The incidence of a cardiovascular disease (CVD) was explored in a consecutive sleep clinic cohort of 182 middle-aged men (mean age, 46.8 +/- 9.3; range, 30-69 years in 1991) with or without obstructive sleep apnea (OSA). All subjects were free of hypertension or other CVD, pulmonary disease, diabetes mellitus, psychiatric disorder, alcohol dependency, as well as malignancy at baseline. Data were collected via the Swedish Hospital Discharge Register covering a 7-year period before December 31, 1998, as well as questionnaires. Effectiveness of OSA treatment initiated during the period as well as age, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP) at baseline, and smoking habits were controlled. The incidence of at least one CVD was observed in 22 of 60 (36.7%) cases with OSA (overnight oxygen desaturations of 30 or more) compared with in 8 of 122 (6.6%) subjects without OSA (p < 0.001). In a multiple logistic regression model, significant predictors of CVD incidence were OSA at baseline (odds ratio [OR] 4.9; 95% confidence interval [CI], 1.8-13.6) and age (OR 23.4; 95% CI, 2.7-197.5) after adjustment for BMI, SBP, and DBP at baseline. In the OSA group, CVD incidence was observed in 21 of 37 (56.8%) incompletely treated cases compared with in 1 of 15 (6.7%) efficiently treated subjects (p < 0.001). In a multiple regression analysis, efficient treatment was associated with a significant risk reduction for CVD incidence (OR 0.1; 95% CI, 0.0-0.7) after adjustment for age and SBP at baseline in the OSA subjects. We conclude that the risk of developing CVD is increased in middle-aged OSA subjects independently of age, BMI, SBP, DBP, and smoking. Furthermore, efficient treatment of OSA reduces the excess CVD risk and may be considered also in relatively mild OSA without regard to daytime sleepiness.

Previous studies of sleep and breathing suggest an independent association between coronary artery disease (CAD) and obstructive sleep apnoea (OSA) in middle-aged males and females. These studies, however, were criticized because they did not properly adjust for all important confounding factors. In order to better control for the impact of these confounders, a case-control study was performed, matching for age, sex and body mass index (BMI), and additionally adjusting for hypertension, hypercholesterolemia, diabetes mellitus and current smoking.A consecutive selection of 62 patients (44 males and 18 females, mean age 69 yrs, range 44±88 yrs) requiring intensive care for angina pectoris or myocardial infarction at the County Hospital of Skaraborg, Sko Èvde, Sweden, as well as 62 age-, sex-and BMI-matched control subjects without history or signs of heart disease underwent an overnight sleep/ventilatory monitoring study. The time interval between discharge from the intensive care unit and the overnight study ranged between 4 and 21 months.OSA, defined as a Respiratory Disturbance Index (RDI) of $10 . h -1 , was present in 19 CAD patients but only in eight control subjects (p=0.017). Using a univariate logistic regression analysis, current smoking (odds ratio (OR) 8.1, 95% confidence interval (CI) 2.2±29.0), diabetes mellitus (OR 4.2, 95% CI 1.1±16.1) and OSA (OR 3.0, 95% CI 1.2±7.5), but not hypertension (OR 1.5, 95% CI 0.7±3.2) and hypercholesterolaemia (OR 1.8, 95% CI 0.7±4.1) were significantly correlated with CAD. In a multiple logistic regression model, current smoking (OR 9.8, 95% CI 2.6±36.5), diabetes mellitus (OR 4.2, 95% CI 1.1±17.1) and OSA (OR 3.1, 95% CI 1.2±8.3) all remained independently associated with CAD.In summary, these data suggest a high occurrence of obstructive sleep apnoea in middle-aged and elderly patients with coronary artery disease requiring intensive care, which should be taken into account when considering risk factors for coronary artery disease. Eur Respir J 1999; 14: 179±184. Coronary artery disease (CAD) is associated with a high mortality. Male sex, obesity, smoking, diabetes mellitus, hypertension and hypercholesterolemia are all traditionally considered as risk factors for CAD. Obstructive sleep apnoea (OSA) is common in the adult population [1]. A substantial proportion of patients with OSA are overweight [2] and suffer from systemic hypertension [3]. Retrospective studies suggest that untreated OSA is associated with increased mortality [4], which may be due to coexisting cardiovascular morbidity [5]. Previous studies of sleep and breathing in CAD patients suggest an independent association between CAD and OSA in middle-aged males [6,7] and females [8]. These studies [6,7], however, were criticized because they did not properly adjust for all of the important confounding factors [9]. Moreover, it is unclear whether the association between OSA and CAD remains independent when including elderly subjects in the analysis.In order to better control for the impact of t...

