Abnormal Circadian Blood Pressure Rhythm Research Articles

Cognitive impairment in heart failure patients: association with abnormal circadian blood pressure rhythm: a review from the HOPE Asia Network.

Cognitive impairment (CI) is frequently a comorbid condition in heart failure (HF) patients, and is associated with increased cardiovascular events and death. Numerous factors contribute to CI in HF patients. Decreased cerebral blood flow, inflammation, and activation of neurohumoral factors are all thought to be factors that exacerbate CI. Hypoperfusion of the brain due to decreased systemic blood flow, cerebral venous congestion, and atherosclerosis are the main mechanism of CI in HF patients. Abnormal circadian BP rhythm is one of the other conditions associated with CI. The conditions in which BP does not decrease sufficiently or increases during the night are called non-dipper or riser BP patterns. Abnormal circadian BP rhythm worsens CI in HF patients through cerebral congestion during sleep and atherosclerosis due to pressure overload. Interventions for CI in HF patients include treatment for HF itself using cardiovascular drugs, and treatment for fluid retention, one of the causes of abnormal circadian rhythms. Proposed pathways of cognitive impairment in heart failure through abnormal circadian blood pressure rhythm.

Ambulatory Blood Pressure Characteristics of Patients with Alzheimer's Disease: A Multicenter Study from China.

Previous studies revealed that abnormal blood pressure (BP) plays an important role in the pathogenesis of Alzheimer's disease (AD). However, little is known about the ambulatory BP characteristics of AD in the mild or severe stage. We explored the ambulatory BP characteristics of AD in the mild or severe stage. In the present study, 106 AD patients (42.5%male, average age 81.6 years) were enrolled from three centers in China. Clinal BP measurements at the supine and standing positions, neurological evaluations, and the 24 h ambulatory BP monitoring were performed. In the 106 AD patients, 49.2%, 36.8%, and 70%of patients had 24 h, daytime, and nighttime systolic hypertension, respectively, while 19.8%, 29.2%, and 5.7%had 24 h, daytime, and nighttime diastolic hypotension. The prevalence of the reduced and reverse dipping pattern was 34.0%and 48.1%for systolic BP and 32.1%and 45.3%for diastolic BP, respectively. The daytime diastolic BP was significantly correlated with cognitive performance. After adjustment for age, sex, and body mass index, only daytime diastolic BP was associated with remarkable cognitive deterioration (p≤0.008). Further, AD patients in the severe stage had significantly lower levels of the 24 h, daytime, and nighttime diastolic BP, compared with those in the mild stage. In general, AD patients were featured with high nighttime systolic BP, low daytime diastolic BP, and abnormal circadian BP rhythm of reduced and reverse dipping. The diastolic BP, especially daytime diastolic BP, was adversely correlated with the cognitive deterioration in AD.

MORNING SURGE IN BLOOD PRESSURE AS A PREDICTOR OF WORSENING HEART FAILURE IN HEART FAILURE WITH REDUCED EJECTION FRACTION

Objective: Abnormal circadian blood pressure (BP) rhythm is observed in heart failure (HF) patients. Rising BP in the morning known as the morning surge (MS) is one of the abnormal circadian BP rhythm, and a cardiovascular risk factor in hypertensives. However, the significance of MS is not established in patients with HF. Design and method: We performed a prospective, observational cohort study of hospitalized HF patients who underwent ambulatory BP monitoring (ABPM). Four hundred fifty seven hospitalized HF patients (age, 68 ± 13 yrs; 63.9% males [n = 292] and 36.1% females [n = 165]) were followed up for 20.0 (median) months. Results: HF with reduced ejection fraction (HFrEF) was 197 (43.1%), HF with mid-range ejection fraction (HFmrEF) was 101 (22.1%), and HF with preserved ejection fraction (HFpEF) was 159 (34.8%). The composite outcome consisting of all-cause mortality and worsening HF was observed in 143 patients. In a Kaplan-Meier analysis, the MS group had a significantly higher incidence of the composite outcome than the non-MS group in HFrEF and HFmrEF patients.(figure) However, in multivariate Cox regression analysis, MS was a significant predictor for adverse outcomes only in HFrEF patients (HR 2.63, 95%CI 1.11–6.25, p = 0.03). Conclusions: The MS was found to be a novel predictor of worsening HF in patients with HFrEF.

