Basal sympathetic predominance in periodic limb movements in sleep with obstructive sleep apnea

Because the impact of periodic limb movements in sleep (PLMS) is controversial, no consensus has been reached on the therapeutic strategy for PLMS in obstructive sleep apnea (OSA). To verify the hypothesis that PLMS is related to a negative impact on the cardiovascular system in OSA patients, this study investigated the basal autonomic regulation by heart rate variability (HRV) analysis. Sixty patients with mild‐to‐moderate OSA who underwent polysomnography (PSG) and completed sleep questionnaires were analysed retrospectively and divided into the PLMS group (n = 30) and the non‐PLMS group (n = 30). Epochs without any sleep events or continuous effects were evaluated using HRV analysis. No significant difference was observed in the demographic data, PSG parameters or sleep questionnaires between the PLMS and non‐PLMS groups, except for age. Patients in the PLMS group had significantly lower normalized high frequency (n‐HF), high frequency (HF), square root of the mean of the sum of the squares of difference between adjacent NN intervals (RMSSD) and standard deviation of all normal to normal intervals index (SDNN‐I), but had a higher normalized low frequency (n‐LF) and LF/HF ratio. There was no significant difference in the Epworth Sleepiness Scale, the Pittsburgh Sleep Quality Index, the Short‐Form 36 and the Hospital Anxiety and Depression Scale between the two groups. After adjustment for confounding variables, PLMS remained an independent predictor of n‐LF (β = 0.0901, P = 0.0081), LF/HF ratio (β = 0.5351, P = 0.0361), RMSSD (β = ?20.1620, P = 0.0455) and n‐HF (β = ?0.0886, P = 0.0134). In conclusion, PLMS is related independently to basal sympathetic predominance and has a potentially negative impact on the cardiovascular system of OSA patients.     

Change in periodic limb movement index during treatment of obstructive sleep apnea with continuous positive airway pressure

STUDY OBJECTIVES: The following hypotheses were investigated: 1) severe obstructive sleep apnea (OSA) can mask concurrent periodic limb movement (PLM) disorder (PLMD), which becomes evident or worsens after treatment with continuous positive airway pressure (CPAP); 2) in patients with mild OSA, PLMs are not masked but may be triggered by subclinical hypopneas or respiratory effort-related arousals and improve after CPAP. DESIGN: Retrospective analysis was performed on 2 polysomnographic studies per patient--1 baseline, the second with CPAP titration. The apnea-hypopnea index (AHI) and PLM index (PLMI) under the 2 conditions were statistically analyzed. SETTING: University hospital sleep disorders center. PATIENTS: Patients were selected if they had a baseline AHI of 5 or greater and CPAP titration resulted in reduced AHI. Also, each needed to have either a PLMI of 5 or greater on baseline PSG or during CPAP titration. Patients who started or discontinued a medication that could affect PLMs after the baseline PSG were excluded. INTERVENTIONS: As clinically indicated, CPAP for OSA. MEASUREMENTS AND RESULTS: Eighty-six patients qualified and were divided into 3 groups based on OSA severity. Significant correlations (P < 0.05) were found between AHI and PLMI on the baseline PSG (-0.50), between AHI on baseline PSG and PLMI on CPAP titration (0.49), and between PLMI on baseline PSG and on CPAP titration (-0.21). The increase in PLMI during CPAP titration in patients with severe OSA was statistically significant (P < 0.001). The PLMI decreased with CPAP in 20 of 86 patients, mostly in the mild OSA subgroup. Regression of post-CPAP reduction of AHI and change in PLMI yielded a significant logarithmic relationship (R2 = 0.3042). CONCLUSIONS: Severity of OSA may determine the effect of CPAP on PLMs. The PLMs may increase in moderate to severe OSA due mainly to "unmasking" of underlying PLMD. The PLMs may decrease in mild OSA post-CPAP due to resolution of PLMs associated with respiratory effort-related arousals. This suggests that PLMs may have more than 1 etiology and may be categorized as spontaneous (as in PLMD) and induced (when secondary to respiratory effort-related arousals).     

