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Background: Gender-related differences in the symptom profile of patients with suspected sleep disordered breathing (SDB) may be one explanation of the clinical underrecognition of SDB in women., Study Objectives: The aim of this study was to prospectively assess gender-related differences in presenting symptoms in a clinical sample of patients with suspected sleep disordered breathing., Design: Administration of the Sleep Disorders Questionnaire prior to clinical and polysomnographic evaluation. Responses obtained from the questionnaire were used to construct 4 independent symptom scales: sleep apnea (SA), periodic limb movement syndrome (PLM), psychiatric sleep disorder (PSY), and narcolepsy (NAR). Analyses of variance were used to examine the effect of gender, AHI, and age on the symptom scales. Associations between gender and each diagnostic scale of the questionnaire were determined by multiple analyses of covariance., Setting: Tertiary pulmonary referral center., Participants: 2739 men and 782 women with suspected SDB. All patients who were referred to the sleep laboratory underwent full-night polysomnography, irrespective of the likelihood of SDB., Interventions: N/A., Measurements and Results: Overall, men scored significantly higher on items related to worsening of snoring/breathing with alcohol (P < 0.001) and smoking history (P < 0.01) than women. Complaints such as witnessed apneas (P < 0.001) and worsening of snoring in supine position (P < 0.05), however, were more frequently reported by men with an apnea-hypopnea index (AHI) < 5/hr, compared with AHI-matched women. There were no significant differences in these items in patients with an AHI > 15/hr. In contrast, women complained significantly more often of insomnia, restless legs, depression, nightmares, palpitations at night, and hallucinations than men. As a result, women had significantly higher scores on the PLM, PSY, and NAR scales of the Sleep Disorders Questionnaire (P < 0.001, for all). After adjustments for age, body mass index, AHI, arousal index, oxygen saturation data, and smoking history, by means of multiple analyses of covariances, gender differences remained significant (P < 0.001, for all scales)., Conclusions: We observed significant gender-related differences in presenting symptoms of patients with sleep disordered breathing at a tertiary level. These differences should be taken into consideration in clinical evaluation of women with suspected sleep disordered breathing.

To estimate reliability of self-reported compliance with nasal continuous positive airway pressure (CPAP) therapy for obstructive sleep apnea (OSA), we studied 63 OSA patients aged 53.7 +/- 1.2 years (mean +/- SEM) with an apnea hypopnea index (AHI) of 50.8 +/- 2.9 and lowest sleep SaO2 of 65.6 +/- 2.3 percent receiving nasal CPAP for 539 +/- 44 days. During a follow-up polysomnography (PSG) on the pressure prescribed for home therapy (10.3 +/- 0.3 cm H2O), the hours of operation shown on the built-in time counter of the patients' devices were read to determine objective compliance by dividing the run time by the days since initiation of therapy. This parameter was compared with subjective compliance reported in a self-administered questionnaire. Mean measured use time was 4.9 +/- 0.3 h per night, whereas reported daily use time calculated from reported nights a week and hours a night was 6.1 +/- 0.3 h per night. As predominantly patients with poor compliance misestimated daily use time, we conclude that self-reports are unable to distinguish between compliant and noncompliant patients.

Background: The high prevalence of obstructive sleep apnoea (OSA) in patients with systemic hypertension and of hypertension in patients with OSA suggests a causal link between the two disorders. This study was carried out to determine whether nasal continuous positive airway pressure (CPAP) and weight loss affect daytime hypertension in OSA., Methods: Sixty hypertensive patients with OSA took part in the study; 33 accepted nasal CPAP and used their machine for 5.7 (0.2) hours per night, and the remaining 27 patients refused nasal CPAP and upper airway surgery so the only therapeutic intervention was a recommendation of weight loss. A significant change in hypertension during follow up was defined as either a change in mean blood pressure of at least 10 mm Hg (or more than 8%) without a change in drug treatment, or a reduction in drug dosage with mean blood pressure within these limits. Weight loss was defined as a body mass index of at least 5% below the baseline value., Results: After 512 (41) days, hypertension had become less severe in seven of 12 patients (58%) treated with weight loss only, in eight of 28 patients (29%) with nasal CPAP only, in two of five patients with nasal CPAP and weight loss, and in one of 15 patients without nasal CPAP or weight loss. Multivariate analysis of variance with the outcome of hypertension at follow up as the dependent variable revealed that only the percentage change in body mass index significantly contributed to the course of hypertension., Conclusion: The course of hypertension in OSA is more closely linked to weight loss than to elimination of sleep apnoea by nasal CPAP.

