Weight and metabolic effects of cpap in obstructive sleep apnea patients with obesity

Abstract

BackgroundObstructive sleep apnea (OSA) is associated with obesity, insulin resistance (IR) and diabetes. Continuous positive airway pressure (CPAP) rapidly mitigates OSA in obese subjects but its metabolic effects are not well-characterized. We postulated that CPAP will decrease IR, ghrelin and resistin and increase adiponectin levels in this setting.MethodsIn a pre- and post-treatment, within-subject design, insulin and appetite-regulating hormones were assayed in 20 obese subjects with OSA before and after 6 months of CPAP use. Primary outcome measures included glucose, insulin, and IR levels. Other measures included ghrelin, leptin, adiponectin and resistin levels. Body weight change were recorded and used to examine the relationship between glucose regulation and appetite-regulating hormones.ResultsCPAP effectively improved hypoxia. However, subjects had increased insulin and IR. Fasting ghrelin decreased significantly while leptin, adiponectin and resistin remained unchanged. Forty percent of patients gained weight significantly. Changes in body weight directly correlated with changes in insulin and IR. Ghrelin changes inversely correlated with changes in IR but did not change as a function of weight.ConclusionsWeight change rather than elimination of hypoxia modulated alterations in IR in obese patients with OSA during the first six months of CPAP therapy.

Impact of Treatment with Continuous Positive Airway Pressure (CPAP) on Weight in Obstructive Sleep Apnea

“…12 Furthermore, in a small randomized controlled study, Garcia et al observed a small amount of weight gain in 20 obese OSA subjects over the course of 6 months. 13 Our study extends these latter findings by documenting weight gain with CPAP in a much larger cohort and showing that it is a function of adherence. Thus, our findings and those of previous studies suggest that CPAP is inducing a state of positive energy balance resulting in weight gain.…”

“…However, the levels of adherence in this study are similar to those in other long-term randomized controlled trials. 13,14,32 Furthermore, given our current findings, greater adherence would likely have made the differences in weight between CPAP and Sham even more striking. Second, in comparison to the CPAP group, more participants in the Sham group failed to complete the study.…”

“…15 In two other randomized controlled studies of CPAP compared to sham CPAP, CPAP treatment for 12 weeks or 24 weeks also did not result in weight loss. 13,14 However, the latter four studies may have been inadequately powered to detect a small change in weight. In a much larger, although non-blinded randomized study, CPAP treatment for a median of four years failed to result in weight loss.…”

“…However, available evidence is confl icting, with two studies demonstrating CPAP users losing weight 8,9 while others observed either no change or increases in weight. [11][12][13][14][15] However, these studies have been retrospective, small in size, lacked a parallel control group, or were not blinded. Thus, it is unclear whether treatment of OSA with CPAP results in any changes in weight.…”

Effect of Continuous Positive Airway Pressure on Adiponectin in Patients With Obstructive Sleep Apnea: A Meta-analysis

“…One of them was randomized clinical trial (RCT) [19], the remaining studies were observational [20][21][22][23][24][25][26][27][28][29]. One study [27] reported results separately for obese group and non-obese group.…”