Introduction: Interleukine-6 (IL-6) is one of the cytokines, excreting by adipocytes, which increases in obesity. These cytokines participate in very complicated mechanisms of developing insulin resistance that accompany obesity. The aim of the study was to:
1) evaluate the influence of weight loss on insulin resistance and serum concentration of IL-6,
2) evaluate the hypothetical association between serum concentration of IL-6 and the improvement of insulin sensitivity in obese women after weight loss.
Material and methods: The study involved 27 obese women (age 40.3 ± 11.1 year; BMI 37.4 ± 5.2 kg/m²) with insulin resistance diagnosed using HOMA index, without concomitant diseases and without any medication. All the patients participated in complex weight reduction treatment (diet, physical activity and psychotherapy). Before and after weight reduction therapy weight and height were measured, body composition was determined using bioimpedance analysis. Serum concentration of glucose was determined by enzymatic procedure, serum concentration of insulin was measured by radioimmunoassay, serum concentration of IL-6 was measured by ELISA. HOMA index was calculated with formula. Results: The mean weight loss after 3-month was 9.2 ± 4.5 kg (approximately 10% of initial weight). After weight reduction significant decreases in HOMA index, insulin and IL-6 concentrations was observed. However, no correlations between changes in insulin concentrations, HOMA index and decrease of IL-6 concentration were showed. We observed significant correlations between ΔHOMA and ΔBMI (r = 0.48; p = 0.012) and Δ percentage fat mass (r = 0.39; p < 0.05).
Conclusions: A moderate weight loss improves insulin sensitivity and decreases serum concentrations of IL-6. However improvement of insulin sensitivity is the effect of fat mass reduction and does not change serum concentration of IL-6.