The Relationship between Abnormal Circadian Blood Pressure Rhythm and Risk of Readmission in Patients with Heart Failure with Preserved Ejection Fraction

Objective: Abnormal circadian blood pressure rhythm has been revealed to be associated with hypertensive target organ damage and cardiovascular events, but its association with readmission risk in patients with heart failure with preserved ejection fraction (HFpEF) remains unknown. We conducted a retrospective study to explore the relationship between circadian blood pressure rhythm and readmission risk in HFpEF patients. Methods: We retrospectively collected baseline and follow-up data on HFpEF patients who underwent ambulatory blood pressure monitoring (ABPM) from May 2015 to October 2019. Patient circadian blood pressure rhythms defined by ABPM were grouped as dipper, nondipper, or riser patterns. Univariate and multivariate linear regression analyses were performed to assess the association between circadian blood pressure rhythm and readmission risk. Results: A total of 122 patients were enrolled in this study. The mean age and ejection fraction were 69.87 years and 61.44%, respectively, with mean the N-terminal pro-B-type natriuretic peptide (NT-proBNP) level being 1048.15 pg/mL. There were significant differences in the 24-hour systolic blood pressure (SBP), sleep SBP, and sleep diastolic blood pressure (DBP) among the three groups, where the 24-hour SBP, sleep SBP, and sleep DBP in the riser pattern group were markedly higher than in the dipper pattern group. Notably, serum NT-proBNP levels, the proportion of patients readmitted for heart failure and the mean number of admissions differed markedly among three groups. Instructively, multivariate linear regression analysis showed that the riser pattern was a significant and independent risk factor for increased serum NT-proBNP level (β = 929.16, 95% confidence interval 178.79–1679.53, P = 0.016). In multivariate logistic regression analysis, the riser pattern was demonstrated to be a significant risk factor for readmission (odds ratio 11.23, 95% confidence interval 2.01–62.67, P = 0.006) in HFpEF patients. Conclusion: The riser blood pressure pattern is a potential risk factor for elevated serum NT-proBNP level and readmission in HFpEF patients.

The Effects of Sodium-Glucose Cotransporter 2 Inhibitors on Sympathetic Nervous Activity.

The EMPA-REG OUTCOME study revealed that a sodium-glucose cotransporter 2 (SGLT2) inhibitor, empagliflozin, can remarkably reduce cardiovascular (CV) mortality and heart failure in patients with high-risk type 2 diabetes. Recently, the CANVAS program also showed that canagliflozin, another SGLT2 inhibitor, induces a lower risk of CV events. However, the precise mechanism by which an SGLT2 inhibitor elicits CV protective effects is still unclear. Possible sympathoinhibitory effects of SGLT2 inhibitor have been suggested, as significant blood pressure (BP) reduction, following treatment with an SGLT2 inhibitor, did not induce compensatory changes in heart rate (HR). We have begun to characterize the effects of SGLT2 inhibitor on BP and sympathetic nervous activity (SNA) in salt-treated obese and metabolic syndrome rats, who develop hypertension with an abnormal circadian rhythm of BP, a non-dipper type of hypertension, and do not exhibit a circadian rhythm of SNA. Treatment with SGLT2 inhibitors significantly decreased BP and normalized circadian rhythms of both BP and SNA, but did not change HR; this treatment was also associated with an increase in urinary sodium excretion. Taken together, these data suggest that an SGLT2 inhibitor decreases BP by normalizing the circadian rhythms of BP and SNA, which may be the source of its beneficial effects on CV outcome in high-risk patients with type 2 diabetes. In this review, we briefly summarize the effects of SGLT2 inhibitors on BP and HR, with a special emphasis on SNA.

