title: Comparison of BMI, AHI, and apolipoprotein E ε4 (APOE-ε4) alleles among sleep apnea patients with different skeletal classifications.
abstract: OBJECTIVE
  This case-control study investigated whether variations within the APOE-ε gene were associated with having a convex facial profile (skeletal Class II) compared to exhibiting a straight or concave facial profile (Class I or Class III) among patients with obstructive sleep apnea (OSA). Associations between the apnea-hypopnea index (AHI) and body mass index (BMI) scores for these OSA patients were also examined in the context of facial profile.
  
  
  METHODS
  OSA patients with an AHI ≥ 15 were recruited from a sleep clinic and classified by facial and dental occlusal relationships based on a profile facial analysis, lateral photographs, and dental examination. Saliva was collected as a source of DNA. The APOE-ε1-4 allele-defining single nucleotide polymorphisms (SNPs) rs429358 and rs7412 were genotyped. A χ(2) analysis was used to assess Hardy-Weinberg equilibrium and for association analysis (significance at p < 0.05). ANOVA and Fisher exact test were also used.
  
  
  RESULTS
  Seventy-six Caucasian OSA patients participated in the study-25 Class II cases and 51 non-Class II cases. There was no association of the APOE-ε4 allele with facial profile among these OSA patients. Class II OSA patients had significantly lower BMIs (30.7 ± 5.78) than Class I (37.3 ± 6.14) or Class III (37.8 ± 6.17) patients (p < 0.001), although there was no statistical difference in AHI for Class II patients compared with other groups.
  
  
  CONCLUSIONS
  OSA patients with Class II convex profile were more likely to have a lower BMI than those in other skeletal groups. In fact 20% of them were not obese, suggesting that a Class II convex profile may influence or be associated with OSA development independent of BMI.
authors.affiliation: College of Dentistry, University of Kentucky, Lexington, KY.
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Roedig
authors.affiliation: College of Medicine, University of Kentucky, Lexington, KY.
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Phillips
authors.affiliation: College of Dentistry, University of Kentucky, Lexington, KY.
authors.forename: Lorri A
authors.initials: LA
authors.lastname: Morford
authors.affiliation: College of Dentistry, University of Kentucky, Lexington, KY.
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Van Sickels
authors.affiliation: College of Dentistry, University of Kentucky, Lexington, KY.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Falcao-Alencar
authors.affiliation: College of Public Health, University of Kentucky, Lexington, KY.
authors.forename: David W
authors.initials: DW
authors.lastname: Fardo
authors.affiliation: College of Dentistry, University of Kentucky, Lexington, KY ; College of Medicine, University of Kentucky, Lexington, KY.
authors.forename: James K
authors.initials: JK
authors.lastname: Hartsfield
authors.affiliation: College of Public Health, University of Kentucky, Lexington, KY.
authors.forename: Xiuhua
authors.initials: X
authors.lastname: Ding
authors.affiliation: College of Dentistry, University of Kentucky, Lexington, KY.
authors.forename: G Thomas
authors.initials: GT
authors.lastname: Kluemper
mesh_terms: D000483:Alleles; D053327:Apolipoprotein E4 / Q000235:genetics*; D015992:Body Mass Index; D016022:Case-Control Studies; D005147:Facial Bones / Q000473:pathology*; D005838:Genotype; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000150:complications / Q000473:pathology; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D012307:Risk Factors; D012891:Sleep Apnea Syndromes / Q000209:etiology / Q000235:genetics* / Q000473:pathology; D020181:Sleep Apnea, Obstructive / Q000209:etiology / Q000235:genetics* / Q000473:pathology
chemical_list: D053327:Apolipoprotein E4
keywords: AHI; APOE-ε; BMI; Obstructive sleep apnea; facial profile; skeletal malocclusion
references.citation: J Oral Maxillofac Surg. 1998 May;56(5):596-602; discussion 602-3
references.pmid: 9590342
references.citation: Sleep. 2009 Nov;32(11):1507-11
references.pmid: 19928390
references.citation: Neurology. 2004 Aug 24;63(4):664-8
references.pmid: 15326239
references.citation: J Oral Maxillofac Surg. 2010 Nov;68(11):2846-55
references.pmid: 20869147
references.citation: Am J Respir Crit Care Med. 2002 May 1;165(9):1217-39
references.pmid: 11991871
references.citation: Neth J Med. 2006 Sep;64(8):280-9
references.pmid: 16990691
references.citation: Intern Med. 2008;47(18):1573-8
references.pmid: 18797115
references.citation: Clin Genet. 1998 Feb;53(2):147-8
references.pmid: 9611077
references.citation: Eur J Orthod. 2011 Oct;33(5):509-14
references.pmid: 21118908
references.citation: Am J Orthod Dentofacial Orthop. 1996 Jul;110(1):28-35
references.pmid: 8686675
references.citation: Eur Respir J. 2011 Aug;38(2):348-58
references.pmid: 21233264
references.citation: Am J Hum Genet. 2003 Feb;72(2):340-50
references.pmid: 12506338
references.citation: JAMA. 2001 Jun 13;285(22):2888-90
references.pmid: 11401610
references.citation: Sleep Breath. 2013 Dec;17(4):1275-80
references.pmid: 23536260
references.citation: Angle Orthod. 1981 Jul;51(3):177-202
references.pmid: 7023290
references.citation: J Neurol. 2009 Mar;256(3):493-8
references.pmid: 19308307
references.citation: J Appl Physiol (1985). 2005 Oct;99(4):1600-6
references.pmid: 16160021
references.citation: JAMA. 2001 Sep 26;286(12):1447-8
references.pmid: 11572727
references.citation: Indian J Med Res. 2010 Feb;131:126-40
references.pmid: 20308738