Sleep Apnea Syndromes: Kryger M

Fleetham J, Ayas N, Bradley D, Ferguson K, Fitzpatrick M, George C, Hanly P, Hill F, Kimoff J, Kryger M, Morrison D, Series F, Tsai W, Anonymous00098. · Comité des troubles respiratoires du sommeil de la SCT. · Can Respir J. · Pubmed #17315056 links to  free full text

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Fleetham J, Ayas N, Bradley D, Ferguson K, Fitzpatrick M, George C, Hanly P, Hill F, Kimoff J, Kryger M, Morrison D, Series F, Tsai W, Anonymous00045. · Respiratory Medicine, Diamond Health Care Centre, Vancouver, British Columbia V5Z 1M9. · Can Respir J. · Pubmed #17036094 links to  free full text

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Kryger M. · No affiliation provided · Sleep Med Rev. · Pubmed #12531137 No free full text.

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Orr WC, Heading R, Johnson LF, Kryger M. · Lynn Health Science Institute, Oklahoma City, Oklahoma 73112, USA. · Aliment Pharmacol Ther. · Pubmed #15527463 links to  free full text

Abstract: Gastro-oesophageal reflux disease (GERD) is among the most common gastrointestinal conditions in the USA. For most symptomatic patients, reflux events occur during both daytime and night-time hours. Whereas daytime reflux events tend to be frequent but brief, reflux events that occur during sleep are comparatively less frequent but significantly longer. Longer oesophageal acid-clearance and acid-mucosal contact times during sleep are at least partly due to several physiological changes associated with sleep, including dramatic declines in saliva production and frequency of swallowing, decreased conscious perception of heartburn and consequent arousal and clearance behaviours, and slower gastric emptying. Obstructive sleep apnea syndrome and obesity seem to predispose some patients to nocturnal GERD, and the presence of either of these conditions may help to identify patients with symptoms consistent with GERD. Recognition and treatment of night-time GERD are important because it can be associated with decreased quality of life (including sleep disruption) and increased risk of serious oesophageal and respiratory complications.

Kapsimalis F, Varouchakis G, Manousaki A, Daskas S, Nikita D, Kryger M, Gourgoulianis K. · Department of Pulmonary Medicine, Sleep Laboratory, Henry Dunant Hospital, 107 Mesogeion Avenue, Athens, Greece. · Lung. · Pubmed #18365276 No free full text.

Abstract: Obesity is the major confounding factor in the relationship between obstructive sleep apnea and increased risk for cardiovascular disease. The aim of the study was to investigate the association of sleep apnea severity with insulin resistance, leptin, and CRP levels in a cohort of male patients. Sixty-seven men referred to our sleep laboratory for evaluation of suspected obstructive sleep apnea syndrome (OSAS) were divided into three groups according to apnea severity: non-OSAS group (n=15), mild to moderate OSAS group (n=26), and severe OSAS (n=26). Insulin resistance was estimated by the homeostasis model assessment method. HOMA values were similar in the three groups: (3.2+/-2.2 vs. 3.3+/-1.8 vs. 3.6+/-1.5, respectively, p=0.71). Leptin levels were higher in the mild to moderate OSAS group (23.1+/-21.8 ng/ml, p<0.05) and in the severe OSAS group (20.2+/-17.5 ng/ml, p<0.05) than in the non-OSAS group (9.4+/-6.4 ng/ml). CRP levels were significantly higher in severe sleep apnea (0.35+/-0.3 vs. 0.19+/-0.1 mg/dl, p<0.05). In multiple regression analyses, waist-to-hip ratio (WHR) was the most significant determinant of HOMA estimation for insulin resistance. WHR and the percentage of total sleep time spent with hypoxemia (%TST with SaO2 <90%) were significant predictors for leptin levels, while body mass index (BMI) and the %TST with SaO2 <90% were the best predicting parameters for CRP levels. Insulin resistance estimated by the HOMA method in male patients with OSAS was not associated with sleep apnea severity independent of obesity. The severity of nocturnal hypoxemia was associated with leptin and CRP levels independent of obesity.

Kryger M, Wang-Weigand S, Roth T. · Gaylord Hospital, Sleep Research and Education, 400 Gaylord Farm Road, Wallingford, CT 06492, USA. · Sleep Breath. · Pubmed #17294232 No free full text.

