Prevalence of moderate or severe left ventricular diastolic dysfunction in obese persons with obstructive sleep apnea

We investigated prior to gastric bypass surgery the prevalence of left ventricular diastolic dysfunction (LVDD) by Doppler and tissue Doppler echocardiography in 14 obese women and in 6 obese men, mean age 45 years, with a mean body mass index of 49+/-5 kg/m2 who had nocturnal polysomnography for obstructive sleep apnea (OSA). The Doppler and tissue Doppler echocardiographic data were analyzed blindly without knowledge of the clinical characteristics or whether OSA was present or absent. Of 20 patients, 8 (40%) had no OSA, 4 (20%) had mild OSA, and 8 (40%) had moderate or severe OSA. Moderate or severe LVDD was present in 4 of 8 patients (50%) with moderate or severe OSA and in none of 12 patients (0%) with no or mild OSA (p<0.01). Obese patients with moderate or severe OSA have a higher prevalence of moderate or severe LVDD than obese patients with no or mild OSA.     

Left ventricular hypertrophy and abnormal ventricular geometry in children and adolescents with obstructive sleep apnea

Obstructive sleep apnea (OSA) has been shown to be an independent risk factor for cardiovascular disease in adults. However, there are severe limitations in the extent to which the cardiovascular consequences of OSA are being studied in children. To investigate the echocardiographic changes in children with OSA, right and left ventricular (RV, LV) dimensions and LV mass index and geometry were measured in 28 children with OSA and 19 children with primary snoring (PS). The study showed that LV mass index and relative wall thickness were greater in the OSA group compared with those with PS (p = 0.012 and p < 0.0001, respectively). An apnea-hypopnea index of more than 10 per hour was significantly associated with RV dimension above the 95th percentile (odds ratios, 6.7; 95% confidence interval, 1.4-32) and LV mass index above the 95th percentile (odds ratios, 11.2; confidence interval, 1.9-64). Abnormality of LV geometry was present in 15% of children with PS compared with 39% of children with OSA. We conclude that OSA in children is associated with increased LV mass.     

Prevalence of ventricular late potentials in patients with obstructive sleep apnea syndrome

BACKGROUND: It is known from various cardiac disorders that the presence of ventricular late potentials (VLP) in the signal-averaged electrocardiogram (ECG) is associated with an increased risk of sudden cardiac death. HYPOTHESIS: In view of the increased cardiovascular mortality of patients with obstructive sleep apnea syndrome (OSAS), we assessed the prevalence of VLP in these patients. METHODS: In all, 118 consecutive patients with polysomnographically verified OSAS were prospectively studied; 21 snorers without evidence of a sleep-related breathing disorder served as a control group. Signal-averaged ECG and 24-h Holter ECG were performed in all patients and controls, and left ventricular function was determined by radionuclide ventriculography in the OSAS group. Furthermore, patients and controls were followed for up to 45.5 months for arrhythmic events, syncopes, or sudden cardiac death. RESULTS: An abnormal signal-averaged ECG was seen in seven patients (5.9%) and in one snorer (4.8%). Patients with and without VLP did not differ with respect to age, body mass index, left ventricular ejection fraction, or ectopic activity in the 24-h Holter ECG, but the former had significantly higher mean (standard deviation) apnea/hypopnea indices [55.4 (25.2)/h vs. 37.4 (22.6)/h; p < 0.05]. Of the 118 patients, 110 could be followed for 26.7 (7.9) months. During this period, two patients had syncopes and one patient had sudden cardiac death. The seven patients with VLP remained free of events during the follow-up period, as did the 21 snorers. CONCLUSIONS: Patients with OSAS have a low prevalence of VLP in the signal-averaged ECG, not exceeding that in normal subjects. Moreover, abnormal signal-averaged ECGs do not appear to be useful as a prognostic marker.     

