In clinical practice, it is not always a clinical history of symptomatic OSA that provides the suspicion that a patient may have OSA. There are phenotypic presentations that may be suggestive of OSA. A large neck (or neck circumference), older age, or retrognathic jaw position may all be indicators that a patient may require further investigation into the clinical history with a view to sleep disordered breathing. These presentations may differ between ethnic groups however.
Sutherland et al. recently looked not only at phenotypic presentations on photos (front and side), but the gender and ethnic differences of these presentations. They found there were ethnic and sex differences between craniofacial features that can be used to screen or flag likelihood of having OSA.
Study objectives: Craniofacial abnormalities are a risk factor for obstructive sleep apnea (OSA). We have previously shown that phenotypic information derived from craniofacial photographs predict OSA in sleep clinic populations. However, there are likely ethnic and sex differences in craniofacial phenotypes related to OSA. We aimed to assess the use of craniofacial photography to identify interactions between OSA, ethnicity, and sex in craniofacial phenotype.
Conclusions: We provide evidence of ethnic and sex differences in facial phenotype related to OSA. Furthermore, we demonstrate that craniofacial photography can be used as a phenotypic tool to assess these differences and allow investigation of OSA phenotypes in large samples. This has relevance to personalizing OSA recognition strategies across different populations.
Methods: Frontal and profile craniofacial photographs were analyzed from two sleep clinic populations of different ethnicity (Hong Kong Chinese, Australian Caucasians). OSA was defined as apnea-hypopnea index (AHI) > 10 events/h. Ten craniofacial measurements (three angles relating to jaw position and seven ratios describing proportions of the face) were examined for interactions between OSA status and sex or ethnicity) using factorial analysis of variance.
Results: A total of 363 subjects (25% female) were included (n = 200 Chinese, n = 163 Caucasian), of which 33% were controls. There were two-way interactions for OSA with both sex (mandibular plane angle [F = 7.0, P = .009], face / eye width ratio [F = 4.7, P = .032], maxillary / mandibular volume ratio [F = 9.2, P = .003]) and ethnicity (face / nose width ratio [F = 4.0, P = .045], mandibular width / length ratio [F = 5.1, P = .024], maxillary / mandibular volume ratio [F = 11.0, P = .001]).
Citation
Sutherland K, Lee RW, Chan TO, Ng S, Hui DS, Cistulli PA. Craniofacial phenotyping in Chinese and Caucasian patients with sleep apnea: influence of ethnicity and sex. J Clin Sleep Med. 2018;14(7):1143–1151.