Rotigotine Improves Abnormal Circadian Rhythm of Blood Pressure in Parkinson’s Disease

Introduction: Cardiovascular autonomic failure is commonly associated with Parkinson’s disease (PD), affecting the daily lives of patients. Rotigotine was recently reported not to influence cardiovascular autonomic responses in contrast to other dopaminergic drugs. The effect of rotigotine on daily blood pressure (BP) fluctuations might reflect autonomic failure in patients with PD. Methods: Twenty-five PD patients who were receiving rotigotine and 12 patients not receiving rotigotine were recruited. Systolic BP during the daytime and nighttime was measured by 24-h BP monitoring at an interval of 2 years. The patients were divided into 3 groups according to the BP fluctuation type: dippers (nocturnal fall in BP ≥10%), non-dippers (0–10%), and risers (< 0%). The time course of BP was compared between the patients given rotigotine and those not given rotigotine. Results: Among the 25 patients who received rotigotine, the BP type worsened in 2 patients, was unchanged in 16 patients, and improved in 7 patients. Among the 12 patients who were not receiving rotigotine, the BP type worsened in 5 patients, was unchanged in 4 patients, and improved only in 3 patients (p = 0.042). Conclusion: Rotigotine improves the abnormal circadian rhythm of BP in patients with PD. Rotigotine was suggested to have favorable effects on cardiovascular autonomic responses and circadian rhythm in patients with PD.

O6-5 - Abnormal Circadian Blood Pressure Rhythm Was One of the Indicators of Fluid Retention in Heart Failure Patients

O6-5 - Abnormal Circadian Blood Pressure Rhythm Was One of the Indicators of Fluid Retention in Heart Failure Patients

Clinical and prognostic significance of a reverse dipping pattern on ambulatory monitoring: An updated review.

Reverse or inverted dipping (ie, the phenomenon characterized by higher nighttime compared with daytime blood pressure values) is an alteration of circadian blood pressure rhythm frequently documented in hypertension, type 2 diabetes mellitus, chronic kidney disease, and sleep apnea syndrome, and generally regarded as a harmful condition. Available literature on the clinical and prognostic implications of reverse dipping is scanty. The present article will review a number of relevant issues concerning reverse dipping, in particular: (1) its possible mechanisms; (2) prevalence and clinical correlates, (3) concomitant cardiac and extracardiac subclinical organ damage; (4) association with acute and chronic cardiovascular diseases; (5) prognostic value in predicting cardiovascular events and mortality; and (6) therapeutic interventions aimed at reverting this abnormal circadian blood pressure rhythm.

The impact of non-dipper circadian rhythm of blood pressure on left ventricular hypertrophy in patients with non-dialysis chronic kidney disease

Objective The aim of this study was to investigate the correlation between non-dipper circadian rhythm of blood pressure (BP) and left ventricular hypertrophy (LVH) in patients with chronic kidney disease (CKD).Methods and results All 257 patients with stage 1 to 5 CKD were enrolled in the study and classified into a CKD1-3 group and a CKD4-5 group according to renal function. The parameters and circadian rhythm of BP were measured by a GE Marquette Tonoport V Eng dynamic sphygmomanometer, and cardiac structure was examined by echocardiography. The incidence of abnormal circadian BP rhythm (non-dipper rhythm) was quite high (75.4% in all enrolled patients and 71.3% in the patients with normal BP levels) in CKD patients and increased with the deterioration of renal function. Changes of cardiac structure such as LVH in patients with non-dipper BP were more distinct than in patients with dipper BP. The development of left ventricular mass index (LVMI) correlated positively with the incidence of non-dipper BP rhythm. Multiple regression analysis showed that 24-h systolic BP (β = 0.417, P < 0.01), triglycerides (TG) (β = –0.132, P = 0.007), Hb (β = –0.394, P = 0.016) and gender (β = 0.158, P = 0.039) were independent risk factors of LVMI.Conclusions The incidence of non-dipper circadian rhythm of blood pressure was quite high in CKD patients and increased with the deterioration of renal function. Non-dipper circadian rhythm of BP is closely related with LVMI.

