Obstructive sleep apnoea (OSA) syndrome is common, and obesity is a major risk factor. Increased peripharyngeal and central adiposity result in increased pharyngeal collapsibility, through increased mechanical loading around the upper airway, reduced tracheal traction on the pharynx, and reduced neuromuscular activity, particularly during sleep. Significant and sustained weight loss, if achieved, is likely to be a useful therapeutic option in the management of OSA and may be attempted by behavioural, pharmacological, and surgical approaches. Behavioural therapy programs that focus on aspects such as dietary intervention, exercise prescription patients and general lifestyle counselling have been tested. Bariatric surgery is an option in the severely obese when nonsurgical measures have failed, and laparoscopic adjustable gastric banding and Roux-en-Y gastric bypass are the most commonly employed techniques in the United Kingdom. Most evidence for efficacy of surgery comes from cohort studies. The role of sibutramine in OSA in the obese patients has been investigated, however, there are concerns regarding associated cardiovascular risk. In this paper the links between obesity and OSA are discussed, and the recent studies evaluating the behavioural, pharmacological and surgical approaches to weight loss in OSA are reviewed. 1. Introduction Obstructive sleep apnoea (OSA) syndrome is common with a prevalence of approximately 4% in middle-aged men and 2% in middle-aged women [1]. Frequent partial (hypopnoea) or complete (apnoea) closure of the upper airway during sleep leads to oxygen desaturation, increased respiratory effort, arousal, and sleep fragmentation. Patients typically present with witnessed apnoeas, loud intermittent snoring, and excessive daytime somnolence [2]. The syndrome is associated with impairment in quality of life [3], cognitive functioning, and work performance [4], and with an increased risk of road-traffic accidents [5]. OSA is considered an independent risk factor for hypertension [6, 7] and has associations with coronary artery disease [8], stroke [9], heart failure [10], arrhythmias [11], metabolic syndrome [12], and type 2 diabetes [13]. Obesity is an important risk factor for the development of OSA [14–16] and is unique amongst the major risk factors in being modifiable [17]. There is a wealth of studies evaluating the effects of weight loss, achieved by behavioural, pharmacological, and surgical approaches, in the management of OSA in the obese patients. In this review, we will discuss the links between excess body weight and
References
[1]
T. Young, M. Palta, J. Dempsey, J. Skatrud, S. Weber, and S. Badr, “The occurrence of sleep-disordered breathing among middle-aged adults,” The New England Journal of Medicine, vol. 328, no. 17, pp. 1230–1235, 1993.
[2]
W. T. McNicholas, “Diagnosis of obstructive sleep apnea in adults,” Proceedings of the American Thoracic Society, vol. 5, no. 2, pp. 154–160, 2008.
[3]
Y. Lacasse, C. Godbout, and F. Sériès, “Health-related quality of life in obstructive sleep apnoea,” European Respiratory Journal, vol. 19, no. 3, pp. 499–503, 2002.
[4]
H. M. Engleman and N. J. Douglas, “Sleep · 4: sleepiness, cognitive function, and quality of life in obstructive apnoea/hypopnoea syndrome,” Thorax, vol. 59, no. 7, pp. 618–622, 2004.
[5]
J. Terán-Santos, A. Jiménez-Gómez, and J. Cordero-Guevara, “The association between sleep apnea and the risk of traffic accidents,” The New England Journal of Medicine, vol. 340, no. 11, pp. 847–851, 1999.
[6]
G. V. Robinson, J. R. Stradling, and R. J. O. Davies, “Sleep · 6: obstructive sleep apnoea/hypopnoea syndrome and hypertension,” Thorax, vol. 59, no. 12, pp. 1089–1094, 2004.
[7]
J. D. L. Lattimore, D. S. Celermajer, and I. Wilcox, “Obstructive sleep apnea and cardiovascular disease,” Journal of the American College of Cardiology, vol. 41, no. 9, pp. 1429–1437, 2003.
[8]
Y. Peker, H. Kraiczi, J. Hedner, S. L？th, A. Johansson, and M. Bende, “An independent association between obstructive sleep apnoea and coronary artery disease,” European Respiratory Journal, vol. 14, no. 1, pp. 179–184, 1999.
[9]
H. Yaggi and V. Mohsenin, “Obstructive sleep apnoea and stroke,” The Lancet Neurology, vol. 3, no. 6, pp. 333–342, 2004.
[10]
E. Shahar, C. W. Whitney, S. Redline et al., “Sleep-disordered breathing and cardiovascular disease: cross-sectional results of the sleep heart health study,” American Journal of Respiratory and Critical Care Medicine, vol. 163, no. 1, pp. 19–25, 2001.
