The prevalence of the hypoventilation syndrome varies with the underlying cause. Approximately 10% to 20% of patients with obstructive sleep apnoea (OSA) are reported to have obesity hypoventilation syndrome (OHS).[2]Mokhlesi B, Tulaimat A, Faibussowitsch I, et al. Obesity hypoventilation syndrome: prevalence and predictors in patients with obstructive sleep apnea. Sleep Breath. 2007;11:117-124.
http://www.ncbi.nlm.nih.gov/pubmed/17187265?tool=bestpractice.com
[3]Kessler R, Chaouat A, Schinkewitch P, et al. The obesity-hypoventilation syndrome revisited: a prospective study of 34 consecutive cases. Chest. 2001;120:369-376.
http://journal.publications.chestnet.org/article.aspx?articleid=1079891
http://www.ncbi.nlm.nih.gov/pubmed/11502631?tool=bestpractice.com
[4]Lecube A, Sampol G, Lloberes P, et al. Asymptomatic sleep-disordered breathing in premenopausal women awaiting bariatric surgery. Obes Surg. 2010;20:454-461.
http://www.ncbi.nlm.nih.gov/pubmed/20020222?tool=bestpractice.com
However, approximately 10% of patients with OHS have an apnoea-hypopnoea index that is normal at <5 events/hour.[2]Mokhlesi B, Tulaimat A, Faibussowitsch I, et al. Obesity hypoventilation syndrome: prevalence and predictors in patients with obstructive sleep apnea. Sleep Breath. 2007;11:117-124.
http://www.ncbi.nlm.nih.gov/pubmed/17187265?tool=bestpractice.com
[3]Kessler R, Chaouat A, Schinkewitch P, et al. The obesity-hypoventilation syndrome revisited: a prospective study of 34 consecutive cases. Chest. 2001;120:369-376.
http://journal.publications.chestnet.org/article.aspx?articleid=1079891
http://www.ncbi.nlm.nih.gov/pubmed/11502631?tool=bestpractice.com
In patients with congestive heart failure and a left ventricular ejection fraction of <45%, Cheyne-Stokes respiration is reported in 33% to 42% of patients, with a prevalence as high as 56% in inpatients awaiting cardiac transplantation.[5]Javaheri S, Parker TJ, Liming JD, et al. Sleep apnea in 81 ambulatory male patients with stable heart failure: types and their prevalences, consequences, and presentations. Circulation. 1998;97:2154-2159.
http://circ.ahajournals.org/cgi/content/full/97/21/2154
http://www.ncbi.nlm.nih.gov/pubmed/9626176?tool=bestpractice.com
[6]Sin DD, Fitzgerald F, Parker JD, et al. Risk factors for central and obstructive sleep apnea in 450 men and women with congestive heart failure. Am J Respir Crit Care Med. 1999;160:1101-1106.
http://www.atsjournals.org/doi/full/10.1164/ajrccm.160.4.9903020
http://www.ncbi.nlm.nih.gov/pubmed/10508793?tool=bestpractice.com
[7]Oldenburg O, Lamp B, Faber L, et al. Sleep-disordered breathing in patients with symptomatic heart failure: a contemporary study of prevalence in and characteristics of 700 patients. Eur J Heart Fail. 2007;9:251-257.
http://www.ncbi.nlm.nih.gov/pubmed/17027333?tool=bestpractice.com
[8]Krachman SL, D'Alonzo GE, Berger TJ, et al. Comparison of oxygen therapy with nasal continuous positive airway pressure on Cheyne-Stokes respiration during sleep in congestive heart failure. Chest. 1999;116:1550-1557.
http://journal.publications.chestnet.org/article.aspx?articleid=1078359
http://www.ncbi.nlm.nih.gov/pubmed/10593775?tool=bestpractice.com
In patients with underlying COPD, approximately 27% developed nocturnal hypoxaemia, but only those with associated OSA (referred to as the overlap syndrome) or with severe obstruction (FEV1 <35% predicted) may demonstrate associated hypercapnia. In patients with restrictive thoracic disorders, such as chest wall deformities (e.g., kyphoscoliosis), the prevalence of hypoventilation is dependent on the degree of spinal curvature (Cobb angle >120°), while patients with neuromuscular diseases may all eventually develop hypoventilation syndrome, depending on the underlying disease (e.g., Duchenne muscular dystrophy).