AHI, BMI, and TNFa -rs1800629 Comparison Among Obstructive-Sleep-Apnea-Patients With Different-Facial-Profiles

Objectives: The purpose was to determine whether facial profile (skeletal classification) correlated with the Apnea-Hypopnea-Index (AHI) and/or Body-Mass-Index (BMI) of patients with Obstructive-Sleep-Apnea (OSA). We also determined whether the Single Nucleotide Polymorphism (SNP) rs1800629 in the TNFa gene promoter region was associated with profile classification among OSA patients.
Methods: One-hundred forty-nine Caucasian subjects (99 males, 50 females) with moderate to severe OSA (AHI > 15) were recruited, and underwent an intraoral and extraoral exam to evaluate facial profile/skeletal classification. A lateral photograph was taken for a soft tissue profile analysis. BMI, AHI, and a saliva sample were collected. Genomic DNA was isolated from saliva and genotyped for rs1800629 utilizing Taqman®-based methodology. ANOVA, T-tests, X² tests, and logistic regression (LR) were used to analyze the data.
Results: The average age+std error of all participants was 55.6+1.1 years, with no difference (LR, p=0.7) in age based on skeletal classification. AHI was not different when comparing Class I, II and III cases (ANOVA, p=0.25) or Class-II versus Class-I+III cases (T-test, p=0.12; LR, p=0.14). In contrast, BMI was significantly different when comparing Class I, II and III cases (ANOVA, p=0.001) or Class-II versus Class-I+III cases (T-test, p=0.0003; LR=0.0002). Eighteen percent of the Class II cases had a normal BMI compared to 2% of the Class-I+III cases (X², p=0.006). No associations were identified with rs1800629 genotypes when comparing Class-I, -II and -III cases (X², p=0.2) or Class II versus Class I+III cases (X² and LR, p=0.8).
Conclusions: Class II profile OSA patients are more likely to have a lower BMI than non-Class II subjects. Class II profile may be a contributing factor for OSA independent of BMI.