[11]
A. Adlakha and J. W. Shepard Jr., “Cardiac arrhythmias during normal sleep and in obstructive sleep apnea syndrome,” Sleep Medicine Reviews, vol. 2, no. 1, pp. 45–60, 1998.
[12]
A. Svatikova, R. Wolk, A. S. Gami, M. Pohanka, and V. K. Somers, “Interactions between obstructive sleep apnea and the metabolic syndrome,” Current Diabetes Reports, vol. 5, no. 1, pp. 53–58, 2005.
[13]
N. Meslier, F. Gagnadoux, P. Giraud et al., “Impaired glucose-insulin metabolism in males with obstructive sleep apnoea syndrome,” European Respiratory Journal, vol. 22, no. 1, pp. 156–160, 2003.
[14]
T. Young, P. E. Peppard, and D. J. Gottlieb, “Epidemiology of obstructive sleep apnea: a population health perspective,” American Journal of Respiratory and Critical Care Medicine, vol. 165, no. 9, pp. 1217–1239, 2002.
[15]
T. Young, J. Skatrud, and P. E. Peppard, “Risk Factors for Obstructive Sleep Apnea in Adults,” Journal of the American Medical Association, vol. 291, no. 16, pp. 2013–2016, 2004.
[16]
T. Young, P. E. Peppard, and S. Taheri, “Excess weight and sleep-disordered breathing,” Journal of Applied Physiology, vol. 99, no. 4, pp. 1592–1599, 2005.
[17]
K. Sutherland, R. W. W. Lee, C. L. Phillips et al., “Effect of weight loss on upper airway size and facial fat in men with obstructive sleep apnoea,” Thorax, vol. 66, no. 9, pp. 797–803, 2011.
[18]
J. Durán, et al., “Obstructive sleep apnea-hypopnea and related clinical features in a population-based sample of subjects aged 30 to 70 yr,” American Journal of Respiratory and Critical Care Medicine, vol. 163, no. 3, pp. 685–689, 2001.
[19]
O. Resta, M. P. Foschino-Barbaro, G. Legari et al., “Sleep-related breathing disorders, loud snoring and excessive daytime sleepiness in obese subjects,” International Journal of Obesity, vol. 25, no. 5, pp. 669–675, 2001.
[20]
M. Valencia-Flores, A. Orea, V. A. Casta？o et al., “Prevalence of sleep apnea and electrocardiographic disturbances in morbidly obese patients,” Obesity Research, vol. 8, no. 3, pp. 262–269, 2000.
[21]
D. M. Hiestand, P. Britz, M. Goldman, and B. Phillips, “Prevalence of symptoms and risk of sleep apnea in the US population: results from the National Sleep Foundation Sleep in America 2005 Poll,” Chest, vol. 130, no. 3, pp. 780–786, 2006.
[22]
T. Young, E. Shahar, F. J. Nieto et al., “Predictors of sleep-disordered breathing in community-dwelling adults: the Sleep Heart Health Study,” Archives of Internal Medicine, vol. 162, no. 8, pp. 893–900, 2002.
[23]
P. E. Peppard, T. Young, M. Palta, J. Dempsey, and J. Skatrud, “Longitudinal study of moderate weight change and sleep-disordered breathing,” Journal of the American Medical Association, vol. 284, no. 23, pp. 3015–3021, 2000.
[24]
A. B. Newman, G. Foster, R. Givelber, F. J. Nieto, S. Redline, and T. Young, “Progression and regression of sleep-disordered breathing with changes in weight: the Sleep Heart Health Study,” Archives of Internal Medicine, vol. 165, no. 20, pp. 2408–2413, 2005.
[25]
P. V. Tishler, E. K. Larkin, M. D. Schluchter, and S. Redline, “Incidence of sleep-disordered breathing in an urban adult population: the relative importance of risk factors in the development of sleep-disordered breathing,” Journal of the American Medical Association, vol. 289, no. 17, pp. 2230–2237, 2003.
[26]
J. R. Stradling and J. H. Crosby, “Predictors and prevalence of obstructive sleep apnoea and snoring in 1001 middle aged men,” Thorax, vol. 46, no. 2, pp. 85–90, 1991.
[27]
L. Ferini-Strambi, M. Zucconi, S. Palazzi et al., “Snoring and nocturnal oxygen desaturations in an Italian middle-aged male population: epidemiologic study with an ambulatory device,” Chest, vol. 105, no. 6, pp. 1759–1764, 1994.