Interaction effect of obstructive sleep apnea and periodic limb movements during sleep on heart rate variability

We aimed at assessing cardiac autonomic function by heart rate variability during sleep in patients with obstructive sleep apnea and periodic limb movements during sleep, and to compare it with that of patients with obstructive sleep apnea only, periodic limb movements during sleep only, and controls. We also aimed at investigating the interaction effect between apnea–hypopnea index and periodic limb movement index on heart rate variability. Four groups of patients (n = 42 each, total = 168) were identified based on the presence/absence of obstructive sleep apnea and periodic limb movements during sleep: + obstructive sleep apnea/? periodic limb movements during sleep (5 ≤ apnea–hypopnea index < 30 events per hr), ? obstructive sleep apnea/+ periodic limb movements during sleep (periodic limb movement index > 15 events per hr), + obstructive sleep apnea/+ periodic limb movements during sleep, ? obstructive sleep apnea/? periodic limb movements during sleep (controls). All groups were matched for age, sex and body mass index. Time‐ and frequency‐domain heart rate variability measures were calculated over 5‐min periods of stable stage 2 non‐rapid eye movement sleep. In patients with both obstructive sleep apnea and periodic limb movements during sleep, LFnu and LF/HF ratio were higher than in those with obstructive sleep apnea only, periodic limb movements during sleep only, and controls, while HFnu was the lowest among the four groups. LFnu, HFnu and LF/HF ratio were significantly and independently associated with minimal oxygen saturation in the + obstructive sleep apnea/+ periodic limb movements during sleep group. There was a significant interaction effect between apnea–hypopnea index and periodic limb movement index on LF/HF ratio (p = 0.038) in patients with obstructive sleep apnea. Patients with elevated apnea–hypopnea index and elevated periodic limb movement index exhibited higher sympathovagal balance compared with those with high apnea–hypopnea index and low periodic limb movement index, and compared with those with low apnea–hypopnea index (regardless of periodic limb movement index). Increased sympathetic activation and decreased parasympathetic control appear to be related to the severity of oxygen desaturation. Apnea–hypopnea index and periodic limb movement index had interactive effects on increased sympathovagal balance in patients with obstructive sleep apnea.     

Cognitive and behavioral anomalies among insomnia patients with mixed restless legs and periodic limb movement disorder

This study examined whether patients who have periodic limb movement disorder (PLMD), with or without comorbid restless legs syndrome (RLS), display the sleep-disruptive cognitive and behavioral anomalies found among primary insomnia sufferers. Archival data from a Sleep History Questionnaire, home-based polysomnography, and a sleep log were obtained for matched RLS/PLMD, primary insomnia, and noncomplaining volunteer samples. Statistical comparisons showed that the RLS/PLMD and primary insomnia samples differed significantly from the normal sleepers in regard to their propensities for certain sleep disruptive habits, perceived difficulties controlling pre-sleep cognitive activity, and their subjective sleep appraisals. These findings suggest RLS/PLMD patients display many of the cognitive and behavioral anomalies thought to perpetuate primary insomnia. Hence, behavioral interventions may be warranted for RLS/PLMD patients.     

Periodic limb movement disorder of sleep in children

To characterize periodic limb movement disorder (PLMD) in a cohort of prepubertal children we examined sleep-related identifiable differences between children with PLMD and attention-deficit/hyperactivity disorder (ADHD), PLMD alone, and age-matched controls. Children were selected from a chart review of all children referred to a pediatric sleep medicine center and from a community survey of 5-7-year-old-children. Polysomnography (PSG) and parental report data from all children identified as having periodic limb movement index (PLMI) >5 were reviewed and compared with a cohort of age-matched controls. A total of 8.4% of children in the clinic-referred sample, and 11.9% of the children recruited from the community had PLMI >5. Of those, 44.4% were identified as having ADHD. Children with PLMD had significantly lower percentage of rapid eye movement (REM) than control children (P < 0.001). Children in the PLMD/ADHD group had a significantly greater number of arousals associated with PLM (PLMa) than children with PLMD only (P < 0.05). While a relationship between ADHD and PLMD was observed, it was weaker than previous reports (Chervin, R. D. et al. Sleep, 2002; 25: 213; Chervin, R. D. and Archbold, K. H. Sleep, 2001; 24: 313; Picchietti et al. J. Child Neurol., 1999; 13: 588; Picchietti et al. Mov. Disord., 1999; 14: 1000; Picchietti and Walters Sleep, 1999; 22: 297). Children in the PLMD/ADHD group were more likely to have PLMas than were children with PLMD only. We postulate that rather than a direct relationship between ADHD and PLMD, this link may be mediated by the presence of reduced REM sleep and more importantly by the sleep fragmentation associated with PLM-induced arousals.     

Moderate to severe periodic limb movement disorder in childhood and adolescence.

