Circulating Tumor Necrosis Factor α is Elevated in Male but Not in Female Patients With Type II Diabetes Mellitus

The cytokine tumor necrosis factor α (TNF α) was proposed to mediate obesity related insulin resistance upon production in fat cells and to participate in tissue remodelling leading to vascular complications upon being released by macrophages. To assess its putative role in diabetes we determined plasma levels of TNF α in 105 adult humans. Male nondiabetic subjects had significantly lower TNF α levels than female controls (4.4 ± 0.3, n = 17 vs. 6.6 ± 1.0 pg/ml, n = 13; p = 0.049). Men with NIDDM had elevated TNF α (6.7 ± 0.6 pg/ml, n = 34) compared to nondiabetic subjects (4.4 ± 0.3 pg/ml, n = 17; p = 0.012). Such a difference was not apparent in women. Levels of TNF α were correlated with serum triglyceride levels in male controls (r² = 0.64; p = 0.007) but not in NIDDM. Neither body mass index nor glycosylated hemoglobin correlated with TNF α in any of the groups. The presence of retinopathy (p = 0.046) but not of neuropathy or nephropathy or macroangiopathy was associated with significantly elevated plasma TNF α. We conclude that plasma levels of TNF α are sex-dependent and that increased TNF α occurs in male but not female NIDDM and may participate in the development of diabetic complications.

Key words

TNF α - Cytokine, Effect on Triglycerides - NIDDM - Diabetes, Retinopathy - Diabetes, CHD