Low sleep quality is associated with progression of arterial stiffness in patients with cardiovascular risk factors: HSCAA study

Cardio-Ankle Vascular Index: Test-Retest Reliability and Agreement in People With Stroke

The cardio-ankle vascular index (CAVI) is superior to traditional methods of measuring arterial stiffness. However, its application in clinical practice has lagged behind the science. This study aimed to (1) examine its test-retest reliability and agreement between repeated measurements, (2) identify the correlation with fatigue and sleep quality, and (3) compare the CAVI values of the bilateral sides of people with stroke, and those of stroke survivors with and without fatigue. Participants (n = 67) were assessed using the CAVI, Fatigue Assessment Scale, and Pittsburgh Sleep Quality Index. The test-retest reliability ranged from 0.77 to 0.86. The Bland-Altman plots showed good agreement between test and retest. The standard error of measurement ranged from 0.59 to 0.66. The minimal detectable change ranged from 1.15 to 1.29. The CAVI values of the bilateral sides correlated with fatigue and those at the paretic side correlated with sleep quality. The CAVI values of the paretic side were higher than those of the non-paretic side in people with stroke. Stroke participants with fatigue had higher CAVI values than those without fatigue. CAVI has good test-retest reliability and agreement between repeated measurements for clinical use.

Sleeping habits and aortic stiffness in middle-aged men and women from the general population: insights from the SCAPIS study

BACKGROUND

The relationship between sleeping habits and aortic stiffness remains inconclusive and is not fully explored in the European general population.

METHODS

We examined cross-sectionally 8659 participants from the Swedish population-based cohort Swedish CArdioPulmonary bioImage Study (SCAPIS), mean age 57.5 years, 52.1% women. A self-administered questionnaire on sleeping habits (duration, quality, insomnia, and daytime sleepiness) was administered. Aortic stiffness was examined by the gold-standard method, carotid-femoral pulse wave velocity (c-f PWV) using Sphygmocor® XCEL, continuously and stratified by cut-off of >10 m/s. Multivariable linear and logistic regression were performed stratified by sex.

RESULTS

Out of 8659 subjects (mean c-f PWV of 9.4 ± 1.9 m/s), 32.3% had c-f PWV >10 m/s, defined as aortic stiffness. Compared with subjects with c-f PWV ≤10 m/s, individuals with aortic stiffness reported more insomnia (p = 0.01) but less daytime sleepiness (p = 0.008). Men and women with poor sleep quality had 0.2 m/s lower mean c-f PWV compared with subjects with good sleep quality (p = 0.004). No difference in mean PWV was found in men and women with shorter/longer sleep duration (p > 0.05). In the multivariable regression models, no significant association was found between poor sleep quality, shorter (≤6 h) or longer (≥9 h) sleep duration and aortic stiffness in the total population, neither among men nor women (all p > 0.05), independently of cardiovascular risk factors.

CONCLUSIONS

Short and long sleep duration and poor sleep quality are not associated with aortic stiffness, measured with the gold-standard method c-f-PWV, in middle-aged men and women from the Swedish general population, independently of cardiovascular risk factors.

Associations of sleep disorders and autonomic dysfunction with cardio-renal function

PURPOSE

Studies have found that sleep disorders and autonomic dysfunction are associated with several metabolic diseases. Moreover, these factors also been reported to be related with the development of atherosclerosis and cardiovascular disease independent of other known factors, and details related to their pathogenesis have recently received increased attention. Additionally, the rates of incidence of heart and renal failure are showing an increasing trend.

METHODS

A literature search was conducted to explore the interrelationship between sleep disorders, autonomic dysfunction, and cardio-renal function.

RESULTS

Sleep disorders and autonomic dysfunction have been shown to be strongly and directly linked to cardio-renal function, as well as various metabolic disorders, while cardiac and renal diseases themselves have been found to have a bidirectional relationship, and can also cause sleep disorders and autonomic dysfunction.

CONCLUSION

Reported findings indicate that sleep disorders and autonomic dysfunction cause metabolic abnormalities, thus are directly or indirectly related to cardio-renal function. With increased attention given to this research field and more focused studies performed, sleep conditions and autonomic function are expected to receive greater recognition as promising clinical targets for the prevention of heart failure and chronic kidney disease in the future.

