Neck Circumference as a Simple Screening Tool for Metabolic Syndrome in Urban Adults: A Community-Based Cross-Sectional Study From Jaipur, India.

backgroundMetabolic syndrome (MetS) is a constellation of cardiometabolic risk factors like abdominal obesity, hypertension, hyperglycemia, and dyslipidemia associated with substantially increased risk of cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM). Conventional screening methods involving waist circumference (WC) measurements can be challenging in resource-limited settings. Neck circumference (NC) has emerged as a simpler, non-invasive anthropometric marker of upper-body adiposity with potential utility for MetS screening.

objectiveTo determine the prevalence of MetS and its sociodemographic correlates in an urban community, to examine the association and correlation of NC with MetS and other anthropometric indices, and to establish optimal NC cut-off values for predicting MetS in adult males and females.

methodsA community-based cross-sectional study was conducted from April to July 2023 in the field practice area of the Urban Health Training Centre (UHTC) attached to Sawai Man Singh (SMS) Medical College, Jaipur. A total of 400 adults aged 18-60 years were enrolled using systematic random sampling. MetS was diagnosed using the National Heart, Lung, and Blood Institute (NHLBI) criteria (presence of ≥3 of five components). NC was measured at the level of the thyroid cartilage with an inelastic tape. Associations were analyzed using the chi-square test; correlations using Pearson's coefficient; and optimal NC cut-off values using receiver operating characteristic (ROC) curve analysis.

resultsThe mean age of participants was 39.11 ± 12.7 years, with a slight female predominance (M: F = 0.93). MetS was present in 43.5% of subjects. Abnormal NC was observed in 33.5% of participants (mean NC: 35.0 ± 3.1 cm). NC was significantly associated with MetS (chi-square = 218.71, p < 0.001); 95.5% of those with abnormal NC had MetS versus 17.3% with normal NC. NC showed strong positive correlations with WC (r = 0.705, p < 0.001) and BMI (r = 0.581, p < 0.001). ROC analysis identified optimal NC cut-off values of 37 cm in males (sensitivity 87.0%, specificity 96.0%, diagnostic accuracy 92.7%) and 34 cm in females (sensitivity 71.4%, specificity 92.2%, diagnostic accuracy 81.6%). Age, sex, education, occupation, socioeconomic status, personal habits, and marital status were significantly associated with MetS.

conclusionsNC is a reliable, inexpensive, and clinically practical screening tool for MetS in urban Indian adults. Cut-off values of 37 cm for males and 34 cm for females demonstrate excellent and clinically meaningful diagnostic performance, respectively, facilitating population-level MetS screening in primary care settings in Rajasthan and comparable populations.