The purpose of this study is to review clinical features of children with moderate to severe Periodic Limb Movement Disorder (PLMD). Because of our interest in both Restless Legs Syndrome (RLS) and Attention-Deficit Hyperactivity Disorder (ADHD), many of our patients had one or both of these conditions. We did a retrospective review of 129 children and adolescents who were found to have Periodic Limb Movements in Sleep (PLMS) > 5/hour of sleep. Sixty five had PLMS of 5-10/hour of sleep, 48 had PLMS of 10-25/hour of sleep and 16 had PLMS > 25/hour of sleep. One hundred and seventeen of the original 129 had ADHD. Stimulant medication did not seem to play a role in the production of PLMS. In only 25 of the 129 cases did parents note the presence of PLMS before being specifically asked to look, and even after specific instructions to look, PLMS were not noted by the parents in 39 patients. The sub-group of 16 children and adolescents--6 female, 10 male (average age 11.1 years--range 6-17 years) with moderate to severe PLMS > 25/hour of sleep are described in more detail. Fifteen of the 16 patients had ADHD. Four of the 16 had RLS and 10 of 13 patients for whom a family history was available had a parent with RLS. Two of the 16 patients had their PLMS initially misdiagnosed as seizures. Sleep disturbance was present in all 16 patients and 7 of the 16 had daytime somnolence which resolved with dopaminergic medications. To our knowledge this is the first clinical series of moderate to severe PLMS in children and adolescents to be fully described in the literature.     

Neural alterations and depressive symptoms in obstructive sleep apnea patients

STUDY OBJECTIVES: Depressive symptoms are common in obstructive sleep apnea (OSA) patients, and brain injury occurs with both OSA and depression independently. The objective was to determine whether brain alterations in OSA bear relationships to depressive symptoms. DESIGN: Cross-sectional study. SETTING: University-based medical center. PARTICIPANTS: 40 treatment-naive OSA subjects and 61 control subjects without diagnosed psychopathology. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Whole-brain maps of T2 relaxation time, a measure sensitive to injury, were calculated from magnetic resonance images, transformed to common space, and smoothed. Control and OSA groups were classified by Beck Depression Inventory (BDI)-II scores (> or =12 symptomatic, <10 asymptomatic for depressive symptoms). The OSA group separated into 13 symptomatic (mean +/- SD: BDI-II 21 +/- 8; age 47.6 +/- 11; apnea hypopnea index [AHI] 28.3 +/- 17), and 27 asymptomatic (4 +/- 3; 47.5 +/- 8; 31.5 +/- 16) subjects. The control group included 56 asymptomatic (BDI-II 2.5 +/- 2.6; age 47.3 +/- 9) subjects. Asymptomatic OSA subjects exhibited higher AHI. T2 maps were compared between groups (ANCOVA), with age and gender as covariates. Injury appeared in symptomatic vs asymptomatic OSA subjects in the mid- and anterior cingulate, anterior insular, medial pre-frontal, parietal, and left ventrolateral temporal cortices, left caudate nucleus, and internal capsule. Relative to asymptomatic controls, symptomatic OSA patients showed damage in the bilateral hippocampus and caudate nuclei, anterior corpus callosum, right anterior thalamus, and medial pons. CONCLUSIONS: Neural injury differed between OSA patients with and without depressive symptoms. Depressive symptoms may exacerbate injury accompanying OSA, or introduce additional damage in affective, cognitive, respiratory, and autonomic control regions.     

Depressive symptoms in patients with obstructive sleep apnea: biological mechanistic pathways

This study examined the association between depressive symptoms, as well as depressive symptom dimensions, and three candidate biological pathways linking them to Obstructive sleep apnea (OSA): (1) inflammation; (2) circulating leptin; and (3) intermittent hypoxemia. Participants included 181 obese adults with moderate-to-severe OSA enrolled in the Cardiovascular Consequences of Sleep Apnea (COSA) trial. Depressive symptoms were measured using the Beck Depression Inventory-II (BDI-II). We assessed inflammation using C-reactive protein levels (CRP), circulating leptin by radioimmunoassay using a double antibody/PEG assay, and intermittent hypoxemia by the percentage of sleep time each patient had below 90% oxyhemoglobin saturation. We found no significant associations between BDI-II total or cognitive scores and CRP, leptin, or percentage of sleep time below 90% oxyhemoglobin saturation after controlling for relevant confounding factors. Somatic symptoms, however, were positively associated with percentage of sleep time below 90% saturation (β = 0.202, P = 0.032), but not with CRP or circulating leptin in adjusted models. Another significant predictor of depressive symptoms included sleep efficiency (β_{BDI Total} = ?0.230, P = 0.003; β_cognitive = ?0.173, P = 0.030 (β_somatic = -0.255, P = 0.001). In patients with moderate-to-severe OSA, intermittent hypoxia may play a role in somatic rather than cognitive or total depressive symptoms.     

