Association between nontraditional lipid profiles and the severity of obstructive sleep apnea: A retrospective study

BACKGROUND

Due to the significant role of dyslipidemia, cardiovascular diseases (CVDs) are very common in obstructive sleep apnea (OSA). Nontraditional lipid indices are considered to be a better predictive index for cardiovascular risk. Nevertheless, the association between nontraditional lipid profiles and the severity of OSA is not clear.

METHODS

A retrospective study was proceeded on 635 patients. Subjects were diagnosed with OSA through polysomnography (PSG). The association between severe OSA and nontraditional lipid profiles [triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C) ratio, total cholesterol (TC)/HDL-C ratio, low-density lipoprotein cholesterol (LDL-C)/HDL-C ratio, non-high-density lipoprotein cholesterol (non-HDL-C), atherogenic index (AI), and lipoprotein combine index (LCI)] was examined by utilizing the restricted cubic spline and multivariate logistic regression analysis.

RESULTS

All nontraditional lipid indices had positive relationships with the severity of OSA. By multivariable adjustment, the per SD increment of the TG/HDL-C, TC/ HDL-C, LDL-C/HDL-C, non-HDL-C, AI, and LCI were significantly associated with 88%, 50%, 42%, 40%, 50%, and 125% higher risk for severe OSA respectively. Compared with the lowest tertiles, the adjusted ORs (95% CI) were 2.42 (1.57-3.75), 2.39 (1.53-3.73), 2.35 (1.52-3.64), 1.86 (1.21-2.86), 2.39 (1.53-3.73), and 2.23 (1.43-3.48) for the top tertiles of TG/HDL-C, TC/ HDL-C, LDL-C/HDL-C, non-HDL-C, AI, and LCI respectively.

CONCLUSION

All nontraditional lipid indices had positive relationship with the severity of OSA. In addition, TG/HDL-C, TC/HDL-C, and AI had better performance than the other nontraditional lipid indices for predicting severe OSA. These findings could help to determine the risk of cardiovascular diseases and improve the dyslipidemia management of OSA patients.

Sleep profile status based on substance use, lipids and demographic variables in Tabari cohort study

BACKGROUND

This study aims to investigate the situation of sleep profile and its related factors in the Tabari Cohort Tabari (TCS) population.

METHODS

The information of 10255 of the Tabari cohort population in the enrolment phase was used in this study. The sleep profile data was collected and recorded by trained questioners. The sleep duration in day & night, the time interval between going bed and falling asleep, continuous use of sedatives, involuntary nap, limb hypermobility during sleep and shift working were determined for each person. Data analysis was performed by independent T test and Pearson correlation coefficient.

RESULTS

Mean, standard deviation, median, minimum and maximum of sleep duration in this population were 7.6, 1.6, 7.5, 0.5 and 17 h. Frequency of sleeping less than 6 h, 6-10 h and more than 10 h were 1168(11.4%), 8463(82.5%) and 624(6.1%) respectively. Prevalence of sleeping more than 10 h among men and women were 5% and 6.8% respectively (P < 0.001). Prevalence of sedative routine use among men and women were 4.7% and 9.6% respectively (P < 0.001). There were significant relationships between sleep duration and area residence, age group (P < 0.001), education level (P < 0.001), socioeconomic level (P < 0.001), triglyceride (P = 0.002), HDL-cholesterol (P = 0.013) and Cholesterol total (P = 0.021). There was a negative correlation between age and sleep duration (r = -0.062, P < 0.001).

CONCLUSION

The results showed the association of the quality and quantity of sleep with personal, social, environmental and biological factors such as gender, age, economic status, educational status, and lipid profile. Therefore without proper intervention, the incidence of outcomes associated with these risk factors can be predicted in TCS In later years.

Relationship between lipids and sleep apnea: Mendelian randomization analysis

BACKGROUND

Lipids increase the risk of sleep apnea; however, the causality between them is still inconclusive.

AIM

To explore the causal relationship between serum lipids and sleep apnea using two-sample Mendelian randomization (MR) analysis.

METHODS

Single nucleotide polymorphism (SNP) data related to serum lipids were obtained from the Global Lipids Genetics Consortium study, which included 188578 individuals of European ancestry. Additionally, sleep apnea-related SNP data were collected from the United Kingdom Biobank study, which comprised 463005 individuals of European ancestry. Two-sample MR analysis was performed to assess the causality between serum lipids and sleep apnea based on the above public data.

RESULTS

Genetically predicted low-density lipoprotein (odds ratio [OR] = 0.99, 95% confidence interval [CI] = 0.99 to 1.00; P = 0.58), high-density lipoprotein (OR = 0.99, 95%CI = 0.99 to 1.00; P = 0.91), triglyceride (OR = 1.00, 95%CI = 0.99 to 1.00; P = 0.92), and total cholesterol (OR = 0.99, 95%CI = 0.99 to 1.00; P = 0.33) were causally unrelated to sleep apnea.

CONCLUSION

Our MR analysis suggests that genetically predicted serum lipids are not risk factors of sleep apnea.

ABOSA - Freely available automatic blood oxygen saturation signal analysis software: Structure and validation

BACKGROUND AND OBJECTIVE

Many sleep recording software used in clinical settings have some tools to automatically analyze the blood oxygen saturation (SpO₂) signal by detecting desaturations. However, these tools are often inadequate for scientific research as they do not provide SpO₂ signal-based parameters which are superior in the estimation of sleep apnea severity and related medical consequences. In addition, these software require expensive licenses and they lack batch analysis tools. Thus, we developed the first freely available automatic blood oxygen saturation analysis software (ABOSA) that provides sophisticated SpO₂ signal-based parameters and enables batch analysis of large datasets.

METHODS

ABOSA was programmed with MATLAB. ABOSA automatically detects desaturation and recovery events from the SpO₂ signals (EDF files) and calculates numerous parameters, such as oxygen desaturation index (ODI) and desaturation severity (DesSev). The accuracy of the ABOSA software was evaluated by comparing its desaturation scorings to manual scorings in Kuopio (n = 1981) and Loewenstein (n = 930) sleep apnea patient datasets. Validation was performed in a second-by-second manner by calculating Matthew's correlation coefficients (MCC) and median differences in parameter values. Finally, the performance of the ABOSA software was compared to two commercial software, Noxturnal and Profusion, in 100 patient subpopulations. As Noxturnal or Profusion does not calculate novel desaturation parameters, these were calculated with custom-made functions.

