Comparison of Polysomnographic and Clinical Presentations and Predictors for Cardiovascular-Related Diseases between Non-Obese and Obese Obstructive Sleep Apnea among Asians

Abstract

Introduction: Unlike Caucasians, many Asians with obstructive sleep apnea (OSA) are non-obese but are affected by the disease due to predisposing craniofacial structure. Therefore, non-obese and obese OSA may represent different disease entities. The associated risk factors for developing cardiovascular-related diseases, consequently, may be considered separately for the two types of OSA. Method: We reviewed polysomnographic studies performed in adults (aged ≥ 18 years) diagnosed with OSA (respiratory disturbance index [RDI] ≥ 5). We divided the patients into obese (body mass index [BMI] ≥ 25) and non-obese (BMI < 25) groups. We aimed to determine the differences between these two groups in terms of clinical presentations, polysomnographic fi ndings, and association with cardiovascular-related diseases including hypertension, diabetes mellitus, coronary artery disease, and/or cerebrovascular disease. Results: Among 194 patients with OSA (RDI ≥ 5), 63.4% were non-obese and 36.6% were obese. Compared with obese OSA patients, non-obese OSA patients were noted to have smaller neck size, less prevalence of hypertension, and less history of frequent nocturia (> 3-4/week), with equal prevalence of excessive daytime sleepiness. Overall, non-obese OSA patients were noted to have milder disease indicated by lower total, supine, and non-supine, NREM RDI and higher mean and nadir oxygen saturations. In the non-obese group, only total obstructive apnea index (OAI) was noted to be a predictor for developing any of the cardiovascular-related diseases after controlling for age, sex, and RDI (odds ratio = 9.7). However, in the obese OSA group, frequent snoring (> 50% of total sleep time), low sleep effi ciency (≤ 90%), and low mean oxygen saturation (< 95%) were noted to be signifi cant predictors of cardiovascular-related diseases (odds ratios = 12.3, 4.2, and 5.2, respectively). Conclusion: Among Asians, most OSA patients were not obese. Compared to obese OSA patients, non-obese OSA patients were noted to have less prevalence of hypertension and less history of nocturia. They were also noted to have overall milder OSA. Only OAI was noted to be a signifi cant predictor for cardiovascular-related disease in the non-obese OSA group. keywords: Obstructive sleep apnea, obesity Citation: Chirakalwasan N; Teerapraipruk B; Simon R; Hirunwiwatkul P; Jaimchariyatam N; Desudchit T; Charakorn N; Wanlapakorn C. Comparison of polysomnographic and clinical presentations and predictors for cardiovascular-related diseases between non-obese and obese obstructive sleep apnea among Asians. J Clin Sleep Med 2013;9(6):553-557.http://dx.doi.org/10.5664/jcsm.2748 S C I E N T I F I C I N V E S T I g A T I O N SO bstructive sleep apnea (OSA) is characterized by repetitive episodes of complete (apnea) or partial (hypopnea) upper airway obstruction occurring during sleep. These events often result in reduction in blood oxygen saturation and are usually terminated by brief arousals from sleep.1 Prior study has shown that obesity is one of the important ri...

Simplified Berlin Questionnaire for Screening of High Risk for Obstructive Sleep Apnea Among Thai Male Healthcare Workers

“…Another classic symptom of OSA, daytime sleepiness, was not a strong item of the Berlin questionnaire to detect high-risk subjects for OSA (P value 0.059; Table 2) in Thai male subjects. A previous study indicated that Thai male patients with OSA may not have tiredness or daytime sleepiness [7]. Hypertension is known to be associated with OSA [13].…”

“…Asian OSA patients are different from Western OSA patients in several aspects. Thai OSA patients seemed to be less obese, have fewer symptoms, or have fewer complications [7,8]. The Berlin questionnaire for the Thai population may need some modifications.…”

Rethinking AASM guideline for split-night polysomnography in Asian patients with obstructive sleep apnea

“…Furthermore, there was no difference in diagnostic accuracy when using criterion 1 (AHI≥30) or criterion 2 (AHI≥ 40). Several studies have reported racial/ethnic differences in the clinical presentation, sleep study findings, and OSArelated morbidity of OSA [8][9][10][11]. In addition, Asian patients with OSA are reported to be less obese but have a greater OSA severity than Caucasian patients with OSA [8][9][10].…”

Sleep apnoea adversely affects the outcome in patients who undergo posterior lumbar fusion

“…[[41]] Additionally, up to > 60% of patients with a definitive diagnosis of sleep apnoea have been reported to be non-obese. [[42]] Intra-operative events and preventive treatment measures including the application of continuous positive airway pressure (CPAP) used as a ‘pneumatic airway splint’, were not captured. Lack of this information makes it impossible to determine whether this form of treatment modifies the outcome.…”