Sleep Duration and Quality as Related to Left Ventricular Structure and Function

Chronic sleep fragmentation reduces left ventricular contractile function and alters gene expression related to innate immune response and circadian rhythm in the mouse heart

Sleep disorders have emerged as a widespread public health concern, primarily due to their association with an increased risk of developing cardiovascular diseases. Our previous research indicated a potential direct impact of insufficient sleep duration on cardiac remodeling in children and adolescents. Nevertheless, the underlying mechanisms behind the link between sleep fragmentation (SF) and cardiac abnormalities remain unclear. In this study, we aimed to investigate the effects of SF interventions at various life stages on cardiac structure and function, as well as to identify genes associated with SF-induced cardiac dysfunction. To achieve this, we established mouse models of chronic SF and two-week sleep recovery (SR). Our results revealed that chronic SF significantly compromised left ventricular contractile function across different life stages, leading to alterations in cardiac structure and ventricular remodeling, particularly during early life stages. Moreover, microarray analysis of mouse heart tissue identified two significant modules and nine hub genes (Ddx60, Irf9, Oasl2, Rnf213, Cmpk2, Stat2, Parp14, Gbp3, and Herc6) through protein-protein interaction analysis. Notably, the interactome predominantly involved innate immune responses. Importantly, all hub genes lost significance following SR. The second module primarily consisted of circadian clock genes, and real-time PCR validation demonstrated significant upregulation of Arntl, Dbp, and Cry1 after SF, while subsequent SR restored normal Arntl expression. Furthermore, the expression levels of four hub genes (Ddx60, Irf9, Oasl2, and Cmpk2) and three circadian clock genes (Arntl, Dbp, and Cry1) exhibited correlations with structural and functional echocardiographic parameters. Overall, our findings suggest that SF impairs left ventricular contractile function and ventricular remodeling during early life stages, and this may be mediated by modulation of the innate immune response and circadian rhythm. Importantly, our findings suggest that a short period of SR can alleviate the detrimental effects of SF on the cardiac immune response, while the influence of SF on circadian rhythm appears to be more persistent. These findings underscore the importance of good sleep for maintaining cardiac health, particularly during early life stages.

Effect of insomnia and excessive daytime sleepiness on cardiac functions in older adults

BACKGROUND

We investigated the potential harmful effect in older adults of insomnia and excessive daytime sleepiness (EDS) on myocardial functions and electrophysiologic changes of the heart in terms of heart rate and QT intervals corrected for heart rate (QTc).

METHODS

The study included 32 insomnia patients and 30 control subjects. An Insomnia Severity Index score of ≥15 indicated insomnia, while a score of <8 was accepted as the control group. The Epworth Sleepiness Scale was used to assess EDS, with a score of ≥11/24 points indicating EDS. Diastolic and systolic functions were evaluated in each patient by transthoracic two-dimensional, conventional and tissue Doppler echocardiography. Heart rate and QTc were calculated for electrophysiologic changes.

RESULTS

The mean age was 73.2 ± 7.9 years, with 59.7% being female. Biventricular systolic and diastolic functions were impaired in the insomnia patients. The E' value for diastolic function was lower in the patients with insomnia than the controls (5.99 ± 1.59 vs. 6.88 ± 0.97, P = 0.053). Furthermore, values for the systolic function parameters Lateral-S (7.41 ± 1.92 vs. 9.37 ± 1.83, P < 0.001), Septal-S (6.69 ± 1.40 vs. 8.10 ± 1.30, P = 0.001), and Tricuspid-S (12.25 ± 2.00 vs. 14.37 ± 3.13, P = 0.004) were lower for insomnia patients than for controls. In the case of EDS coexistence, the heart rate and QTc values were higher than the controls (76.47 ± 7.18 vs. 71.03 ± 10.95, P = 0.001, and 413.72 ± 28.24 vs. 394.67 ± 24.47, P = 0.015, respectively).

CONCLUSION

Insomnia is associated with impaired systolic-diastolic functions, independent of EDS. The co-existence of insomnia and EDS may lead to electrophysiological changes in older adults, including increased heart rate and longer QTc.

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.

A nomogram integrating non-ECG factors with ECG to screen left ventricular hypertrophy among hypertensive patients from northern China

OBJECTIVE

We aimed to establish and validate a user-friendly and clinically practical nomogram for estimating the probability of echocardiographic left ventricular hypertrophy (echo-LVH) indexed to BSA among hypertensive patients from northern China.

METHODS

A total of 4954 hypertensive patients were recruited from a population-based cohort study from January 2012 to August 2013. The dataset was randomly split into two sets: training (n = 3303) and validation (n = 1651). Three nomograms were initially constructed. That is the Cornell product nomogram, the non-ECG nomogram, and the integrated nomogram which integrated non-ECG risk factors and Cornell-voltage duration product. The least absolute shrinkage and selection operator strategies were employed to screen for non-ECG features. The performance of the nomograms was evaluated using discrimination, calibration, and decision curve analysis (DCA). The net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were also calculated.

RESULTS

The AUCs, NRIs, IDIs, and DCA curves of the nomograms demonstrated that the integrated nomogram performed best among all three nomograms. The integrated nomogram incorporated age, sex, educational level, hypertension duration, SBP, DBP, eGFR, sleep duration, tea consumption, and the Cornell-voltage duration product. The AUC was 0.758 and had a good calibration (Hosmer-Lemeshow test, P = 0.73). Internal validation showed an acceptable AUC of 0.735 and good calibration was preserved (Hosmer-Lemeshow test, P = 0.19). The integrated nomogram was clinically beneficial across a range of thresholds of 10-50%.