Abstract: Ramelteon is a selective MT(1)/MT(2)-receptor agonist indicated for insomnia treatment. Because it has no depressant effects on the nervous system, it is not expected to affect the control of breathing. The potential effects of ramelteon on apneic and hypopneic events and arterial oxygen saturation (SaO(2)) in individuals with obstructive sleep apnea were assessed. In this double-blind, randomized, crossover study, 26 adults with mild to moderate obstructive sleep apnea received ramelteon 16 mg and placebo for one night each, with a 5- to 12-day washout period between treatments. Treatments were administered 30 min before habitual bedtime. Respiratory effort was monitored using respiratory inductance plethysmography, SaO(2) was measured by pulse oximetry, and sleep onset and duration were measured by polysomnography and post-sleep questionnaire. Post-sleep questionnaire also measured next-day residual effects. The primary measure was apnea-hypopnea index. Apnea-hypopnea index was similar in ramelteon and placebo groups (11.4 vs 11.1, respectively; CI = -2.1, 2.6, P = 0.812). Ramelteon had no effect on the number of central, obstructive, or mixed apnea episodes. No significant differences were observed in SaO(2) for the entire night between ramelteon and placebo (95.1 vs 94.7%; P = 0.070). Ramelteon did not meaningfully affect sleep when evaluated by polysomnography and post-sleep questionnaire. Compared with placebo, ramelteon had no significant effect on next-day residual effects. Adverse events were reported by three subjects in the ramelteon group: headache (n = 2) and urinary tract infection (n = 1). No adverse events were reported with placebo. Ramelteon was well-tolerated and, as expected, did not worsen sleep apnea when administered to subjects with mild to moderate obstructive sleep apnea.

Vagiakis E, Kapsimalis F, Lagogianni I, Perraki H, Minaritzoglou A, Alexandropoulou K, Roussos C, Kryger M. · Critical Care and Pulmonary Services, Medical School, Sleep Disorders Center, Evangelismos Hospital, University of Athens, Athens, Greece. · Sleep Med. · Pubmed #16740405 No free full text.

Abstract: BACKGROUND AND PURPOSE: Studies from North American clinics have reported that females with obstructive sleep apnea syndrome (OSAS) are about the same age as males but are heavier, have less severe apnea and make up a much smaller proportion of cases. We examined polysomnographic differences between Greek men and women with OSAS in order to study the influence of gender on clinical presentation and laboratory findings. PATIENTS AND METHODS: This retrospective study included a cohort of 1,010 Greek patients (844 males, 166 females) diagnosed with OSAS by overnight polysomnography (PSG), who were referred to the Sleep Disorders Center of Evangelismos Hospital, Athens Medical School, University of Athens. All patients were studied over a period of three consecutive years, during which time clinical and polysomnography (PSG) findings were compared. RESULTS: Body mass index (BMI) was similar in men and women with OSAS (BMI=31.6+/-5.5kg/m(2) in men versus BMI=32.5+/-8.1 (SD) kg/m(2) in women). Female patients were significantly older than male patients (56.9+/-10.6 versus 50.6+/-11.7 year, P=0.001). The mean apnea-hypopnea index (AHI) during total sleep time was higher in men than in women (42.4+/-28.2 versus 33.2+/-27.7 events/h, P<0.001). The AHI in non-rapid eye movement (NREM) sleep was higher in men than in women (42.9+/-28.9 versus 32.6+/-28.7 events/h, P<0.001), but in rapid eye movement (REM) sleep AHI was similar in men and women (36.0+/-23.3 versus 34.9+/-25.4 events/h). Forty percent of men had AHI-REM sleep >AHI-NREM compared to 62% of women, and the difference between REM and NREM-AHI was significantly less in men than in women (14.21+/-11.18 versus 19.76+/-13.43 events/h, P<0.001)). Several aspects of sleep were worse in women versus men: sleep efficiency index was lower (79.4+/-16.1% versus 85.1+/-12.5%, P<0.001); sleep onset latency (27.7+/-27.7 versus 17.9+/-18.1min, P<0.001), and REM onset latency (161.5+/-76.2 versus 145.7+/-71.4min, P<0.018) were longer; wake time after sleep onset (WASO) was also greater in women (42.6+/-46.5 versus 30.7+/-34.9min, P<0.003). CONCLUSIONS: In Greek subjects with OSAS, there was no difference in BMI, and female patients were significantly older than male patients. OSAS was diagnosed in men five times more often than in women. AHI was greater in men than in women, but women are more likely than men to have a higher AHI in REM than NREM. Sleep quality is worse in female than in male patients.

Singh H, Pollock R, Uhanova J, Kryger M, Hawkins K, Minuk GY. · Section of Hepatology, Department of Medicine University of Manitoba, Winnipeg, Manitoba, Canada. · Dig Dis Sci. · Pubmed #16416185 No free full text.