Severe obstructive sleep apnea is associated with left ventricular diastolic dysfunction

INTRODUCTION: Hypertension is common in patients with obstructive sleep apnea (OSA). However, the effect of OSA on ventricular function, especially diastolic function, is not clear. Therefore, we have assessed the prevalence of diastolic dysfunction in patients with OSA and the relationship between diastolic parameters and severity of OSA. METHODS: Sixty-eight consecutive patients with OSA confirmed by polysomnography underwent echocardiography. Diastolic function of the left ventricle was determined by transmitral valve pulse-wave Doppler echocardiography. Various baseline characteristics, severity of OSA, and echocardiographic parameters were compared between patients with and without diastolic dysfunction. RESULTS: There were 61 male and 7 female patients with a mean age of 48.1 +/- 11.1 years, body mass index of 28.5 +/- 4.3 kg/m(2), and apnea/hypopnea index (AHI) of 44.3 +/- 23.2/h (mean +/- SD). An abnormal relaxation pattern (ARP) in diastole was noted in 25 patients (36.8%). Older age (52.7 +/- 8.9 years vs 45.1 +/- 11.3 years, p = 0.005), hypertension (56% vs 20%, p = 0.002), and a lower minimum pulse oximetric saturation (SpO(2)) during sleep (70.5 +/- 17.9% vs 78.8 +/- 12.9%, respectively; p = 0.049) were more common in patients with ARP. By multivariate analysis, minimum SpO(2) < 70% was an independent predictor of ARP (odds ratio, 4.34; 95% confidence interval, 1.23 to 15.25; p = 0.02) irrespective of age and hypertension. Patients with AHI > or = 40/h had significantly longer isovolumic relaxation times than those with AHI < 40/h (106 +/- 19 ms vs 93 +/- 17 ms, respectively; p = 0.005). CONCLUSION: Diastolic dysfunction with ARP was common in patients with OSA. More severe sleep apnea was associated with a higher degree of left ventricular diastolic dysfunction in this study.     

Decreased right and left ventricular myocardial performance in obstructive sleep apnea

BACKGROUND: Obstructive sleep apnea (OSA) may predispose patients to congestive heart failure (CHF), suggesting a deleterious effect of OSA on myocardial contractility. METHODS: A cross-sectional study of 85 subjects with suspected OSA who had undergone their first overnight polysomnogram, accompanied by an echocardiographic study. Patients were divided according to the apnea-hypopnea index as follows: < 5 (control subjects); 5 to 14 (mild OSA); and >or= 15 (moderate-to-severe OSA). Right and left ventricular function was evaluated using the myocardial performance index (MPI) and other echocardiographic parameters. For the right ventricle analyses, we excluded patients with a Doppler pulmonary systolic pressure of >or= 45 mm Hg, while for the left ventricle we excluded patients with an ejection fraction of 相似文献   

Impact of obstructive sleep apnea on left ventricular diastolic function

The aim of this study was to investigate the impact of obstructive sleep apnea (OSA) on left ventricular (LV) functional changes by using tissue Doppler imaging-derived indexes in patients with OSA. We studied 62 patients classified into 3 groups, namely 18 with mild to moderate OSA, 24 with severe OSA, and 20 control subjects without OSA according to the apnea-hypopnea index (AHI) on complete overnight polysomnogram. All underwent conventional and tissue Doppler echocardiographies. Only early diastolic velocity (Ea; -6.2 +/- 0.3 vs -7.1 +/- 0.3 vs -7.3 +/- 0.3 cm/s, respectively, for the 3 groups, p = 0.023) was significantly decreased in the severe OSA group. Other echocardiographic parameters of diastolic function such as isovolumic relaxation time, deceleration time, mitral inflow early/late wave velocity ratio, and pulmonary vein systolic/diastolic pulmonary vein velocity ratio were comparable among the 3 groups. AHI was correlated only with tissue Doppler imaging-derived indexes of LV diastolic function (Ea r = -0.382, p = 0.002; Ea/late diastolic velocity r = -0.329, p = 0.009), but not with conventional Doppler indexes. AHI remained a significant predictor of Ea after adjusting for age, heart rate, fasting glucose level, blood pressure, body mass index, and LV mass index in a multiple stepwise linear regression model (p = 0.007). In conclusion, only patients with severe OSA showed a greater impairment of LV diastolic function. Of all echocardiographic parameters of diastolic dysfunction investigated, only Ea was identified as the best index to demonstrate an association between LV diastolic dysfunction and severity of OSA independently of body mass index, diabetes mellitus, and hypertension.     

