[Leptin to adiponectin ratio, as an index of insulin resistance and atherosclerosis development]

Obesity is an effect of interaction of genetic and environmental factors. It leads to development of serious complications, like insulin resistance, diabetes type 2, arterial hypertension and atherosclerosis. The adipose tissue is a place where many adipokines, mainly leptin and adiponectin, are produced and released. Adiponectin, which blood level is decreased in obesity is considered to have antidiabetic and antiatherogenic effect. While leptin, which blood level is increased in obesity, is associated with regulation of appetite, energy expenditure, lipids and carbohydrates metabolism, cellular differentiation and puberty. The aim of this research was estimation of leptin to adiponectin ratio (Lep/AdipoR) in the blood of patients who came from obese families. The study was carried out on 80 patients (43 female and 37 male). The antropometric examination with proportional contents of adipose tissue, oral glucose tolerance test (OGTT) and oral postprandial lipaemia test (OPLT) were performed. The fasting level of leptin (Elisa), adiponectin (Elisa) and von Willebrand factor (Elisa) lipidogram were performed. During OGTT blood was sampled in intervals of 30 minutes up to 2 hours, to measure glucose and insulin concentration. In fasting state and then every 2 hours after consumption of a high-fat meal (OPLT), (0, 2 hours, 4 hours, 6 hours, and 8 hours) blood was sampled for: trigliceride, glucose, free fatty acids and insulin concentration. The insulin resistance ratio (HOMA-IR) was calculated for each patient according to the formula: [insulin (mU/ml) x glucose (mmol/l)]/22.5. Adiponectin blood level was higher in the examined women than in men. It (regardless to the sex) was decreased with decrease of body mass index (BMI). Blood level of leptin (also higher in women) was positively corelated with BMI. In the group of patients with low level of adiponectin in serum (below 5mg/ml in men and 10 mg/ml in women) the highest con- centration of glucose and insulin in successive time points of OGTT and the highest HOMA-IR value (4.79 in men and 4.38 in women) were observed. In patients with high level of leptin in serum (over 20 ng/ml), the highest concentration of insulin, especially in 2 hours of the test (101.75 micromol/ l), and the highest HOMA-IR value (4.30 during OPLT ) were found. The Lep/AdipoR in the blood was significantly higher in obese patients in comparison to people with normal BMI. Lep/AdipoR had high correlation factor with BMI (r = 0.6267, p < 0.001), with HOMA-IR (r = 0.5080, p < 0.001), with fasting insulin concentration (r = 0.5444, p < 0.001), and in 2 hour of OPLT (r = 0.5552, p < 0.001). ROC analysis (Receiver or Relative Operating Characteristic) showed that with reference to obesity Lep/AdipoR had the highest discriminatory value. The estimation of Lep/AdipoR can be used as additional index in evaluation of obesity complications such as insulin resistance and endothelial dysfunction.