Abstract: Nonalcoholic fatty liver disease (NAFLD) is a term often used to describe two related conditions: a relatively benign, nonalcoholic fatty liver (NAFL) and potentially aggressive, nonalcoholic steatohepatitis (NASH). Both conditions (NAFL and NASH) occur in the setting of peripheral insulin resistance. Recently, obstructive sleep apnea (OSA) has been proposed as an independent risk factor for insulin resistance. To date, few studies have documented the prevalence of OSA or symptoms of OSA (SOSA) in NAFLD patients. The objectives of this study were (1) to document the prevalence of SOSA in patients with NAFLD and (2) to determine whether prevalence rates for SOSA differ in NAFL versus NASH patients. One hundred ninety biochemically defined NAFLD patients (116 NAFL and 74 NASH), of whom 50 (18 NAFL and 32 NASH) had undergone liver biopsy, completed a Modified Berlin Sleep Apnea Questionnaire for SOSA. Risk factors for NAFLD were also documented in NAFL and NASH patients. Eighty-seven of the 190 (46%) NAFLD patients met questionnaire criteria for SOSA. The prevalence of SOSA was similar in both biochemically (45% versus 49%, respectively; P = 0.66) and histologically (39% versus 63%, respectively; P = 0.11) defined NAFL and NASH patients. Other risk factors for NAFLD such as body mass index, plasma cholesterol and triglyceride levels, and prevalence of diabetes were also similar in the two groups. Approximately one-half of NAFLD patients, whether NAFL or NASH, have SOSA. Further studies are required to determine whether a causal link exists between NAFLD and OSA.

Sassani A, Findley LJ, Kryger M, Goldlust E, George C, Davidson TM. · University of California, San Diego, School of Medicine Department of Radiology, 92103-8765, USA. · Sleep. · Pubmed #15164898 No free full text.

Abstract: STUDY OBJECTIVES: Drivers suffering from obstructive sleep apnea syndrome (OSAS) have an increased risk for being involved in motor-vehicle collisions. This study estimates, for the first time, the annual OSAS-related collisions, costs, and fatalities in the United States and performs a cost-benefit analysis of treating drivers suffering from OSAS with continuous positive airway pressure (CPAP). DESIGN: The MEDLINE-PubMed database (1980 to 2003) was searched for information on OSAS. A meta-analysis was performed of studies investigating the relationship between collisions and OSAS. Data from the National Safety Council were used to estimate OSAS-related collisions, costs, and fatalities and their reduction with treatment. Next, the annual cost of treating OSAS with CPAP was calculated. Finally, multiple 1-way sensitivity analyses were performed. SETTING: N/A. PATIENTS OR PARTICIPANTS: N/A. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: More than 800,000 drivers were involved in OSAS-related motor-vehicle collisions in the year 2000. These collisions cost 15.9 billion dollars and 1,400 lives in the year 2000. In the United States, treating all drivers suffering from OSAS with CPAP would cost 3.18 billion dollars, save 11.1 billion dollars in collision costs, and save 980 lives annually. CONCLUSION: Annually, a small but significant portion of motor-vehicle collisions, costs, and deaths are related to OSAS. With CPAP treatment, most of these collisions, costs, and deaths can be prevented. Treatment of OSAS benefits both the patient and the public.

Brown DJ, Kerr P, Kryger M. · Department of Otolaryngology, University of Manitoba, Winnipeg. · J Otolaryngol. · Pubmed #11771028 No free full text.

Abstract: OBJECTIVE: Radiofrequency volumetric reduction of the palate has been advocated as a treatment for mild sleep-disordered breathing (SDB). Our study examines the efficacy of this procedure on patients with mostly moderate SDB. DESIGN: Prospective, nonrandomized, consecutive series. SETTING: St. Boniface Hospital, Sleep Disorders Centre, University of Manitoba, Winnipeg. METHOD: Twelve patients with polysomnographically proven moderate SDB were given a total of 2400 to 3600 joules of radiofrequency energy to their soft palate over two to three treatments. Follow-up examined the effect of treatment on subjective and objective parameters including the Epworth Sleepiness Scale, loudness of snoring, Apnea-Hypopnea Index (AHI), and Arousal Index. RESULTS: Two of 12 patients had a good objective response to treatment in that their AHI dropped by more than 50% and to a value of less than 20. However, none of the patients claimed to have a satisfactory subjective response. There was a slight reduction in the mean AHI from 31.2+/-5.1 to 25.3+/-4.2 (p < .05), but no clinically significant difference was found between pre- and post-treatment groups with respect to other sleep parameters. There was no improvement in daytime sleepiness or snoring. CONCLUSIONS: Radiofrequency tissue ablation of redundant soft palate tissues lacks clinical efficacy in patients with moderate SDB.

Leslie WD, Wali S, Kryger M. · No affiliation provided · Stroke. · Pubmed #9880413 links to  free full text

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