Sustained improvement in mild obstructive sleep apnea after a diet- and physical activity-based lifestyle intervention: postinterventional follow-up.

BACKGROUND: Obesity is the most important risk factor for obstructive sleep apnea (OSA). Weight-reduction programs have been observed to represent effective treatment of overweight patients with OSA. However, it is not known whether beneficial changes remain after the end of the intervention. OBJECTIVE: The aim of the study was to assess the long-term efficacy of a lifestyle intervention based on a healthy diet and physical activity in a randomized, controlled, 2-y postintervention follow-up in OSA patients. DESIGN: Eighty-one consecutive overweight [body mass index (in kg/m(2)): 28-40] adult patients with mild OSA were recruited. The intervention group completed a 1-y lifestyle modification regimen that included an early 12-wk weight-reduction program with a very-low-calorie diet. The control group received routine lifestyle counseling. During the second year, no dietary counseling was offered. Change in the apnea-hypopnea index (AHI) was the main objective outcome variable, and changes in symptoms were used as a subjective measurement. RESULTS: A total of 71 patients completed the 2-y follow-up. The mean (± SD) changes in diet and lifestyle with simultaneous weight reduction (-7.3 ± 6.5 kg) in the intervention group reflected sustained improvements in findings and symptoms of OSA. After 2 y, the reduction in the AHI was significantly greater in the intervention group (P = 0.049). The intervention lowered the risk of OSA at follow-up; the adjusted odds ratio for OSA was 0.35 (95% CI: 0.12-0.97; P = 0.045). CONCLUSION: Favorable changes achieved by a 1-y lifestyle intervention aimed at weight reduction with a healthy diet and physical activity were sustained in overweight patients with mild OSA after the termination of supervised lifestyle counseling. This trial was registered at clinicaltrials.gov as NCT00486746.

Lifestyle intervention with weight reduction: first-line treatment in mild obstructive sleep apnea.

RATIONALE: Obesity is the most important risk factor for obstructive sleep apnea (OSA). However, although included in clinical guidelines, no randomized controlled studies have been performed on the effects of weight reduction on mild OSA. OBJECTIVES: The aim of this prospective, randomized controlled parallel-group 1-year follow-up study was to determine whether a very low calorie diet (VLCD) with supervised lifestyle counseling could be an effective treatment for adults with mild OSA. METHODS: Seventy-two consecutive overweight patients (body mass index, 28-40) with mild OSA were recruited. The intervention group (n = 35) completed the VLCD program with supervised lifestyle modification, and the control group (n = 37) received routine lifestyle counseling. The apnea-hypopnea index (AHI) was the main objectively measured outcome variable. Change in symptoms and the 15D-Quality of Life tool were used as subjective measurements. MEASUREMENTS AND MAIN RESULTS: The lifestyle intervention was found to effectively reduce body weight (-10.7 +/- 6.5 kg; body mass index, -3.5 +/- 2.1 [mean +/- SD]). There was a statistically significant difference in the mean change in AHI between the study groups (P = 0.017). The adjusted odds ratio for having mild OSA was markedly lowered (odds ratio, 0.24 [95% confidence interval, 0.08-0.72]; P = 0.011) in the intervention group. All common symptoms related to OSA, and some features of 15D-Quality of Life improved after the lifestyle intervention. Changes in AHI were strongly associated with changes in weight and waist circumference. CONCLUSIONS: VLCD combined with active lifestyle counseling resulting in marked weight reduction is a feasible and effective treatment for the majority of patients with mild OSA, and the achieved beneficial outcomes are maintained at 1-year follow-up.

Thirty-year cumulative incidence of chronic bronchitis and COPD in relation to 30-year pulmonary function and 40-year mortality: a follow-up in middle-aged rural men.

