In vitro evidence that hyperglycemia stimulates tumor necrosis factor-α release in obese women with polycystic ovary syndrome

Abstract

Women with polycystic ovary syndrome (PCOS) are often insulin resistant and have chronic low-level inflammation. The purpose of this study was to determine the effects of hyperglycemia in vitro on tumor necrosis factor (TNF)-α release from mononuclear cells (MNC) in PCOS. Twelve reproductive-age women with PCOS (six lean, six obese) and 12 age-matched controls (six lean, six obese) were studied. Insulin sensitivity (ISHOMA) was estimated from fasting levels of glucose and insulin and percent truncal fat was determined by dual energy absorptiometry (DEXA). TNFα release was measured from MNC cultured under euglycemic and hyperglycemic conditions. ISHOMA was higher in obese women with PCOS than in lean women with PCOS (student’s t-test; 73.7 ± 14.8 vs 43.1 ± 8.6, P < 0.05), but similar to that of obese controls. ISHOMA was positively correlated with percent truncal fat (r=0.57, P < 0.04). Obese women with PCOS exhibited an increase in the percent change in TNFα release from MNC in response to hyperglycemia compared with obese controls (10 mM, 649 ± 208% vs 133 ± 30%, P < 0.003; 15 mM, 799 ± 347% vs 183 ± 59%, P < 0.04). The TNFα response directly correlated with percent truncal fat (r=0.45, P < 0.03) and ISHOMA (r=0.40, P < 0.05) for the combined groups, and with plasma testosterone (r=0.60, P < 0.05) for women with PCOS. MNC of obese women with PCOS exhibit an increased TNFα response to in vitro physiologic hyperglycemia. MNC-derived TNFα release may contribute to insulin resistance and hyperandrogenism, particularly when the combination of PCOS and increased adiposity is present.