[Relationship between sleep disordered breathing and body weight loss in patients with chronic obstructive pulmonary...

We evaluated body weight loss and growth hormone secretion in patients with sleep-disordered breathing associated with chronic obstructive pulmonary disease. Of 11 patients hospitalized for pulmonary rehabilitation, five (WL group) had a history of body weight loss within two years before their interviews, while the other 6 patients (NWL group) had no changes in body weight. All patients underwent body index measurements, pulmonary function tests, blood gas analyses, assessments of nutritional status, and full night polysomnography for two consecutive days. Growth hormone levels were measured in the first 3-hour period following falling asleep. There were no significant inter-group differences between the results of pulmonary function tests, blood gas analyses, or nutritional status assessment. The WL group had a significantly higher percentage loss of body weight than the NWL group (mean +/- S.D. 11.5 +/- 4.7% in the WL group versus 2.7 +/- 1.8% in the NWL group, p < 0.01). The WL group had a significantly higher sleep apnea/hypopnea index than the NWL group (42.4 +/- 9.5/hr in the WL group versus 7.8 +/- 2.9/hr in the NWL group, p < 0.01). The WL group showed a higher rate of stage I + II sleep than the NWL group (84.9 +/- 7.0% versus 64.5 +/- 8.7%), with lower rates of slow wave sleep (2.2 +/- 2.1% versus 15.0 +/- 8.7%) and rapid eye movement sleep (12.9 +/- 6.3% versus 20.6 +/- 1.0%). The WL group showed a low level of growth hormone secretion with no peak in the sequential curve, but had a higher level of insulin growth factor-1 than the NWL group (148 +/- 36 ng/ml versus 90 +/- 22 ng/ml, p < 0.01). These results suggest that chronic obstructive pulmonary disease patients undergoing weight loss are likely to have an increase of growth hormone secretions in the daytime, possibly induced by underlying psychiatric disorders such as depression. Patients with chronic obstructive pulmonary disease may lose weight regardless of nutritional status because of a disturbance of growth hormone secretion resulting of sleep-disordered breathing.