Autobiographical memory impairment in obstructive sleep apnea patients with and without depressive symptoms

Obstructive sleep apnea is associated with memory impairments, and higher rates of depressive symptoms and major depressive disorder compared with community estimates. Autobiographical memory overgenerality, a behaviour characterized by difficulty recalling specific memories from one's own life, is recognized as a marker of depression. Previous studies have demonstrated the predictive quality of specific autobiographical memory recall on the course of depression in patients with obstructive sleep apnea. However, it remains unclear whether impaired autobiographical memory is simply a feature of depression, or whether it is also impaired in patients with obstructive sleep apnea without depression. This study aimed to investigate whether autobiographical memory impairments can be observed in patients with obstructive sleep apnea, independent of the severity of depressive symptoms. Twenty‐one patients with obstructive sleep apnea symptomatic for depressive symptoms (mean age = 43.43 years, SD = 9.97), 17 patients with obstructive sleep apnea asymptomatic for depressive symptoms (mean age = 40.65 years, SD = 9.39), and 20 healthy controls without sleep‐disordered breathing (mean age = 32.80 years, SD = 6.69) completed an Autobiographical Memory Test. Patients with obstructive sleep apnea symptomatic for depressive symptoms recalled significantly fewer specific memories when compared with healthy controls (P = 0.010). No difference in the recall of specific autobiographical memory was observed between symptomatic and asymptomatic patients with obstructive sleep apnea. With regard to valence, symptomatic patients with obstructive sleep apnea recalled significantly fewer negative specific memories when compared with controls (P = 0.010). Impairment in specific autobiographical memory recall can be observed in patients with obstructive sleep apnea, regardless of the severity of depressive symptoms; however, this effect may not be as prominent in younger patients with obstructive sleep apnea.     

Narcolepsy-like symptoms in a patient with down syndrome and without obstructive sleep apnea

OBJECTIVE: The study reports on a 33-year-old Caucasian female with Down syndrome and narcolepsy-like symptoms. METHOD: After medical and genetic screening, docturnal polysomnography followed by a Multiple Sleep Latency Test and HLA typing were performed. The patient was medication free and reported a number of cataplexy attacks everyday. Each time that she came to the sleep disorders clinic, she was observed to have cataplexy. She also felt extremely drowsy. A mean sleep latency of 8.8 minutes with 4 sleep-onset rapid eye movement periods in the Multiple Sleep Latency Test, with no other sleep disorder that accounts for the symptoms, was obtained. The patient was DQB1*0301, DQB1*0602, as revealed by the last high-resolution serologic typing.     

Parent-reported periodic limb movement, sleep disordered breathing, bedtime resistance behaviors, and ADHD

The purpose of this study was to compare the relative strength of association between symptoms of attention deficit/hyperactivity disorder (ADHD) with sleep disordered breathing (SDB), periodic limb movement disorder (PLMD), and bedtime resistance behaviors (BRBs). The Pediatric Sleep Questionnaire was completed by parents of 283 children. Scales were derived to indicate risk for specific sleep disorders, then correlated with symptoms of ADHD. Strong independent interrelationships between symptoms of PLMD and symptoms of ADHD emerged, with potential additional contributions by bedtime resistance. These interrelationships remained after controlling for age, SDB, sleepiness, or BRBs. These data suggest ADHD symptoms may be especially related to PLMD but that insufficient sleep duration secondary to bedtime resistance and noncompliance may make an independent contribution.     

Mechanisms of reduced sleepiness symptoms in heart failure and obstructive sleep apnea

Patients with both heart failure and obstructive sleep apnea often have poor, repeatedly disrupted sleep, and yet they frequently do not complain of excessive daytime sleepiness. Understanding this lack of perceived sleepiness is crucial for the case identification and treatment of obstructive sleep apnea in the heart failure population at high risk of this disease, especially given the association between untreated obstructive sleep apnea and mortality among patients with heart failure. In this review, we present epidemiologic evidence concerning the lack of sleepiness symptoms in heart failure and obstructive sleep apnea, explore possible mechanistic explanations for this relationship, assess the benefits of treatment in this population, discuss implications for clinical practice and explore directions for future research.     

Types of coping strategies are associated with increased depressive symptoms in patients with obstructive sleep apnea.

