Background

The use of BMI combined with indicators of central adiposity –particularly for visceral adipose tissue- has been proposed because it is predictive of cardiometabolic risk. Neck circumference (NC) is a promising alternative to waist circumference (WC) in patients with BMI ≥35 because of practical considerations.Evaluation of patients with obesity, beyond BMI, is challenging due to technical difficulties to perform the measurements. Our aim was to evaluate the association between NC and WC with markers of cardiometabolic risk and treatment success in patients undergoing an obesity program in a real-life setting in a National Institute of Health in Mexico.

Methods

We studied 470 patients, age 39.3±11.4years, initial BMI 44.1±8.4Kg/m2(63.6% with BMI≥40); 73.5% women. Initial and final BMI, neck, waist and hip circumferences, and cardio-metabolic markers (glucose, lipid profile, blood pressure) were evaluated. Success was defined as weight loss ≥5% after a 6-month multidisciplinary program.

Results

Success was attained in 56.1% of men and 42.1% of women. Significant correlations were found between WC and NC (r=0.353 and 0.558 in men and women; p<0.01), and of these with markers of cardiometabolic risk, as well as between changes in NC and WC and treatment success. Neck but not waist circumference predicted treatment success in logistic regression models.

Conclusions

We documented the association of waist and neck circumferences with indicators of cardiometabolic risk, and the association of neck circumference with treatment success in patients with extreme obesity. Neck circumference could be an alternative to waist circumference in the evaluation, diagnosis and monitoring of patients with obesity who undergo a treatment program, particularly in those with class III obesity. Its use could complement BMI, being an indicator of central adiposity and associated with obstructive sleep apnea syndrome, insulin resistance and diabetes, frequent in these patients.