[28]
R. J. O. Davies, N. J. Ali, and J. R. Stradling, “Neck circumference and other clinical features in the diagnosis of the obstructive sleep apnoea syndrome,” Thorax, vol. 47, no. 2, pp. 101–105, 1992.
[29]
R. Grunstein, et al., “Snoring and sleep apnoea in men: association with central obesity and hypertension,” International Journal of Obesity, vol. 17, no. 9, pp. 533–540, 1993.
[30]
A. N. Vgontzas, “Does obesity play a major role in the pathogenesis of sleep apnoea and its associated manifestations via inflammation, visceral adiposity, and insulin resistance?” Archives of Physiology and Biochemistry, vol. 114, no. 4, pp. 211–223, 2008.
[31]
E. Shinohara, S. Kihara, S. Yamashita et al., “Visceral fat accumulation as an important risk factor for obstructive sleep apnoea syndrome in obese subjects,” Journal of Internal Medicine, vol. 241, no. 1, pp. 11–18, 1997.
[32]
K. E. Shelton, H. Woodson, S. Gay, and P. M. Suratt, “Pharyngeal fat in obstructive sleep apnea,” American Review of Respiratory Disease, vol. 148, no. 2, pp. 462–466, 1993.
[33]
R. J. Schwab, M. Pasirstein, R. Pierson et al., “Identification of upper airway anatomic risk factors for obstructive sleep apnea with volumetric magnetic resonance imaging,” American Journal of Respiratory and Critical Care Medicine, vol. 168, no. 5, pp. 522–530, 2003.
[34]
S. P. Patil, H. Schneider, A. R. Schwartz, and P. L. Smith, “Adult obstructive sleep apnea: pathophysiology and diagnosis,” Chest, vol. 132, no. 1, pp. 325–337, 2007.
[35]
A. R. Schwartz, S. P. Patil, A. M. Laffan, V. Polotsky, H. Schneider, and P. L. Smith, “Obesity and obstructive sleep apnea: pathogenic mechanisms and therapeutic approaches,” Proceedings of the American Thoracic Society, vol. 5, no. 2, pp. 185–192, 2008.
[36]
T. J. T. Sutherland, J. O. Cowan, S. Young et al., “The association between obesity and asthma: interactions between systemic and airway inflammation,” American Journal of Respiratory and Critical Care Medicine, vol. 178, no. 5, pp. 469–475, 2008.
[37]
K. Spiegel, E. Tasali, P. Penev, and E. Van Cauter, “Brief communication: sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite,” Annals of Internal Medicine, vol. 141, no. 11, pp. 846–850, 2004.
[38]
A. Romero-Corral, S. M. Caples, F. Lopez-Jimenez, and V. K. Somers, “Interactions between obesity and obstructive sleep apnea: implications for treatment,” Chest, vol. 137, no. 3, pp. 711–719, 2010.
[39]
P. M. Suratt, R. F. McTier, L. J. Findley, S. L. Pohl, and S. C. Wilhoit, “Effect of very-low-calorie diets with weight loss on obstructive sleep apnea,” American Journal of Clinical Nutrition, vol. 56, no. 1, supplement, pp. 182S–184S, 1992.
[40]
M. Kansanen, E. Vanninen, A. Tuunainen et al., “The effect of a very low-calorie diet-induced weight loss on the severity of obstructive sleep apnoea and autonomic nervous function in obese patients with obstructive sleep apnoea syndrome,” Clinical Physiology, vol. 18, no. 4, pp. 377–385, 1998.
[41]
K. Johansson, M. Neovius, Y. T. Lagerros et al., “Effect of a very low energy diet on moderate and severe obstructive sleep apnoea in obese men: a randomised controlled trial,” British Medical Journal, vol. 339, article b4609, 2009.
[42]
K. Johansson, E. Hemmingsson, R. Harlid et al., “Longer term effects of very low energy diet on obstructive sleep apnoea in cohort derived from randomised controlled trial: prospective observational follow-up study,” British Medical Journal, vol. 342, no. 7809, article d3017, 2011.
[43]
B. Lam, K. Sam, W. Y. W. Mok et al., “Randomised study of three non-surgical treatments in mild to moderate obstructive sleep apnoea,” Thorax, vol. 62, no. 4, pp. 354–359, 2007.