The measurement of orthostatic blood pressure as a screening tool for masked hypertension with abnormal circadian blood pressure rhythm.

It has been repeatedly noted that cardiovascular events often occur in individuals who have never been diagnosed with hypertension. These events occur in part because it is difficult to identify masked hypertension in untreated individuals. However, the elevation of subclinical blood pressure (BP) in individuals with masked hypertension can exacerbate damage to the hypertensive target organ and result in an overt cardiovascular event.1, 2

Riser Pattern: Another Determinant of Heart Failure With Preserved Ejection Fraction.

Paradoxical increase in blood pressure (BP) during sleep, exceeding those of awake BP, is called the "riser" BP pattern, and known as an abnormal circadian BP rhythm, has been reported to be associated with adverse cardiovascular prognoses. However, the significance of ambulatory BP in heart failure patients with preserved ejection fraction (HFpEF) has never been reported. Here, we tested our hypothesis that abnormal circadian BP rhythm is associated with HFpEF. The authors enrolled 508 patients with hospitalized HF (age 68±13 years; 315 men, 193 women). There were 232 cases of HFpEF and 276 cases of heart failure with reduced ejection fraction (HFrEF). The riser BP pattern was significantly more frequent in the HFpEF (28.9%) group compared with the HFrEF group (19.9%). In a multivariable logistic regression analysis, the riser BP pattern was associated with HFpEF (odds ratio, 1.73; 95% confidence interval, 1.02-2.91; P=.041) independent of the other covariates. In conclusion, the riser BP pattern was associated with HFpEF.

Nocturnal and Circadian Rhythm of Blood Pressure Is Associated with Renal Structure Damage and Function in Patients with IgAN

Abnormal circadian rhythm of blood pressure (BP) is closely related to target organ damage in hypertension. However, the association between abnormal circadian rhythm of BP and renal injury is not clear. We investigated whether renal injury is associated with nocturnal BP and circadian rhythm of BP in Chinese IgAN patients. Clinic and 24h ambulatory BP monitoring data were obtained from 330 Chinese IgAN patients with mean 24h BP < 130/80 and mean daytime BP < 135/85mmHg. Renal histopathological injury was determined according to the Oxford classification of IgAN. Among the 330 IgAN subjects, 35.8% suffered from nocturnal hypertension, 61.5% had abnormal circadian BP, and 27% had nocturnal hypertension with a nondipping pattern. Compared with nocturnal normotensive patients, patients with nocturnal hypertension had significantly higher levels of blood cystatin C, blood uric acid, and lower estimated glomerular filtration rate (eGFR), and significantly a higher mean renal tissue injury score. The nondipping hypertensive group had significantly higher nocturnal diastolic and systolic BP, blood uric acid, and glomerulosclerosis rates, whereas eGFR was lower. In nondipping hypertensive patients, urinary sodium excretion and renal tissue injury scores were significantly higher than dipping patients. Nocturnal hypertension and abnormal circadian BP correlated with renal tissue injury, renal interstitial fibrosis, and aortic arch atherosclerosis. Abnormal circadian rhythm of BP and nocturnal hypertension are common clinical manifestations in Chinese IgAN patients with normal mean 24h BP. Abnormal circadian BP and nocturnal hypertension may accelerate IgAN progression by inducing renal dysfunction and histopathological damage.

Higher blood pressure as a risk factor for diseases other than stroke and ischemic heart disease.