RESULTS

The agreements between ABOSA and manual scorings were great in both Kuopio (MCC = 0.801) and Loewenstein (MCC = 0.898) datasets. However, ABOSA slightly overestimated the desaturation parameter values. The median differences in ODIs were 0.8 (Kuopio) and 0.0 (Loewenstein) events/h. Similarly, the median differences in DesSevs were 0.02 (Kuopio) and 0.01 (Loewenstein) percentage points. In a second-by-second analysis, ABOSA performed very similarly to Noxturnal and Profusion software in both Kuopio (MCC_ABOSA = 0.807, MCC_Noxturnal = 0.807, MCC_Profusion = 0.811) and Loewenstein (MCC_ABOSA = 0.904, MCC_Noxturnal = 0.911, MCC_Profusion = 0.871) datasets. Based on Noxturnal and Profusion scorings, the desaturation parameter values were similarly overestimated compared to ABOSA.

CONCLUSIONS

ABOSA is an accurate and freely available software that calculates both traditional clinical parameters and novel parameters, provides a detailed characterization of desaturation and recovery events, and enables batch analysis of large datasets. These are features that no other software currently provides making ABOSA uniquely suitable for scientific research use.

Effect of Continuous Positive Airway Pressure on Lipid Profiles in Obstructive Sleep Apnea: A Meta-Analysis

BACKGROUND

Obstructive sleep apnea (OSA) is associated with dyslipidemia. However, the effects of continuous positive airway pressure (CPAP) treatment on lipid profiles are unclear.

METHODS

PubMed/Medline, Embase and Cochrane were searched up to July 2021. Randomized controlled trials (RCTs) of CPAP versus controls with ≥4 weeks treatment and reported pre- and post-intervention lipid profiles were included. Weighted mean difference (WMD) was used to assess the effect size. Meta-regression was used to explore the potential moderators of post-CPAP treatment changes in lipid profiles.

RESULTS

A total of 14 RCTs with 1792 subjects were included. CPAP treatment was associated with a significant decrease in total cholesterol compared to controls (WMD = -0.098 mmol/L, 95% CI = -0.169 to -0.027, p = 0.007, I² = 0.0%). No significant changes in triglyceride, high-density lipoprotein nor low-density lipoprotein were observed after CPAP treatment (all p > 0.2). Furthermore, meta-regression models showed that age, gender, body mass index, daytime sleepiness, OSA severity, follow-up study duration, CPAP compliance nor patients with cardiometabolic disease did not moderate the effects of CPAP treatment on lipid profiles (all p > 0.05).

CONCLUSIONS

CPAP treatment decreases total cholesterol at a small magnitude but has no effect on other markers of dyslipidemia in OSA patients. Future studies of CPAP therapy should target combined treatment strategies with lifestyle modifications and/or anti-hyperlipidemic medications in the primary as well as secondary cardiovascular prevention models.

CPAP Intervention as an Add-On Treatment to Lipid-Lowering Medication in Coronary Artery Disease Patients with Obstructive Sleep Apnea in the RICCADSA Trial

Dyslipidaemia is a well-known risk factor for coronary artery disease (CAD), and reducing lipid levels is essential for secondary prevention in management of these high-risk individuals. Dyslipidaemia is common also in patients with obstructive sleep apnea (OSA). Continuous positive airway pressure (CPAP) is the first line treatment of OSA. However, evidence of a possible lipid-lowering effect of CPAP in CAD patients with OSA is scarce. We addressed the effect of CPAP as an add-on treatment to lipid-lowering medication in a CAD cohort with concomitant OSA. This study was a secondary analysis of the RICCADSA trial (Trial Registry: ClinicalTrials.gov; No: NCT00519597), that was conducted in Sweden between 2005 and 2013. In total, 244 revascularized CAD patients with nonsleepy OSA (apnea-hypopnea index ≥ 15/h, Epworth Sleepiness Scale score < 10) were randomly assigned to CPAP or no-CPAP. Circulating triglycerides (TG), total cholesterol (TC), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) levels (all in mg/dL) were measured at baseline and 12 months after randomization. The desired TG levels were defined as circulating TG < 150 mg/dL, and LDL levels were targeted as <70 mg/dL according to the recent guidelines of the European Cardiology Society and the European Atherosclerosis Society. A total of 196 patients with available blood samples at baseline and 12-month follow-up were included (94 randomized to CPAP, 102 to no-CPAP). We found no significant between-group differences in circulating levels of TG, TC, HDL and LDL at baseline and after 12 months as well as in the amount of change from baseline. However, there was a significant decline regarding the proportion of patients with the desired TG levels from 87.2% to 77.2% in the CPAP group (p = 0.022), whereas there was an increase from 84.3% to 88.2% in the no-CPAP group (n.s.). The desired LDL levels remained low after 12 months in both groups (15.1% vs. 17.2% in CPAP group, and 20.8% vs. 18.8% in no-CPAP group; n.s.). In a multiple linear regression model, the increase in the TG levels was predicted by the increase in body-mass-index (β = 4.1; 95% confidence interval (1.0-7.1); p = 0.009) adjusted for age, sex and CPAP usage (hours/night). CPAP had no lipid-lowering effect in this revascularized cohort with OSA. An increase in body-mass-index predicted the increase in TG levels after 12 months, suggesting that lifestyle modifications should be given priority in adults with CAD and OSA, regardless of CPAP treatment.

Association between obstructive sleep apnea and lipid metabolism during REM and NREM sleep

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is thought to be associated with dyslipidemia. However, differences concerning dyslipidemia during rapid eye movement (REM) and non-REM (NREM) sleep have yet to be determined. This study was designed to explore the association between lipid profiles and OSA during REM or NREM sleep.

METHODS

This is a clinical cohort. A total of 2,619 participants with at least 30 minutes of REM sleep were included. Sleep variables and fasting lipid profiles [total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), apolipoprotein (apo)A-I, apoB, apoE, and lipoprotein(a) (Lp(a))] were obtained from each participant. Apnea-hypopnea indices in REM and NREM sleep (AHI_REM and AHI_NREM, respectively) were recorded. Linear regression analysis was used to assess the associations of AHI_REM and AHI_NREM with lipid profiles.

RESULTS

When stratified by the AHI_REM severity of OSA, all demographics, clinical variables, and sleep parameters differed between the groups except for apoA-I. In fully-adjusted multivariate linear regression models, AHI_REM was independently associated with increasing levels of TG, HDL-C, and apoE (P = .04, P = .01 and P = .01, respectively). AHI_NREM was independently associated with increasing levels of TC, TG, LDL, and apoB, and lower level of HDL-C (all P < .05). In sensitivity analyses by only exploring associations in patients who had an AHI_NREM or AHI_REM < 5 events/h in separate regression models, AHI_REM was not associated with all-lipid profile in almost all adjusted models (all P > .05), whereas AHI_NREM was associated with elevated TC, LDL-C, and apoB (P = .03, P = .01 and P = .01, respectively).