STUDY OBJECTIVES: Some, but not all, researchers report that obstructive sleep apnea (OSA) patients experience increased depressive symptoms. Many psychological symptoms of OSA are explained in part by other OSA comorbidities (age, hypertension, body mass). People who use more passive and less active coping report more depressive symptoms. We examined relationships between coping and depressive symptoms in OSA. SETTING: N/A. DESIGN/PARTICIPANTS: 64 OSA (respiratory disturbance index (RDI) > or = 15) patients were studied with polysomnography and completed Ways of Coping (WC), Profile of Mood States (POMS), Center for Epidemiological Studies-Depression (CESD) scales. WC was consolidated into Approach (active) and Avoidance (passive) factors. Data were analyzed using SPSS 9.0 regression with CESD as the dependent variable and WC Approach and Avoidance as the independent variables. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: WC Approach factor (B=-1.105, beta=-.317, p=.009) was negatively correlated and WC Avoidance factor (B=1.353, beta=.376, p=.007) was positively correlated with CESD scores. These factors explained an additional 8% of CESD variance (p<.001) beyond that explained by the covariates: demographic variables, RDI, and fatigue (as measured by the POMS). CONCLUSIONS: More passive and less active coping was associated with more depressive symptoms in OSA patients. The extent of depression experienced by OSA patients may not be due solely to effects of OSA itself. Choice of coping strategies may help determine who will experience more depressive symptoms.     

Effect of cognitive behavioural therapy for insomnia on sleep architecture and sleep EEG power spectra in psychophysiological insomnia

There is now an overwhelming preponderance of evidence that cognitive behavioural therapy for insomnia (CBT-I) is effective, as effective as sedative hypnotics during acute treatment (4-8 weeks), and is more effective in long term (following treatment). Although the efficacy of CBT-I in the treatment of chronic insomnia is well known, however there is little objective data on the effects of CBT-I on sleep architecture and sleep EEG power densities. The present study evaluated, first, subjective change in sleep quality and quantity, and secondly the modifications occurring in polysomnography and EEG power densities during sleep after 8 weeks of CBT-I. Nine free drug patients with psychophysiological insomnia, aged 33-62 years (mean age 47 +/- 9.7 years), seven female and two male participated in the study. Self-report questionnaires were administered 1 week before and 1 week after CBT-I, a sleep diary was completed each day 1 week before CBT-I, during CBT-I and 1 week after CBT-I. Subjects underwent two consecutive polysomnographic nights before and after CBT-I. Spectral analysis was performed the second night following 16 h of controlled wakefulness. After CBT-I, only scales assessing insomnia were significantly decreased, stages 2, REM sleep and SWS durations were significantly increased. Slow wave activity (SWA) was increased and the SWA decay shortened, beta and sigma activity were reduced. In conclusion CBT-I improves both subjective and objective sleep quality of sleep. CBT-I may enhance sleep pressure and improve homeostatic sleep regulation.     

Effects of exercise training on autonomic modulation and mood symptoms in patients with obstructive sleep apnea

We evaluated the effects of exercise training (ET) on the profile of mood states (POMS), heart rate variability, spontaneous baroreflex sensitivity (BRS), and sleep disturbance severity in patients with obstructive sleep apnea (OSA). Forty-four patients were randomized into 2 groups, 18 patients completed the untrained period and 16 patients completed the exercise training (ET). Beat-to-beat heart rate and blood pressure were simultaneously collected for 5 min at rest. Heart rate variability (RR interval) was assessed in time domain and frequency domain (FFT spectral analysis). BRS was analyzed with the sequence method, and POMS was analyzed across the 6 categories (tension, depression, hostility, vigor, fatigue, and confusion). ET consisted of 3 weekly sessions of aerobic exercise, local strengthening, and stretching exercises (72 sessions, achieved in 40±3.9 weeks). Baseline parameters were similar between groups. The comparisons between groups showed that the changes in apnea-hypopnea index, arousal index, and O₂ desaturation in the exercise group were significantly greater than in the untrained group (P<0.05). The heart rate variability and BRS were significantly higher in the exercise group compared with the untrained group (P<0.05). ET increased peak oxygen uptake (P<0.05) and reduced POMS fatigue (P<0.05). A positive correlation (r=0.60, P<0.02) occurred between changes in the fatigue item and OSA severity. ET improved heart rate variability, BRS, fatigue, and sleep parameters in patients with OSA. These effects were associated with improved sleep parameters, fatigue, and cardiac autonomic modulation, with ET being a possible protective factor against the deleterious effects of hypoxia on these components in patients with OSA.     

