Effects of continuous positive airway pressure on energy balance regulation: a systematic review

Abstract

Obesity is both a cause and a possible consequence of obstructive sleep apnoea (OSA), as OSA seems to affect parameters involved in energy balance regulation, including food intake, hormonal regulation of hunger/satiety, energy metabolism and physical activity. It is known that weight loss improves OSA, yet it remains unclear why continuous positive airway pressure (CPAP) often results in weight gain. The goal of this systematic review is to explore if and how CPAP affects the behaviour and/or metabolism involved in regulating energy balance. CPAP appears to correct for a hormonal profile characterised by abnormally high leptin and ghrelin levels in OSA, by reducing the circulating levels of each. This is expected to reduce excess food intake. However, reliable measures of food intake are lacking, and not yet sufficient to make conclusions. Although studies are limited and inconsistent, CPAP may alter energy metabolism, with reports of reductions in resting metabolic rate or sleeping metabolic rate. CPAP appears to not have an appreciable effect on altering physical activity levels. More work is needed to characterise how CPAP affects energy balance regulation. It is clear that promoting CPAP in conjunction with other weight loss approaches should be used to encourage optimal outcomes in OSA patients.

Abnormal Growth and Feeding Behavior in Upper Airway Obstruction in Rats

“…First, it is possible that dysphagia ( 18 ) is due to enlarged tonsils and adenoids, and decreased appetite due to changes in olfactory acuity in some cases. Second, it has been postulated that dysregulation of energy supply/energy expenditure balance ( 3 , 18 – 20 ), due to the increased respiratory efforts (work of breathing) during sleep, will lead to increased metabolic expenditure and contribute to slow weight gain in these children ( 3 ). However, this mechanism has been disputed, as total energy expenditure was not affected by OSA ( 21 ).…”

Sleep apnea in relation to metabolism: An urgent need to study underlying mechanisms and to develop novel treatments for this unmet clinical need

“…While we are striving to understand the full spectrum of metabolic consequences of sleep disorders, including OSA, and we have initiated significant efforts towards understanding the underlying mechanisms, we do not yet know whether these changes may be corrected, and if yes, to what extent, by treatments for OSA, such as continuous positive air pressure (CPAP) for which conflicting evidence exists [57]. A greater understanding of underlying pathophysiological mechanisms, including mechanisms in utero or during early life, which may contribute to the development of OSA and/or metabolic dysfunction resulting from OSA later in life, is urgently needed.…”

A comprehensive diagnostic approach to detect underlying causes of obesity in adults

“…OSA occurs more frequently in obesity, but the sleep disturbances belonging to it may again promote weight gain enhancing behavioral, metabolic, and/or hormonal . It is not fully clear whether OSA treatment has an effect on body weight …”