UBC Theses and Dissertations
Survey of obese men with obstructive sleep apnea : variables linked to body weight Travis, Karol Ann
Obstructive sleep apnea (OSA), a disorder characterized by intermittent cessation of breathing during sleep, is most prevalent in obese middle-aged men and is associated with considerable morbidity and mortality. The purpose of this study was to characterize newly diagnosed obese men with OSA regarding several variables linked to body weight. Although the association between OSA and obesity is clear, very little is known about factors influencing body weight in OSA. Studies have failed to uncover a metabolic defect in obese individuals with the disorder, raising speculation that obesity may be related to lifestyle or psychological factors. Patients meeting study criteria were recruited following the overnight sleep study at which the diagnosis of OSA was confirmed. Data were collected using chart reviews, anthropometric measurements, food records, written questionnaires, and subject interviews. Forty-nine men participated, about two-thirds of whom completed and returned useable written questionnaires. All completed other study components. Food record analysis showed that reported energy intake was highly variable, but the mean intake reported was moderate, and should not have resulted in weight gain. However, qualitative problems with subjects' diets were evident, including high intake of meats and alternatives and fat, and low intakes of vegetables and fruits and milk products. Binge eating scores were significantly correlated with BMI, indicating increasing eating behaviour dysfunction with increasing relative weight. No subjects appeared to have the night eating syndrome (NES); however, three described eating behaviour suggestive of nocturnal binge eating (NBE). Physical activity questionnaire results indicated that many subjects were physically inactive, and few participated in recreational sports. Similar to previous studies of psychological variables in OSA, about one third of patients were found to have symptoms of depression, anxiety, or both. Many of the psychological and eating behaviour variables were significantly correlated. The interview component of the study revealed that the symptom profile of obese men with OSA was variable, although fatigue, unrefreshing sleep, and snoring were common. In most cases, it was a family member or friend who had prompted the subject's visit to the clinic. The majority of subjects had experienced a substantial increase in body weight since onset of OSA symptoms. Most felt their weight gain was attributable to identifiable lifestyle factors. The amount of weight gain reported was significantly correlated with binge eating and depression scores. As well, subjects who felt that fatigue or stressful life events had affected their food intake had gained significantly more weight than those who had not had these perceptions. Most subjects reported that they had not become obese until adulthood. More than twothirds of subjects reported that weight loss attempts had been infrequent. Eating habit changes were the most predominant weight loss strategy used. Most subjects reported some initial success with weight loss efforts, but virtually all had regained weight following weight loss attempts. Overall, this study provides a profile of a patient population in which debilitating symptoms, sub-optimal diets, low physical activity, symptoms of depression and anxiety, and escalating weight are common. These patients appear to need weight gain prevention strategies, qualitative dietary changes, regular physical activity, and psychological support. A multidisciplinary and community-based approach may be necessary to assist them in making desirable lifestyle changes.