Heritability of Upper Airway Dimensions Derived Using Acoustic Pharyngometry

¹ Division of Pulmonary, Critical Care and Sleep Medicine, University Hospitals Case Medical Center and Case Western Reserve University, Cleveland, OH; and Center for Clinical Investigation, Case Western Reserve University, Cleveland, OH
² Center for Clinical Investigation, Case Western Reserve University, Cleveland, OH

^* To whom correspondence should be addressed. E-mail: srp20{at}case.edu.

	Abstract

Acoustic pharyngometry represents a simple, quick, non-invasive method for measuring upper airway dimensions which are predictive of sleep apnoea risk. In this study we sought to assess the genetic basis for upper airway size as obtained by pharyngometry.

Participants over age 14 y in the Cleveland Family Study underwent three acoustic pharyngometry measurements. Variance component models adjusted for age and sex were used to estimate heritability of pharyngometry-derived airway measures.

A total of 568 of 655 subjects (87%) provided quality pharyngometry curves. Although African-Americans tended to have narrower airways compared to Caucasians, heritability patterns were similar in these two groups. Minimum cross-sectional area had a heritability of 0.34 (p=0.004) in Caucasians and 0.39 (p<0.001) in African-Americans, suggesting that 30–40% of the total variance in this measure is explained by shared familial factors. Estimates were unchanged after adjustment for body mass index or neck circumference. In contrast, oropharyngeal length did not have significant heritability in either ethnic group.

The minimum cross-sectional area in the oropharynx is a highly heritable trait suggesting the presence of an underlying genetic basis. These findings demonstrate the potential utility of acoustic pharyngometry in dissecting the genetic basis of sleep apnoea.