title: Neck circumference is a predictor of metabolic syndrome and obstructive sleep apnea in short-sleeping obese men and women.
abstract: BACKGROUND
  The constellation of metabolic syndrome, although controversial with regard to its clinical usefulness, is epidemiologically related to increased diabetes risk and cardiovascular mortality. Our goal was to investigate the associations among neck circumference (NC), obstructive sleep apnea syndromes (OSAS), and metabolic syndrome in obese men and women sleeping less than 6.5 hr per night.
  
  
  METHODS
  This was a cross-sectional study of obese men and premenopausal obese women sleeping less than 6.5 hr per night. We enrolled 120 individuals (92 women), age 40.5±6.9 years and body mass index (BMI) 38.6±6.5 kg/m(2). Metabolic syndrome severity was assessed by a score and OSAS was defined as a respiratory disturbance index (RDI) ≥5. Metabolic end endocrine parameters were measured, and sleep duration was determined by actigraphy and validated questionnaires.
  
  
  RESULTS
  Metabolic syndrome was found in 41% and OSAS in 58% (28% had both). Subjects with metabolic syndrome were 3 years older and more often Caucasian; they had higher RDI scores, larger NC, more visceral fat, lower serum adiponectin, higher 24-hr urinary norepinephrine (NE) excretion, and lower growth hormone concentrations. A NC of ≥38 cm had a sensitivity of 54% and 58% and a specificity of 70% and 79% in predicting the presence of metabolic syndrome and OSAS, respectively. RDI, adiponectin, and NC accounted for approximately 30% of the variability in the metabolic syndrome score, as estimated by an age-, gender-, and race-corrected multivariate model (R(2)=0.376, P<0.001).
  
  
  CONCLUSIONS
  Greater NC is associated with OSAS and metabolic syndrome in short-sleeping obese men and premenopausal obese women. Addition of NC to the definition of metabolic syndrome should be considered and needs to be validated in future studies.
authors.affiliation: 1 Section on Neuroendocrinology of Obesity, Diabetes, Endocrinology, and Obesity Branch/National Institute of Diabetes & Digestive & Kidney Diseases (DEOB/NIDDK) , Bethesda, Maryland.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cizza
authors.forename: Lilian
authors.initials: L
authors.lastname: de Jonge
authors.forename: Paolo
authors.initials: P
authors.lastname: Piaggi
authors.forename: Megan
authors.initials: M
authors.lastname: Mattingly
authors.forename: Xiongce
authors.initials: X
authors.lastname: Zhao
authors.forename: Eliane
authors.initials: E
authors.lastname: Lucassen
authors.forename: Kristina I
authors.initials: KI
authors.lastname: Rother
authors.forename: Anne E
authors.initials: AE
authors.lastname: Sumner
authors.forename: Gyorgy
authors.initials: G
authors.lastname: Csako
mesh_terms: D056044:Actigraphy; D052242:Adiponectin / Q000097:blood; D000293:Adolescent; D000328:Adult; D000886:Anthropometry; D001823:Body Composition; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D019382:Human Growth Hormone / Q000652:urine; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications* / Q000175:diagnosis; D008875:Middle Aged; D015999:Multivariate Analysis; D009333:Neck / Q000502:physiology*; D009638:Norepinephrine / Q000652:urine; D009765:Obesity / Q000150:complications* / Q000175:diagnosis; D012372:ROC Curve; D012680:Sensitivity and Specificity; D012890:Sleep; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000175:diagnosis; D011795:Surveys and Questionnaires
chemical_list: D052242:Adiponectin; D019382:Human Growth Hormone; D009638:Norepinephrine