Hypertension is an established risk factor for stroke, ischemic heart disease,1,2 and renal dysfunction.3 The management and prevention of hypertension are important to the prevention of these diseases. Recent evidence has suggested that hypertension also plays a central role in the underlying pathophysiological condition or at prodromal stages before the development of these diseases. Accumulating evidence also indicates that hypertension seems to be linked with common noncardiovascular diseases including dementia, cancer, oral health diseases (OHDs), and osteoporosis. In this brief review, we organize the reported results about the associations between hypertension and these diseases, discussing mainly epidemiological surveys, with the goal of clarifying the relationships between these diseases and hypertension. ### Atrial Fibrillation Atrial fibrillation (AF) is one of the most common types of chronic arrhythmia and is a risk factor for ischemic stroke.4 The Framingham Heart Study revealed that hypertension increases the risk of AF by factors of 1.5 for men and 1.4 for women.5 The Women’s Health Study and a cohort study of Norwegian men showed that high-normal blood pressure (BP) was associated with incident AF.6,7 All of these cohort studies were conducted in Westerners, and these associations were also confirmed in a recent Japanese cohort study.8 In that investigation, compared with normal BP and normal weight, systolic prehypertension with overweight was shown to be associated with an increased risk of incident AF ( P for interaction=0.04). Arterial stiffness, left ventricular hypertrophy, and increased left atrial size are important mediators of the relationship between BP and incident AF.9 Higher systolic BP (SBP) and overweight may mutually exacerbate left ventricular hypertrophy and hypertension, and consequently, they may synergistically increase the risk of AF. ### Chronic Kidney Disease and High BP Chronic kidney disease (CKD) is characterized by a progressive decline in an individual’s glomerular filtration rate over several decades, …

Riser Blood Pressure Pattern Is Associated With Mild Cognitive Impairment in Heart Failure Patients.

The riser pattern, an abnormal blood pressure (BP) rhythm in which sleep BP exceeds awake BP, is a predictor of future stroke events. Although the riser pattern is caused by autonomic dysfunction, its significance in heart failure (HF) patients is not established. HF patients often suffered from cognitive impairment (CI), but the relationship between riser pattern and CI is not clearly understood. We tested the hypothesis that the riser pattern is associated with mild CI, a form of brain damage that could develop to dementia. We performed Mini-Mental State Examination (MMSE), ambulatory BP monitoring (ABPM), echocardiography, and blood tests in 444 HF patients just before leaving hospitals. Mild CI, a measure of cognitive function, was defined as the score <26. The mean age of the patients was 68±13 years; 61.5% were male; 22.5% were riser pattern. The MMSE score was significantly lower in the Riser group than in the Non-dipper and Dipper group (23±4 vs. 25±5, 26±4, respectively, P < 0.01). In multivariable logistic regression analysis, a riser pattern was significantly associated with mild CI (odds ratio 2.38, 95% confidence intervals 1.29-4.42, P < 0.01) after adjusting for significant covariates. The riser pattern was associated with mild CI in HF patients. An abnormal circadian BP rhythm in HF patients is clinically significant as a potential indicator of subclinical brain damage.

PP.38.07

Objective: The risk of hypertension is estimated to occur in 7–17% of children and 24–40% of adults with TS. Furthermore, even girls with TS who are normotensive have been shown to have an abnormal circadian blood pressure rhythm, with loss of nocturnal reduction in blood pressure, increasing the risk of end-organ hypertensive damage. We performed this study to assess the effects of GH treatment combine with estrogens for short stature on left ventricular (LV) dimensions, systemic blood pressure (BP) and lipid metabolism in girls with TS without clinically relevant cardiac abnormalities. Design and method: systemic BP assessed every 3 months, LV dimensions measured on echocardiography every 6 months in 20 girls with TS treated GH and estrogens simultaneous. Total cholesterol (TH), low density lipoproteins (LDL), high density lipoproteins (HDL), triglycerides (TG) levels were measured every 6 months. Treatment duration was 2 years. Dose of estradiol gel was 100 mg/daily by transdermal application, GH dose was 0,05 mg/kg/daily subcutaneous. Results: Before the start of GH treatment, mean BP was within the normal range but significantly higher than in healthy control subjects. Diastolic BP and systolic BP were above the 90 percentile. After 2 years of treatment SBP and DBP levels were not significantly different from baseline in both of the groups (p < 0,01). The SD score of the diastolic BP showed f small decrease after 2 years of treatment. At baseline the LV dimensions of all the girls were within normal range, the mean SD scores were close to zero. During 2 years of GH therapy no signs of LV hypertrophy were found. TG and LDL were age-related increased in TS girls. In the course of GH therapy the TG and LDL levels were decreased (p < 0,01). Conclusions: 1. GH treatment does not result in LV hypertrophy or hypertension in girls with TS during 2-years therapy, despite the dramatic body height gain. But continued observation under long-term therapy is recommended. 2. GH therapy combine with estrogens in girls with TS was demonstrated a favored changes in TG and LDL levels that indicates the beneficial impact on atherogenic risk.

