Increased Activation of Nuclear Factor κB Triggers Inflammation and Insulin Resistance in Polycystic Ovary Syndrome

Abstract

Context: Insulin resistance and chronic low level inflammation are often present in women with polycystic ovary syndrome (PCOS). Objective: The purpose of this study was to determine the effects of hyperglycemia on nuclear factor κB (NFκB) activation and inhibitory κB (IκB) from mononuclear cells (MNC) in PCOS. Design and Setting: This was a prospective controlled study conducted at an academic medical center. Patients: The study population consisted of 16 reproductive-age women with PCOS (eight lean, eight obese) and 16 age- and body composition-matched controls (eight lean, eight obese). Main Outcome Measures: Insulin sensitivity (IS) was derived from a 2-h 75-g oral glucose tolerance test (ISOGTT). Intranuclear NFκB and IκB protein expression were quantitated from MNC obtained from blood drawn fasting and 2 h after glucose ingestion. Results: ISOGTT was lower in PCOS compared with controls (3.3 ± 0.3 vs. 6.4 ± 0.9, P < 0.004). The percent change in intranuclear NFκB was higher in lean and obese PCOS compared with lean controls (42.5 ± 19.1 and 54.5 ± 12.5 vs. −14.1 ± 10.9, P < 0.006). The percent change in intranuclear NFκB correlated positively with 2-h post-glucose ingestion levels (r = 0.37; P < 0.04) and plasma testosterone (r = 0.49; P < 0.006) and correlated negatively with ISOGTT (r = 0.39; P < 0.04). The percent change in IκB was lower in lean and obese PCOS compared with lean controls (−22.3 ± 3.2 and −17.0 ± 5.0 vs. 8.4 ± 11.8, P < 0.02). Conclusion: In response to hyperglycemia, intranuclear NFκB increases and IκB decreases in MNC of women with PCOS independent of obesity. This may represent a cardinal inflammatory signal that contributes to the induction of insulin resistance and hyperandrogenism in PCOS.