Background: Overnight polysomnography is expensive and time consuming. An approach based on a logistic regression model and overnight pulse oximetry has been developed to determine which of the snorers referred to our sleep laboratory need polysomnography., Methods: The variables entered in the regression model were derived from questionnaires completed by 95 habitual snorers and 89 patients with obstructive sleep apnoea. The resulting regression equation included weight, height, sex, witnessed episodes of apnoea, and reports of falling asleep when reading. This prediction equation was applied to a sample of 116 consecutive patients referred for investigation of heavy snoring. Pulse oximetry data on the 116 test subjects were obtained during polysomnography and analysed separately. Pulse oximetry was judged to indicate obstructive sleep apnoea when it showed cyclic oscillations of oxyhaemoglobin saturation or heart rate, or both, for more than 30 minutes during the study night., Results: A cut off probability of 0.31 gave the prediction model a sensitivity of 94% to predict an apnoea-hypopnoea index above 10, with a specificity of 45%. When this cutoff point was used to predict an apnoea-hypopnoea index of over 20 sensitivity was 95% and specificity 41%. Combined with oximetry our regression model had a sensitivity of 100% for predicting an apnoea-hypopnoea index of more than 10. On the other hand, all patients with negative results from oximetry and a probability value below 0.31 had an apnoea-hypopnoea index lower than 10 according to polysomnography., Conclusions: It is concluded that snorers with negative results from oximetry classified as not having obstructive sleep apnoea according to this model do not need polysomnography.

To investigate the impact of sleep-disordered breathing events on daytime hypertension (HT) in patients with increased upper airway resistance during sleep, we studied 191 male snorers aged 49.9 +/- 0.8 years. In 116 of them, an apnea-hypopnea index (AHI) above 10--defined as the presence of obstructive sleep apnea (OSA)--was found; the other 75 subjects had an AHI lower than 10 and were classified as habitual snorers (HSN). Prevalence of HT was not different between OSA (56 of 116 = 48 percent) and HSN (33 of 75 = 44 percent) and there was also no difference in systolic, diastolic, and mean blood pressures between the two groups. Hypertensive OSA patients had higher body mass index (BMI) than normotensive OSA subjects (31.4 +/- 0.7 vs 29.4 +/- 0.6; p less than 0.05), but there was no difference in age, AHI, and nocturnal oxygenation parameters. The same was true for the HSN group, with hypertensive subjects being more obese than normotensive subjects (BMI: 30 +/- 0.8 vs 27.3 +/- 0.8; p less than 0.05), but no difference in age and polysomnographic features. Discriminant analysis with HT as the classification variable and age, BMI, AHI, mean, and lowest nocturnal oxyhemoglobin saturation as independent variables, revealed an independent influence on HT only for BMI (F-prob = 0.001). Thus, our results stand against the hypothesis of a causal relationship between sleep-disordered breathing events and daytime hypertension. We conclude that the high prevalence of HT in male snorers is more directly linked to obesity than to sleep apnea, but an independent effect of snoring per se cannot be excluded.

Although NCPAP is the most efficient nonsurgical treatment for patients with OSA, many patients do not accept sleeping with a nose mask. To determine the factors influencing acceptance, treatment with NCPAP was offered to 95 patients with an AHI greater than 15. After the first night on NCPAP, 47 of 65 patients decided to have NCPAP as a home therapy. Excessive daytime sleepiness was more frequently reported by acceptors than refusers. The frequency of complaints about psychomental symptoms such as poor mental performance and bad memory, was not different between the two groups. There was a close correlation between the rate of acceptance and the AHI as well as the number of positive answers to questions about symptoms of daytime sleepiness in a questionnaire, which correlated with the number and length of apneas. Acceptance of NCPAP was found to be dependent on the subjective feeling of impairment by hypersomnolence due to OSA.

To determine whether long-term NCPAP therapy influences severity of sleep disordered breathing during the second part of a night when NCPAP is applied for only the first four hours of sleep, we studied 21 patients with OSA receiving NCPAP therapy for 253 +/- 41.6 days. Results from polysomnography for the period after withdrawal from NCPAP (night B) were compared to the corresponding period of sleep prior to initiation of NCPAP therapy (night A). There was no significant change in RDI from night A (53.9 +/- 8.6) to night B (28.7 +/- 3.3), but maximal apnea length diminished from 55 +/- 2.9 s to 40 +/- 2.9 s (p less than 0.05). Whereas daytime Po2 and the amplitude of desaturations during sleep remained equal, overall oxygenation during sleep improved slightly (mean SaO2 night A = 90.6 +/- 0.9 percent; night B = 92.8 +/- 0.5 percent; p less than 0.05). Differences between nights A and B were more prominent the more severe sleep apnea had been prior to treatment and could not be explained by weight loss. There was strong correlation between improvements in oxygenation measurements and the daily time of NCPAP use. In conclusion, we found a subgroup of OSA patients receiving long-term NCPAP therapy with less disturbed ventilation during sleep following use of NCPAP for only the first part of the night, but in the majority of patients, sleep disordered breathing off NCPAP remained unchanged.

