Additive Effects of Obstructive Sleep Apnea and Hypertension on Early Markers of Carotid Atherosclerosis
Hypertension Unit, Pulmonary Division, Heart Institute (InCor), University of Saõ Paulo Medical School, Saõ Paulo, Brazil. Hypertension
(Impact Factor: 6.48).
11/2008; 53(1):64-9. DOI: 10.1161/HYPERTENSIONAHA.108.119420
Obstructive sleep apnea (OSA) has emerged as an independent risk factor for atherosclerosis. However, OSA is frequently associated with several risk factors for atherosclerosis, including hypertension (HTN). The impact of OSA and HTN alone compared with the association of both conditions on carotid atherosclerosis is not understood. We studied 94 middle-aged participants free of smoking and diabetes mellitus who were divided into 4 groups: controls (n=22), OSA (n=25), HTN (n=20), and OSA+HTN (n=27). All of the participants underwent polysomnography and carotid measurements of intima-media thickness, diameter, and distensibility with an echo-tracking device. Compared with controls, intima-media thickness and carotid diameter were similarly higher in OSA (713+/-117 and 7117+/-805 microm), and HTN groups (713+/-182 and 7191+/-818 microm), with a further significant increase in OSA+HTN patients (837+/-181 and 7927+/-821 microm, respectively; P<0.01). Carotid distensibility was significantly lower in HTN (P<0.05) and OSA+HTN subjects (P<0.001) compared with controls. In the OSA+HTN group, carotid distensibility was significantly lower than in the OSA group and controls (P<0.05 for each comparison). Multivariate analysis showed that intima-media thickness was positively related to systolic blood pressure and apnea-hypopnea index. Apnea-hypopnea index was the only factor related to carotid diameter. Age and systolic blood pressure were independently related to carotid distensibility. In conclusion, the association of OSA and HTN has additive effects on markers of carotid atherosclerosis. Because early markers of carotid atherosclerosis predict future cardiovascular events, including not only stroke but also myocardial infarction, these findings may help to explain the increased risk of cardiovascular disease in patients with OSA.
Available from: Israel Dos Reis Dos Santos
- "The prevalence rate of sleep disorders in patients with CKD ranges from 40% to 80%, which is higher than those in the general population . The most frequent comorbidities include diabetes mellitus type 2 , periodic leg movements during sleep , obstructive sleep apnea (OSA) and nocturnal hypoxemia , dyslipidaemia, coronary disease, heart failure [6,7], systemic arterial hypertension [8,9], respiratory disorders [10,11], stress[12 ], depression [12-14], anxiety . "
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ABSTRACT: Background: Chronic kidney disease (CKD) is one of the most serious public health problems. The increasing prevalence of CKD in developed and developing countries has led to a global epidemic. The hypothesis proposed is that patients undergoing dialysis would experience a marked negative influence on physiological variables of sleep and autonomic nervous system activity, compromising quality of life. Methods/Design: A prospective, consecutive, double blind, randomized controlled clinical trial is proposed to address the effect of dialysis on sleep, pulmonary function, respiratory mechanics, upper airway collapsibility, autonomic nervous activity, depression, anxiety, stress and quality of life in patients with CKD. The measurement protocol will include body weight (kg); height (cm); body mass index calculated as weight/height(2); circumferences (cm) of the neck, waist, and hip; heart and respiratory rates; blood pressures; Mallampati index; tonsil index; heart rate variability; maximum ventilatory pressures; negative expiratory pressure test, and polysomnography (sleep study), as well as the administration of specific questionnaires addressing sleep apnea, excessive daytime sleepiness, depression, anxiety, stress, and quality of life. Discussion: CKD is a major public health problem worldwide, and its incidence has increased in part by the increased life expectancy and increasing number of cases of diabetes mellitus and hypertension. Sleep disorders are common in patients with renal insufficiency. Our hypothesis is that the weather weight gain due to volume overload observed during interdialytic period will influence the degree of collapsibility of the upper airway due to narrowing and predispose to upper airway occlusion during sleep, and to investigate the negative influences of haemodialysis in the physiological variables of sleep, and autonomic nervous system, and respiratory mechanics and thereby compromise the quality of life of patients.