CONCLUSIONS

AHI_NREM was independently associated with the greatest alterations in serum lipids, including TC, LDL-C, and apoB.

Obstructive sleep apnea is associated with lower adiponectin and higher cholesterol levels independently of traditional factors and other sleep disorders in middle-aged adults: the ELSA-Brasil cohort

PURPOSE

Obstructive sleep apnea (OSA) may contribute to metabolic and inflammatory deregulation but previous studies failed to consider sleep duration, sleep fragmentation, insomnia, and daytime sleepiness as potential confounders.

METHODS

Consecutive non-diabetic middle-aged participants from the ELSA-Brasil cohort were invited to perform a clinical evaluation, home sleep study for 1 night, and wrist actigraphy for 7 days. OSA was defined by an apnea-hypopnea index ≥ 15 events/h. Participants were stratified according to the presence of OSA measuring the following markers: fasting glucose, glucose tolerance test, homeostatic model assessment of insulin resistance (HOMA-IR) index, fasting insulin, insulin after 2 h of glucose load, glycated hemoglobin, total cholesterol and their fractions, triglycerides, C-reactive protein, TNF-alpha, interleukin-6, interleukin-10, leptin, adiponectin, E-selectin, ADMA, MCP-1, TGF, apolipoprotein B, fibrinogen, and lipoprotein(a). Differences between groups were identified by chi-square test and ANOVA.

RESULTS

We studied 708 participants (mean age: 46 ± 5 years, men: 44%, BMI 26.1 ± 4.1 kg/m²). Compared to no OSA, participants with OSA presented higher levels while fasting and after 2 h glucose load of insulin, HOMA-IR, cholesterol, triglycerides, and C-reactive protein (all p < 0.001). After linear regression analysis adjusting for traditional risk factors plus sleep duration, fragmentation, insomnia, and daytime sleepiness, OSA was negatively associated with adiponectin (β = - 0.271 CI 95% - 0.456 - 0.085) and positively associated with cholesterol (β = 9.707 CI 95% 2.737 16.678). Sex-stratification revealed that these associations were significant for men but not women.

CONCLUSIONS

In non-diabetic middle-age adults, men with OSA presented with lower adiponectin and higher cholesterol levels independently of sleep duration, sleep fragmentation, insomnia, and daytime sleepiness.

Decreased serum betatrophin may correlate with the improvement of obstructive sleep apnea after Roux-en-Y Gastric Bypass surgery

Obesity is strongly correlated with obstructive sleep apnea (OSA), and bariatric surgery can effectively treat obesity and alleviate OSA. However, the contributing factors are still unclear. We aimed to explore the relationship between betatrophin and OSA in patients undergoing Roux-en-Y gastric bypass (RYGB) surgery. Our study consisted of thirty-seven individuals with OSA and type 2 diabetes (16 males, 21 females) undergoing RYGB surgery. The polysomnography test, anthropometric results, serum betatrophin, and abdominal magnetic resonance images were evaluated both before and 1 year after RYGB surgery. Factors that may correlate with the alleviation of OSA were investigated. In our study, RYGB surgery significantly decreased apnea hypopnea index (AHI) and serum betatrophin concentration (p < 0.001). The abdominal visceral fat area, subcutaneous fat area and HOMA-IR were also significantly decreased (p < 0.001). The preoperative AHI, postoperative AHI and the change in AHI were significantly correlated with the preoperative betatrophin, postoperative betatrophin and the change in betatrophin, respectively (p < 0.05). These correlations were still significant after adjustment for other risk factors. The change in betatrophin was also independently associated with the change in minimum oxygen saturation (p < 0.001). Our data might indicate that serum betatrophin was significantly independently correlated with the improvement of OSA after bariatric surgery.

Relationship between sleep duration and sociodemographic characteristics, mental health and chronic diseases in individuals aged from 18 to 85 years old in Guangdong province in China: a population-based cross-sectional study

BACKGROUND

Sleep is vital for maintaining individual's physical and mental health. Prior studies have reported close relationships between sleep duration and chronic diseases. However, in China, the prevalence of aberrant sleep duration and the associations between sleep duration and chronic conditions still merit studying in Guangdong province. This study aimed at examining the relationship between sleep duration and multiple dimensions of sociodemographic characteristics, mental health and chronic diseases in Guangdong province in China, with a large population-based data of individuals aged from 18 to 85 years old.

METHODS

This study aimed at analyzing the sociodemographic and clinical characteristics of the population in Guangdong province. Multistage stratified cluster sampling was applied for this study. 13,768 participants from Guangdong province were interviewed with standardized assessment tools, including Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder (GAD-7). Basic socio-demographic information, mental health and chronic diseases information were collected. Self-reported sleep duration was classified as three types: short (< 7 h), normative (7-9 h) and long (≥9 h).

RESULTS

The mean sleep duration was 6.75 ± 1.11 h. Short sleepers had a higher prevalence of chronic diseases, including anemia (6.2%, p = 0.024), gout (2.8%, p = 0.010), hyperlipidemia (3.9%, p = 0.003) and low back pain (5.6%, p = 0.020) than other types of sleeper. Multinomial logistic regression analysis revealed that short sleepers were more likely to have low income level, have depressive symptoms, be ex- or current drinkers and be overweight. Anemia, hyperlipidemia and low back pain were all risk factors for short sleep, while malignant tumor was risky for long sleep.

CONCLUSIONS

Low income level, drinking status, being overweight, and chronic conditions may be associated with aberrant sleep duration in Guangdong province general population. Short sleepers have a higher risk of suffering from anemia, hyperlipidemia, and low back pain, while long sleepers are more likely to have malignant tumor. Health professionals should value the sleep patterns in general health care and attach importance to conduct further epidemiologic surveys to explore the relationship between sleep duration and health.

Sleep disturbances: one of the culprits of obesity-related cardiovascular risk?

