Comparison of the severity of sleep-disordered breathing in Asian and Caucasian patients seen at a sleep disorders center

Abstract

Race can be considered a risk factor for sleep-disordered breathing (SDB), with higher prevalences and greater severity of the disorder documented among persons of certain racial groups compared with others. Based on clinical observation, it was hypothesized that, other risk factors being equal, Asian patients with SDB have greater severity of their illness compared to Caucasian patients. A cross-sectional study was conducted at a sleep disorders clinic involving 105 Asian patients diagnosed as having SDB after undergoing polysomnography and 99 similarly diagnosed Caucasian patients matched for the following variables: age, gender and body mass index (BMI). The main outcome measure of interest was objective assessment of severity based on polysomnographic data of respiratory disturbance index (RDI) and minimum oxygen saturation (SaO2) during sleep. Symptom scores between patients of the two racial groups were also compared. There were significantly larger proportions of Asians compared to Caucasians with severe obstructive sleep apnea (OSAS) as defined by respiratory disturbance index (RDI) > or = 50 (25.0% vs 11.1%; P = 0.0288) or minimum oxygen saturation (SaO2) < or = 69% (20.6% vs 4.2%; P = 0.0113). The mean minimum SaO2 was significantly lower (P = 0.0001) while the mean (log transformed) esophageal pressure (Pes) value was significantly higher (P = 0.0090) in the Asian group. Logistic regression analysis showed that race was associated with severe SDB (RDI > or = 50) independent of age, sex and BMI. The estimated odds ratio for Asians having severe OSAS compared with Caucasians was 2.51 [95% Confidence Interval (CI) 0.98-6.64]. There was no significant difference in the severity of questionnaire-based symptoms of snoring, apneas during sleep and the median Epworth scores between Asian and Caucasian patients. Based on objective polysomnographic results, Asian patients with OSAS have greater severity of their illness compared to Caucasian patients matched for age, gender and BMI. There was, however, no significant difference in severity of questionnaire-based symptoms between Asian and Caucasian patients with SDB.

To the Editors: Sleep apnoea in Asians and Caucasians: comparing apples and oranges

“…Genta and G. Lorenzi-Filho was that ethnic differences in body fat composition need to be considered when comparing the prevalence or severity of SDB. Based on their clinical findings [2], they suggested using different cut-offs for defining obesity (i.e. o30 kg?m -2 for Caucasians and o25 kg?m -2 for Asians).…”

“…However, as stated in the Methods section of our study: ''The survey was sent to all members of the Respiratory Intensive Care Assembly from the European Respiratory Society (ERS), members of the Acute Respiratory Failure Group from the European Society of Intensive Care Medicine (ESICM), and physicians working in the emergency department (ED) known to be involved in NIV practice or to have published articles on the topic'' [2]. This means that, as pointed out by the authors and as we stated in the Strengths and limitations section of our manuscript, our data cannot be generalised, as we may have missed physicians who are not members of any of these associations.…”

“…Finally, we would like to point out that, as stated in the manuscript's introduction section, the primary aim of our study was to characterise the pattern of NIV utilisation, ''placing emphasis on the technical aspects of NIV use'' [2] (ventilator and interface type) in different scenarios among European NIV users, rather than identify the prevalence of NIV utilisation in European countries per se.…”

“…than Caucasians. These observations have lead to the concept that Asians are at increased risk of OSA [2]. One attractive explanation is that Asians have decreased cranial base dimensions that would render the upper airways more prone to collapse.…”

Obstructive Sleep Apnea Syndrome

“…Irk: Afrika-Amerikan ırksal kökenlilerde ve Asyalılarda görülme sıklığı daha fazla bulunmuştur 15,31,33,34 .…”