Patients with obstructive sleep apnea are often obese. Obesity may contribute to both sleep apnea itself and to the cardiovascular risk associated with sleep apnea. Weight loss in obese patients with sleep apnea may alleviate symptoms and decrease the severity of sleep apnea. Whether patients with obstructive sleep apnea are indeed predisposed to recent weight gain, as compared with similarly obese subjects without sleep apnea, is not known.
We compared 1-year weight histories in 53 male and female patients newly diagnosed with obstructive sleep apnea, compared with 24 controls matched for gender, age, body mass index, and percent body fat. Sleep apnea patients had never been treated. Control subjects were proven to be free of sleep-disordered breathing by overnight polysomnography.
Patients with obstructive sleep apnea (n = 53) had a significant recent weight gain of 7.4 ± 1.5 kg compared with a weight loss of 0.5 ± 1.7 kg (P = 0.001) in similarly obese controls (n = 24). Male patients with obstructive sleep apnea (n = 28) had a history of significant weight gain (6.8 ± 2.3 kg) over the year preceding the study compared with male control subjects (n = 13), in whom average weight fell by 0.58 ± 2.4 kg (P = 0.03). Female patients (n = 25) with obstructive sleep apnea had an 8.0 ± 1.9 kg weight gain compared with female controls (n = 11) who had a history of weight loss of 0.46 ± 2.6 kg (P = 0.02).
These findings support the concept that patients with obstructive sleep apnea may be susceptible to increasing obesity in the period preceding the diagnosis of obstructive sleep apnea.
1Division of Clinical and Administrative Pharmacy, University of Iowa College of Pharmacy, Iowa City, Iowa 52242, USA.
2Department of Internal Medicine, University of Iowa College of Pharmacy, Iowa City, Iowa 52242, USA.
3Department of Neurology, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA.
4Correspondence and requests for reprints to Virend K. Somers MD PhD, University of Iowa College of Medicine, Department of Internal Medicine, Cardiovascular Center, 200 Hawkins Drive, Iowa City, IA 52242, USA. Tel: +1 319 353 6576; fax: +1 319 353 6343; e-mail: email@example.com
Sponsorship: These studies were supported by a National Institutes of Health Sleep Academic Award and NIH/HL14388, 60618 and 61560 (B.G.P. and V.K.S.). V.K.S. is an Established Investigator of the American Heart Association.
Received 3 February 1999, Revised 22 April 1999, Accepted 4 May 1999