MMPI correlates of sleep and respiratory disturbance in obstructive sleep apnea.

STUDY OBJECTIVE: To evaluate associations between polysomnographic variables in obstructive sleep apnea (OSA) and a variety of psychological responses (including depressive symptoms) as assessed by the Minnesota Multiphasic Personality Inventory (MMPI). DESIGN: Cross-sectional. SETTING: University sleep disorders center. PATIENTS: One-hundred seventy eight consecutive clinical OSA patients. INTERVENTIONS: Not applicable. MEASUREMENTS AND RESULTS: Patients completed the MPI prior to overnight diagnostic polysomnography. Fifty-eight percent demonstrated at least one MMPI elevation (mean = 1.8 elevations), with Depression (D) elevated for 32%, Hypochondriasis (Hs) for 30%, and Hysteria (Hy) for 21%. Thirty-eight percent demonstrated two or more elevations, with several variations of Hs-D and Hs-D-Hy configurations evident. "Conversion V" profiles were fairly rare, and a large number of miscellaneous configurations occurred once. Significant correlations were detected between several MMPI scale scores and total sleep time, the apnea-hypopnea index (AHI) during REM, and particularly arterial oxygen saturation, even when partialling out variance related to body mass index (BMI). In contract, D scores were not correlated with any polysomnographic parameters. Based upon MMPI configuration, the sample was subdivided into the following seven profile groups: Nonelevated (n = 74); Single D (n = 11); Single non-D (n = 25); Combined D plus (a) HS or HY (n = 7), (b) Hs and Hy (n = 10), or (c) other (n = 29); and Multiple non-D (n = 22). Multivariate analysis controlling for age and gender indicated higher AHI in the Single non-D, Combined D plus other, and Multiple non-D groups, compared to the Single D group. Also, there was lower average oxygen saturation in the Multiple non-D group, compared to Single D, Single non-D, and Nonelevated groups. The Combined D plus HS and/or Hy groups did not differ from each other or from other groups, even when merged. The Multiple non-D findings were unattributable to any specific scale or overall number of elevations. CONCLUSIONS: OSA patients who have core depressive symptoms (as measured by MMPI scale D) without significant psychological symptoms in other areas tend to have less severe OSA, whereas those with a diverse set of other psychological symptoms overshadowing depressive symptoms (e.g., somatic focus, emotional reactivity, family/marital problems, cognitive problems, etc.) tend to have greater AHI and lower oxygen saturation. Although it seems probable that these MMPI differences primarily reflect OSA effects, prospective research is needed to confirm this hypothesis.     

Occult sleep apnea in a recruited sample of older adults with insomnia.

Although costly polysomnography (PSG) is not routinely performed with people with insomnia, it may be more necessary with recruited older adults with insomnia because this population may pose a greater risk of veiled sleep disorders compared with younger age groups and with referred samples. The present PSG screening of a recruited sample of older adults with insomnia found a 29%-43% rate of undiagnosed sleep apnea (SA), depending on whether an apnea-hypopnea index of 15 or 5 was used, after interviews had already screened out obvious cases of SA. Also, PSGs revealed a 4% rate of occult periodic limb movements. A discriminant analysis identified overweight men reporting dry mouth at highest risk for occult SA, with an apnea-versus-insomnia classification success rate of 78%. Using PSG evaluations in research on insomnia in recruited older adults is requisite to preclude substantial representation of occult SA.     

Prevalence of obstructive sleep apnea symptoms and risk factors in an Armenian population sample

Aim

Obstructive sleep apnea (OSA) is a common medical condition with significant adverse consequences. OSA awareness among the general population and physicians in Armenia is quite low. This study aimed to estimate the prevalence of OSA symptoms and risk factors in Armenia, which has not been investigated so far.

Patients and methods

This was a cross-sectional study of 1,500 randomly selected adults from the capital city and regions of the country. The instrument used to assess the risk of OSA was the Berlin questionnaire.

Results

Of the 1,500 respondents, 44% (49% of men and 37% of women) were identified as being at high risk of OSA. In both genders the risk of OSA increased with age achieving the maximum level of 60% at the age of 50?C69?years and declining to 45% after the age of 70?years. Before the age of 50?years, men were at higher risk of OSA than women (42% vs. 19%, p?<?0.001). After 50 the risk of having OSA was almost the same in men and women (57% vs. 56%).

Conclusion

Almost every second Armenian male and every third female citizen could benefit from evaluation for OSA.