Arterial stiffness progression in metabolic dysfunction-associated fatty liver disease subtypes: A prospective cohort study

BACKGROUND AND AIMS

We aimed to investigate the correlation and to explore which MAFLD subtypes have the greatest influence on progression of arterial stiffness risk.

METHODS AND RESULTS

Using data from a health examination-based cohort, a total of 12,129 participants who underwent two repeated health examinations that included brachial-ankle pulse wave velocity (baPWV) from 2012 to 2020 were enrolled. Participants were separated into non-MAFLD, overweight/obese (OW-MAFLD), lean/normal weight (lean-MAFLD) and diabetes (DM-MAFLD) groups. Among the participants with a median follow-up of 2.17 years, 4511 (37.2%) participants had MAFLD at baseline, among which 3954 (87.7%), 123 (2.7%), and 434 (9.6%) were OW-, lean- and DM-MAFLD, respectively. Analyses using linear regression models confirmed that compared with the non-MAFLD group, the elevated baPWV change rates (cm/s/year) were 12.87 (8.81-16.94), 25.33 (7.84-42.83) and 38.49 (27.88-49.10) in OW, lean and DM-MAFLD, respectively, while the increased change proportions (%) were 1.53 (1.10-1.95), 3.56 (1.72-5.40) and 3.94 (2.82-5.05), respectively. Similar patterns were observed when these two baPWV parameters were transformed in the form of the greatest increase using Cox proportional hazards model analyses. Furthermore, the risk of arterial stiffness progression across MAFLD subtypes presented a significant, gradient, inverse relationship in the order of DM-, lean-, OW with metabolic abnormalities (MA)-, and OW without MA-MAFLD.

CONCLUSION

MAFLD, especially DM-MAFLD and lean-MAFLD, was significantly associated with arterial stiffness progression, providing evidence that stratification screening and surveillance strategies for CVD risk have important clinical implications.

Nocturnal Hypertension and Left Ventricular Diastolic Dysfunction in Patients With Diabetes With the Absence of Heart Failure: Prospective Cohort HSCAA Study

BACKGROUND

Diabetes is an important risk factor for heart failure (HF) and is associated with left ventricular (LV) diastolic dysfunction. However, diabetic comorbid conditions, such as nocturnal hypertension, as predictors of diastolic dysfunction are not known in the absence of an HF period. The present study was conducted as the longitudinal examination of the predictive value of nocturnal hypertension profiles on the progression of LV diastolic dysfunction in patients with and without diabetes without HF.

METHODS

The subjects (154 diabetes and 268 nondiabetes) in the absence of HF were followed for 36.8±18.2 months. The relationships among the patterns of nocturnal hypertension and the outcome of LV diastolic dysfunction, defined as an increase in E/e'>14, were investigated in the patients with and without diabetes.

RESULTS

The interaction effect of the diabetes status and the patterns of nocturnal hypertension on the hazard rate of the occurrence of E/e'>14 was statistically significant (P=0.017). Kaplan-Meier analysis results revealed that patients with diabetes with nondipper (P=0.021 versus dipper) and riser (P=0.006 versus dipper) had a greater risk for a diastolic dysfunction event. Furthermore, multivariable Cox proportional hazards analysis revealed that nondipper (hazard ratio, 4.56 [95% CI, 1.49-13.96]; P=0.007) and riser (hazard ratio, 3.89 [95% CI, 1.31-11.57]; P=0.014) patterns were associated with elevated risk of the outcome of LV diastolic dysfunction. In contrast, no similar significant associations were found in patients without diabetes.

CONCLUSIONS

During the absence of HF periods, nocturnal hypertension is an important predictor for the progression of LV diastolic dysfunction in patients with diabetes.

Sleep measures and cardiovascular disease in type 2 diabetes mellitus

OBJECTIVE

The objective of this study was to assess whether poor sleep is independently associated with cardiovascular disease in people with type 2 diabetes mellitus (T2DM).

METHODS

A cross-sectional study was performed in subjects with T2DM aged between 40 and 80 years. Sleep assessment was achieved by actigraphy and Pittsburgh Sleep Quality Index (PSQI) score.