CONCLUSION

The integrated nomogram is a convenient and reliable tool that enables early identification of hypertensive patients at high odds of LVH and can assist clinicians in their decision-making.

Association of Sleep Quality With Greater Left Ventricular Mass in Children Aged 9 to 11 Years

OBJECTIVE

Research has consistently found associations between sleep characteristics and cardiovascular disease risk in children, adolescents, and adults. Although primarily investigated in clinical samples (e.g., in those with sleep disorders), greater left ventricular mass is associated with poor sleep quality in nonclinical adult populations as well; however, this has not been evaluated in children or adolescents. Our study aim was to consider the relationship between objectively measured sleep characteristics and left ventricular mass in children.

METHODS

We assessed sleep and cardiac structure in a biracial sample of 9- to 11-year-old children (n = 176; 41% White, 59% Black; 50% female). Sleep was assessed with actigraphy for five nights. Cardiac dimensions were assessed using echocardiography.

RESULTS

After adjusting for covariates, we found that poor sleep quality was associated with significantly greater left ventricular mass (β = 0.13, t(167) = 2.14, p = .034, Cohen d = 0.16, for activity during sleep; β = 0.15, t(167) = 2.43, p = .016, Cohen d = 0.18, for sleep fragmentation). Other cardiac dimensions (namely, relative wall thickness and right ventricular dimension) were also significantly associated with sleep characteristics. Notably, associations did not differ as a function of sex or race.

CONCLUSIONS

The present findings are novel and unique because no prior reports have systematically documented the association between poor sleep quality with potentially detrimental cardiac remodeling in a nonclinical sample of children. However, the novelty and importance of these findings require additional research for confirmation.

Metabolic syndrome is associated with better quality of sleep in the oldest old: results from the "Mugello Study"

BACKGROUND AND AIMS

Reduced sleep quality is common in advanced age. Poor sleep quality is associated with adverse outcomes, chiefly cardiovascular, in young and middle-aged subjects, possibly because of its association with metabolic syndrome (MetS). However, the correlates of sleep quality in oldest populations are unknown. We evaluated the association of sleep quality with MetS in a cohort of subjects aged 90+.

METHODS AND RESULTS

We analysed data of 343 subjects aged 90+ living in the Mugello area (Tuscany, Italy). Quality of sleep was assessed using the Pittsburgh Sleep Quality Assessment Index (PSQI). Good quality of sleep was defined by a PSQI score < 5. MetS was diagnosed according to the National Cholesterol Education Program's ATP-III criteria; 83 (24%) participants reported good quality of sleep. MetS was diagnosed in 110 (24%) participants. In linear and logistic models, MetS was inversely associated with PSQI score ((B = - 1.04; 95% CI - 2.06 to - .03; P = .044), with increased probability of good sleep quality (OR = 2.52; 95% CI 1.26-5.02; P = .009), and with a PSQI below the median (OR = 2.11; 95% CI 1.11-3.40, P = .022), after adjusting. None of the single components of MetS were associated with PSQI (all P values > .050). However, an increasing number of MetS components was associated with increasing probability of good quality of sleep (P for trend = .002), and of PSQI below the median (P for trend = .007). Generalized Additive Model analysis documented no smoothing function suggestive of nonlinear association between PSQI and MetS.

CONCLUSION

Our results confirm a high prevalence of poor sleep quality in oldest age; however, in these subjects, MetS seems to be associated with better sleep quality. Additional larger, dedicated studies are required to confirm our results, and, if so, to identify the subsystems involved and the potential therapeutic implications of such an association.

Association Between Sleep Duration, Quality and Body Mass Index in the Korean Population

STUDY OBJECTIVES

Mounting evidence indicates that sleep disturbance contributes to the increased risk for cardiometabolic diseases. Obesity and underweight are also closely linked to cardiometabolic risk. Thus, the objective of this study was to examine the association between sleep duration, quality, and body mass index (BMI) categories.

METHODS

Using data from a cohort of 107,718 Korean individuals (63,421 men and 44,297 women), we conducted cross-sectional analysis with sex subgroup analysis. Sleep duration was classified into 3 groups-short (< 7 hours), normal (7-9 hours) and long sleep (> 9 hours)-and Pittsburgh Sleep Quality Index (PSQI) score was used to divide sleep quality into 2 groups-poor (PSQI > 5) and good sleep (PSQI ≤ 5). Compared to normal sleep and good sleep quality, adjusted odds ratios of short and long sleep and poor sleep for BMI categories were calculated. BMI categories included underweight (BMI < 18.5 kg/m²), overweight (BMI 23 to < 25 kg/m²), obesity (BMI 25 to < 30 kg/m²) and severe obesity (BMI ≥ 30 kg/m²).

RESULTS

Short sleep duration had the dose-dependent relationship with obesity categories from overweight to severe obesity, and inverse relationship with underweight (adjusted odds ratios [95% confidence intervals] for underweight, overweight, obesity, and severe obesity versus normal weight; 0.88 [0.82-0.94], 1.15 [1.11-1.20], 1.31 [1.26-1.37], 1.70 [1.54-1.85]). Poor sleep quality was significantly associated with severe obesity in male subgroup (1.16 [1.05-1.27]) and with obesity (1.18 [1.10-1.25]) and severe obesity in female subgroup (1.66 [1.40-1.98]).

CONCLUSIONS

Short sleep duration and poor sleep quality was more positively associated with obesity across BMI than underweight.