The association of obstructive sleep apnea and left ventricular hypertrophy in obese and overweight children with history of elevated blood pressure

Obesity is a potent cardiovascular disease (CVD) risk factor and is associated with left ventricular hypertrophy (LVH). Obstructive sleep apnea (OSA) is common among individuals with obesity and is also associated with CVD risk. The authors sought to determine the association of OSA, a modifiable CVD risk factor, with LVH among overweight/obese youth with elevated blood pressure (EBP). This was a cross‐sectional analysis of the baseline visit of 61 consecutive overweight/obese children with history of EBP who were evaluated in a pediatric obesity hypertension clinic. OSA was defined via sleep study or validated questionnaire. Children with and without OSA were compared using Fisher's exact tests, Student's t tests, and Wilcoxon rank sum test. Multivariable logistic regression evaluated the association between OSA and LVH. In this cohort, 71.7% of the children had LVH. Children with OSA were more likely to have LVH (85.7% vs 59.4%, P = 0.047). OSA was associated with 4.11 times greater odds of LVH (95% CI 1.15, 14.65; P = 0.030), remaining significant after adjustment for age, sex, race, and BMI z‐score (after adjustment for hypertension, P = 0.051). A severe obstructive apnea‐hypopnea index (AHI >10) was associated with 14 times greater odds of LVH (95% CI 1.14, 172.64, P = 0.039). OSA was significantly associated with LVH among overweight/obese youth with EBP, even after adjustment for age, sex, race, and BMI z‐score. Those with the most severe OSA (AHI >10) had the greatest risk for LVH. Future studies exploring the impact of OSA treatment on CVD risk in children are needed.     

Aortic elastic properties and left ventricular diastolic dysfunction in patients with obstructive sleep apnea

Although the responsible mechanisms are not yet fully known, obstructive sleep apnea is associated with an increased risk for cardiovascular disease and events. The aorta is not only a conduit delivering blood to the tissues but is also an important modulator of the entire cardiovascular system, its elastic properties also affecting left ventricular function and coronary blood flow. The aim of this study was to determine left ventricular diastolic function and aortic elastic properties in patients with obstructive sleep apnea syndrome. Fourteen male patients with obstructive sleep apnea and 14 age- and body mass index-matched healthy male controls took part in the study as a control group. All subjects underwent echocardiographic examination; left ventricular cavity dimension, standard and tissue Doppler parameters, and aortic diameter (3 cm above aortic valve) at systole and diastole were measured. While the aortic stiffness index in patients with obstructive sleep apnea was significantly higher than that of the control group (4.5 ± 0.3 vs 2.1 ± 0.1, P = 0.001), the aortic distensibility index was found to be lower in this group compared with controls (2.4 ± 1.2 vs 3.9 ± 1.5 cm² dynes⁻¹ 10⁻⁶, P = 0.009). Furthermore, peak velocity of myocardial systolic wave and peak velocities of myocardial diastolic waves in sleep apnea patients were lower than in controls. There was an association between aortic stiffness and the apnea hypopnea index (coefficient = 0.49, P = 0.002). We also found an inverse correlation between peak velocity of myocardial diastolic wave and aortic stiffness (coefficient = −0.43, P = 0.003), using multiple linear regression. Increased aortic stiffness that is associated with the severity of disease in patients with obstructive sleep apnea may lead to diastolic dysfunction of the left ventricle.     

Impact of obstructive sleep apnea on left ventricular mass and diastolic function

We wished to determine if obstructive sleep apnea (OSA) is associated with increased left ventricular mass (LVM) and impaired left ventricular diastolic function (LVDF) independently of coexisting obesity, hypertension (HTN), and diabetes mellitus (DM). Patients without primary cardiac disease, referred for evaluation of OSA (n = 533), had overnight polysomnography and Doppler echocardiography while awake. Patients were divided, according to the apnea-hypopnea index (AHI), into an OSA group (AHI > or = 5/h, n = 353) and a non-OSA group (AHI < 5/h, n = 180). In men, LVM was greater in the OSA group (98.9 +/- 25.6 versus 92.3 +/- 22.5 g/m, p = 0.023) despite exclusion of those with HTN and DM. A similar trend was noted in women. Regression analysis revealed that LVM was correlated with body mass index (BMI) (beta = 0.480, p < 0.0005), age (beta = 0.16, p = 0.001), and the presence of HTN (beta = 0.137, p = 0.003) in men and with BMI (beta = 0.501, p < 0.0005) in women, but not with AHI or oxygen saturation during sleep. The ratio of peak early filling velocity to peak late filling velocity (E/A), an index of LVDF, was similar in both groups (1.28 +/- 0.32 versus 1.34 +/- 0.31, p = 0.058); it was correlated with age (beta = -0.474, p < 0.0005), but not with AHI or oxygen saturation during sleep. We conclude that OSA is not associated with increased LVM or impaired LVDF independently of obesity, HTN, or advancing age.     

