CPAP improves weight loss in obese patients with OSA
In addition to an intensive weight loss programme, the use of continuous positive airway pressure (CPAP) could improve absolute weight loss in individuals with obesity and obstructive sleep apnoea (OSA), according to a study presented at ENDO 2019.
This retrospective study involved 300 adults (mean age 55 years, 78.7 percent female) with obesity (BMI of ≥30 to <50 kg/m2) who presented at the weight loss clinic of the University of Arkansas for Medical Science in Little Rock, Arkansas, US, between January 2014 and August 2017. Individuals with thyroid dysfunction, active infection or malignancy, end-organ damage, and uncontrolled diabetes were excluded.
Participants underwent a strict calorie-restricted weight loss programme for 16 weeks with calorie intake restricted to 800 kcal/day, in addition to exercise programmes, cognitive behavioural therapy, and weekly individual counselling sessions.
Participants were divided into three groups based on their OSA symptoms and CPAP status – asymptomatic OSA (n=89), symptomatic OSA (n=164), and OSA treated with CPAP (n=47).
At 16 weeks, participants who had undergone CPAP treatment had significantly greater absolute weight loss compared with participants with asymptomatic OSA (-12.1 vs -8.7 kg) or symptomatic OSA (-9.5 kg) who did not undergo CPAP treatment (p<0.01). [ENDO 2019, abstract GP04]
Absolute weight loss was comparable between participants with asymptomatic and symptomatic OSA who did not receive CPAP treatment.
There was no significant difference in percentage of weight loss between participants with OSA treated with CPAP and those with asymptomatic and untreated symptomatic OSA (-10.46 vs -9.14 vs -8.47 percent; p=0.065).
After adjusting for baseline BMI, age, and sex, there was a correlation between CPAP treatment and absolute weight loss (Spearman’s correlation coefficient, -0.181; p=0.013).
OSA is a major obesity-related comorbidity and CPAP is a first-line treatment strategy for OSA along with weight loss in patients with obesity. However, there is little scientific evidence supporting this method, said study lead investigator Dr Yuanjie Mao from the University of Arkansas for Medical Science.
“Our results showed that the patients who had CPAP treatment achieved a larger weight reduction than non-CPAP treatment patients in a 16-week intensive calorie restriction weight loss programme,” he said.
“Some people may think if they lost weight, they may not need the CPAP machine,” said Mao. “However, our study finds the opposite for people with obesity and OSA who try to lose weight by restricting calories; CPAP treatment can actually result in more weight loss.”
According to Mao, the results point to a potential role of sleep quality on the effectiveness of weight loss programmes, with “underlying neuroendocrine changes” one of the possible mechanisms behind this effect.