PURPOSE: To describe the 30-year cumulative incidence of chronic bronchitis and COPD in relation to smoking habits. The effect of chronic bronchitis on pulmonary function and mortality was also examined. METHODS: Middle-aged men belonging to two rural Finnish cohorts of the Seven Countries Study (n = 1,711 in 1959) were followed up for up to 40 years until 2000. Standard questionnaires were used to measure chronic bronchitis, and repeated spirometry was used to evaluate pulmonary function during the 30 years. Forty-year mortality data were examined. RESULTS: The cumulative incidence of chronic bronchitis and COPD was 42% and 32%, respectively, in continuous smokers, compared to 26% and 14% in ex-smokers and 22% and 12% in never-smokers. During the follow-up, subjects with chronic bronchitis had on average 252 mL (95% confidence interval, 211 to 293 mL) lower forced expiratory volume than those without it. The decrease in forced expiratory volume attributable to chronic bronchitis was most pronounced in those with persistent symptoms and in smokers. In subjects with chronic bronchitis, all-cause mortality was increased by a hazard ratio of 1.30 (95% confidence interval, 1.02 to 1.65). Smokers with chronic bronchitis who decreased their daily cigarette consumption increased their median life span by 2.4 years. CONCLUSIONS: The lifetime risk of chronic bronchitis among smokers is approximately two in five, and almost one half of smokers who have chronic bronchitis also acquire COPD. Chronic bronchitis is related to earlier death, also in never-smokers, probably partly through a rapid decline in pulmonary function.

Experimental PVC material challenge in subjects with occupational PVC exposure.

BACKGROUND: Polyvinyl chloride (PVC) materials have been linked to asthma in several epidemiologic studies, but the possible causal factors remain unknown. PARTICIPANTS: We challenged 10 subjects experimentally to degraded PVC products under controlled conditions. All of the subjects had previously experienced respiratory symptoms suspected to be caused by this kind of exposure in their work place. Five subjects had doctor-diagnosed asthma. METHODS: The subjects were exposed to degraded PVC material in an exposure chamber ; a challenge with ceramic tile was used as the control test. We followed exhaled nitric oxide, nasal NO, lung functions, cytokines [tumor necrosis factor-alpha (TNF-alpha) , interleukin-4 (IL-4) , IL-6, and IL-12] and NO in nasal lavage fluid (NAL) during and after the exposures. We also measured 2-ethylhexanol in exhaled breath samples and NAL. RESULTS: On the morning after the PVC exposure, subjects reported respiratory tract symptoms significantly more often than they did after the control test (50% vs. 0%, respectively ; p = 0.029 ; n = 10) . We did not detect any changes in lung functions or levels of exhaled NO, nasal NO, or NO in NAL after PVC challenge compared with the control test. Cytokine levels increased after both exposures, with no statistically significant difference between situations. All of the exhaled breath samples collected during the PVC exposure contained 2-ethylhexanol. CONCLUSIONS: PVC flooring challenge can evoke respiratory tract symptoms in exposed subjects. Our results do not support the hypothesis that PVC materials themselves evoke immediate asthmatic reactions. The chamber test used is well suited to this type of exposure study.

Delaying decline in pulmonary function with physical activity: a 25-year follow-up.

The importance of physical activity for health is well recognized, but little is known about the influence of physical activity on pulmonary function. We have examined whether physical activity could slow down the decline in pulmonary function among the southwestern rural Finnish cohort of the Seven Countries Study. Physical activity was estimated by kilometers walked, cycled, and skied daily. We had complete data for 429 men for 10 years, 275 men for 20 years, and 186 men for 25 years. During the first 10 years, the decline in FEV was 9.8 ml/year less among men in the highest tertile of baseline physical activity than in men in the lowest tertile. According to the mean physical activity over either 20 or 25 years, men in the highest tertile also lost less pulmonary function (p = 0.009 and p = 0.043, respectively). A similar beneficial effect was observed in all smoking categories. In mortality analysis, continued high physical activity and an increase in activity to high level were associated with lower mortality. In conclusion, results indicated that physical activity is associated with a slower decline in pulmonary function and with lower mortality, and thus, middle-aged and older people should be encouraged to enjoy exercise.