RESULTS

The study population comprised 108 subjects with T2DM. The mean age was 64.9 years, the median diabetes duration was 6 years and 73.1% were men. No association was shown between sleep parameters as assessed by actigraphy and T2DM-associated micro- and macrovascular complications. However, sleep quality as assessed by PSQI was significantly associated with macrovascular disease in univariate analysis. Multivariate logistic regression analysis showed red blood cell distribution width (RDW) (odds ratio (OR) 1.79, p=0.018) and good sleep quality (OR 0.35, p=0.017) to be independently associated. Binary logistic regression analysis revealed that body mass index (BMI) (OR 1.11, p=0.024), RDW (OR 1.95, p=0.007) and Center for Epidemiologic Studies Depression score (OR 1.06, p=0.012] were independently associated with abnormal carotid intima-media thickness (CIMT).

CONCLUSIONS

Poor sleep quality and higher RDW levels are associated with macrovascular disease in a T2DM population. Increased BMI as well as depression also appear to have an independent role in subclinical atherosclerosis, as assessed by CIMT.

Association of Sleep Duration and Cardio-Ankle Vascular Index in Community-Dwelling Older Adults

AIM

This study aims to investigate the association of the Cardio-Ankle Vascular Index (CAVI) with self-reported sleep duration and sleep quality in community-dwelling older adults aged ≥ 65 years.

METHODS

The Tarumizu Study was a cohort of community-based health checkups conducted in the Tarumizu City, Japan, in 2018 and 2019. In total, 997 participants aged ≥ 65 years (median age, 74 years) were examined. We obtained the average sleep duration and sleep quality using self-reported questionnaires and classified them into three separate groups according to sleep duration (＜6 h, 6-8 h, and ≥ 8 h) and sleep quality (good, medium, and poor). The arterial stiffness was measured using the CAVI.

RESULTS

As per our findings, the CAVI was significantly higher in the ≥ 8 h sleep group (CAVI=9.6±1.3) than in the ＜6 h (CAVI=9.1±1.1) or 6-8 h (CAVI=9.1±1.2) groups (p＜0.001). After adjustment for age, sex, systolic blood pressure, current smoking status, body mass index, frequency of exercise, educational background, frailty, sleep medication, sleep quality, and nap duration, multivariable regression analysis demonstrated that the CAVI was significantly higher in the ≥ 8 h group than in the 6-8 h group (p=0.016). In contrast, multivariable regression analysis showed that there was no significant association between sleep quality and CAVI.

CONCLUSIONS

A significant association was noted between long sleep duration (≥ 8 h) and elevated CAVI in community-dwelling older adults aged ≥ 65 years. We, therefore, suggest that long sleep duration, not sleep quality, is correlated with arterial stiffness in older adults.

Association between sleep duration and sleep quality with arterial stiffness: A systematic review and meta-analysis

BACKGROUND

Altered sleep parameters, such as duration and quality, play an important role in the pathogenesis and progression of cardiovascular diseases, as well as in all-cause morbidity and mortality. It has been suggested that the specific mechanisms underlying this association could be through the influence of sleep parameters on vascular markers, such as arterial stiffness (AS), although this remains unclear. Thus, in this meta-analysis, we aimed to assess the association between sleep duration and sleep quality with AS in adults.

METHODS

PubMed, Scopus, Web of Science and Cochrane Library databases were searched from inception to July 30, 2021. The DerSimonian and Laird method was used to compute pooled effect size estimates and their respective 95% confidence intervals (95% CIs) of the association of sleep duration and sleep quality with AS. The Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies from the United States National Institute of Health National Heart, Lung, and Blood Institute was used to assess the risk of bias.

RESULTS

Finally, 14 studies (8 cross-sectional studies and baseline data from 6 prospective longitudinal studies) involving 97,837 individuals between 18 and 92 years of age were included. Our results showed that increased sleep duration, as continuous values, does not influence AS (effect size [ES]: 0.00; 95% CIs: -0.15, 0.15) in the general population. However, when sleep duration was longer than 8 hours (ES: 0.21; 95% CIs: 0.06, 0.36), according to sleep categories, a significant increase in pulse wave velocity was shown. Poor sleep quality was associated with increased AS (ES: 0.13; 95% CIs: 0.04, 0.21) in the general population. The overall risk of bias for studies examining sleep duration was fair in 77.8% of the included studies and the overall risk of bias for studies examining sleep quality was fair in 55.6%.

