Association of sleep duration and quality with elevated hs-CRP among healthy Korean adults

Evaluation of risk factors related to sleep disorders in patients undergoing hemodialysis using a nomogram model

This study aimed to investigate the risk factors related to sleep disorders in patients undergoing hemodialysis using a nomogram model. A cross-sectional survey was conducted in a hospital in Zhejiang province, China from January 1, 2020, to November 31, 2022 among patients undergoing hemodialysis. Dietary intake was assessed applying a Food Frequency Questionnaire. Sleep quality was evaluated by the Pittsburgh Sleep Quality Index. Evaluation of risk factors related to sleep disorders in patients undergoing hemodialysis was using a nomogram model. This study included 201 patients and 87 individuals (43.3%, 87/201) exhibited sleep disorders. The average age of included patients was 51.1 ± 9.0 years, with males accounting for 55.7% (112/201). Results from nomogram model exhibited that potential risk factors for sleep disorders in patients undergoing hemodialysis included female, advanced age, increased creatinine and alanine aminotransferase levels, as well as higher red meat consumption. Inversely, protective factors against sleep disorders in these patients included higher consumption of poultry, fish, vegetables, and dietary fiber. The C-index demonstrated a high level of discriminative ability (0.922). This study found that age, sex, and dietary factors were associated with sleep disorders in hemodialysis patients. Hemodialysis patients with sleep disorders require urgent dietary guidance.

Associations between sleep duration, sleep disturbance and cardiovascular disease biomarkers among adults in the United States

BACKGROUND

Sleep problems are associated with abnormal cardiovascular biomarkers and an increased risk of cardiovascular diseases (CVDs). However, studies investigating associations between sleep problems and CVD biomarkers have reported conflicting findings. This study examined the associations between sleep problems and CVD biomarkers in the United States.

METHODS

Data were from the National Health and Nutrition Examination Survey (NHANES) (2007-2018) and analyses were restricted to adults ≥ 20 years (n = 23,749). CVD biomarkers [C-reactive Protein (CRP), low-density lipoproteins, high-density lipoproteins (HDL), triglycerides, insulin, glycosylated hemoglobin (HbA1c), and fasting blood glucose] were categorized as abnormal or normal using standardized cut-off points. Sleep problems were assessed by sleep duration (short [≤ 6 h], long [≥ 9 h], and recommended [> 6 to < 9 h) and self-reported sleep disturbance (yes, no). Multivariable logistic regression models explored the associations between sleep duration, sleep disturbance, and CVD biomarkers adjusting for sociodemographic characteristics and lifestyle behaviors.

RESULTS

The mean sleep duration was 7.1 ± 1.5 h and 25.1% of participants reported sleep disturbances. Compared to participants with the recommended sleep duration, those with short sleep duration had higher odds of abnormal levels of HDL (adjusted odds ratio [aOR] = 1.20, 95% confidence interval [CI] = 1.05-1.39), CRP (aOR = 3.08, 95% CI = 1.18-8.05), HbA1c (aOR = 1.25, 95% CI = 1.05-1.49), and insulin (aOR = 1.24, 95% CI = 1.03-1.51). Long sleep duration was associated with increased odds of abnormal CRP (aOR = 6.12, 95% CI = 2.19-17.15), HbA1c (aOR = 1.54, 95% CI = 1.09-2.17), and blood glucose levels (aOR = 1.45, 95% CI = 1.07-1.95). Sleep disturbance predicted abnormal triglyceride (aOR = 1.18, 95% CI = 1.01-1.37) and blood glucose levels (aOR = 1.24, 95% CI = 1.04-1.49).

CONCLUSION

Short and long sleep durations were positively associated with abnormal CRP, HDL, HbA1c, blood glucose, and insulin levels, while sleep disturbance was associated with abnormal triglyceride and blood glucose levels. Since sleep is a modifiable factor, adopting healthy sleeping habits may create a balanced metabolism and reduce the risk of developing a CVD. Our study may provide insights into the relationship between sleep duration, sleep disturbance, and CVD risk.

The association between energy-adjusted dietary inflammatory index and physical activity with sleep quality: a cross-sectional study

BACKGROUND

The study aimed to assess the independent and interactive association of energy-adjusted dietary inflammatory index (E-DII) and physical activity (PA) with sleep quality.

