Sleep apnoea and obesity

Obstructive sleep apnoea syndrome is a common disorder with an estimated prevalence of at least 2 to 4% among middle-aged adults, especially common in obesity.

Leptin is a substance produced in the adipose tissue and which plays an important role in the control of body weight, but also in reproduction and neuroendocrine signalling.

Recent studies could document that there is a relation between sleep apnoea and leptin levels. Bernd M. Sanner (Department of Medicine, Bethesda Krankenhaus, Wuppertal, Germany) and his colleagues therefore tested the hypothesis that treatment of the sleep disorder influences leptin levels.
Eighty-six patients participated in the study. They all had obstructive sleep apnoea syndrome, as diagnosed in a university sleep laboratory. The patients were examined at baseline and after a treatment period of 6 months. During this period 59 of the patients were treated effectively and 27 patients were treated ineffectively or not at all.

Interestingly, effective treatment reduced the blood levels of leptin, while they remained unchanged or even increased in the other group. Furthermore, there was an independent relation between the change of leptin levels with treatment and the degree of improvement of nocturnal respiration.

The authors therefore conclude that obstructive sleep apnoea syndrome is not only a condition that worsens quality of sleep or disturbs bed partners, but also a disease with a substantial influence on human's health.