Growing evidence suggested that Sleep Disorders (SD) could increase the risk of developing obesity and could contribute to worsen obesity-related cardiovascular risk. Further, obesity per se has been reported to blunt sleep homeostasis. This happens through several mechanisms. First of all, the excessive adipose tissue at neck and chest levels could represent a mechanical obstacle to breathe. Moreover, the visceral adipose tissue is known to release cytokines contributing to low-grade chronic inflammation that could impair the circadian rhythm. Also, nutrition plays an important role in sleep homeostasis. High fat and/or high carbohydrate diets are known to have a negative impact on both sleep quality and duration. In addition, obesity predisposes to a condition called "obstructive sleep apnea" that has a detrimental effect on sleep. SD could increase the risk and/or could contribute to worsen cardiovascular risk usually associated with obesity. The chronic low grade inflammation associated with obesity has been reported to increase the risk of developing hypertension, type 2 diabetes and dyslipidemia. In turn, improving quality of sleep has been reported to improve the management of these cardiovascular risk factors. Thus, the aim of this manuscript is to provide evidence on the association of obesity and SD and on how they could contribute to the risk of developing cardiovascular risk factors such as hypertension, dyslipidemia and type 2 diabetes in obesity.

Sleep disordered breathing and metabolic comorbidities across sex and menopausal status in East Asians: the Nagahama Study

It is well known that the prevalence of sleep disordered breathing (SDB) is increased in patients with obesity or metabolic comorbidities. However, the way in which the prevalence of SDB increases in relation to comorbidities according to the severity of obesity remains unclear.

This cross-sectional study evaluated 7713 community participants using nocturnal oximetry ≥2 nights. SDB was assessed by the 3% oxygen desaturation index corrected for sleep duration obtained by wrist actigraphy (acti-ODI3%). SDB severity was defined by acti-ODI3%. Obesity was defined as body mass index ≥25 kg·m−2.

The prevalence of SDB was 41.0% (95% CI 39.9–42.1%), 46.9% (45.8–48.0%), 10.1% (9.5–10.8%) and 2.0% (1.7–2.3%) in normal, mild, moderate and severe SDB, respectively, with notable sex differences evident (males>post-menopausal females>premenopausal females). Comorbidities such as hypertension, diabetes and metabolic syndrome were independently associated with the prevalence of moderate-to-severe SDB, and coincidence of any one of these with obesity was associated with a higher probability of moderate-to-severe SDB (hypertension OR 8.2, 95% CI 6.6–10.2; diabetes OR 7.8, 95% CI 5.6–10.9; metabolic syndrome OR 6.7, 95% CI 5.2–8.6). Dyslipidaemia in addition to obesity was not additively associated with the prevalence of moderate-to-severe SDB. The number of antihypertensive drugs was associated with SDB (p for trend <0.001). Proportion of a high cumulative percentage of sleep time with oxygen saturation measured by pulse oximetry <90% increased, even among moderate-to-severe SDB with increases in obesity.

Metabolic comorbidities contribute to SDB regardless of the degree of obesity. We should recognise the extremely high prevalence of moderate-to-severe SDB in patients with obesity and metabolic comorbidities.

Short sleep is associated with higher prevalence and increased predicted risk of cardiovascular diseases in an Iranian population: Fasa PERSIAN Cohort Study

Cardiovascular disease (CVD) is the leading cause of death worldwide. One common factor that may affect CVD risk factors is sleep disturbance. The factors influencing an individual’s sleep may vary among different cultures. The current study investigated sleep quality and quantity in the Fasa cohort population as an Iranian population. In a cross-sectional study using the Fasa PERSIAN cohort study data, 10,129 subjects aged 35–70 were entered. Self-reported sleep duration and cardiovascular events were recorded. The Framingham risk score (FRS) is used to predict cardiovascular events. Adjusted logistic regression showed significant odds ratios in subjects who sleep less than 6 hours for CVD (OR = 1.23; 95% CI:1.03–1.48), coronary heart disease (CHD) (OR = 1.21; 95% CI:1.009–1.46), and hypertension (HTN) (OR = 1.37; 95% CI:1.16–1.62). Higher risk profiles were also seen in the FRS for short sleepers. The highest significant odds ratios in FRS profiles in the intermediate high-risk group compared with the low-risk group were (1.44; 95% CI:1.18–1.75) in CVD and (1.48; 95% CI:1.16–1.88) in CHD risk score profiles. It can be suggested that participants with short durations of sleep had significantly higher CVD, HTN prevalence, and 10-year FRS. Participants with long sleep durations had no increase in CVD, CHD, myocardial infarction (MI), or HTN prevalence. MI prevalence was at the lowest level in subjects who got 8 to 8.9 hours of sleep.

Obstructive sleep apnea and dyslipidemia: from animal models to clinical evidence

Lipid metabolism deregulation constitutes the pathogenic basis for the development of atherosclerosis and justifies a high incidence of cardiovascular-related morbidity and mortality. Some data suggest that dyslipidemia may be associated with sleep-disordered breathing, mainly obstructive sleep apnea (OSA), due to alterations in fundamental biochemical processes, such as intermittent hypoxia (IH). The aim of this systematic review was to identify and critically evaluate the current evidence supporting the existence of a possible relationship between OSA and alterations in lipid metabolism. Much evidence shows that, during the fasting state, OSA and IH increase lipid delivery from the adipose tissue to the liver through an up-regulation of the sterol regulatory element-binding protein-1 and stearoyl-CoA desaturase-1, increasing the synthesis of cholesterol esters and triglycerides. In the postprandial state, lipoprotein clearance is delayed due to lower lipoprotein lipase activity, probably secondary to IH-up-regulation of angiopoietin-like protein 4 and decreased activity of the peroxisome proliferator-activated receptor alpha. Moreover, oxidative stress can generate dysfunctional oxidized lipids and reduce the capacity of high-density lipoproteins (HDL) to prevent low-density lipoprotein (LDL) oxidation. In the clinical field, several observational studies and a meta-regression analysis support the existence of a link between OSA and dyslipidemia. Although there is evidence of improved lipid profile after apnea-hypopnea suppression with continuous positive airway pressure (CPAP), the majority of the data come from observational studies. In contrast, randomized controlled trials evaluating the effects of CPAP on lipid metabolism present inconclusive results and two meta-analyses provide contradictory evidence.

Sleep duration and risk of cardiovascular events: The SAVE study

Background and aim

Controversy exists regarding cardiovascular risk in relation to sleep duration. We determined sleep duration and major recurrent cardiovascular event associations in patients with obstructive sleep apnoea and established cardiovascular disease.

Methods

Secondary analyses of the international, multicenter, Sleep Apnea Cardiovascular Endpoints trial. Sleep duration was estimated from overnight home oximetry (ApneaLink monitor) used for obstructive sleep apnoea diagnosis. Cox proportional hazards models were used to determine associations of categorized sleep duration (<6 h, 6–8 h (reference), and >8 h) and major cardiovascular outcomes: primary composite of cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, and any hospitalization for unstable angina, heart failure, or transient ischemic attack; secondary composite of cardiac and cerebral (stroke/transient ischemic attack) events.

