Abstract P431: Neck Circumference as a New Clinical Predictor of Incident Diabetes Mellitus: Results from 9-Year Follow-Up of the Jackson Heart Study
Background-Upper body subcutaneous fat, as estimated by neck circumference (NC), has been demonstrated to confer cardiometabolic risk above and beyond visceral abdominal fat. However, it is unclear whether neck circumference is independently associated with incident Type 2 diabetes mellitus (DM).
Methods-The study participants with NC measures (n=2945, mean age 60 years, 63% women) were derived from the Jackson Heart Study (JHS) who completed the baseline exam (2000-2004) and had been followed up to JHS Exam 3 (2009-2012). DM was defined if A1c ≥ 6.5% or fasting glucose ≥ 126 ml/dl or taking diabetic medication (American Diabetes Association Guideline 2010). Sex-specific associations between NC and DM were assessed using a logistic regression model adjusted for age, gender, smoking and alcohol status, education levels, family income, physical activity score, baseline fasting plasma glucose, triglycerides and HDL-C levels.
Results-There were 447 incident cases of DM diagnosed after 10-years follow-up. NC was correlated with body mass index (BMI) (women: r=0.60; men: r=0.71; p=0.0001) and waist circumference (WC) (women: r=0.64; men: r=0.69; p=0.0001) as well as fasting glucose (women: r=0.23; men: r=0.23; p=0.0001), insulin (women: r=0.44; men: r=0.49; p=0.0001). In women, an increase in NC (per 1-SD) was associated with incident DM with multivariable adjustment (OR 1.85, 95% CI 1.5-2.3, p=0.0001), which persisted after additional adjustment for WC (OR 1.79, 95% CI 1.4-2.3), BMI (OR 1.86, 95% CI 1.4-2.4) or WC and BMI together (OR 1.82, 95% CI 1.4-2.4) (all p values < 0.0001). WC and BMI were also associated with DM after multivariable adjustment (WC: OR 1.33, 95%CI 1.1-1.6, p=0.001; BMI: OR 1.27, 95%CI 1.1-1.5, p=0.005) but not significant when additionally adjusted for NC. There was no statistically significant association observed in men for NC, BMI and WC with incident DM in multivariable-adjusted models.
Conclusion-NC is associated with incident DM in women independently of WC and BMI, but neither are associated with DM in the presence of NC. Our results suggest that NC may be a unique, new clinical marker to screen DM in African American women.
- © 2013 by American Heart Association, Inc.