Available from: Mahnoor Khan
- "Also, studies in which the additive effects of OSA and another disease process, that is, HTN, metabolic syndrome (MetS) on CIMT, were evaluated; both sets of data were included separately into the meta-analysis. For example, Drager and colleagues   measured CIMT on patients diagnosed with hypertension and without hypertension with and without OSA. Similarly, Monneret and colleagues  measured CIMT on patients diagnosed with metabolic syndrome, with and without OSA. "
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ABSTRACT: Background. Obstructive sleep apnea (OSA) is associated with coronary artery disease. Intermittent hypoxia associated with OSA increases sympathetic activity and may cause systemic inflammation, which may contribute to atherosclerosis leading to an increase in the size of carotid intima media thickness (CIMT). Methods. PubMed and Cochrane library were reviewed by utilizing different combinations of key words: sleep apnea, carotid disease, intima media thickness, and carotid atherosclerosis. Inclusion criteria were English articles; studies with adult population with OSA and without OSA; CIMT recorded by ultrasound in mean and standard deviation or median with 95% confidence interval; and OSA defined as apnea hypopnea index of ≥5/h. A total of 95 studies were reviewed for inclusion, with 16 studies being pooled for analysis. Results. Ninety-five studies were reviewed, while 16 studies were pooled for analysis; since some studies have more than one data set, there were 25 data sets with 1415 patients being pooled for meta-analysis. All studies used ultrasound to measure CIMT. CIMT standardized difference in means ranged from -0.883 to 8.01. The pooled standardized difference in means was 1.40 (lower limit 0.996 to upper limit 1.803, (P < 0.0001). Conclusion. Patients with OSA appear to have increased CIMT suggestive of an atherosclerotic process.
Available from: Magali Saint Martin
- "As recently reported , several studies performed in middle-aged SDB patients have demonstrated an association between SDB and atherogenesis, IMT and diameter and number of atheromatous plaques increasing in SDB patients    . However, when we considered the atherosclerotic risk, this was significantly greater in hypertensive patients  , in patients with metabolic syndrome  and in severe SDB cases   suggesting the interplay of several factors in the association between atherosclerosis and SDB. "
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ABSTRACT: BACKGROUND: Sleep-disordered breathing (SDB) has emerged as an independent risk factor for carotid atherosclerosis (CA) and cerebrovascular disease in middle-aged subjects. Currently, there is no study providing a causal relationship between SDB and cerebrovascular lesions in elderly. OBJECTIVE: To assess the impact of SDB on CA in a cohort of healthy elderly subjects. METHODS: Seven hundred and fifty-five participants of a cross-sectional study on the association between SDB and cardiovascular morbidity, aged 68yr at study entry, were examined. All subjects underwent carotid ultrasonography and risk factors for atherosclerosis including smoking, metabolic syndrome and hypertension were examined. An apnea + hypopnea index (AHI)>15 was considered indicative of SDB. RESULTS: Presence of carotid lesion was found in 35% of the sample, predominantly in men and in overweight subjects. The most frequent alteration was arteriosclerosis present in 74% of cases, with stenosis >50% found in only 9% of subjects. No significant difference in the prevalence of carotid lesion was found between subjects with and without SDB, subjects with an AHI>30, even though, having a slight increase in CA. At the logistic regression analysis, male gender (p<0.001), systolic and diastolic blood pressure (p<0.001), dyslipidemia (p=0.003) and hypertension (p=0.009) were the variables independently associated with carotid lesions even in severe cases. CONCLUSION: The incidence of CA in healthy elderly subjects is mediated more by gender, metabolic factors and hypertension than by presence of SDB. Further clinical studies including extensive evaluation of all atherosclerotic factors are needed to elucidate the predisposing role of SDB for cerebrovascular risk.
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