Could Ambulatory Blood Pressure Monitoring Be a Routine Investigation for Patients with Mild Cognitive Impairment?

Objectives: To study the ambulatory measured blood pressure (ABPM) profile in normotensive patients with mild cognitive impairment (MCI). Patients and Methods: The study was designed as a case control study including 50male patients with mild cognitive impairment in the age group of 30 - 50 years old. The control group included 30 volunteers with no cognitive impairment and in the same age group (30 - 50 years old) and same gender. Mini-mental estate examination, office and ABP monitoring (ABPM) and brain MRI scans were done for cases and controls. Results: Thirty patients (60%) with MCI revealed a non-dipper blood pressure pattern. Sleeping systolic blood pressure and sleeping systolic load were significantly higher in patients with MCI than in normal volunteers (p = 0.01). MRI brain showed more white matter lesions (WMLs) in patients with MCI than in normal volunteers; however, this didn’t reach significance level (p = 0.056). Conclusion: MCI in normotensive young adult patients could reflect an abnormal circadian blood pressure rhythm. Ambulatory blood pressure monitoring could be an essential investigation in young adult MCI patients.

Abstract 11658: Riser Pattern is Associated With Mild Cognitive Impairment in Heart Failure Patients

Introduction: The riser pattern, an abnormal blood pressure (BP) pattern in which sleep BP exceeds awake BP, is a predictor of adverse cardiovascular outcomes. Although the riser pattern is associated with various factors, its significance in heart failure (HF) patients has not been established. HF patients often suffer from cognitive impairment (CI), but the relationship between the riser pattern and CI is not clearly understood. Hypothesis: We tested the hypothesis that the riser pattern is associated with mild CI, a form of brain damage that could develop to dementia. Methods: We performed the Mini-Mental State Examination (MMSE), ambulatory BP monitoring, echocardiography, and blood tests in 444 HF patients just before they left the hospital. Mild CI, a measure of cognitive function, was defined as a score &lt;26. Results: The mean age of the patients was 68±13 years; 61.5% were male; and 22.5% exhibited a riser pattern. The MMSE score was significantly lower in the Riser group than in the Non-riser group (23±5 vs 25±5, p&lt;0.01). In multivariable logistic regression analysis, a riser pattern was significantly associated with mild CI (odds ratio 2.07, 95% confidence intervals 1.19-3.61, p&lt;0.01) after adjusting for significant covariates. Conclusions: A riser pattern was associated with mild CI in HF patients. An abnormal circadian BP rhythm in HF patients is clinically significant as a potential indicator of subclinical brain damage.

Abnormal Circadian Blood Pressure Rhythm is Associated with Heart Failure with Preserved Ejection Fraction

Riser pattern, defined by higher nocturnal BP than awake BP, has been reported to be associated with adverse cardiovascular prognosis. However the significance of ambulatory blood pressure (ABP) in heart failure with preserved ejection fraction (HFpEF) has never been reported. We aimed to clarify the hypothesis that abnormal circadian BP rhythm is associated with HFpEF. HFpEF was defined as EF gt;45%. We enrolled 508 patients with hospitalized HF (age, 68±13 years; male sex, 62%). There were 232 cases of HFpEF and 276 case of heart failure with reduced ejection fraction (HFrEF).

