Background: Neck circumference has been
reported to be related to the other anthropometric
measures of obesity and also associated with the
metabolic disorders related to insulin resistance. The
measurement of neck circumference could be useful
in clinical screening for persons at an enhanced risk
for insulin resistance. The aim of this study was to
determine whether a single measure of neck
circumference might be correlated with other obesity
indices and HOMA score and to define neck
circumference cutoff levels for obesity.
Methods: We examined 364 consecutive persons
(199 men and 165 women), who visited konyang
university hospital health examination center during
August, 2002. To find the optimal, maximal
sensitivity and specificity for neck circumference, the
receiver output curve (ROC) analysis of cutoff points
against BMI (25 kg/m2) was performed using the test
group (136 men and 113 women). We validated the
cutoff level using validation group (63 men and 52
women). Other obesity indices and fasting glucose
and insulin were measured to find the correlation between neck circumference.
Results: Neck circumference was significantly
correlated with waist circumference, hip circumference,
waist hip ratio, BMI, total body fat percent,
fasting insulin and HOMA score. Neck
circumference 36.6 cm for men and 32.3 cm for
women was the best cutoff levels for determining
the subjects with BMI over 25 kg/m2. In the
validation unrelated group, the test characteristics
were acceptable with 91.9% sensitivity, 53.9%
specificity, and 76.1% accuracy for men, and
81.25% sensitivity, 85% specificity, and 82.69%
accuracy for women.
Conclusion: Neck circumference as a simple and
easy screening method for obesity was strongly
correlated with the other conventional obesity indices
and HOMA score as a index of insulin resistance
and we defined neck circumference cutoff level for
obesity according existing BMI cutoff levels.

Keywords: Obesity, Neck circumference, Obesity indices, HOMA score