The association between neck adiposity and long-term outcome.

Sigal Tal,Itzhak Vitkon-Barkay,Tomer Ziv-Baran,Oran Tzuman,Gil Marcus,Miriam M Klar,Hillel S Maresky,Ilya Litovchik,David Pereg,Noam Grysman,Sa’Ar Minha,Shmuel Fuchs,Victoria Rum,Itay Wiser,Giacomo Pucci

doi:10.1371/journal.pone.0215538

Abstract

Anthropometric indices of obesity (e.g. body mass index, waist circumference and neck circumference) are associated with poor long-term cardiovascular outcome. Prior studies have associated neck circumference and central body adiposity. We explored the association between neck fat volume (NFV) and long-term cardiovascular outcome. The study provides a retrospective analysis of all patients undergoing computerized tomography angiography for suspected cerebrovascular accident between January and December 2013. NFV was assessed by three dimensional reconstructions and was adjusted to height to account for differences in body sizes, thus yielding the NFV/height ratio (NHR). Univariate and multivariate analysis were utilized to explore the association between various indices including NHR and all-cause mortality. The analysis included 302 patients. The average age was 61.9±14.3 years, 60.6% of male gender. Diabetes mellitus, hypertension and cardiovascular disease were frequent in 31.5%, 69.9%, and 72.2% of patients, respectively. The median NHR was 492.53cm2 [IQR 393.93–607.82]. Median follow up time was 41.2 months, during which 40 patients (13.2%) died. Multivariate analysis adjusting for age, sex, and diabetes mellitus indicated an independent association between the upper quartile of NHR and all-cause mortality (hazard ratio = 2.279; 95% CI = 1.209–4.299; p = .011). NHR is a readily available anthropometric index which significantly correlated with poor long-term outcome. Following validation in larger scale studies, this index may serve a risk stratifying tool for cardiovascular disease and future outcome.

Highlights

Obesity is global epidemic associated with increased morbidity and mortality
We described the methodology of calculating neck fat volume (NFV) in an unselected cohort of patients and its association with short-term outcome [12]
A total of 302 patients that underwent computed tomography angiography (CTA) for suspected stroke were included in the final statistical analysis

Summary

Introduction

Obesity is global epidemic associated with increased morbidity and mortality. Defined as an abnormally high proportion of adipose tissue, obesity assessment is traditionally based on body weight, body weight doesn’t necessarily correlate with the proportion of body fat content. Anthropometric indices describing fat distribution, such as waist-tohip ratio, have been shown to identify patients with increased cardiovascular risk better than indices based on weight (i.e. body mass index [BMI]) [1, 2]. Percentage of body fat is linearly correlated with mortality while this is not the case for BMI [3]. Abdominal, and liver fat, as measured by computed tomography (CT), have demonstrated associations with increased cardiovascular risk and poor outcome [4,5,6]. Similar to abdominal (waist) circumference, neck circumference emerged as a readily available anthropometric index, which has demonstrated associations with cardiovascular risk factors and with poor outcome [7,8,9,10,11]

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Discussion

Conclusion