Neck Circumference Is Better Associated Than Waist Circumference at Insulin Resistance in Bantu Population from Brazzaville in Republic of Congo

Background: it is difficult to measure directly insulin sensitivity in routine practice. An easily measured anthropometric parameter associated with insulin resistance (IR) would be a very useful tool in detecting people at risk. Objective: To investigate the association between neck circumference (NC) and Insulin Resistance (IR) in Bantu population. Methods: Cross-sectional health screening conducted between February and May 2019, among Bantu population from Brazzaville in Republic of Congo. The analysis included 500 participants, aged ≥ 20 years. Anthropometric indices and blood pressure were measured by standard protocol. Fasting lipid profile, blood glucose and insulin were determined. Triglyceride Glucose index (TyG index) and triglyceride/high density lipoprotein ratio (TG/HDL) were calculated. IR was defined as HOMA-IR ≥ 2. TyG index was calculated by using the formula: Ln [TG (mg/dL) x FPG (mg/dL)/2]. To investigate if there was a statistically association between NC and IR parameters, a correlation was computed. To evaluate the influence of NC on IR parameters, the study population was divided in 3 groups by tertiles of NC in both men and women The diagnostic ability of NC, WC, TyG index and TG/HDL ratio to identify people with IR was determined with the receiver operating characteristic (ROC) curves. Results: NC was positively correlated with insulin, TG/HDL, TyG index and HOMA-IR. For all variables, this correlation was stronger in comparison with WC. In all participants, TG/HDL shows the largest AUC for IR detection (0.810, 95% CI: 0.765–0.855) followed by TyG index (0.799, 95% CI: 0.754–0.844), NC (0.624, 95% CI: 0.572–0.677), and WC (0.616, 95% CI: 0.560–0.672) in that order. Conclusion: NC is associated with IR. NC is better than WC to identify IR in Bantu population from Brazzaville in republic of Congo.