Correct assessment of the overall treatment effectiveness requires knowledge about therapy compliance and efficacy. This study aimed to determine overall long-term apnoea alleviation after continuous positive airway pressure (CPAP) in a complete sleep laboratory cohort.Out of 209 consecutive CPAP candidates (mean age 5712 yrs, body mass index (BMI) 30.05.1 kg . m 2 , respiratory disturbance index (RDI) 32.929 h), follow-up treatment was performed in 149 of them at 9, 18 and 30 months after CPAP prescription. Compliance with CPAP (machine run time/days CPAP available) was adjusted for the individual subjective sleep-time. Apnoea alleviation was defined as adjusted compliance multiplied by the CPAP effect (RDI with CPAP applied), remaining RDI was calculated.The baseline RDI, age or BMI in 75 patients, who did not tolerate nasal continuous positive airway pressure (nCPAP), did not differ from those accepting CPAP (acceptors, n=74). In acceptors at 9 months follow-up RDI with CPAP applied was 1.42.6 (CPAP effect, n=66), mean CPAP use was 3.62.5 . 24 h -1 (n=68), mean apnoea alleviation was 52.432.0% (range 1±100%, n=47), the average remaining wholenight RDI was 17.826. At 9, 18 and 30 months (n=47), the mean daily CPAP use increased from 3.62.5 h to 4.12.5 h and 4.42.4 h (p<0.01).Effectiveness of continuous positive airway pressure is potentially high but acceptance was low. When accounting for sleep-time, its actual effect and use, only 50% adjusted continuous positive airway pressure effectiveness was observed. Eur Respir J 2000; 16: 921±927.

We compared the effects of atenolol (50 mg), amlodipine (5 mg), enalapril (20 mg), hydrochlorothiazide (25 mg), and losartan (50 mg) given in once-daily oral doses on office and ambulatory blood pressures (BPs) in patients with hypertension and obstructive sleep apnea (OSA). Each of 40 randomized patients was treated in sequence with two of the five agents (balanced incomplete block design). Treatment periods lasted 6 wk and were separated by a 3-wk washout period. Changes in BP from baseline with the study substances were compared through analysis of variance. Office diastolic BP, our primary outcome variable, was most effectively lowered by atenolol, with all four post hoc differences between atenolol and the remaining substances being statistically significant. Reductions in office systolic and daytime ambulatory BP were not significantly different among the five compounds. However, atenolol reduced mean nighttime ambulatory diastolic and systolic BP more effectively than did amlodipine, enalapril, or losartan (but not hydrochlorothiazide). Severity of sleep-disordered breathing and well-being during the day were not significantly influenced by any of the study compounds. Our findings are in accordance with the hypothesis that an overactivity of the sympathetic nervous system is an important mechanism behind the development or maintenance of hypertension in patients with OSA.

We studied vasoconstrictor sensitivity and cholinergic responsiveness of the forearm vasculature in 10 male patients with obstructive sleep apnea (OSA) and 10 healthy controls. Subjects with regular medication, known arterial hypertension, diabetes mellitus, or dyslipidemia were not included in this study. Age, body mass index, blood pressure, blood glucose, serum lipids, and baseline forearm vascular conductance (derived from venous occlusion plethysmography and intra-arterial blood pressure measurement) did not differ significantly between these two groups. With use of three dosage steps each, angiotensin II and acetylcholine were successively infused into the brachial artery. During infusion of angiotensin II, mean conductance was 39.6% lower (P = 0.002) in the OSA patients compared with that in the control subjects. Vascular responsiveness to increasing dosages of acetylcholine was not significantly altered in the OSA group. These findings suggest an enhanced vasoconstrictor sensitivity in the forearm vasculature in OSA. The hypothesis that endothelial function in OSA is impaired independently of other cardiovascular risk factors is not supported by the present results.