Background:
Neck circumference is a proxy for upper body fat and it is a simple anthropometric measure. Therefore it could be a useful tool to identify individuals with cardiometabolic risk factors in the context of primary care.
Hypothesis:
Neck circumference is independently associated to cardiometabolic risk factors in an apparently healthy population.
Methods:
This is a cross-sectional analysis of baseline data of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), a cohort of 15105 civil servants aged 35-74 years. We excluded from this analysis those who fulfilled American Diabetes Association criteria for diabetes diagnosis, were taking antihypertensive and/or lipid-lowering drugs. A sex-specific analysis was conducted. Partial correlation (age-adjusted) was used. Risk factors were set as low HDL<50mg/dL for women and <40mg/dL for men, hypertriglyceridemia ≥ 150 mg/dl , hypertension as systolic blood pressure ≥130 mg/dl or diastolic blood pressure ≥85 mm Hg and insulin resistance(HOMA-IR ≥ 75th percentile). Logistic regression models were built to analyze the association between individual and clustered risk factors as dependent variables and 1-SD increase in neck circumference as independent variable. Multiple adjustments were subsequently performed for age, smoking, alcohol, body-mass index, waist and physical activity. Receiver Operating Curves were employed to find the best NC cut-off points for clustered risk factors.
Results:
We analyzed 3810 men (mean age= 49.0 ±8.3 yrs) and 4916 women (49.2 ±8.0 yrs). Mean NC was 38.9 (±2.6)cm for men and 33.4(±2.6)cm for women. NC positively correlated with systolic and diastolic blood pressure (r=0.21 and r=0.27), HOMA - IR (r=0.44), triglycerides (r=0.31) and negatively correlated with HDL (r= -0.21) in men (p<0.001 for all) with similar results in women. Fully adjusted Odds Ratio (OR) (95% CI) of risk factor per SD increase in neck circumference in men and women were 1.29(1.14;1.46) and 1.42(1.28;1.57) for insulin resistance; 1.24(1.11;1.39) and 1.25(1.11;1.40) for hypertension; 1.33(1.19;1.49) and 1.42(1.29;1.63) for hypertriglyceridemia; 1.07(0.92;1.23) and 1.32 (1.19;1.43) for low HDL. Fully adjusted OR (95% CI) of 2 clustered risk factor per SD increase in neck circumference in men and women were 1.29(1.14;1.48) and 1.37(1.21;1.54 ). Fully adjusted OR (95% CI) of 3 or more clustered risk factors per SD increase in neck circumference in men and women were 1.33 (1.02;1.74) and 1.62 (1.33;1.92). Values of neck circumference of >40 cm for men and >34.1 cm for women were the best cut-off points for 3 or more clustered risk factors.
Conclusion:
Neck circumference is significantly and independently associated to cardiometabolic risk factors in a well-defined non-treated population. It should be considered as a marker of cardio metabolic risk factors in primary care settings.
A CROSS-SECTIONAL SURVEY OF CARDIOMETABOLIC RISK FACTORS IN PRIMARY CARE PATIENTS WITH ABDOMINAL OBESITY IN CANADA
