Impact of a brief dietary self-monitoring intervention on weight change and CPAP adherence in patients with obstructive sleep apnea

Abstract

Objective

Weight loss can decrease the severity of obstructive sleep apnea (OSA) in many obese individuals; however, very few studies have investigated the effects of behavioral weight loss interventions for patients with OSA. The aims of this pilot study were to determine the feasibility and initial effects on weight and continuous positive airway pressure (CPAP) use of a brief minimal-contact self-monitoring-based weight loss intervention (SM). An additional aim was to investigate the association between weight loss and CPAP adherence.

Methods

Forty obese men and women diagnosed with mild or moderate OSA were randomized to either the SM or an attention-control (AC) condition. SM participants completed daily dietary logs for 6 weeks. Participants were weighed at baseline, post-treatment (6 weeks), and at a 6-week follow up.

Results

Recruitment and retention were good in this study and attrition rates did not differ significantly by group. Intent to treat repeated measures ANOVA indicated a main effect of time (but not group), such that both groups lost weight over time. Pearson r correlations between weight change and CPAP adherence indicated that among SM participants, 6-week weight loss was correlated with CPAP adherence at post-treatment and follow-up, such that SM participants with greater weight loss at 6 weeks had greater CPAP adherence at 6 and 12 weeks.

Conclusion

This study provides initial support for the beneficial effects of a minimal-contact weight loss intervention for patients with obstructive sleep apnea and highlights a possible association between weight loss and CPAP adherence.

Introduction

Obesity is one of the strongest risk factors for the development of obstructive sleep apnea (OSA), a sleep-related breathing disorder that is associated with increased medical and psychosocial comorbidities and high economic burden [1], [2]. Obese individuals with OSA are at increased risk for further weight gain due to a number of factors, including the negative impact of OSA on metabolic and hormonal functioning as well as the association between increased daytime sleepiness and fatigue and decreased physical activity [1].

Weight loss has consistently been shown to decrease OSA severity in bariatric surgery and very low calorie diet programs [3], [4]. In one of the few studies that has evaluated the effects of behavioral weight loss treatments in this population, Johansson and colleagues [5] investigated the effects of a 9-week very low calorie diet followed by participation in monthly behavioral weight loss groups lasting up to 1-year post-baseline. At the 1-year follow up assessment, 48% of participants no longer required continuous positive airway pressure (CPAP) treatment. These results highlight the potential benefits of a behavioral weight loss treatment in decreasing weight and the severity of OSA. In order to develop effective treatments for this population, further studies are needed to investigate the feasibility and effects of the interventions, particularly treatments that are easily disseminated to the large number of patients with OSA who could benefit from them.

Commercial weight loss programs can be expensive [6] and insurance coverage of weight loss treatment is often less than ideal [7], so cost of treatment may serve as a barrier for individuals to participate in many weight loss programs [8]. Weight loss experts have stressed the importance of developing professionally supervised, self-help weight loss treatments to increase the availability of cost-efficient and accessible interventions [9], [10]. Effective self-help treatments tend to focus on a small number of manageable yet effective behavior changes in order to induce long-term lifestyle change.

Dietary self-monitoring via food logs is considered the cornerstone of behavioral weight control programs [11]. In terms of its utility as a weight loss behavior, self-monitoring has the benefit of being effective, easy to understand, and low-cost. Though it is typically used as a component of a comprehensive behavioral weight loss program, dietary self-monitoring has been shown to be effective in producing weight loss even with no [12] or minimal [13] concurrent behavioral treatment. Studies of individuals who successfully maintain weight loss after self-directed or formal weight loss programs highlight that long-term self-monitoring is a crucial component of weight loss maintenance [14], [15]. Studies of minimal-contact weight loss programs using dietary self-monitoring along with self-administered weight management manuals have shown promising results over 3 month periods [13], [16], though no such programs have been studied specifically with individuals with OSA.

Regular use of CPAP treatment during sleep is currently the gold standard for treating OSA symptoms. Yet, adherence to CPAP use is notoriously suboptimal, with estimates that up to 54% of patients do not meet minimal criteria for regular CPAP use [17], and a large percentage (around 32%) discontinue CPAP use completely by 4 years post-treatment [18]. Poor adherence to CPAP treatment and hence residual OSA can lead to significant medical consequences, such as increased risk for cardiovascular disease and stroke, as well as decreased quality of life and increased economic burden [19]. The ideal treatment for obese patients with OSA, therefore, should include a focus on both weight loss and maintaining optimal adherence to CPAP.

While regular use of CPAP and enhanced weight loss efforts are the primary treatment recommendations for obese individuals diagnosed with OSA [20], the relationship between CPAP use and weight loss is, at present, not well understood. However, some research has suggested that the introduction of one or more health-promoting behavior changes may lead to improvement in other health behaviors [21]. If this is true, then in obese patients with OSA, effective implementation of health behaviors consistent with weight loss may favorably impact CPAP adherence.

The primary aim of this pilot study was to determine the feasibility of a brief self-monitoring-based weight loss intervention using daily dietary self-monitoring and a self-administered cognitive behavioral weight loss manual (SM) on weight change among patients with mild or moderate obstructive sleep apnea. Secondary aims were 1) to establish initial estimates of the effect of the intervention on weight via comparison with an attention-control group (AC), 2) to investigate the impact of the weight loss intervention on CPAP adherence behavior, and 3) to explore the association between weight change and CPAP adherence at the end of the 6-week treatment and at a 6-week follow up.