports have shown that serum SIRT1 levels correlated negatively with BMI and were elevated in patients with anorexia nervosa (1,45). It is well known that caloric restriction contributes to a state of growth hormone resistance and is associated with a decrease in serum IGF-1 levels, which is a main mediator of growth hormone (GH) action in peripheral tissues.…”