Chemerin is an adipokine that may mediate the link between obesity, inflammation, insulin resistance, type 2 diabetes mellitus, and cardiovascular disease. In this study, we examined the association between chemerin and various cardiometabolic risk factors in cross-sectional setting and tested the hypothesis that a 6-month combined exercise program decreases serum chemerin in overweight or obese, non-diabetic individuals. Serum chemerin concentration was measured in a cross-sectional analysis including 98 individuals with a wide range of age and body mass index (BMI). In addition, chemerin was measured in 79 sedentary, overweight or obese, non-diabetic individuals who completed a 6-month combined endurance and resistance exercise program (CEP, n = 51) or served as controls (C, n = 28). Chemerin was significantly associated with total cholesterol (p = 0.04), triglycerides (p < 0.001), fasting insulin (p < 0.001), homeostasis model assessment of insulin resistance (HOMA-IR, p < 0.001), systolic blood pressure (p = 0.04), highly sensitive C-reactive protein (p = 0.03), leucocytes count (p = 0.047), and leptin (p = 0.008) independently of age and BMI. In multiple regression analysis, chemerin was an independent determinant of HOMA-IR. As a result of the 6-month training program, serum chemerin decreased significantly in CEP group (-13.8 ± 13.2 ng/ml, p < 0.001). A significant association between the changes in chemerin and improved HOMA-IR were found even after adjustment for changes in waist circumference. Among non-diabetic individuals serum chemerin was associated with various cardiometabolic risk factors independently of BMI. In addition, the 6-month combined strength and endurance training program led to a significant reduction in circulating chemerin levels in overweight or obese individuals.

SUMMARYObjective: We examined the effect of a 6-month combined aerobic and resistance training programme on cardiometabolic risk factors in nondiabetic subjects and compared its effectiveness when executed under strict professional supervision or without direct supervision.Methods: Eighty-five sedentary, non-diabetic subjects (27 men and 58 women), mean age 47.5±0.6 years, mean body mass index (BMI, 33.8±0.6 kg/m 2 ) participated in a combined exercise programme assigned to supervised (S, n=31), non-supervised (NS, n=24) or control group (C, n=30). Cardiometabolic risk parameters were assessed at baseline and after the 6-month training.Results: In both the S and NS group there was a significant decrease in BMI (−1.6±0.3, p<0.001 and −1.0±0.3 kg/m 2 , p=0.004), waist circumference (−10.1±1.1 cm, p<0.001 and −7.8±0.8 cm, p<0.001), fat mass (−1.8±0.4%, p<0.001 and −2.1±0.6%, p=0.003), and a significant increase in fat-free mass (+1.7±0.4%, p<0.001 and +2.0±0.7%, p=0.008), and aerobic capacity (+6.9±1.1, p<0.001 and +6.9±0.8 ml/kg per min, p=0.008). Fasting glucose did not change in S and NS, but increased in C (p=0.048). In the S group a significant decrease in fasting insulin (p<0.001), homeostasis model assessment of insulin resistance (p<0.001), highly sensitive C-reactive protein (p=0.004), leucocytes count (p=0.04), systolic high (p<0.001) and diastolic (p=0.009) blood pressure was found. Comparable significant decreases in total and low-density lipoprotein cholesterol were observed in all study groups.Conclusions: A 6-month combined exercise programme led to substantial improvement of various cardiometabolic risk factors. This programme was effective even when executed without direct supervision, although the effects were more pronounced in the supervised group. Our findings suggest that non-supervised exercise programmes may be a valuable, cost-effective tool to translate the current physical activity guidelines in a real-life setting.

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The evaluation of the absolute (VO2peak) and relative (VO2peak/kg) values of the peak oxygen consumption is an essen-tial component of exercise testing in athletes. However, according to many researchers, VO2peak/kg values in adolescent athletes do not provide sufficiently reliable information to assess their functional work capacity. The present research aims to investigate the applicability of relative values of oxygen consumption for accurate estimation of functional work capacity in adolescent athletes. The research subjects were twelve basketball players from a junior club team participating in the state championship of Bulgaria. They carried out two maximum bicycle exercise tests with a twelve-month period between the two tests. We analyzed the registered absolute and relative peak power output (Wattpeak, Wattpeak/kg) and peak oxygen consumption. It was established that there was a significant increase in average Wattpeak (8.5%), Wattpeak/kg (6.2%), and VO2peak (3.7%) during the second test as compared to the first one. At the same time, in all subjects, no signif-icant increase in VO2peak/kg (average of 0.9%) was registered. This result is associated with the athletes’ increased body weight (average of 2.7%) during the second test. Based on the lack of VO2peak/kg dynamics compared to the significant increase of Wattpeak, Wattpeak/kg, VO2peak, it can be concluded that the isolated use of VO2peak/kg for functional capacity analysis may result in significant errors in estimating the functional work capacity of adolescent athletes.