title: Relationship between Neck Length, Sleep, and Cardiovascular Risk Factors.
abstract: BACKGROUND
  Neck circumference, as a predicator of obesity, is a well-known risk factor for obstructive sleep apnea and cardiovascular diseases. However, little research exists on neck length associated with these factors. This study explored the association of neck length with sleep and cardiovascular risk factors by measuring midline neck length (MNL) and lateral neck length (LNL).
  
  
  METHODS
  We examined 240 patients aged 30 to 75 years who visited a health check-up center between January 2012 and July 2012. Patients with depressive disorder or sleep disturbance were excluded from this study. MNL from the upper margin of the hyoid bone to the jugular notch and LNL from the mandibular angle to the mid-portion of the ipsilateral clavicle were measured twice and were adjusted by height to determine their relationship with sleep and cardiovascular disease risk factors.
  
  
  RESULTS
  Habitual snorers had shorter LNL height ratios (P = 0.011), MNL height ratios in men (P = 0.062), and MNL height ratios in women (P = 0.052). Those snoring bad enough to annoy others had shorter MNL height ratios in men (P = 0.083) and women (P = 0.035). Men with objective sleep apnea had longer distances from the mandible to the hyoid bone to the mandible (P = 0.057). Men with metabolic syndrome had significantly shorter LNL height ratios (P = 0.021), and women with diabetes, hyperlipidemia, and metabolic syndrome had shorter MNL height ratios (P < 0.05).
  
  
  CONCLUSIONS
  This study shows that a short neck by measuring the MNL is probably associated with snoring. In addition, MNL is related to cardiovascular disease risk factors in women.
authors.affiliation: Department of Family Medicine, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea.
authors.forename: Tae Seung
authors.initials: TS
authors.lastname: Han
authors.affiliation: Department of Family Medicine, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea.
authors.forename: Mi Kyeong
authors.initials: MK
authors.lastname: Oh
authors.affiliation: Department of Family Medicine, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea.
authors.forename: Su Min
authors.initials: SM
authors.lastname: Kim
authors.affiliation: Department of Family Medicine, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea.
authors.forename: Hyun Ju
authors.initials: HJ
authors.lastname: Yang
authors.affiliation: Department of Family Medicine, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea.
authors.forename: Bum Soon
authors.initials: BS
authors.lastname: Lee
authors.affiliation: Department of Family Medicine, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea.
authors.forename: Soon Yeob
authors.initials: SY
authors.lastname: Park
authors.affiliation: Department of Family Medicine, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea.
authors.forename: Won Joon
authors.initials: WJ
authors.lastname: Lee
keywords: Anthropometry; Cardiovascular Diseases; Neck Length; Obesity; Risk Factors; Sleep Apnea Syndromes; Snoring