Results

Oximetry-derived sleep duration estimates were available in 2687 participants (mean 61.2 years, 80.9% males) who experienced a total of 436 cardiovascular events over a mean follow-up of 3.7 years. Compared to the reference category, sleep duration was not associated with risk of the primary composite cardiovascular outcome (adjusted hazard ratio (HR) 1.00, 95% confidence interval 0.76–1.33, and HR 1.22, 95% confidence interval 0.98–1.52, for sleep duration <6 and >8 h, respectively). However, long sleep was associated with increased cerebral events (HR 1.67, 95% confidence interval 1.17–2.39; P = 0.005) and stroke alone (HR 1.79, 95% confidence interval 1.22–2.63; P = 0.003).

Conclusions

Long sleep duration is associated with an increased risk of stroke but not cardiac events in obstructive sleep apnoea patients with existing cardiovascular disease.

Clinical trial registration

The trial is registered at ClinicalTrials.gov (NCT00738179).

Metabolomics, sleepiness, and sleep duration in sleep apnea

PURPOSE

Although the mechanism is unclear, daytime sleepiness, a common sequela of obstructive sleep apnea (OSA), has been found to be correlated with a adverse cardiovascular outcomes. Reviewing metabolomics mechanisms of sleep disturbances and cardiovascular disease may help to explain this correlation.

METHODS

This review examines the current literature on the relationships between sleepiness, sleep duration, and metabolites in sleep apnea.

RESULTS

Although there is a lack of comprehensive literature in this emerging area, existing studies point to a variety of metabolites in different pathways that are associated with sleepiness and sleep duration.

CONCLUSION

Advancing metabolomics research in sleep apnea will guide symptom research and provide alternate and novel opportunities for effective treatment for patients with OSA.

Thinning of Macular Neuroretinal Layers Contributes to Sleep Disorder in Patients With Type 2 Diabetes Without Clinical Evidences of Neuropathy and Retinopathy

Aims: To investigate the impact of thinning at individual grids of macular neuroretinal layers, clinical factors, and inadequate light exposure on the specific components of sleep disorder in patients with type 2 diabetes. Methods: One hundred twenty-four patients with type 2 diabetes without clinical evidences of diabetic retinopathy and neuropathy (HbA1c: 8.3%, diabetes duration; 8.7 years) and 54 age- and sex-matched control subjects (HbA1c: 5.6%) underwent detailed clinical, neurological, and ophthalmological examinations. The sleep disorder was assessed by the Pittsburgh Sleep Quality Index Japanese Version (PSQI-J). The temporal structures of daily life were assessed by the Munich Chronotype Questionnaire Japanese Version. The thickness at nine grids defined by the Early Treatment Diabetic Retinopathy Study of nine macular neuroretinal layers was determined by swept-source optical coherence tomography and OCT-Explorer. The associations between the individual components of sleep disorders and the thickness at each grid of macular neuroretinal layers, clinical factors, or the temporal structures of daily life were examined. Results: The prevalence of the sleep disorder, global score, and four individual PSQI-J scores in patients with type 2 diabetes were higher than control subjects. The thickness of two and five grids of two inner retinal layers and four to seven grids of four outer retinal layers in patients with type 2 diabetes was thinner than those in control subjects. The thickness at one to eight grids of four outer retinal layers in type 2 diabetic patients was inversely associated with global score and five individual scores of sleep disorder. The thinning at one to two grids of the inner plexiform layer was related to three high individual scores of sleep disorder. The inappropriate light exposure was associated with the sleep disorder and altered macular neuroretinal layers. The high HbA1c and LDL-cholesterol levels were related to the high global score and two individual scores of sleep disorder, respectively. Conclusion: In patients with type 2 diabetes, the thinning at grids of the inner plexiform layer and outer retinal layers was associated with the high scores of specific components of the sleep disorder. The sleep disorder was also related to hyperglycemia, dyslipidemia, and inappropriate light exposure.

Effect of maternal sleep in late pregnancy on leptin and lipid levels in umbilical cord blood

OBJECTIVES

To study the impact of maternal sleep in late pregnancy on birth weight (BW) and leptin and lipid levels in umbilical cord blood.

STUDY DESIGN

A total of 277 healthy and singleton pregnancy women were recruited for participation in the Shanghai Sleep Birth Cohort Study (SSBC) during their 36-38 weeks of pregnancy, from May 2012 to July 2013. Maternal night sleep time (NST), sleep efficiency (SE), sleep onset latency (SOL) and the percentage of wake after sleep onset (WASO) in NST and midpoint of sleep (MSF) were measured by actigraphy for seven consecutive days. The leptin and lipid levels were determined in cord blood samples collected from the umbilical vein immediately after delivery. Birth information (birth weight, gender, delivery type, etc.) was extracted from medical records. A multivariable linear regression model was applied to examine the effect of maternal sleep in late pregnancy on newborn leptin and lipid levels in umbilical cord blood.

RESULTS

A total of 177 women and their infants were included in the analysis. Maternal mean NST was 7.03 ± 1.10 h in late pregnancy, and 48% had a shorter sleep time (NST < 7 h). The average maternal SE was 72.54% ± 9.66%. The mean percentage WASO/NST was 21.62% ± 9.98%; the average MSF was about 3:34 (0:53); and the SOL was 46.78 ± 36.00 min. After adjustment for confounders, both maternal NST and SE were found to be significantly associated with triglyceride levels (β = -0.219, p = 0.006; β = -0.224, p = 0.006) in umbilical cord blood; and maternal NST was also observed to have positive association with newborn leptin levels (β = 0.146, p = 0.047). However, we did not find significant association between other maternal sleep parameters in late pregnancy and leptin and lipid levels and birth weight.

CONCLUSIONS

Short sleep duration and poor sleep quality during late pregnancy were associated with newborn leptin and lipid levels, and efforts on improving maternal sleep during late pregnancy should be advocated for children's health.

Effect modification by gender of the influence of obstructive sleep apnoea characteristics on dyslipidaemia in China: a cross-sectional study

OBJECTIVES

Obstructive sleep apnoea (OSA) characteristics differ by gender, possibly affecting any association between OSA and dyslipidaemia. We explored whether gender influenced any association between OSA characteristics and dyslipidaemia.

METHODS/DESIGN

This was a cross-sectional, large-scale hospital-based study. Male and female risks of dyslipidaemia by OSA characteristics were assessed with logistic regression. Additive interactions were measured using three indices: the relative excess risk due to interaction, the attributable proportion due to interaction and the synergy index. Multiplicative interaction was evaluated via logistic regression.