Prevalence of concomitant sleep disorders in patients with obstructive sleep apnea

We determined the prevalence of concomitant sleep disorders in patients with a primary diagnosis of obstructive sleep apnea (OSA). We retrospectively analyzed 643 patients, aged 18, with a primary diagnosis of OSA, evaluated by sleep specialists, in whom clinical and polysomnographic data were derived using standardized techniques by reviewing data from a standardized database and clinical charts. Concomitant sleep disorders were listed according to the International Classification of Sleep Disorders (American Academy of Sleep Medicine, 2000). The mean age was 48.5±13.5 years and 55% were male. Racial distributions were African–Americans 51.8% and Caucasian 47%. Indices of disordered breathing were respiratory disturbance index 32.4±30.4/h sleep and time <90% O₂ saturation 44.5±81.6 min. Thirty-one percent of patients had a concomitant sleep disorder. The most common were inadequate sleep hygiene (14.5%) and periodic limb movement disorder (PLMD, 8.1%). Of patients with other sleep disorders, 66.8% had treatment initiated for these disorders. Predictors of inadequate sleep hygiene (logistic regression) were: age (each decade OR=0.678, P=0.000000), gender (for M, OR=0.536), and the presence of at least one other major system disorder (OR=2.123, P=0.0015). Predictors of PLMD were: age (each decade OR=0.794, P=0.0005), gender (for M, OR=0.433, P=0.004), and total sleep time (for each 10 min, OR=0.972, P=0.0013). We conclude that approximately one third of patients with sleep apnea have another identifiable sleep disorder, usually requiring treatment. This suggests that practitioners evaluating and treating sleep apnea ought to be prepared to deal with other sleep disorders as well.     

Right ventricular hypertrophy detected by echocardiography in patients with newly diagnosed obstructive sleep apnea.

We used polysomnography, echocardiography and ventilatory measurements to study 50 patients suspected of having OSA to determine a link to RVH. Twenty-eight patients (56 percent) had OSA and 20 (71 percent) of those had isolated RVH. We evaluated patients with RVH and divided them into two groups, those with apnea and those without apnea. The patients with sleep apnea were younger, weighed more, had greater BSA and had lower average oxygen saturations during the sleep study period. We divided the group with apnea into those with RVH and those without it. Those patients with RVH had a higher AI, longer average apnea time, a greater duration of longest apnea and a lower average oxygen saturation for the period of the sleep study. In addition, those with RVH had a lower average oxygen saturation during each apneic episode with a p value equaling 0.09.     

Prevalence of left ventricular diastolic dysfunction in obese persons with and without diabetes mellitus

Forty obese diabetic patients (mean age 48 +/- 9 years) and 93 obese nondiabetic patients (mean age 43 +/- 9 years) underwent Doppler and tissue Doppler echocardiographic evaluation of left ventricular diastolic function before gastric bypass surgery. Moderate or severe left ventricular diastolic dysfunction was present in 24 of 40 obese diabetics (60%) and in 21 of 93 obese nondiabetics (23%) (p <0.001).     

Influence of obstructive sleep apnea on left ventricular mass and global function: sleep apnea and myocardial performance index

Obstructive sleep apnea (OSA) is associated with cardiovascular mortality and morbidity. It may predispose patients to left ventricular hypertrophy and heart failure. The aim of this study was to determine the left ventricular mass (LVM) and myocardial performance index (MPI) reflecting left ventricular global function in uncomplicated OSA patients. Sixty-four subjects without hypertension, diabetes mellitus, and any cardiac or pulmonary disease referred for evaluation of OSA underwent overnight polysomnography and complete echocardiographic assessment. According to the apnea hypopnea index (AHI), subjects were divided into three groups: group 1, control subjects with nonapneic snorers (AHI < 5, n = 18); group 2, patients with mild to moderate OSA (AHI: 5–30, n = 25); and group 3, severe OSA (AHI > 30, n = 21). Basic echocardiographic measurements, LVM, and LVM index were measured. Left ventricular MPI was calculated as (isovolumic contraction time+isovolumic relaxation time)/aortic ejection time by Doppler echocardiography. There were no significant differences in age, sex, body mass index, heart rate, and systolic and diastolic blood pressure among the three groups. Left atrium, interventricular septum, left ventricular posterior wall, left ventricular end-diastolic and end-systolic diameters, LVM mass, and LVM index were not significantly different among the three groups. Left ventricular MPI was significantly higher in severe OSA patients (0.64 ± 0.18) than in controls (0.49 ± 0.18; P < 0.05). There was no significant difference between controls (0.49 ± 0.18) and mild to moderate OSA (0.61 ± 0.16; P = 0.08) and between mild to moderate OSA (0.61 ± 0.16) and severe OSA (0.64 ± 0.18; P = 0.84). The present study demonstrates that patients with severe OSA have global left ventricular dysfunction.     

