THE RELATIONSHIP OF SERUM LEPTIN AND PLASMA APELIN LEVELS IN MEN WITH METABOLIC SYNDROME

Abstract

Background: The metabolic syndrome is seen as a cluster of high cardiovascular risk factors. New hormone-like substances, such as adipokines leptin and apelin, produced by fat tissue, are important for the pathophysiology of the metabolic syndrome.Aim: To evaluate levels of plasma apelin and serum leptin in patients with metabolic syndrome.Materials and methods: We examined 122 male patients with metabolic syndrome and 30 healthy males aged from 25 to 60 years. All patients were assessed accordingly to confirm the diagnosis of the metabolic syndrome, with additional measurements of serum leptin and plasma apelin.Results: Serum leptin levels were 10-fold higher and plasma apelin levels 3-fold higher in patients with metabolic syndrome (n=122), compared to the controls (n=30): 25.43 vs. 3.99 ng/mL (p<0.05) and 1.13 vs. 0.66 ng/mL (p<0.05), respectively. Serum leptin levels correlated with all parameters of the excess body weight, such as body mass (r=0.79, р<0.05), body mass index (r=0.93, р<0.05), waist circumference (r=0.61, р<0.05), hip circumference (r=0.57, р<0.05), and waist-to-hip ratio (WHR; r=0.4, р<0.05). Plasma apelin levels correlated with the waist circumference (r=0.27, р<0.05) and WHR (r=0.29, р<0.05). There was a significant increase of serum leptin dependent on the bodyweight category: 19.8 ng/mL in patients with obesity Grade I (n=49) and 28.7 ng/mL in those with obesity Grade II (n=46) (р<0.05). There was a non-significant trend towards an increase in plasma apelin depending on bodyweight. As far as abdominal obesity is concerned, in patients with WHR<1 (n=35), plasma apelin level was 0.36 ng/mL, whereas in those with WHR of ≥1 (n=87), it was 3-fold higher (1.09 ng/mL, р<0.05); the increase in serum leptin levels was non-significant. There was no association between plasma apelin and serum leptin in patients with metabolic syndrome (r=0.1, р>0.05).Conclusion: The adipokine levels in men with metabolic syndrome are higher than in normal men. Serum leptin level is a sensitive parameter indicating accumulation of the fat tissue, irrespective of its localization. Plasma apelin is less sensitive, but it does reflect fat accumulation of the central (abdominal) type.