[44]
T. Kemppainen, P. Ruoppi, J. Sepp？ et al., “Effect of weight reduction on rhinometric measurements in overweight patients with obstructive sleep apnea,” American Journal of Rhinology, vol. 22, no. 4, pp. 410–415, 2008.
[45]
M. Barnes, U. R. Goldsworthy, B. A. Cary, and C. J. Hill, “A diet and exercise program to improve clinical outcomes in patients with obstructive sleep apnea—a feasibility study,” Journal of Clinical Sleep Medicine, vol. 5, no. 5, pp. 409–415, 2009.
[46]
H. P. I. Tuomilehto, J. M. Sepp？, M. M. Partinen et al., “Lifestyle intervention with weight reduction: first-line treatment in mild obstructive sleep apnea,” American Journal of Respiratory and Critical Care Medicine, vol. 179, no. 4, pp. 320–327, 2009.
[47]
P. Nerfeldt, B. Y. Nilsson, L. Mayor, J. Uddén, and D. Friberg, “A two-year weight reduction program in obese sleep apnea patients,” Journal of Clinical Sleep Medicine, vol. 6, no. 5, pp. 479–486, 2010.
[48]
S. Kajaste, P. E. Brander, T. Telakivi, M. Partinen, and P. Mustajoki, “A cognitive-behavioral weight reduction program in the treatment of obstructive sleep apnea syndrome with or without initial nasal CPAP: a randomized study,” Sleep Medicine, vol. 5, no. 2, pp. 125–131, 2004.
[49]
J. F. Norman, S. G. Von Essen, R. H. Fuchs, and M. McElligott, “Exercise training effect on obstructive sleep apnea syndrome,” Sleep Research Online, vol. 3, no. 3, pp. 121–129, 2000.
[50]
G. Sampol, X. Mu？oz, M. T. Sagalés et al., “Long-term efficacy of dietary weight loss in sleep apnoea/hypopnoea syndrome,” European Respiratory Journal, vol. 12, no. 5, pp. 1156–1159, 1998.
[51]
S. S. Smith, G. Doyle, T. Pascoe, J. A. Douglas, and G. Jorgensen, “Intention to exercise in patients with obstructive sleep apnea,” Journal of Clinical Sleep Medicine, vol. 3, no. 7, pp. 689–694, 2007.
[52]
M. J. Stock, “Sibutramine: a review of the pharmacology of a novel anti-obesity agent,” International Journal of Obesity, vol. 21, supplement 1, pp. S25–S29, 1997.
[53]
D. Martinez and B. R. Basile, “Sibutramine does not worsen sleep apnea syndrome: a randomized double-blind placebo-controlled study,” Sleep Medicine, vol. 6, no. 5, pp. 467–470, 2005.
[54]
B. J. Yee, C. L. Phillips, D. Banerjee, I. Caterson, J. A. Hedner, and R. R. Grunstein, “The effect of sibutramine-assisted weight loss in men with obstructive sleep apnoea,” International Journal of Obesity, vol. 31, no. 1, pp. 161–168, 2007.
[55]
C. L. Phillips, B. J. Yee, M. I. Trenell et al., “Changes in regional adiposity and cardio-metabolic function following a weight loss program with sibutramine in obese men with obstructive sleep apnea,” Journal of Clinical Sleep Medicine, vol. 5, no. 5, pp. 416–421, 2009.
[56]
A. Ferland, P. Poirier, and F. Sériès, “Sibutramine versus continuous positive airway pressure in obese obstructive sleep apnoea patients,” European Respiratory Journal, vol. 34, no. 3, pp. 694–701, 2009.
[57]
National Collaborating Centre for Primary Care and the Centre for Public Health Excellence at the National Institute for Health and Clinical Excellence, “NICE Clinical Guideline 43 2006 Obesity guidance on the prevention, identification, assessment and management of overweight and obesity in adults and children,” http://www.nice.org.uk/nicemedia/live/11000/30365/30365.pdf.
[58]
G. de Simone and G. D'Addeo, “Sibutramine: balancing weight loss benefit and possible cardiovascular risk,” Nutrition, Metabolism and Cardiovascular Diseases, vol. 18, no. 5, pp. 337–341, 2008.
[59]
A. Ballinger, “Orlistat in the treatment of obesity,” Expert Opinion on Pharmacotherapy, vol. 1, no. 4, pp. 841–847, 2000.
[60]
S. J. Monkhouse, J. D. Morgan, S. E. Bates, and S. A. Norton, “An overview of the management of morbid obesity,” Postgraduate Medical Journal, vol. 85, no. 1010, pp. 678–681, 2009.
