Increased sodium-proton antiporter activity in patients with obstructive sleep apnoea.
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Cytosolic pH (pH(i)) and the activity of the sodium-proton antiporter (Na(+)/H(+) antiporter) were measured in lymphocytes from 22 patients with obstructive sleep apnoea and from 24 age-matched healthy subjects (Controls). The cellular Na(+)/H(+) antiporter was measured spectrophotometrically using a pH-sensitive fluorescent dye after intracellular acidification using sodium propionate. Resting pHi was similar in lymphocytes from patients with obstructive sleep apnoea and from controls (7.36 +/- 0.20, n=22; vs. 7.35 +/- 0.19, n=24; mean +/- SD). The Na(+)/H(+) antiporter activity was significantly higher in patients with obstructive sleep apnoea than in controls (11.87 +/- 3.26 x 10(-3) pH(i)/s vs. 4.38 +/- 1.40 x 10(-3) pH(i)/s; P < 0. 0001). The apparent affinity of the Na+/H+ antiporter was not significantly different between the groups (6.90 +/- 0.23 vs. 6.87 +/- 0.20). In patients with obstructive sleep apnoea the activity of the Na(+)/H(+) antiporter remained stable during the night. The activity of the Na(+)/H(+) antiporter was 13.49 +/- 4.80 x 10(-3) pH(i)/s at 20.00 and 13.26 +/- 6.13 x 10(-3) pH(i)/s at 02.00. From the present results it is concluded that an increased cellular Na(+)/H(+) antiporter activity may be a genetic marker for patients who are predisposed to obstructive sleep apnoea. (+info)
Excessive daytime sleepiness in patients suffering from different levels of obstructive sleep apnoea syndrome.
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Excessive daytime sleepiness (EDS) is a frequent symptom of patients with obstructive sleep apnoea (OSA). EDS is a high-risk factor for accidents at work and on the road. Thirty untreated patients with different levels of severity of OSA were studied concerning night sleep and EDS. The criterion for severity was the respiratory disturbance index (RDI): 15 patients were classified as 'moderately' apnoeic (RDI < 40), 15 as 'severely' apnoeic (RDI > 40). Following night-time polysomnography, objective and subjective aspects of EDS were studied. To assess objective EDS the Maintenance of Wakefulness Test (MWT) and a computer-based vigilance performance test were used. Subjective EDS was determined using the Stanford Sleepiness Scale (SSS), the Epworth Sleepiness Scale (ESS) and the Visual Analogue Scales for Performance (VAS-P) and Tiredness (VAS-T). Well-being was assessed using the Scale of Well-Being by von Zerssen (Bf-S/Bf-S'). Severe apnoea patients spent more time in stage 1 and less in slow-wave sleep. MWT latencies tended to be shorter in the severe apnoea group. Vigilance testing revealed no group differences. Patients with moderate apnoea described themselves as more impaired in all subjective scales, but only SSS scores reached statistical significance. Our results suggest that there is no simple correlation between polysomnographic and respiratory sleep variables at night on the one hand, and the extent of EDS on the other hand. Furthermore, subjective and objective evaluation of EDS does not yield the same results. New approaches which allow a more detailed analysis of night sleep and daytime function are required to identify high-risked patients. (+info)
Quality of life assessment of treatment with dental appliance or UPPP in patients with mild to moderate obstructive sleep apnoea. A prospective randomized 1-year follow-up study.
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The objectives of this study were: to evaluate the change in the three quality of life (QOL) dimensions of vitality, contentment and sleep before intervention and 1 year after treatment with a dental appliance or uvulopalatopharyngoplasty (UPPP); to compare the effect of treatment between these two treatment groups on these three dimensions; and to determine the relation between the QOL scores and somnographic values. Ninety-five patients with mild to moderate obstructive sleep apnoea (OSA) (AI > 5) were randomly allocated to either a dental appliance or UPPP treatment group. Seven patients withdrew after randomization but before treatment, leaving 88 patients eligible for treatment. The patients were examined using somnography and administered the Minor Symptoms Evaluation-Profile (MSE-P), a QOL questionnaire, before and 1 year after intervention. Thirty-seven patients in the dental appliance group and 43 in the UPPP group completed the 1-year follow-up. The mean values for the three dimensions vitality, contentment and sleep improved significantly 1 year after intervention in the dental appliance and UPPP groups. No difference in the QOL scores at baseline was noted between the groups. One year after intervention the UPPP group showed significantly more contentment than the dental appliance group. In contrast, vitality and sleep dimensions did not differ between the two treatment groups. No significant correlations were observed between the QOL scores and somnographic values. In conclusion, quality of life improved significantly in the dental appliance and UPPP groups 1 year after intervention. However, the dental appliance group showed a lower level of contentment than the UPPP group, even though the somnographic values were superior in the former group. (+info)
Night-time sleep and daytime sleepiness in narcolepsy.
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This report describes night-time sleep and daytime sleepiness in a large (N=530) sample of patients meeting the International Classification of Sleep Disorders criteria for diagnosis of narcolepsy. Sleep data were obtained from polysomnographic recordings on two consecutive nights. Sleepiness was assessed using the Multiple Sleep Latency Test, the Maintenance of Wakefulness Test and the Epworth Sleepiness Scale. Analysis revealed that sleep was mild to moderately disturbed on both recording nights. A first-night effect was suggested by decreased REM latency and increased percentage REM and slow-wave sleep on the second night. Sleepiness and sleep disturbance varied across patient subgroups created based on patient ethnicity and on the presence/absence of cataplexy, sleep apnoea, and periodic limb movements. Covariation of sleep and sleepiness measures across patients was significant but weak. Strong association was found between subgroup means of sleep and sleep disturbance measures. The findings reported here show that sleepiness and sleep disturbance vary across patient subgroups and that sleep disturbance is related to, although unable to account, for the pathological sleepiness of narcolepsy. (+info)
Angiotensin-converting enzyme gene insertion/deletion (I/D) polymorphism in hypertensive patients with different degrees of obstructive sleep apnea.