CONCLUSIONS

Our findings showed that both long sleep duration and poor sleep quality were associated with AS in adults. These findings underscore the influence of sleep on vascular health markers, specifically AS, as a possible pathway to explain the increased cardiovascular morbidity and mortality associated with sleep disorders.

Sleep Apnea and Physical Movement During Sleep, But Not Sleep Duration, Are Independently Associated With Progression of Left Ventricular Diastolic Dysfunction: Prospective Hyogo Sleep Cardio-Autonomic Atherosclerosis Cohort Study

Background

Although co‐occurrence of sleep disorder with heart failure is known, it is not clear whether that condition is a cause or consequence of heart failure. The present study was conducted as a longitudinal examination of the predictive value of sleep parameters on progression of left ventricular diastolic dysfunction.

Methods and Results

Four‐hundred fifty‐two subjects were followed for a mean of 34.7 months. An outcome of diastolic dysfunction was defined as increase in early inflow velocity/early diastolic tissue velocity >14. Sleep apnea‐hypopnea index, minimal oxygen saturation, sleep duration, and activity index (physical movement during sleep time, a potential parameter of poor sleep quality) were determined using apnomonitor and actigraphy findings, while heart rate variability was measured with a 24‐hour active tracer device. Sixty‐six of the patients developed diastolic dysfunction during the follow‐up period, with a median time of 25 months. Kaplan–Meier analysis results revealed that those with sleep apnea classified as moderate (apnea‐hypopnea index 15 to <30, P<0.01 versus none) or severe (apnea‐hypopnea index ≥30, P<0.01 versus none), and with a high activity index (Q3 or Q4, P<0.01 versus Q1), but not short sleep duration (P=0.27) had a significantly greater risk for a diastolic dysfunction event. Results of multivariable Cox proportional hazards regression analysis indicated that moderate to severe sleep apnea after a follow‐up period of 3 years (hazard ratio [HR], 9.26 [95% CI, 1.89–45.26], P<0.01) and high activity index (HR, 1.85 [95% CI, 1.01–3.39], P=0.04) were significantly and independently associated with future diastolic dysfunction. Moreover, significant association of high activity index with the outcome was not confounded by either minimal oxygen saturation or heart rate variability.

Conclusions

Sleep apnea and physical movement during sleep, but not sleep duration and autonomic nervous dysfunction, are independent important predictors for progression of left ventricular diastolic dysfunction.

Sleep quality, autonomic dysfunction and renal function in diabetic patients with pre-CKD phase

Diabetes has been established as a strong risk factor for chronic kidney disease (CKD). Sleep apnea, poor sleep quality (PSQ), and autonomic imbalance are also considered to be potential risk factors for decline in renal function, though no known study has examined their integrated predictive value in diabetic and non-diabetic patients without CKD. The present cohort consisted of 754 serial patients (diabetes; n = 231, non-diabetes; n = 523) without CKD registered in the Hyogo Sleep Cardio-Autonomic Atherosclerosis (HSCAA) study. Patients underwent examinations to determine respiratory event index and objective sleep quality using actigraphy, as well as heart rate variability (HRV). Renal outcome was defined as a decline in estimated glomerular filtration rate to less than 60 ml/min/1.73 m² for more than 3 months. Kaplan–Meier analysis showed that diabetic patients with PSQ or low HRV, but not sleep apnea, had a significantly increased risk for renal outcome. Furthermore, Cox proportional hazards analysis revealed that PSQ was significantly associated with elevated risk of renal outcome (HR: 2.57; 95% CI: 1.01–6.53, p = 0.045) independent of sleep apnea and classical risk factors. Low HRV tended to be, but not significantly (p = 0.065), associated with the outcome. In non-diabetic patients, PSQ was also significantly and independently associated with renal outcome, whereas sleep apnea and low HRV were not. In conclusion, PSQ and low HRV appear to be important predictors of decline in renal function in diabetic patients without CKD.

