Incremental significance and sex discrepancies of neck circumference on the odds of ischaemic stroke: a multistage, population-based, cross-sectional study from Northeast China

OBJECTIVES: Accumulated evidence suggests that neck circumference (NC) is associated with cardiometabolic risk factors. However, limited studies are available regarding the association between NC or height normalised NC (neck-to-height ratio (NHR)) and risk of ischaemic stroke (IS) in the Chinese population. Therefore, we aimed at examining the associations between NC or NHR and odds of IS and exploring the discrepancies between men and women. DESIGN: A multistage cluster cross-sectional study. SETTING: A population-based study carried out in Northeast China. METHODS: A cross-sectional study was undertaken in Northeast China between September 2017 and March 2019, involving 7236 men and 11 352 women, respectively. The median age of participants was 60.30 years, ranging from 40 to 97 years. The associations between NC or NHR and odds of IS were calculated using multiple logistic regression models. Dose–response relationships were depicted using restricted cubic spline functions. Reclassification analyses were carried out to determine the incremental significance of NC or NHR on the odds of IS. RESULTS: In women, NC and NHR were significantly associated with the odds of IS, independent of traditional risk factors and other anthropometric parameters for obesity. The highest quartile of NC and NHR had a 1.60 (95% CI 1.16 to 2.22)-and 1.72 (95% CI 1.23 to 2.41) times higher odds of IS compared with the lowest quartile. Furthermore, the odds of IS increased by 1.10 (95% CI 1.01 to 1.20) and 1.12 (95% CI 1.02 to 1.22) times per 1 SD increase in NC and NHR, respectively. Reclassification analyses showed that the proportion of correct classification increased by 11.5% (95% CI 2.2% to 20.7%) and 22.8% (95% CI 13.5% to 32.0%) after the addition of NC or NHR into established models, respectively. However, the findings could not be replicated in men. CONCLUSION: NC and NHR might be promising independent indicators for women IS. Their incremental value in the risk stratification of IS enables the individualised prevention of IS in women.