Intermittent snoring and cyclic oscillations of heart rate and oxyhaemoglobin saturation (Sao2) are characteristic features of the obstructive sleep apnoea syndrome (OSAS). Thus, overnight recordings of laryngeal sounds and heart rate by a portable device (MESAM) and of Sao2 by oximetry are applicable to screen outpatients for the presence of OSAS. Computerized analysis for time intervals of constant heart rate and intervals between snoring sounds is used by MESAM to quantify respiratory disturbances during sleep. Rapid increases in Sao2 during the postapnoeic hyperventilation period together with the number of desaturations are used by a new software for quantitative analysis of oximetry. To elucidate reliability of results from automatically scored MESAM and oximetry recordings, we compared the four computer calculated respiratory disturbance indices from heart rate (RDIH), snoring (RDIS), resaturations (RDIR) and desaturations (RDID) with the apnoea plus hypopnoea index (AHI) from simultaneously performed polysomnography. The study population consisted of 53 snorers with an AHI of 19.0 +/- 2.6 (median +/- SEM; range 0.7-87.8). Whereas both RDI's from MESAM correlated rather weakly with the AHI from polysomnography (RDIH: r = 0.32, p less than 0.05; RDIS: r = 0.33, p less than 0.05), this correlation was much better for the RDI's from oximetry (RDIR: r = 0.951, RDID: r = 0.93; p much less than 0.0001). Accepting a plus/minus 30 percent difference from the AHI, the RDIR classified 77% of patients correctly, the RDID 62%, the RDIS 32% and the RDIH 23%. In conclusion, results from computerized analysis of oximetry for desaturations and rapid resaturations correlate more closely with polysomnography than those from automatic scoring of MESAM recordings.

A computerized search for rapid resaturation (RES)--defined as increases in oxyhemoglobin saturation (SaO2) of 3% or more within 10 s--was used to detect apneas and hypopneas during sleep by the episodes of compensatory hyperventilation following them. Results were compared to those from computerized search for desaturations (DESAT)--defined as decreases in SaO2 of 4% or more within 40 s--and to simultaneous polysomnography. We studied 30 patients with obstructive sleep apnea (OSA) with an apnea plus hypopnea index (AHI) of 30.8 +/- 6.9 (median +/- SEM) and 23 habitual snorers (HSN) with an AHI of 7 +/- 1.5. Manual scoring of polysomnography revealed 7965 respiratory events (6192 apneas, 1773 hypopneas) in OSA patients and 940 events (411 apneas, 529 hypopneas) in the HSN group. In OSA patients, the computer found 96% of events by searching for RES and 87% by searching for DESAT. The percentage of computer-found events in OSA classified as true positive was 91% for RES and 97% for DESAT. In the HSN group, 83% of polysomnographically scored events were found by RES and 55% by DESAT, with 72% of RES and 84% of DESAT being true positive. The correlation of the number of computer-found RES with the number of events from polysomnography was better in OSA (r = 0.862, p less than 0.0001) than in HSN (r = 0.722, p less than 0.001). The same was true for DESAT (OSA: r = 0.896, p less than 0.0001; HSN: r = 0.637, p less than 0.01). In conclusion, computer-found rapid resaturations are more sensitive than desaturations for the detection of respiratory events during sleep from oximetry.(ABSTRACT TRUNCATED AT 250 WORDS)

The diagnostic value of flow-volume curves for sleep apnea was studied in 32 patients with obstructive sleep apnea, 40 simple snorers, and 30 healthy nonsnorers. A sawtooth appearance of the flow-volume curve was seen in 22 of the sleep apnea patients (69%), 14 of the simple snorers (35%), and 10 of the nonsnorers (33%). The ratio of midexpiratory flow (FEF 50) to midinspiratory flow (FIF 50) was greater than 1 in 6 of the sleep apnea patients (19%), 3 of the simple snorers (8%), and 2 of the nonsnorers (7%). Thus, only the sawtooth sign was more frequently found in sleep apnea patients than in controls (p less than 0.01). Sleep apnea patients with a sawtooth appearance of the flow-volume curve had a higher apnea index (38.7 +/- 22 vs. 21.5 +/- 12.1; p less than 0.01) and lower nocturnal minimum oxygen saturation (68.1% +/- 16.8 vs. 81.3% +/- 9.97; p less than 0.01) than those without. In symptomatic snorers, sensitivity of the sawtooth sign for sleep apnea was 72% and specificity 61%, for a FEF50/FIF50 ratio above 1 sensitivity was 17% and specificity 83%. In asymptomatic patients, sensitivity of either sign was extremely poor (33%) and specificity was 67% for the sawtooth sign and 85% for FEF50/FIF50 greater than 1. We conclude that abnormal flow-volume curves are of limited value for predicting sleep apnea.

Obstructive sleep apnea is frequently found in middle-aged men. Usually, these patients are obese and therefore predisposed to hypertension. This study aimed to elucidate the relationships between hypertension, obesity and obstructive sleep apnea in 48 men suffering from sleep apnea. Hypertension was found in 39 of them (= 81%), 27 patients (= 56%) were morbidly obese (Broca index above 125%), 17 patients (= 36%) were moderately obese (Broca index between 100 and 125%) and 4 patients (= 8%) showed normal weight (Broca index below 100%). Severity of sleep apnea did not correlate with obesity or hypertension. Patients with sleep apnea who were hypertensive were significantly (p less than 0.025) more obese than those with normal blood pressure. Compared with an unselected population showing a similar degree of obesity, patients with obstructive sleep apnea showed a higher prevalence of hypertension and this is independent of age. These findings establish sleep apnea as a risk factor for hypertension.