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To investigate the role of the angiotensin-converting enzyme gene (ACE) insertion (I)/deletion (D) polymorphism in hypertensive patients with different degrees of obstructive sleep apnea (OSA). A case-control study was performed. One hundred seventy four Chinese subjects were divided into four groups depending on the severity of OSA as follows: 1) normal control group (NC, n=68), 2) isolated hypertension group (HT, n=45), 3) hypertensive patients with mild OSA group (MO, n=27), and 4) hypertensive patients with moderate to severe OSA group (MSO, n=34). The distribution of ACE gene I/D allele and genotypes were analyzed in the subject population, as was an OSA pedigree. The study showed that the frequency of ACE gene I/D polymorphism differed significantly among the four groups. The frequency of I allele and II genotype were significantly higher in the MSO group than in the other groups (p<0.05). The distribution of I allele and II genotype showed no significant difference between any of the other groups (p>0.05, respectively). Meanwhile the higher frequency of I allele and II genotype was observed in the OSA pedigree. The higher frequency of ACE gene I allele and II genotype were closely associated with the hypertensive patients with MSO. The inherited factors played an important role in the pathogenesis of hypertensive patients with MSO. (+info)
Endogenous digitalislike factors in obstructive sleep apnea.
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Recent studies have provided evidence that hypoxia may stimulate the release of endogenous digitalislike factors (EDLF). Obstructive sleep apnea (OSA) is characterized by intermittent hypoxia during sleep and may be associated with sympathetic activation and a high risk of developing hypertension. This study was designed to measure EDLF in the plasma of patients with OSA diagnosed by polysomnography, with patients being classified by the number of apneic-hypopneic episodes/h sleep (apnea-hypopnea index, AHI). Plasma was obtained in the morning from 8 male normotensive OSA patients (OSA-N) (AHI 70+/-6), 2 untreated hypertensive OSA patients (OSA-HT), and 11 age-matched healthy male controls (C). EDLFs of different hydrophobicities were separated from the same plasma sample by solid-state C18-cartridges with 25% acetonitrile (ACN) (EDLF-1) followed by 40% ACN (EDLF-2). This procedure recovered ouabain in the first fraction and digoxin and digoxigenin in the second. EDLF was quantified in pM ouabain-equivalents by a human placenta radioreceptor assay. EDLF-1 levels were similar for OSA-N and C (231+/-55 vs. 258+/-58), whereas EDLF-2 levels were increased in OSA-N (244+/-51 vs. 110+/-25 in C, p=0.02). Norepinephrine was increased in apneics. The two OSA-HT had EDLF and norepinephrine levels similar to OSA-N. These preliminary results suggest that OSA is associated with an increase in the more hydrophobic EDLF levels in both normotensive and hypertensive states. No significant increase was found for the less hydrophobic ouabain-like EDLF. (+info)
Influence of chronic barbiturate administration on sleep apnea after hypersomnia presentation: case study.
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When sleepiness is excessive, undesirable, inappropriate or unexplained, it often indicates a clinical disorder that is generically termed hypersomnia. One of the leading causes of hypersomnia is sleep apnea. We present the case of a 44-year-old woman with a history of bipolar spectrum disorder and epilepsy who initially showed evidence of hypersomnia. The hypersomnia settled with changes to her medication, but the patient was subsequently found to have severe obstructive sleep apnea. The relation between the patient's medication and sleep apnea is discussed, and the possible respiratory-suppressant effects of chronic barbiturate treatment are considered. The role of other evoking factors within the context of this case and the mechanisms by which drug interactions and psychotropic treatment may worsen, obscure or perpetuate sleep apnea are also examined. (+info)
A cephalometric comparison of subjects with snoring and obstructive sleep apnoea.
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This prospective study analysed the upright lateral cephalometric radiographs of 115 dentate, Caucasian males. Forty-five subjects exhibited proven obstructive sleep apnoea (OSA), 46 were simple snorers, and the remaining 24 subjects, who had no history of respiratory disease and did not snore, acted as controls. Radiographs were traced and digitized, and comparisons were made of the dento-skeletal, soft tissue, and oropharyngeal features of the three groups. Differences were also sought between the snoring and OSA subjects. Of the hard tissue measurements, only the cranial base angle and mandibular body length showed significant inter-group differences (P < 0.001 and P < 0.05, respectively). When the airway and associated structures were examined, both snorers and OSA subjects exhibited narrower airways, reduced oropharyngeal areas, shorter and thicker soft palates, and larger tongues than their control counterparts. Comparison of the two sleep disordered breathing groups showed no differences in any of the skeletal or dental variables examined. However in OSA subjects, the soft palate was larger and thicker (P < 0.05), both lingual and oropharyngeal areas were increased (P < 0.01 and P < 0.05, respectively) and the hyoid was further from the mandibular plane (P < 0.05). Thus, whilst the dento-skeletal patterns of snorers resembled those of subjects with OSA, some differences in soft tissue and hyoid orientation were apparent. There was not, however, a recognizable gradation in size of the airway and its associated structures from control through snoring to OSA subjects. This suggests that there may be a cephalometrically recognizable predisposition towards the development of sleep disordered breathing, but that this is only one facet of the condition. (+info)