Neck circumference as a measure of central obesity: associations with metabolic syndrome and obstructive sleep apnea syndrome beyond waist circumference.
OBJECTIVE
To investigate the relationship of neck circumference (NC) to metabolic syndrome (MetS) and obstructive sleep apnea syndrome (OSAS) and whether it adds information to that provided by waist circumference.


METHODS
Cross-sectional analysis of a population sample of 1,912 men and women, aged 55.1 +/- 12 years, representative of Turkish adults. MetS was identified based on modified criteria of the ATP-III, OSAS when habitual snoring and episodes of apnea were combined with another relevant symptom.


RESULTS
NC measured 36.7 (+/- 3.5) cm in the total sample. It was significantly correlated with numerous risk factors, above all body mass index and waist girth (r > or = 0.6), homeostatic model-assessed insulin resistance, blood pressure and, inversely, with smoking status and sex hormone-binding globulin. Sex- and age-adjusted NC was associated significantly with MetS, at a 2-3-fold increased likelihood for 1 standard deviation (SD) increment. After further adjustment for waist circumference and smoking status, a significant residual odds ratio (OR, 1.13 [95% CI 1.08; 1.19]) persisted, corresponding to ORs of 1.53 and 1.27 in males and females, respectively, for 1 SD increment. Even when adjusted for all MetS components, a residual OR (1.08 [95% CI 1.000; 1.17]) remained. Sex- and age-adjusted NC was associated significantly also with OSAS in genders combined, independent of waist girth, yielding an added OR of 1.3 for 1 SD increment.


CONCLUSIONS
NC contributes to MetS likelihood beyond waist circumference and the MetS components. Regarding association with OSAS, NC is of greater value than WC among Turkish men, not women.
Onat
Altan
A
Turkish Society of Cardiology, Istanbul University, Istanbul, Turkey. alt_onat@yahoo.com.tr
Hergenç
Gülay
G
Yüksel
Hüsniye
H
Can
Günay
G
Ayhan
Erkan
E
Kaya
Zekeriya
Z
Dursunoğlu
Dursun
D
D015992:Body Mass Index; D015897:Comorbidity; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000175:diagnosis / Q000453:epidemiology*; D008875:Middle Aged; D009333:Neck / Q000033:anatomy & histology*; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology*; D016017:Odds Ratio; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000453:epidemiology*; D012907:Smoking; D014421:Turkey / Q000453:epidemiology; D055105:Waist Circumference