[61]
H. Ashrafian, M. Bueter, K. Ahmed et al., “Metabolic surgery: an evolution through bariatric animal models,” Obesity Reviews, vol. 11, no. 12, pp. 907–920, 2010.
[62]
M. Kalra and T. Inge, “Effect of bariatric surgery on obstructive sleep apnoea in adolescents,” Paediatric Respiratory Reviews, vol. 7, no. 4, pp. 260–267, 2006.
[63]
A. D. Rao, H. T. Beng, G. Ramalingam, and A. G. H. Poh, “Obstructive Sleep Apnoea (OSA) patterns in bariatric surgical practice and response of OSA to weight loss after laparoscopic adjustable gastric banding (LAGB),” Annals of the Academy of Medicine Singapore, vol. 38, no. 7, pp. 587–593, 2009.
[64]
R. R. Grunstein, K. Stenl？f, J. A. Hedner, M. Peltonen, K. Karason, and L. Sj？str？m, “Two year reduction in sleep apnea symptoms and associated diabetes incidence after weight loss in severe obesity,” Sleep, vol. 30, no. 6, pp. 703–710, 2007.
[65]
C. Behrens, B. Q. Tang, and B. J. Amson, “Early results of a Canadian laparoscopic sleeve gastrectomy experience,” Canadian Journal of Surgery, vol. 54, no. 2, pp. 138–143, 2011.
[66]
M. Kalra, T. Inge, V. Garcia et al., “Obstructive sleep apnea in extremely overweight adolescents undergoing bariatric surgery,” Obesity Research, vol. 13, no. 7, pp. 1175–1179, 2005.
[67]
M. Valencia-Flores, A. Orea, M. Herrera et al., “Effect of bariatric surgery on obstructive sleep apnea and hypopnea syndrome, electrocardiogram, and pulmonary arterial pressure,” Obesity Surgery, vol. 14, no. 6, pp. 755–762, 2004.
[68]
J. J. Omana, S. Q. Nguyen, D. Herron, and S. Kini, “Comparison of comorbidity resolution and improvement between laparoscopic sleeve gastrectomy and laparoscopic adjustable gastric banding,” Surgical Endoscopy and Other Interventional Techniques, vol. 24, no. 10, pp. 2513–2517, 2010.
[69]
K. L. Haines, L. G. Nelson, R. Gonzalez et al., “Objective evidence that bariatric surgery improves obesity-related obstructive sleep apnea,” Surgery, vol. 141, no. 3, pp. 354–358, 2007.
[70]
D. A. Lankford, C. D. Proctor, and R. Richard, “Continuous positive airway pressure (CPAP) changes in bariatric surgery patients undergoing rapid weight loss,” Obesity Surgery, vol. 15, no. 3, pp. 336–341, 2005.
[71]
S. A. Guardiano, J. A. Scott, J. C. Ware, and S. A. Schechner, “The long-term results of gastric bypass on indexes of sleep apnea,” Chest, vol. 124, no. 4, pp. 1615–1619, 2003.
[72]
J. Peiser, P. Lavie, A. Ovnat, and I. Charuzi, “Sleep apnea syndrome in the morbidly obese as an indication for weight reduction surgery,” Annals of Surgery, vol. 199, no. 1, pp. 112–115, 1984.
[73]
C. J. Lettieri, A. H. Eliasson, and D. L. Greenburg, “Persistence of obstructive sleep apnea after surgical weight loss,” Journal of Clinical Sleep Medicine, vol. 4, no. 4, pp. 333–338, 2008.
[74]
S. Rasheid, M. Banasiak, S. F. Gallagher et al., “Gastric bypass is an effective treatment for obstructive sleep apnea in patients with clinically significant obesity,” Obesity Surgery, vol. 13, no. 1, pp. 58–61, 2003.
[75]
J. B. Dixon, L. M. Schachter, and P. E. O'Brien, “Polysomnography before and after weight loss in obese patients with severe sleep apnea,” International Journal of Obesity, vol. 29, no. 9, pp. 1048–1054, 2005.
[76]
G. Pillar, R. Peled, and P. Lavie, “Recurrence of sleep apnea without concomitant weight increase 7.5 years after weight reduction surgery,” Chest, vol. 106, no. 6, pp. 1702–1704, 1994.
[77]
I. Charuzi, P. Lavie, J. Peiser, and R. Peled, “Bariatric surgery in morbidly obese sleep-apnea patients: short- and long-term follow-up,” American Journal of Clinical Nutrition, vol. 55, no. 2, supplement, pp. 594S–596S, 1992.