SETTING

A single secondary-care setting in China.

PARTICIPANTS

3760 patients with OSA.

PRIMARY AND SECONDARY OUTCOME MEASURES

Outcomes were male and female risks of dyslipidaemia, and the associated additive and multiplicative interactions between the apnoea-hypopnea index (AHI), the oxygen-desaturation index (ODI), the microarousal index (MAI), and gender.

RESULTS

After controlling for confounding factors, males (but not females) with AHIs>30 were at higher risk of hyper-total cholesterol (TC), hypo-high-density lipoprotein cholesterol (HDL-C) status and a hyper-TC/HDL-C ratio than males with AHIs≤30. Positive additive interactions were evident between the male gender and AHI on a hyper-TC/HDL-C ratio and hypo-HDL-C status. Males with ODIs>40.1 were at higher risk of hypo-HDL-C status and a hyper-TC/HDL-C ratio than males with ODIs≤40.1. Positive additive and multiplicative interactions were evident between male gender and ODI on hyper-TC/HDL-C ratio. Males with MAIs>28.6 were at higher risk of hyper-TC and hyper-low-density lipoprotein cholesterol status than males with MAIs≤28.6, but no statistically significant interactions were apparent between gender and MAI.

CONCLUSIONS

Males (but not females) with higher AHIs, ODIs or MAIs were at higher risks of some measures of dyslipidaemia. Positive interactions between male and severe OSA or intermittent hypoxia on some measures of dyslipidaemia were apparent. Thus, dyslipidaemia should be evaluated in patients with OSA, especially males with severe OSA or intermittent hypoxia.

Association between sleep duration, sleep quality and hyperlipidemia in middle-aged and older Chinese: The Dongfeng–Tongji Cohort Study

Aims

This study aimed to evaluate the relationship between sleep duration, sleep quality and hyperlipidemia in middle-aged and older Chinese.

Methods

We included 20,712 individuals at baseline from September 2008 to June 2010, and they were followed-up until October 2013. Hyperlipidemia was defined according to the Chinese guidelines on the prevention and treatment of dyslipidemia in adults. Sleep duration was self-reported and sleep quality was evaluated with a questionnaire that was designed according to the Pittsburgh Sleep Quality Index. Logistic regression and Cox proportional hazard models were conducted to explore the associations.

Results

In the cross-sectional analyses, longer sleep duration (≥10 h) was significantly associated with higher prevalence of hyperlipidemia (odds ratio (OR) = 1.17, 95% confidence interval (CI) = 1.02–1.35) after adjusting for potential confounders. The ORs of hyperlipidemia were significantly elevated among participants with impaired sleep quality (OR = 1.14, 95% CI = 1.08–1.22) and poor sleep quality (OR = 1.20, 95% CI = 1.08–1.34) when compared to those with good sleep quality. In the longitudinal analyses, compared to participants with a sleep duration of 7–<8 h, those with a sleep duration of 9–<10 h (hazard ratio (HR) = 1.19, 95% CI = 1.04–1.35) and ≥10 h (HR = 1.27, 95% CI = 1.02–1.58) showed significantly higher risk of hyperlipidemia after adjusting for potential confounders. However, no statistically significant association was found between impaired or poor sleep quality and hyperlipidemia.

Conclusions

Longer sleep duration was significantly associated with higher risk of hyperlipidemia. Impaired or poor sleep quality were associated with elevated prevalence of hyperlipidemia, but not with the incidence of hyperlipidemia.

Effects of Ramelteon and Other Sleep-Promoting Drugs on Serum Low-Density Lipoprotein and Non-high-density Lipoprotein Cholesterol: A Retrospective Comparative Pilot Study

Melatonin has been suggested to play important roles in lipid metabolism as well as circadian rhythm; however, very few studies explored the effects of ramelteon, a selective melatonin receptor agonist, on serum lipid profiles. In this study effects of ramelteon on serum lipid profiles were explored, comparing to those of other sleep-promoting drugs including benzodiazepines and non-benzodiazepines, in patients with insomnia. We retrospectively reviewed medical charts of outpatients who were treated with ramelteon (8 mg/d) or other sleep-promoting drugs for no less than 8 weeks during the period between October 1st, 2011 and September 30th, 2014, and compared the changes in serum lipid profiles between the two groups. Patients with regular dialysis or malignant diseases treated with cytotoxic anti-cancer drugs, or whose lipid-lowering drugs were altered during the study period, were excluded. Among 365 or 855 outpatients treated with ramelteon or other sleep-promoting drugs, 35 or 46 patients, respectively, had complete serum low-density lipoprotein cholesterol (LDL-C) or non-high-density lipoprotein cholesterol (non-HDL-C) data. Serum LDL-C was significantly reduced from 103.1±4.4 to 94.6±4.2 mg/dL (8.2% reduction, p<0.05, n=31) in the ramelteon group, and was not significantly changed (p=0.23, n=40) in the other sleep-promoting drug group. Non-HDL-C was significantly decreased from 138.8±6.0 to 130.6±4.9 mg/dL (5.9% reduction, p<0.05, n=32) in the ramelteon group, and was not significantly altered (p=0.29, n=42) in the other sleep-promoting drug group. Ramelteon, but not other sleep-promoting drugs, specifically lowers serum LDL-C and non-HDL-C levels.

Pathogenesis of Abnormal Hepatic Lipid Metabolism Induced by Chronic Intermittent Hypoxia in Rats and the Therapeutic Effect of N-Acetylcysteine

BACKGROUND The pathogenesis of chronic intermittent hypoxia (CIH)-induced abnormal hepatic lipid metabolism in rats remains unclear. Here, we investigated the therapeutic effect of N-acetylcysteine (NAC) on abnormal hepatic lipid metabolism. MATERIAL AND METHODS Rats were subjected to hypoxia and NAC treatment, and evaluated in terms of hepatic lipid metabolism, hepatocyte ultrastructure, oxidative stress in hepatocytes, expression of nuclear factor-kappa B (NF-κB) and inflammatory cytokines (IL-1β, IL-6, and TNFα), serum lipoprotein lipase (LPL) levels, and blood lipids (triglycerides and cholesterol). RESULTS Compared to the normoxic control group, animals in the hypoxic model group showed significant body weight gain; abnormal hepatic lipid metabolism; lipid vacuolization; accumulation of lipid droplets; abundant autophagosomes and lysosomes; significant increases in oxidative stress, inflammation level, and blood lipid levels; and significantly reduced LPL levels. Compared to control animals, rats in the treatment group exhibited normal body weight gain, improved lipid metabolism, fewer lipid droplets, alleviated ultrastructural injuries, decreased oxidative stress and inflammation level, as well as elevated LPL and reduced blood lipid levels. CONCLUSIONS The harmful effects of CIH on rat liver are possibly associated with the reactive oxygen species (ROS)/NF-κB signaling pathway. NAC is capable of attenuating lipid metabolism alterations and abnormal body weight gain in the CIH rat model, via a possible mechanism related to inhibition of ROS/NF-κB signaling.

