A Lifestyle Modification Program Associated With Weight Loss Reduces the Severity of OSA

Abstract

Synopsis: Obesity is a major risk factor for OSA. The study by Ng and colleagues assessed the impact of weight loss reduction through a lifestyle modification program on patients with moderate to severe OSA. They found a reduction in OSA severity and daytime sleepiness that was directly associated with weight loss. Source: Ng SS, Chan RS, Woo J, Chan TO, Cheung BH, Sea MM, To KW, Chan KK, Ngai J, Yip WH, Ko FW, Hui DS. A randomized controlled study to examine the effect of a lifestyle modification program in OSA. Chest. 2015; 148(5):1193-1203. (Clin Pulm Med 201623:95-96) O bstructive sleep apnea (OSA) is a breathing disorder that occurs when recurrent upper-airway obstruction during sleep leads to episodes of apnea, hypopnea, and/or respiratory effort awakenings. These respiratory disturbances often lead to sleep fragmentation, hypoxemia, hypercapnia, and increased sympathetic activity. 1,2 As a result, patients with OSA commonly describe symptoms of loud snoring, sleep disturbances, concentration difficulties, daytime sleepiness, and witnessed breathing interruptions. Studies have shown that OSA is associated with an increased risk of hypertension, congestive heart failure, type II diabetes, stroke, and premature death. [1][2][3][4] This is an area of growing public health concern as the most current data show that the prevalence of moderate to severe OSA ranges from 10% to 17% in men and from 3% to 9% in women, a notable increase of >25% over the last 2 decades. 5 Obesity is a known causal factor for OSA, and studies estimate that over 50% of the moderate to severe OSA cases occur in patients with an elevated body mass index (BMI). 6 Hence, many investigators postulate that the obesity epidemic is one of the main drivers responsible for the increase in the prevalence of OSA. Although continuous positive airway pressure (CPAP) is the first-line therapy for the treatment of OSA, significant efforts have been made to address the impact of obesity management on the severity of OSA. 7 Recent studies that questioned the utility of low-calorie diets and surgically induced weight-loss programs show promising results, but they are limited by a lack of feasibility and small sample populations. 8,9 In this study, Ng et al 10 hypothesized that weight reduction through a lifestyle modification program (LMP) would benefit patients with moderate to severe OSA. This was a single-center study including patients from the Prince of Wales Center. It was designed as a prospective randomized trial and recruited 104 patients for enrollment. Patients underwent an at-home sleep study and the data were scored by the polysomnographic technologists. The diagnosis and the severity of OSA was determined using the apnea hypopnea index (AHI), the average number of hypopnea or apnea episodes per hour of sleep, where AHI > 15 events/hour was considered as moderate OSA. Inclusion criteria were age 30 to 80 years, BMI > 25 kg/ m 2 , and AHI > 15 events/hour. Patients who were randomized to the intervention group participated in an intensive...