METHOD

A cross-sectional study was conducted on the 2466 participants (60% women). A 116-item food frequency questionnaire (FFQ) was applied to calculate E-DII, the International Physical Activity Questionnaire (IPAQ) long form for PA, and the Pittsburgh sleep quality index (PSQI) to assess sleep quality were collected via interview. Multivariate logistic regression was applied to assess independent and interactive associations of E-DII and PA with sleep quality.

RESULT

No significant association was observed between E-DII and sleep quality (OR: 0.96, 95% CI: 0.92_1.01). Also, there was no significant association between the levels of PA and sleep quality. Women had 70% increased odds for poor sleep quality (OR: 1.7, 95% CI: 1.39_2.09) compared with men. No interactive association was observed between E-DII and PA levels with sleep quality.

CONCLUSION

No significant association was observed between E-DII and PA levels with sleep quality. The study indicates a gender difference in sleep quality. Future prospective studies are required to confirm these findings.

The causal associations of altered inflammatory proteins with sleep duration, insomnia and daytime sleepiness

STUDY OBJECTIVES

Growing evidence linked inflammation with sleep. This study aimed to evaluate the associations and causal effects of sleep traits including insomnia, excessive daytime sleepiness (EDS), and sleep duration (short: <7 h; normal: 7-9 h; long: ≥9 h), with levels of C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), and interleukins.

METHODS

Standard procedures of quantitative analysis were applied to estimate the expression differences for each protein in compared groups. Then, a two-sample Mendelian randomization (MR) analysis was performed to explore their causal relationships with published genome-wide association study summary statistics. The inverse-variance weighted was used as the primary method, followed by several complementary approaches as sensitivity analyses.

RESULTS

A total of 44 publications with 51 879 participants were included in the quantitative analysis. Our results showed that the levels of CRP, interleukin-1β (IL-1β), IL-6, and TNF-α were higher from 0.36 to 0.58 (after standardization) in insomnia compared with controls, while there was no significant difference between participants with EDS and controls. Besides, there was a U/J-shaped expression of CRP and IL-6 with sleep durations. In MR analysis, the primary results demonstrated the causal effects of CRP on sleep duration (estimate: 0.017; 95% confidence intervals [CI], [0.003, 0.031]) and short sleep duration (estimate: -0.006; 95% CI, [-0.011, -0.001]). Also, IL-6 was found to be associated with long sleep duration (estimate: 0.006; 95% CI, [0.000, 0.013]). These results were consistent in sensitivity analyses.

CONCLUSIONS

There are high inflammatory profiles in insomnia and extremes of sleep duration. Meanwhile, elevated CRP and IL-6 have causal effects on longer sleep duration. Further studies can focus on related upstream and downstream mechanisms.

Association of Self-Reported Nighttime Sleep Duration with Chronic Kidney Disease: China Health and Retirement Longitudinal Study

INTRODUCTION

The cohort study aimed to assess the association of nighttime sleep duration and the change in nighttime sleep duration with chronic kidney disease (CKD) and whether the association between nighttime sleep duration and CKD differed by daytime napping.

METHODS

This study included 11,677 individuals from the China Health and Retirement Longitudinal Study (CHARLS) and used data from the 2011 baseline survey and four follow-up waves. Nighttime sleep duration was divided into three groups: short (<7 h per night), optimal (7-9 h), and long nighttime sleep duration (>9 h). Daytime napping was divided into two groups: no nap and with a nap. We used Cox proportional hazards model to examine the effect of nighttime sleep duration at baseline and change in nighttime sleep duration on incident CKD and a joint effect of nighttime sleep duration and nap time on onset CKD.

RESULTS

With a follow-up of 7 years, the incidence of CKD among those with short, optimal, and long nighttime sleep duration was 9.89, 6.75, and 9.05 per 1,000 person-years, respectively. Compared to individuals with optimal nighttime sleep duration, short nighttime sleepers had a 44% higher risk of onset CKD (hazard ratio [HR]: 1.44, 95% confidence interval [CI]: 1.21-1.72). Compared to participants with persistent optimal nighttime sleep duration, those with persistent short or long nighttime sleep duration had an increased risk of incident CKD (HR: 1.44, 95% CI: 1.15-1.80). We found a lower incidence of CKD in participants with short nighttime sleep duration and a nap (HR: 0.74, 95% CI: 0.60-0.93), compared to those with short nighttime sleep duration and no nap.

CONCLUSION

Short nighttime sleep duration and persistent long or short nighttime sleep duration were associated with a higher risk of onset CKD. Keeping persistent optimal nighttime sleep duration may help reduce CKD risk later in life. Daytime napping may be protective against CKD incidence.

