Serum alpha-klotho concentrations in girls with anorexia nervosa.

Background: Soluble α-klotho may influence energy homeostasis. It also plays a role in calcium-phosphate and vitamin D3 metabolism regulation. Two so far published studies have demonstrated that serum α-klotho levels in patients with AN are decreased, but their relationships with BMI and metabolic disturbances in these patients remain unclear.

Objectives: The aim of the study was to assess the association between serum soluble α-klotho levels and glucose, calcium-phosphorus and vitamin D3 metabolism in girls with acute AN.

Methods: Serum soluble α-klotho concentrations were evaluated using commercially available ELISA kit in 31 Polish girls with restrictive AN and 29 healthy controls (C). Moreover, anthropometric measurements (weight, height, BMI) and laboratory assays (serum fasting glucose, insulin, HOMA-IR, total calcium, phosphorus as well as 25-hydroxy vitamin D3 and calcitriol) were performed.

Results: The mean serum α-klotho concentrations in the AN group were significantly lower than in the C group even after adjustment for BMI. Significant correlations between serum α-klotho and body mass (r=0.54; p=0.009), BMI (r=0.48; p=0.02), serum calcitriol (r=0.48; p=0.03), insulin (r=0.49; p=0.008) and HOMA-IR (r=0.54; p=0.006) were observed in the AN, but not in healthy controls.

Conclusions: Serum α-klotho concentrations in female adolescents with AN are decreased in comparison with normal weight girls and strongly associated with their nutritional status, insulin sensitivity and active vitamin D3 levels.