Change of neck circumference in relation to visceral fat area: a Chinese community-based longitudinal cohort study

Background/Objectives: Neck circumference (NC) has been positively associated with visceral fat area (VFA) in cross-sectional studies. This longitudinal cohort study evaluated whether changes in NC predict changes in VFA and incident abdominal obesity in Chinese community residents. Subjects/Methods: Adults from Shanghai communities were followed for 1.1–2.9 years (mean 2.1 years). Anthropometry and biochemistry, including NC, were measured at baseline and follow-up. VFA was quantified by magnetic resonance imaging (MRI) at L4–L5. Abdominal obesity was defined as VFA ≥ 80 cm². Results: Among 1421 participants (578 men, 843 women; mean age 57.8 ± 7.1 years), median VFA increased from 82.43 (58.27–113.10) to 84.55 (59.83–113.50) cm² over follow-up. After adjustment for age, sex, BMI, smoking, drinking, HbA1c, blood pressure, and lipids, individuals with NC gain >5% had 1.26 (95% CI: 1.05–1.49) times more VFA at follow-up than NC maintainers (NC change −2.5% to 2.5%). In participants without abdominal obesity at baseline (n = 683), NC change (%) was associated with abdominal obesity at follow-up (odds ratio [OR] 1.23; 95% CI: 1.09–1.39); a 5% NC increase corresponded to a 36% higher risk (OR 1.36; 95% CI: 1.19–1.68). Conclusions: In this community-based cohort, NC change was positively associated with VFA and incident abdominal obesity, supporting NC as a practical marker for assessing abdominal obesity.