The association of neck circumference with risk of metabolic syndrome and its components in adults: A systematic review and meta-analysis

Abstract

Background & aims: Several prior studies suggested that neck circumference (NC) is a reliable diagnostic tool for risk of metabolic syndrome (MetS) and its features. However, not all studies support this view. Therefore, we aimed to perform a meta-analysis to summarize the association between NC with MetS and its components in adult populations.

Methods and results: PubMed/Medline, Web of Knowledge, and Scopus electronic databases were searched until May 31, 2017 to find relevant English-language papers. We included studies that examined the association of NC with risk of MetS, or at minimum, one of its components as outcomes. Of 2628 publications identified, 19 papers met selection criteria. We found no association between NC and MetS (odd ratio (OR): 0.73; 95% CI: 0.003, 1.47). However, there was a positive association between NC and waist circumference (WC) (r = 0.85; 95%: 0.75, 0.95; I²: 98.2%; p = 0.0001), BMI: (r:0.88; 95% CI: 0.74, 0.91, I²:97.3%), triglycerides (TG) (OR: 1.87; 95% CI: 1.60, 2.19; I²:58.4%; p = 0.03), TC (r:0.14; 95%CI: 0.05, 0.23, I²:94.1%), LDL-C (r: 0.18; 95%CI: 0.07, 0.29, I²:94.3%), hypertension (OR: 1.94; 95% CI:1.43, 2.64, I²:87.3%), systolic (r: 0.21, 95%CI: 0.19, 0.23; I²:67.1%) and diastolic blood pressures (r: 0.20, 95%CI: 0.16, 0.23; I²:79.7%), low HDL-C (r:-0.21; 95% CI: -0.26, -0.15, I² = 92.5%), as well as fasting blood sugar (FBS) concentrations (r: 0.20, 95%CI: 0.16, 0.24; I²:88.1%).

Conclusion: Subjects with higher NC were at approximately two-fold higher risk for hypertriglyceridemia compared to those with lower NC. We found positive associations between NC, WC, BMI, hypertension, FBS, TC, LDL-C, SBP, DBP, and low HDL-C concentrations. However, heterogeneity was considerably high. Therefore, the findings should be taken with caution. Future studies using longitudinal designs are needed to further understand the association between NC and features of MetS.

Keywords: Adults; Cardio-metabolic risks; MetS; Meta-analysis; Neck.