Sleep moderates the association between arterial stiffness and 24-hour blood pressure variability

BACKGROUND

Arterial stiffness and increased blood pressure variability (BPV) are important subclinical cardiovascular diseases (CVDs). Evidence is accumulating that poor sleep is associated with subclinical CVDs. The purpose of our study was to investigate how sleep was related to arterial stiffness and BPV. We also explored whether sleep moderated the association between arterial stiffness and BPV.

METHODS

We conducted a cross-sectional study including 78 healthy adults aged between 35 and 64 years. Variables of interest were: 1) objective seep characteristics, assessed with a wrist actigraphy for two consecutive nights; 2) arterial stiffness, measured by carotid-femoral pulse wave velocity (cfPWV); and 3) BPV, measured using an ambulatory blood pressure monitor over 24 h and estimated by average real variability.

RESULTS

Lower sleep efficiency was an independent predictor of higher cfPWV and higher systolic BPV, while longer wake after sleep onset (WASO) was an independent predictor of higher cfPWV only. In addition, cfPWV showed a positive relationship with systolic BPV, and this relationship was moderated by sleep efficiency and WASO, respectively. The relationship between cfPWV and systolic BPV became stronger among individuals who had a level of sleep efficiency lower than 84% and who had WASO higher than 67 min, respectively.

CONCLUSION

Our study showed that poor sleep not only directly linked with arterial stiffness and BPV but also moderated the relationship between these two subclinical CVDs. These findings suggest that improving sleep quality could be a target intervention to promote cardiovascular health in clinical practice.

On the Association Between Sleep Quality and Arterial Stiffness: A Population Study in Community-Dwelling Older Adults Living in Rural Ecuador (The Atahualpa Project)

STUDY OBJECTIVES

Evidence of an association between atherosclerosis and sleep quality is limited and has not been studied in remote rural settings, where living conditions are different than in urban centers. We aimed to assess the relationship between the aortic pulse wave velocity (PWV) and sleep quality in older adults living in rural Ecuador.

METHODS

Atahualpa residents aged 60 years or older identified during door-to-door surveys, who consented to participate, underwent face-to-face interviews with the Pittsburgh Sleep Quality Index (PSQI) to assess sleep quality. Aortic PWV determinations were performed for arterial stiffness estimation (as a surrogate of atherosclerosis).

RESULTS

A total of 303 individuals were included (mean age: 70.3 ± 7.8 years; 59% women). Univariate logistic regression showed a significant association between the aortic PWV and poor sleep quality (odds ratio [OR] 1.22; 95% confidence interval [CI] 1.07-1.39; P = .003). A multivariate logistic regression model, adjusted for demographics, cardiovascular risk factors, oily fish intake and psychological distress showed a significant association between increased PWV and poor sleep quality (OR 1.59; 95% CI 1.12-2.25; P = .009). Similar significance was noted when the model was adjusted for neuroimaging signatures of cerebral small-vessel disease and stroke (OR 1.47; 95% CI 1.07-2.03; P = .019).

CONCLUSIONS

This study shows a significant independent association between the aortic PWV and poor sleep quality in older adults living in rural Ecuador. Results provide more insights into the relevance of the impact of sleep disorders on cardiovascular diseases.

CLINICAL TRIAL REGISTRATION

The Atahualpa Project has been registered at ClinicalTrials.gov. The identifier number is NCT01627600, and the date was: 10/02/2012.

CITATION

Del Brutto OH, Mera RM, Peñaherrera E, Costa AF, Peñaherrera R, Castillo PR. On the association between sleep quality and arterial stiffness: a population study in community-dwelling older adults living in rural ecuador (the atahualpa project). J Clin Sleep Med. 2019;15(8):1101-1106.