Effects of positive airway pressure therapy on cardiovascular and metabolic markers in males with obstructive sleep apnea

INTRODUCTION

Obstructive sleep apnea syndrome (OSAS) is associated with cardiovascular/metabolic complications. Some analytical parameters (homocysteine, glycemic and lipidic profiles) are recognized markers of these consequences. Limited data is available on the association of these markers and OSAS's severity/response to positive airway pressure therapy (PAP).

MATERIAL AND METHODS

In this prospective study we analyzed polysomnographic and analytical data of male patients admitted to sleep laboratory. The aim was to evaluate metabolic/cardiovascular markers in snorers and OSAS patients, to relate with sleep parameters and PAP response. One-hundred and three patients were included, and 73 (71%) were OSAS patients. OSAS patients were similar to snorers except for higher body mass index (BMI) and dyslipidemia. Severe OSAS patients showed higher glycemia, HbA1c, insulin, and insulin resistance, and lower HDL cholesterol in comparison to mild-moderate (p<0.05, p<0.05, p<0.001, p<0.001, p<0.05, respectively). Glycemic profile and triglycerides were slightly correlated with OSAS severity. 46 OSAS patients were submitted to 6 months of PAP, with a statistical decrease in mean values of homocysteine, glycemia, total and LDL cholesterol (p<0.05, p<0.05, p<0.05, respectively), and in glycemia and LDL cholesterol in severe group only (p<0.05, p<0.05, respectively).

RESULTS

This study demonstrated an association between glucose metabolism parameters and triglycerides with OSAS severity underlying the complexity of the process leading to cardiovascular/metabolic complications in this disorder. Moreover, homocysteine, glycemic and lipidic profiles changed significantly after 6 months of PAP therapy in OSAS, supporting its cardiovascular and metabolic protective effect.

CONCLUSION

Our study has reinforced the importance of analytical cardiovascular/metabolic evaluation as complementary tool of diagnosis/treatment response in OSAS.

Behavioral Characteristics and Cardiovascular Disease Risks Associated With Insomnia and Sleep Quality Among Middle-Aged Women in South Korea

Insomnia is the most common sleep problem in women. Increasing evidence suggests an association between insomnia and cardiovascular disease (CVD). However, information is limited on lifestyle and socio-environmental factors associated with sleep problems in women. In this study directed by Social Cognitive Theory, we examined the personal, behavioral, socio-environmental, and CVD risk factors associated with sleep characteristics (insomnia and sleep quality) in middle-aged women using a cross-sectional design. The study instruments included the Insomnia Severity Index (ISI), the Pittsburg Sleep Quality Index (PSQI), the Center for Epidemiological Studies Depression Scale (CES-D), and measures of social support and behavioral characteristics. Blood was drawn to assess serum glucose and lipids, and BMI was measured. Data were analyzed using hierarchical multiple regression and analysis of covariance (ANCOVA). Of 423 middle-aged women, 25% experienced insomnia (ISI ≥ 10) and 41.3% reported poor sleep quality (PSQI ≥ 5). Lesser education (≤middle school), more depressive symptoms, more screen time (≥ 3 hours/day), and severe stress were associated with greater severity of insomnia and/or poorer sleep quality. Total and LDL cholesterol levels were higher in women with insomnia than normal sleepers, whereas the BMI was higher in those who reported poor sleep quality. Because personal, behavioral, and socio-environmental factors were significantly associated with insomnia and poor sleep quality, multifactorial approaches should be considered in developing sleep interventions and reducing cardiovascular risk. © 2017 Wiley Periodicals, Inc.

Prevalence and Predictors of Atherogenic Serum Lipoprotein Dyslipidemia in Women with Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is associated with dyslipidemia. However, no study has focused on dyslipidemia in women with OSA. The aim of this study was to determine the prevalence and risk factors for dyslipidemia in women with OSA. Between 2007 and 2013, 570 eligible female patients with suspected OSA were consecutively recruited. The analyzed data consisted of polysomnography parameters, biochemical indicators, and anthropometric measurements. Serum lipid levels and dyslipidemia were compared. Binary logistic regression and multivariate linear regression models were used to determine the independent risk factors influencing serum lipids. After multivariate adjustment, there were essentially no major differences in serum lipid levels among patients with no to mild, moderate, and severe OSA nor did serum lipid levels change with OSA severity. Dyslipidemia in total cholesterol, triglycerides, low-density lipoprotein cholesterol, apolipoproteins(apo) B and apoE increased with OSA severity, but only in non-obese subjects and those <55 years of age. Age, body mass index, waist to hip ratio, glucose and insulin were major risk factors for most serum lipids after multivariate adjustments. Our results indicate that, in women with OSA, age, obesity/central obesity, and insulin resistance are major determinants of dyslipidemia.

Overcoming sleep disordered breathing and ensuring sufficient good sleep time for a healthy life expectancy

Recent advances in basic and clinical medicine have resulted in major improvements in human health. Currently sleep has been considered an essential factor in maintaining and promoting a healthy life expectancy. Sleep disorders include more than 60 diseases. Sleep disordered breathings (SDB) have 17 disorders, including sleep apnea. SDB usually induces hypoxemia and hypercapnia, which would have significant effects on cells, organs, and the whole body. We have investigated SDB for nearly 35 years. We found that SDB has significant associations with humoral factors, including coagulation systems, the body's protective factors against diseases, and metabolic and organ diseases. Currently we have been giving attention to the associations among SDB, short sleep duration, and obesity. In addition, SDB is important not only in the home but under critical care such as in the perioperative stage. In this review, I would like to describe several aspects of SDB in relation to systemic diseases and overall health based mainly on our published reports.

The relationship between insomnia with short sleep duration is associated with hypercholesterolemia: a cross-sectional study

AIM

To examine the association between insomnia with short sleep duration and hypercholesterolemia in Taiwanese adults.

BACKGROUND

Previous studies mostly focused on the association between sleep duration and hyperlipidemia, but the results were not consistent. Besides, very few studies extensively examined the association between insomnia and hypercholesterolemia. This study hypothesized that insomnia with short sleep duration is associated with hypercholesterolemia.