Association between Sleep Duration and Incident Diabetes Mellitus in Healthy Subjects: A 14-Year Longitudinal Cohort Study

BACKGROUND

This study aimed to investigate whether sleep duration and/or quality are associated with incident diabetes mellitus (DM).

METHODS

A total of 8816 of 10,030 healthy participants were enrolled in a prospective cohort study. Sleep duration and quality questionnaires were completed. Sleep quality was assessed using the Epworth Sleepiness Scale (ESS), which measures excessive daytime sleepiness in individuals.

RESULTS

During the 14-year follow-up period, 18% (1630/8816) were diagnosed with DM. A U-shaped relationship was observed between sleep duration and incident DM, with the highest risk observed when sleep duration was ≥10 h/day (hazard ratios (HR) 1.65 [1.25-2.17]). This group exhibited decreased insulin glycogenic index, a marker of insulin secretory function, during the study period. Among study participants who slept less than 10 h/day, the risk of incident DM increased when the ESS score was >10.

CONCLUSIONS

We found that the association between sleep duration and incident DM was U-shaped; both short (≤5 h) and long (≥10 h) sleep durations were associated with an increased risk for the occurrence of incident DM. When sleep duration was 10 h or longer per day, there was a tendency to develop DM due to decreased insulin secretory function.

Individual Heterogeneity in the Relations Between Sleep, Inflammation, and Somatic Symptoms

OBJECTIVE

Poor sleep is associated with the experience of more somatic symptoms and a proinflammatory state, whereas a proinflammatory state may also result in the experience of more somatic symptoms. However, existing studies ignore individual differences in these associations. We aimed to study relations between sleep, inflammatory markers, and somatic symptoms at a within-individual level.

METHODS

Time series of daily data on sleep, somatic symptoms, and inflammation markers in 10 healthy individuals (age, 19-58 years; three men) for 63 days were analyzed. Bidirectional lagged ( t - 1) and contemporaneous ( t ) relations between sleep duration, inflammatory markers (C-reactive protein, interferon-α, interleukin 1RA), and somatic symptoms were analyzed using 24-hour urine and diary data. Unified structural equation modeling was used to analyze the association between sleep duration, the three inflammatory markers, and the amount of somatic symptoms at the individual level.

RESULTS

Associations were found between sleep and at least one of three inflammatory markers in four individuals, both positive (three associations) and negative (five associations) and contemporaneous (four associations) and lagged (four associations). Sleep was related to somatic symptoms in four individuals, both positive ( n = 2) and negative ( n = 2) and contemporaneous ( n = 3) and lagged ( n = 1). Inflammatory markers were associated with somatic symptoms in three individuals, both positive (three associations) and negative (one association) and contemporaneous (three associations) and lagged (one associations). Two individuals showed no associations between sleep, inflammatory markers, and somatic symptoms.

CONCLUSIONS

We observed a large variability in presence, strength, and direction of associations between sleep, inflammatory markers, and somatic symptoms.

Effect of weekend catch-up sleep on high-sensitivity C-reactive protein levels according to bedtime inconsistency: a population-based cross-sectional study

To investigate the associations of weekend catch-up sleep (WCS) and high-sensitivity C-reactive protein (hs-CRP) levels according to bedtime inconsistency in the Korean population. In this cross-sectional study using the Korea National Health and Nutrition Examination Survey (2016-2018) with 17,665 participants, four groups were defined: no-WCS (WCS within ± 1 h of weekday sleep time), moderate WCS (1 ≤ , < 3 h), severe WCS (≥ 3 h), and inverse WCS (≤ - 1 h). An inconsistent bedtime was defined as a > 2 h difference between weekend and weekday bedtimes. Outcomes were divided into quartiles based on the hs-CRP level: Lowest (< 0.34), Middle-low (≥ 0.34, < 0.55), Middle-high (≥ 0.55, < 1.10), Highest (≥ 1.10). Adjusted odds ratios (aORs) with 95% confidence intervals (CIs) were calculated using multinomial logistic regression, controlling for relevant covariates. Moderate WCS was associated with a lower risk for the highest hs-CRP levels than no WCS (aOR = 0.87, 95% CI 0.78-0.97), and a similar association was observed only in participants with consistent bedtimes (aOR = 0.88, 95% CI 0.78-0.99). Significant interactions of those associations of WCS and hs-CRP levels with bedtime inconsistency were found. These findings provide evidence that people with inconsistent bedtimes would have limited protective effect of WCS on hs-CRP.