[78]
L. G. Fritscher, S. Canani, C. C. Mottin et al., “Bariatric surgery in the treatment of obstructive sleep apnea in morbidly obese patients,” Respiration, vol. 74, no. 6, pp. 647–652, 2007.
[79]
C. Poitou, M. Coupaye, J. P. Laaban et al., “Serum amyloid A and obstructive sleep apnea syndrome before and after surgically-induced weight loss in morbidly obese subjects,” Obesity Surgery, vol. 16, no. 11, pp. 1475–1481, 2006.
[80]
L. Busetto, G. Enzi, E. M. Inelmen et al., “Obstructive sleep apnea syndrome in morbid obesity: effects of intragastric balloon,” Chest, vol. 128, no. 2, pp. 618–623, 2005.
[81]
C. Martí-Valeri, A. Sabaté, C. Masdevall, and A. Dalmau, “Improvement of associated respiratory problems in morbidly obese patients after open Roux-en-Y gastric bypass,” Obesity Surgery, vol. 17, no. 8, pp. 1102–1110, 2007.
[82]
I. Charuzi, A. Ovnat, and J. Peiser, “The effect of surgical weight reduction on sleep quality in obesity-related sleep apnea syndrome,” Surgery, vol. 97, no. 5, pp. 535–538, 1985.
[83]
J. B. Dixon, L. M. Schachter, and P. E. O'Brien, “Sleep disturbance and obesity: changes following surgically induced weight loss,” Archives of Internal Medicine, vol. 161, no. 1, pp. 102–106, 2001.
[84]
A. Dhabuwala, R. J. Cannan, and R. S. Stubbs, “Improvement in co-morbidities following weight loss from gastric bypass surgery,” Obesity Surgery, vol. 10, no. 5, pp. 428–435, 2000.
[85]
N. V. Christou, D. Look, and L. D. MacLean, “Weight gain after short- and long-limb gastric bypass in patients followed for longer than 10 years,” Annals of Surgery, vol. 244, no. 5, pp. 734–740, 2006.
[86]
C. W. Lee, J. J. Kelly, and W. Y. Wassef, “Complications of bariatric surgery,” Current Opinion in Gastroenterology, vol. 23, no. 6, pp. 636–643, 2007.
[87]
H. Buchwald, R. Estok, K. Fahrbach, D. Banel, and I. Sledge, “Trends in mortality in bariatric surgery: a systematic review and meta-analysis,” Surgery, vol. 142, no. 4, pp. 621–635, 2007.
[88]
T. L. Vasquez and K. Hoddinott, “A potential complication of bi-level positive airway pressure after gastric bypass surgery,” Obesity Surgery, vol. 14, no. 2, pp. 282–284, 2004.
[89]
P. M. Suratt, R. F. McTier, L. J. Findley, S. L. Pohl, and S. C. Wilhoit, “Changes in breathing and the pharynx after weight loss in obstructive sleep apnea,” Chest, vol. 92, no. 4, pp. 631–637, 1987.
[90]
I. Rubinstein, N. Colapinto, L. E. Rotstein, I. G. Brown, and V. Hoffstein, “Improvement in upper airway function after weight loss in patients with obstructive sleep apnea,” American Review of Respiratory Disease, vol. 138, no. 5, pp. 1192–1195, 1988.
[91]
A. R. Schwartz, A. R. Gold, N. Schubert et al., “Effect of weight loss on upper airway collapsibility in obstructive sleep apnea,” American Review of Respiratory Disease, vol. 144, no. 3, pp. 494–498, 1991.
[92]
L. Largerstrand and S. Rossner, “Effects of weight loss on pulmonary function in obese men with obstructive sleep apnoea syndrome,” Journal of Internal Medicine, vol. 234, no. 3, pp. 245–247, 1993.
[93]
R. Pasquali, P. Celella, F. Cirignotta et al., “Treatment of obese patients with obstructive sleep apnea syndrome (OSAS): effect of weight loss and interference of otorhinolaryngoiatric pathology,” International Journal of Obesity, vol. 14, no. 3, pp. 207–217, 1990.
[94]
G. D. Foster, K. E. Borradaile, M. H. Sanders et al., “A randomized study on the effect of weight loss on obstructive sleep apnea among obese patients with type 2 diabetes: the sleep AHEAD study,” Archives of Internal Medicine, vol. 169, no. 17, pp. 1619–1626, 2009.