Prevalence of thyroid disease in patients with obstructive sleep apnea

Objectives

Studies have suggested that ethnicity and environment may influence thyroid disease. We aim in this study to determine the prevalence of thyroid disease among Saudi (Arab) patients with laboratory-diagnosed obstructive sleep apnea (OSA) and the characteristics and predictors of thyroid disease associated with OSA.

Methods

Serum thyroid-stimulating hormone (TSH) and free-thyroxine (FT4) levels were measured in all patients referred to the sleep disorders center for an overnight sleep study. The levels were measured within 4 weeks of the sleep study. Type I attended polysomnography (PSG) was performed for all patients.

Results

During the study period, 271 patients with OSA and a mean age of 48.7 ± 14.1 yr, a body mass index (BMI) of 37.7 ± 9.6 kg/m² and an AHI of 55.2 ± 37/hr as well as 76 non-OSA patients with a mean age of 40.8 ± 14.9 yr, a BMI of 33.7 ± 8.9 kg/m² and an AHI of 3.8 ± 3.1/hr underwent thyroid function tests. In the OSA patients, the prevalence of newly diagnosed clinical hypothyroidism was 0.4%, and the prevalence of newly diagnosed subclinical hypothyroidism was 11.1%. In the non-OSA patients, the prevalence of newly diagnosed clinical hypothyroidism was 1.4%, and the prevalence of newly diagnosed subclinical hypothyroidism was 4%. There were no cases of clinical or subclinical hyperthyroidism in the studied group. Female gender was the only predictor of clinical hypothyroidism.

Conclusion

In the OSA patients, the prevalence of newly diagnosed clinical hypothyroidism was low; however, subclinical hypothyroidism was common among patients with OSA.     

Polysomnographic studies in children with adenotonsillar hypertrophy and suspected obstructive sleep apnea

Upper airway obstruction causes many sleep-related respiratory disorders that can culminate in obstructive sleep apnea syndrome (OSAS). Polysomnography is routinely used to define OSAS in adults, but problems remain in diagnosing children by this method. The current study was designed to analyze the polysomnographic patterns in children with symptomatic adenotonsillar hypertrophy and to determine whether obstructive respiratory events shorter than 10 sec could have pathophysiological significance. Furthermore, we analyzed the correlation between clinical data on children with adenotonsillar hypertrophy and polysomnographic findings. Twelve children (mean age, 4.5 ± 1.5 years) with airflow obstruction due to adenotonsillar hypertrophy were observed in our Sleep Laboratory. Prior to study, a questionnaire was used to score symptom severity. Overnight polysomnography was then performed to measure total sleep time, sleep efficiency, desaturation index, minimal arterial oxygen saturation (SaO₂), apneahypopnea (AH) episodes ≥5 sec and those ≥10 sec, and AH index, AH percentage of total test time, and number of spontaneous and respiratory event-associated desaturations were recorded. Respiratory events of 5 sec or longer resulted in increases in the AH index and an increase in the number of oxyhemoglobin desaturations due to respiratory events. A significant relationship was found between the AH index and AH episodes ≥5 sec and ≥10 sec. There was, however, no association between polysomnographic parameters and symptom severity scores. An appraisal of AH recordings ≥10 sec showed that desaturation episodes were more frequent than respiratory events, and the desaturation index was closely related to spontaneous and respiratory event-associated desaturations. When considering all obstructive episodes ≥5 sec, the number of desaturations did not exceed the number of respiratory events. The correlation between the desaturation index and spontaneous or respiratory event-associated desaturations was similar. The occurrence of short AH episodes that lead to hemoglobin desaturation are important in the evaluation of OSAS in children. Pediatr Pulmonol. 1996;22:101–105. © 1996 Wiley-Liss, Inc.