Background. TNF-alpha, IGF-I and leptin are agents which influence insulin resistance, they play probably a part in the pathogenesis of diabetic nephropathy and influence mutually their production. The objective of the submitted investigation was to assess whether there exist relations between their concentrations in the plasma of diabetic patients. Methods and Results. The authors examined 37 patients aged 18-67 years from a diabetic clinic, 10 with normal albuminuria and normal renal function, 12 with microalbuminuria and 15 with macroalbuminuria and/or reduced renal function. TNF alpha, IGF-I and leptin were assessed in plasma, using commercial kits, by the ELISA method. IgF-I in plasma correlated inversely with glycated haemoglobin (r = -0.20, p < 0.05). In women a correlation was found between IGF-I and TNF-alpha concentrations (r = 0.65, p < 0.01). No other mutual correlations were found between concentrations of the investigated substances and between cytokine concentrations and serum creatinine, glycated haemoglobin, the blood glucose level and body mass index. Conclusions. IGF-I plasma levels correlate inversely with glycated haemoglobin and in women with the TNF-alpha level. No other correlations were found between IGF-I. TNF-alpha and leptin plasma levels. The levels do not correlate with age, renal function and compensation of diabetes.

        Key words: diabetes mellitus, insulin-like growth factor (IGF-I), leptin tumour necrotizing factor-alpha, leptin, glucose metabolism.