RESUMO
STUDY OBJECTIVES: To examine the effect of changes in cardiorespiratory fitness on obstructive sleep apnea (OSA) severity prior to and following adjustment for changes in weight over the course of a 4-y weight loss intervention. METHODS: As secondary analyses of a randomized controlled trial, 263 overweight/obese adults with type 2 diabetes and OSA participated in an intensive lifestyle intervention or education control condition. Measures of OSA severity, cardiorespiratory fitness, and body weight were obtained at baseline, year 1, and year 4. Change in the apnea-hypopnea index (AHI) served as the primary outcome. The percentage change in fitness (submaximal metabolic equivalents [METs]) and change in weight (kg) were the primary independent variables. Primary analyses collapsed intervention conditions with statistical adjustment for treatment group and baseline METs, weight, and AHI among other relevant covariates. RESULTS: At baseline, greater METs were associated with lower AHI (B [SE] = -1.48 [0.71], P = 0.038), but this relationship no longer existed (B [SE] = -0.24 [0.73], P = 0.75) after adjustment for weight (B [SE] = 0.31 [0.07], P < 0.0001). Fitness significantly increased at year 1 (+16.53 ± 28.71% relative to baseline), but returned to near-baseline levels by year 4 (+1.81 ± 24.48%). In mixed-model analyses of AHI change over time without consideration of weight change, increased fitness at year 1 (B [SE] = -0.15 [0.04], P < 0.0001), but not at year 4 (B [SE] = 0.04 [0.05], P = 0.48), was associated with AHI reduction. However, with weight change in the model, greater weight loss was associated with AHI reduction at years 1 and 4 (B [SE] = 0.81 [0.16] and 0.60 [0.16], both P < 0.0001), rendering the association between fitness and AHI change at year 1 nonsignificant (B [SE] = -0.04 [0.04], P = 0.31). CONCLUSIONS: Among overweight/obese adults with type 2 diabetes, fitness change did not influence OSA severity change when weight change was taken into account. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identification number NCT00194259.
Assuntos
Fenômenos Fisiológicos Cardiovasculares , Diabetes Mellitus Tipo 2/complicações , Sobrepeso/complicações , Aptidão Física/fisiologia , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/fisiopatologia , Redução de Peso , Idoso , Índice de Massa Corporal , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Nível de Saúde , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Obesidade/fisiopatologia , Sobrepeso/fisiopatologia , Educação de Pacientes como Assunto , Fenômenos Fisiológicos Respiratórios , Apneia Obstrutiva do Sono/diagnóstico , Resultado do TratamentoRESUMO
BACKGROUND: Obstructive sleep apnea (OSA) is associated with a variety of medical conditions. Positive airway pressure (PAP) is an effective treatment for improving sleep, yet adherence rates are low. The aim of the current study is to test two treatments versus standard care in improving adherence to PAP. METHOD: Two hundred twenty-seven patients with OSA were randomized to standard care (SC), education (ED) and motivational enhancement therapy (MET). Adherence was measured objectively and the first week of adherence (prior to the intervention) was used as an a priori moderator of the effect of the various interventions. Mediators of treatment response were also examined using theory-based measures of decisional balance and self-efficacy. RESULTS: Adherence declined over time for all three groups. There was a significant interaction between level of adherence during the first week of treatment and treatment group. Those who had moderate levels of adherence during their first week of PAP were more likely to adhere to treatment at follow-up if they had MET; those who had high levels of adherence during their first week of PAP were more likely to adhere to treatment at follow-up if they had ED. MET treatment increased the perception of the positive aspects of PAP, but ED did not. CONCLUSIONS: Initial adherence to positive airway pressure could help guide subsequent treatment plans. The results also support social cognitive theory in that educational approaches might be best suited for those who are ready for change whereas more motivational approaches might be best for those who are ambivalent about change.