Melatonin secretion is impaired in women with preeclampsia and an abnormal circadian blood pressure rhythm

Non-dipping circadian blood pressure (BP) is a common finding in preeclampsia, accompanied by adverse outcomes. Melatonin plays pivotal role in biological circadian rhythms. This study investigated the relationship between melatonin secretion and circadian BP rhythm in preeclampsia. Cases were women with preeclampsia treated between January 2006 and June 2007 in the University Hospital of Larissa. Volunteers with normal pregnancy, matched for chronological and gestational age, served as controls. Twenty-four hour ambulatory BP monitoring was applied. Serum melatonin and urine 6-sulfatoxymelatonin levels were determined in day and night time samples by enzyme-linked immunoassays. Measurements were repeated 2 months after delivery. Thirty-one women with preeclampsia and 20 controls were included. Twenty-one of the 31 women with preeclampsia were non-dippers. Compared to normal pregnancy, in preeclampsia there were significantly lower night time melatonin (48.4 ± 24.7 vs. 85.4 ± 26.9 pg/mL, p < 0.001) levels. Adjustment for circadian BP rhythm status ascribed this finding exclusively to non-dippers (p < 0.01). Two months after delivery, in 11 of the 21 non-dippers both circadian BP and melatonin secretion rhythm reappeared. In contrast, in cases with retained non-dipping status (n = 10) melatonin secretion rhythm remained impaired: daytime versus night time melatonin (33.5 ± 13.0 vs. 28.0 ± 13.8 pg/mL, p = 0.386). Urinary 6-sulfatoxymelatonin levels were, overall, similar to serum melatonin. Circadian BP and melatonin secretion rhythm follow parallel course in preeclampsia, both during pregnancy and, at least 2 months after delivery. Our findings may be not sufficient to implicate a putative therapeutic effect of melatonin, however, they clearly emphasize that its involvement in the pathogenesis of a non-dipping BP in preeclampsia needs intensive further investigation.

Evaluation of structure and stiffness of the common carotid artery in patients with obstructive sleep apnea syndrome by RF QIMT and RF QAS technology

Objective To evaluate the structure and stiffness of the common carotid artery (CCA) in patients with obstructive sleep apnea syndrome (OSAS) by RFQIMT and RFQAS technology and analyze the relationships between the parameters of CCA and cardiovascular risk factors.Methods 113 participants with habitual snoring suspected OSAS were divided into control group,mild,moderate and severe OSAS groups according to apnea hypopnea index(AHI)＜5,5-20,20-40,＞40 event/hour respectively.Carotid parameters included intima-media thickness (IMT),diameter (D),distension (Dis),distensibility coefficient (DC),compliance coefficient (CC),pulse wave velocity (PWV),stiffness index α and β were collected by RFQIMT and RFQAS.Multivariate linear regression analysis was applied to analyze the relationships between CCA parameters and cardiovascular risk factors.Results ①The clinical characteristics:blood pressure had significant difference among the four groups (P ＜0.05).SO2,SO2 min decreased and T90,ODI increased significantly in mild,moderate and severe group (P ＜0.05).②The structure parameters of CCA:IMT,D and plaques had no significant difference among the four groups (P ＞0.05).③The elasticity parameters of CCA:Compared with control group,Dis increased significantly in mild group (P ＜0.05).PWV,α,β increased significantly in moderate group (P ＜ 0.05).Compared with mild group,PWV,α,β increased significantly in moderate group (P ＜0.05).Compared with moderate group,α,β increased significantly in severe group (P ＜0.05).④By multivariate linear regression analysis,age was an independent predictor of IMT,Dis,D,CC,PWV,α,β(P ＜0.05).A blunted nocturnal fall was an independent predictor of D,DC,CC,PWV (P ＜0.05),SBP,DBP and PP of daytime had an important effect on D (P ＜0.05).SO2 was independently correlated with PWV (P ＜0.05).PP was an independent predictor of PWV,α,β (P ＜0.05).Smoking was an independent predictor of plaque (P ＜0.05).Conclusions ①Stiffness is damaged earlier than morphology of CCA in patient with OSAS.②PP,a blunted nocturnal fall and SO2 are correlated with stiffness of CCA significantly.It indicates that abnormal circadian blood pressure rhythm and hypoxia are associated significantly with stiffness of CCA in patient with OSAS. Key words: Ultrasonography; Sleep Apnea, obstructive; Carotid arteries; Stiffness; Intima-media thickness