Lack of direct association between viral hepatitis and sleep disturbances

Background

Individuals with chronic viral hepatitis are at increased risk of experiencing poor sleep quality and sleep disturbances. However, it remains unclear whether the sleep disorders associated with viral hepatitis are secondary to the comorbidities related to viral hepatitis or the direct effect of hepatitis viruses on sleep. This study investigated the direct impact of viral hepatitis B and C on sleep quality.

Methods

Individuals with viral hepatitis B or C and their healthy counterparts were recruited for the present study, and they were evaluated with the Parkinson's Disease Sleep Scale-2, the Epworth Sleepiness Scale, and the Pittsburgh Sleep Quality Index in the absence of common comorbidities associated with viral hepatitis.

Results

Neither hepatitis B nor hepatitis C was found to cause significant differences in insomnia symptoms or excessive daytime sleepiness. However, individuals with hepatitis C, but not hepatitis B, tended to be less likely to experience restlessness of the legs or arms at night.

Conclusions

This study suggests that hepatitis viruses B and C may not cause a significant impact on sleep quality and related disorders directly. Sleep disturbances in individuals with chronic viral hepatitis may instead be attributable to hepatic decompensation or the comorbid factors associated with viral hepatitis.

Examining the role of systemic chronic inflammation in diet and sleep relationship

BACKGROUND

It is well known that systemic chronic inflammation (SCI), which can be modulated by diet, is associated with poor sleep outcomes. However, the role of SCI in diet health and sleep quality relationship has not been well established.

METHODS

Here, by using the UK Biobank data set, we assessed the association between markers of SCI (leukocyte, platelet, lymphocyte, neutrophil, and basophil counts; C-reactive protein levels and neutrophil to lymphocyte ratio (NLR)), habitual intake of food groups, diet health and sleep quality in 449,084 participants. We also formally tested the possibility that SCI might mediate the relationship between diet health and sleep quality.

RESULTS

Our results revealed (i) negative associations between SCI and food groups that are abundant in healthy diets (fruit, vegetable and oily and non-oily fish) and (ii) positive associations between SCI and food groups that are abundant in unhealthy diets (processed meat). Sleep quality was also negatively associated with platelet counts, CRP levels and NLR. Crucially, however, while platelet and neutrophil counts, CRP levels and NLR fully mediated the association between diet health and sleep quality, leukocyte, lymphocyte and basophil counts partially mediated the associations between diet health and sleep quality.

CONCLUSION

Reducing SCI via dietary interventions could be an effective primary and/or complementary strategy to increase sleep quality. Further interventional trials are warranted to (i) establish the strength of associations, preferably by using validated diet and sleep measures and (ii) examine longer term effects of anti-inflammatory diets on sleep-, diet- and inflammation-related health outcomes.

Association between sleep characteristics, ideal cardiovascular health, and systemic inflammation, NHANES 2017-2018

There is conflicting evidence regarding the associations between sleep deprivation and inflammatory biomarkers indicative of cardiovascular disease risk, such as high-sensitivity C-reactive protein (hsCRP). The association between sleep habits and hsCRP was quantified in a nationally representative sample of adults in the United States and mediation by ideal cardiovascular health metrics was explored. A cross-sectional analysis of cardiovascular disease-free participants aged 20-79 years from the 2017-2018 National Health and Nutrition Examination Survey was conducted. The primary exposures were self-reported sleep duration, sleep debt (difference between the average weekday and weekend sleep duration), and ideal cardiovascular health (11-14 points). The primary outcome was hsCRP (high-risk ≥ 3.0 mg/L). Multivariable robust Poisson models were used to estimate prevalence ratios after multiple imputation. A subgroup analysis of shift workers was also conducted. Of 4027 participants included (mean age 46 years; 52% female; 41% shift workers), the prevalence of sleeping <6 h on weekdays was 9%, with 40% sleeping ≥9 h on weekends. One-quarter had a high (≥2 h) sleep debt, 82% had poor cardiovascular health, and 34% had high-risk hsCRP. There were no significant associations between weekday sleep duration or sleep debt with high-risk hsCRP, even among shift workers. Mediation analysis was not conducted. Ideal cardiovascular health was associated with a lower prevalence of high-risk hsCRP (prevalence ratios, 0.60, 95% CI, 0.48-0.75). The lack of significant associations suggests a complex interrelationship of hsCRP with factors beyond sleep duration. Examination of populations at highest risk of chronic sleep deprivation could help to elucidate the association with systemic inflammation-related outcomes.