Subclinical decrease in cardiac autonomic and diastolic function in patients with metabolic disorders: HSCAA study

Heart failure due to decreased diastolic function, HFpEF, is a growing health concern with rising prevalence. We examined subclinical cardiac autonomic and diastolic functions in 605 patients with metabolic diseases classified as pre-heart failure. Presence of glucose intolerance or diabetes, or visceral adiposity was significantly associated with reduced cardiac autonomic and diastolic functions. Higher autonomic functions were significantly associated with a parameter of better cardiac diastolic function (E/A) (SDNN: r = 0.306, p < 0.01; HF: r = 0.341, p < 0.01), with the association independent of diabetes, body mass index, visceral adiposity and insulin resistance index. Thus, reduced autonomic function may be a potential predictor for decreased cardiac diastolic functions in metabolic disorders.

•

Metabolic disorders, including diabetes and obesity, are known risk factors for HFpEF.

•

Reduced autonomic function may be involved in pathogenesis of HFpEF.

•

Cardiac diastolic function in metabolic disorders in pre-HF phase is not well examined.

•

In pre-HF subjects, reduced autonomic function is associated with lower cardiac diastolic functions.

•

Our findings provide new insights into HFpEF etiology in metabolic disorders.

Association of self-reported sleep duration and quality with BaPWV levels in hypertensive patients

The association between sleep conditions and arterial stiffness remains inconclusive. We aimed to investigate the relationship of sleep duration and quality with brachial-ankle pulse-wave velocity (baPWV) in hypertensive patients. A total of 14,485 hypertensive adults were included in this cross-sectional analysis. Information about sleep duration and quality was obtained via questionnaire. A baPWV level ≥1800 cm/s was defined as indicative of arterial stiffness. Compared with participants with a sleep duration <8 h per day, participants with a sleep duration ≥8 h per day had a significantly higher baPWV level (β = 13.7 cm/s; 95% CI: 3.9, 23.5) and a nonsignificantly higher prevalence of arterial stiffness (39.7% vs. 33.0%; OR, 1.08; 95% CI: 0.99-1.19). Similarly, compared with participants with good or medium sleep quality, participants with poor sleep quality had a significantly higher baPWV level (β = 16.3 cm/s; 95% CI: 0.1, 32.6) and a nonsignificantly greater prevalence of arterial stiffness (36.6% vs. 35.3%; OR, 1.13; 95% CI: 0.97-1.32). When sleep duration and quality were examined jointly, participants with a sleep duration ≥8 h and/or poor sleep quality had a significantly higher baPWV level (β = 14.4 cm/s; 95% CI: 5.3, 23.4) and a greater prevalence of arterial stiffness (38.8% vs. 32.7%; OR, 1.10; 95% CI: 1.01-1.20) than those with a sleep duration <8 h and good/medium sleep quality. In summary, among hypertensive patients, a longer sleep duration (≥8 h per day) and poor sleep quality were associated with higher baPWV levels and a higher prevalence of arterial stiffness.

State of the Art Review: Brachial-Ankle PWV

The brachial-ankle pulse wave velocity (brachial-ankle PWV), which is measured simply by wrapping pressure cuffs around the four extremities, is a simple marker to assess the stiffness of the medium- to large- sized arteries. The accuracy and reproducibility of its measurement have been confirmed to be acceptable. Risk factors for cardiovascular disease, especially advanced age and high blood pressure, are reported to be associated with an increase of the arterial stiffness. Furthermore, arterial stiffness might be involved in a vicious cycle with the development/progression of hypertension, diabetes mellitus and chronic kidney disease. Increase in the arterial stiffness is thought to contribute to the development of cardiovascular disease via pathophysiological abnormalities induced in the heart, brain, kidney, and also the arteries themselves. A recent independent participant data meta-analysis conducted in Japan demonstrated that the brachial-ankle PWV is a useful marker to predict future cardiovascular events in Japanese subjects without a previous history of cardiovascular disease, independent of the conventional model for the risk assessment. The cutoff point may be 16.0 m/s in individuals with a low risk of cardiovascular disease (CVD), and 18.0 m/s in individuals with a high risk of CVD and subjects with hypertension. In addition, the method of measurement of the brachial-ankle PWV can also be used to calculate the inter-arm systolic blood pressure difference and ankle-brachial pressure index, which are also useful markers for cardiovascular risk assessment.