DESIGN

Secondary data analysis. This study analysed the latest database of the cross-sectional Nutrition and Health Survey in Taiwan which was released on 2011 (data collected between 2005-2008) and collected data using stratified three-staged probability sampling design.

METHODS

This study analysed 1533 participants aged between 19-64 (733 males and 800 females) and used logistic regression model to calculate the odds ratio and the 95% confidence interval of insomnia with short sleep duration to hypercholesterolemia. Controlled confounders included age, gender, sample weight, body mass index, waist circumference, fasting plasma glucose, hypertension and diabetes.

RESULTS

Insomnia with 5-6 hours of sleep duration was significantly associated with hypercholesterolemia. The odds ratio of mild insomnia or moderate/severe insomnia with 5-6 hours of sleep duration to hypercholesterolemia was higher, compared with the reference group (without insomnia and >6 hours of sleep duration).

CONCLUSION

Insomnia with short sleep duration was associated with increased odds of hypercholesterolemia. Caregivers in clinical practice should watch out for the effect brought by this novel factor.

Elevated low-density lipoprotein cholesterol is independently associated with obstructive sleep apnea: evidence from a large-scale cross-sectional study

BACKGROUND

Lipid metabolism disorder is recognized to be associated with obstructive sleep apnea (OSA); however, inconsistent results have been reported. The aim of this study was to evaluate the association between lipid profile and OSA with adjustments for multiple confounding factors.

METHODS

In total, 2983 subjects were recruited from the Shanghai Sleep Health Study (SSHS) during 2007-2013. Data for overnight polysomnography (PSG) parameters, serum lipids, fasting blood glucose, insulin levels, and anthropometric measurements were collected. Multivariable logistic regression analyses were used to determine the correlation between lipid profile and OSA with adjustments for confounders including lipids, age, gender, Epworth sleepiness scale, body mass index, waist/hip ratio, glucose, insulin resistance, hypertension, and smoking.

RESULTS

The prevalence of hyper total cholesterol (TC), hyper triglycerides, hypo high-density lipoprotein cholesterol, hyper low-density lipoprotein cholesterol (LDL-C), hyper apolipoprotein (apo) A-I, and hyper apoB differed significantly between the non-OSA and OSA patients. Without considering the interaction across different lipids, TC, LDL-C, and apoB were independently associated with OSA in primary multivariable logistic regression analyses; the odds ratios (ORs) and 95 % confidence intervals (CIs) were 1.262 (1.109-1.438), 1.432 (1.233-1.664), and 5.582 (2.643-11.787), respectively. However, only LDL-C (OR = 1.430, 95 % CI = 1.221-1.675) was found to be an independent risk factor for OSA in further multivariable logistic regression analyses.

CONCLUSIONS

We demonstrated that patients with OSA had a higher percentage of dyslipidemia than subjects without OSA. Of the various components in serum lipid, only LDL-C was independently associated with OSA.

[Health indicators associated with poor sleep quality among university students]

OBJECTIVE

To associate the sleep quality of Brazilian undergraduate students with health indicators.

METHOD

A cross-sectional study was developed with a random sample of 662 undergraduate students from Fortaleza, Brazil. The demographic data, Pittsburgh Sleep Quality Index and health data indicators (smoking, alcoholism, sedentary lifestyle, nutritional condition and serum cholesterol) were collected through a self-administered questionnaire. Blood was collected at a clinical laboratory. In order to estimate the size of the associations, a Poisson Regression was used.

RESULTS

For students who are daily smokers, the occurrence of poor sleep was higher than in non-smokers (p<0.001). Prevalence rate values were nevertheless close to 1.

CONCLUSION

The likelihood of poor sleep is almost the same in smokers and in alcoholics.


Prevalence of dyslipidemia and its association with insomnia in a community based population in China

Background

Studies of the prevalence of dyslipidemia and its association with insomnia are scarce in China. This study investigated the prevalence of dyslipidemia and its association with insomnia in a community based Chinese population.

Methods

We conducted a cross-sectional survey in Beijing and recruited 10054 participants aged ≥18 years. The association between self-reported insomnia and dyslipidemia was determined by multiple logistic regression models. Age, gender, education, obesity, body mass index, physical activity, current smoking, current drinking, diabetes, and hypertension were adjusted as confounders. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were reported as effect measurements.

Results

The prevalence of dyslipidemia in those with no insomnia, occasional insomnia, and frequent insomnia were 53.3%, 54.3%, and 54.5% in men and 52.0%, 54.8%, and 61.2% in women. Compared with subjects with no insomnia, the multivariate adjusted ORs and 95% CIs for those with occasional insomnia and frequent insomnia were 1.07(0.86 ~ 1.34) and 1.19(0.89 ~ 1.60) for men, and 1.00(0.86 ~ 1.14) and 1.23(1.03 ~ 1.47) for women.

Conclusions

These observations indicate that frequent insomnia was associated with a higher prevalence of dyslipidemia in women. This association was not significant in men.

Effect of continuous positive airway pressure on lipid profile in patients with obstructive sleep apnea syndrome: a meta-analysis of randomized controlled trials

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) is an independent risk factor for development of dyslipidemia. Continuous positive airway pressure (CPAP) is the first-line treatment for OSAS. However, it is unclear whether CPAP improves lipid metabolism.

OBJECTIVES

To review the effect of CPAP on lipid profile of patients with OSAS.

METHODS

We searched PubMed, Embase, and the Cochrane Library to identify eligible articles published prior to October 30, 2013. Six randomized controlled trials (RCTs) were subjected to meta-analysis using Comprehensive Meta-Analysis software.

RESULTS

Six RCTs meeting the inclusion criteria were enrolled. The total numbers of measurements of total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol, in CPAP intervention patients and sham/control groups, were 370 and 371, 330 and 328, 276 and 274, and 269 and 266 respectively. The pooled estimate of the difference in the mean TC level between the CPAP and sham CPAP/control groups was significantly different (-0.15 [95% confidence interval, -0.27 to -0.03]; p = 0.01). Subgroup analysis revealed that OSAS patients of younger age, who were more obese, and who had been treated via CPAP for a longer duration, showed a significant decrease in TC levels (the differences in the means were -0.27, -0.24, and -0.20; and the p values 0.001, 0.01, and 0.04, respectively).

CONCLUSION

We confirmed that CPAP decreases the TC level, especially in OSAS patients who are younger, more obese, and who use CPAP for a longer period. CPAP did not alter TG, LDL, or HDL levels, suggesting that CPAP may have no clinically important effect on lipid metabolism.