Abstract
BACKGROUND: Gestational diabetes mellitus (GDM) results from an imbalance between insulin resistance and insulin secretion capacity during pregnancy. Tumor necrosis factor-alpha (TNF-α) is an inflammatory cytokine that is proposed to be involved in the pathogenesis of the insulin resistance, but the findings from studies across different ethnic groups are inconsistent or even conflicting. AIM: The aim of this study is to determine the relationship between maternal circulating level of TNF-α and insulin resistance in pregnant Nigerian women with GDM. METHODOLOGY: This was a cross-sectional analytical study involving 100 women with GDM and another 100 pregnant women with normal gestation. They were evaluated between 24 and 28 weeks' gestation. Diagnosis of GDM was based on the WHO diagnostic criteria. Fasting serum insulin and TNF-α levels were measured. Insulin resistance index was calculated as homeostasis model assessment of insulin resistance. Multivariate correlation analysis was used to determine the relationship between the maternal serum level of TNF-α and the insulin resistance. RESULTS: Pregnant women with GDM had greater insulin resistance than observed in the normal controls (3.14 ± 0.19 vs. 2.89 ± 0.20, P < 0.05). There was a positive correlation between serum TNF-α level and insulin resistance among the pregnant women with GDM (r = 0.49, P < 0.05). Multiple linear regression analysis indicated that TNF-α is a predictor of insulin resistance in pregnancies complicated by GDM. CONCLUSION: It is concluded that among pregnant Nigerian women with GDM in this study, increased serum TNF-α level is associated with greater insulin resistance independent of age and body mass index.