Associations of sleep quality, sleep apnea and autonomic function with insulin secretion and sensitivity: HSCAA study

RATIONALE AND PURPOSE

Although sleep disorders are shown to be involved in occurrence of diabetes, impacts of several quantitative parameters related to sleep on insulin secretion and sensitivity is yet to be elucidated. We cross-sectionally examined relationships among quantitative sleep quality, sleep apnea, and autonomic function with insulin secretion and sensitivity in 399 patients without previous diagnosed diabetes who underwent 75-g oral glucose tolerance test (75gOGTT).

METHOD

Poor sleep quality (PSQ) was defined as an activity index ≥50 by actigraphy. Sleep apnea was measured by apnomonitor, while standard deviation of all normal-to-normal R-R intervals (SDNN) was measured by active tracer. Parameters of insulin secretion and sensitivity were measured by 75gOGTT.

RESULTS

Patients with PSQ exhibited significantly lower insulinogenic index (r = 0.155, p < 0.01), a parameter of insulin secretion, with the association independent of other clinical factors including apnea and SDNN (β = -0.156, p < 0.01). In contrast, presence of sleep apnea (r = -0.143, p < 0.05) and the lower SDNN (r = -0.150, p < 0.01) were significantly and inversely associated with BIGTT-S, an insulin sensitivity parameter, with the association of SDNN with BIGTT-S remaining significant even after adjustments for PSQ and sleep apnea (β = -0.111, p < 0.05).

CONCLUSION

Poor sleep quality is an independent predictor of pancreatic β-cell function, which could be involved in occurrence of type 2 diabetes.

Increased microparticle levels in middle-aged and elderly patients with insomnia may be involved in the pathogenesis of arteriosclerosis

BACKGROUND

Insomnia may affect vascular factors and promote arteriosclerosis. Microparticles (MPs) are a heterogeneous group of bioactive small vesicles that can be found in blood and body fluids following activation, necrosis or apoptosis of virtually any eukaryotic cells. MPs are believed to participate in the pathogenesis of atherosclerosis. Few studies have been concerned with the microparticle level in patients with sleep disorder. The purpose of the present study is to measure the levels of endothelial microparticles (EMPs), platelet microparticles (PMPs) and leukocyte-derived microparticles (LMPs) in middle-aged and elderly patients with or without insomnia.

METHODS

Patients with insomnia (N.=30) and without insomnia (N.=18) were enrolled. The insomnia group covered patients with chronic insomnia (N.=16) and acute insomnia (N.=14). Levels of EMPs (CD31 +, CD62E +) and PMPs (CD41a +, CD42a +) and granulocyte-derived (CD11a +) MPs were measured. Flow cytometry was performed on the Beckman Coulter analyzer. Reference gate was defined for the level of MPs using 0.22-0.45-0.88μm microspheres, and the size gate for MPs was 0.5-1.0μm.

RESULTS

Of all types of MPs detected, the levels of CD31 +MPs, CD62E +MPs and CD11a +MPs were significantly higher in the insomnia group than in the non-insomnia group (P<0.05). Besides, compared with acute insomnia, the levels of CD31 + MPs and CD11a +MPs were significantly higher in chronic insomnia (P<0.001).

CONCLUSIONS

In insomnia patients, atherosclerosis progression may be increased by the CD31+ EMPs-mediated apoptosis and endothelial injury. The level of CD11a+ LMPs kept increasing as insomnia persisted, which may indicate atherosclerosis progression.

Sleep, Autonomic Nervous Function and Atherosclerosis

Behavioral and psychosocial factors related to development of cardiovascular disease have been gaining increased attention. Notably, sleep is considered to be one of the most important behavioral factors involved in progression of atherosclerosis and cardiovascular events, with autonomic nervous function a potential mechanism. Several studies have shown associations of sleep and autonomic dysfunction with major surrogate markers of atherosclerosis, such as carotid intima-media thickness and arterial stiffness. Endocrinological, immunological, oxidative, inflammatory, and metabolic responses, as well as endothelial dysfunction may mediate the effects of the autonomic nervous system. For this review, we examined recent findings related to sleep, autonomic nervous dysfunction, and atherosclerosis, with the aim of understanding the involved pathophysiological mechanisms.