Association Between Serum Lipid Profile and Obstructive Respiratory Events During REM and Non-REM Sleep

Ferritin is a potential marker of cardiometabolic risk in adolescents and young adults with sleep-disordered breathing

Objective

To explore markers that reflect sleep-disordered breathing (SDB) severity and investigate their associations with cardiometabolic risk factors in adolescents and young adults.

Methods

Participants were recruited from our SDB epidemiological cohort. They underwent overnight polysomnography and ambulatory blood pressure (BP) monitoring. Complete blood count, ferritin, high-sensitivity C-reactive protein (hs-CRP), fasting blood glucose, and lipid profile were measured. Multiple linear regression was used to examine the association between red cell indices (RCIs), ferritin, and obstructive apnea-hypopnea index (OAHI). Subgroup analyses on participants with SDB were performed for the association of RCIs and ferritin with lipid profile, hs-CRP, and BP.

Results

There were 88 participants with SDB and 155 healthy controls aged 16-25 years. Hemoglobin (Hb; p < .001), hematocrit (HCT; p < .001), and ferritin (p < .001) were elevated with increasing SDB severity and were independently associated with OAHI (β=1.06, p < .001; β=40.2, p < .001; β=4.89 × 10-3, p = .024, respectively). In participants with SDB, after adjusting for age, sex, and BMI, significant associations were found between ferritin with low-density lipoprotein (LDL; β=0.936 × 10-3, p = .008) and triglyceride (TG; β =1.08 × 10-3, p < .001), as well as between Hb (β=1.40, p = .007), HCT (β=51.5, p = .010) and mean arterial pressure (MAP). Ferritin (β=0.091, p = .002), Hb (β=0.975, p = .005), and HCT (β=38.8, p = .004) were associated with hs-CRP independent of age, sex, BMI, plasma LDL, and MAP. OAHI was not associated with LDL and TG in the multivariable models.

Conclusions

Serum ferritin, but not OAHI, was associated with LDL and TG in participants with SDB, suggesting it is a potential marker of cardiometabolic risk in patients with SDB.

REM sleep obstructive sleep apnoea

Obstructive sleep apnoea (OSA) can occur in both rapid eye movement (REM) and non-REM sleep or be limited to REM sleep, when the upper airway is most prone to collapse due to REM sleep atonia. Respiratory events are usually longer and more desaturating in REM than in NREM sleep. The prevalence of REM OSA is higher in women than in men and REM OSA usually occurs in the context of mild-moderate OSA based on the apnoea-hypopnoea index calculated for the entire sleep study. Studies have highlighted some detrimental consequences of REM OSA; for example, its frequent association with systemic hypertension and a degree of excessive daytime sleepiness similar to that found in nonsleep-stage-dependent OSA. Moreover, REM OSA could increase cardiometabolic risk. Continuous positive airway pressure (CPAP) treatment aimed at preventing REM OSA should be longer than the 4 h usually considered as good compliance, since REM sleep occurs mostly during the second half of the night. Unfortunately, patients with REM OSA show poor adherence to CPAP. Alternative non-CPAP treatments might be a good choice for REM OSA, but data are lacking. This review summarises the available data on REM OSA and critically examines the weaknesses and strengths of existing literature.

Cardiovascular diseases across OSA phenotypes: A retrospective cohort study

Background

Despite the considerable knowledge of Obstructive Sleep Apnea (OSA) implications for cardiac diseases, the evidence regarding cardiovascular complications across OSA phenotypes including Rapid Eye Movement OSA (REM-OSA) and Positional OSA (POSA) is limited. In this study, we aimed to evaluate the risk of cardiovascular diseases development and progression among patients with REM-OSA and POSA.

Methods

Based on a retrospective cohort analysis, we included polysomnography studies done in the sleep lab at the Jordan University Hospital. Regarding cardiovascular diseases, primary outcomes were Heart Failure, and 1-years Major Adverse Cardiac Events while secondary outcomes were atrial fibrillation, pulmonary hypertension, other arrhythmia, metabolic profile, and echocardiographic measurements of the heart.

Results

The total number of the included patients was 1,026 patients. POSA group had significantly lower percentage of patients with hypertension (P-value = 0.004). Additionally, systolic blood pressure and HbA1c were significantly lower among patients with POSA compared to the NPOSA group (P-value<0.050). Left ventricular end diastolic dimension was significantly higher among patients with POSA while ejection fraction was significantly lower (P-value<0.050). Patients with diabetes and mean HbA1c were significantly lower among patients with REM-OSA compared to patients with NREM-OSA (P-value = 0.015, P-value = 0.046). Multivariate regression analysis revealed that after adjusting for age, gender and preexisting comorbidities, POSA was significantly associated with lower ejection fraction and higher left ventricular diastolic diameter.

Conclusion

In conclusion, our findings indicate that POSA might be associated with huge and clinically significant heart strain and poor cardiac functions, yet it might not have a clinically significant atherogenic effect. This study should guide clinicians to identify OSA phenotypes to imply the best treatment plan to reduce its detrimental impact on cardiac muscle.

Association of modifiable risk factors with obstructive sleep apnea: a Mendelian randomization study

BACKGROUND

The risk factors involved in obstructive sleep apnea (OSA) have not been clearly identified yet. We attempted to systematically investigate genetically predicted modifiable risk factors and lifestyle behaviors associated with OSA.

METHODS

The association between 34 risk factors and OSA was evaluated using the two-sample Mendelian randomization (MR). Genetic variants for risk factors were acquired from European-descent genome-wide studies. Data sources for OSA were extracted from FinnGen study with 16,761 cases and 201,194 controls. The primary analysis chosen was the inverse-variance weighted method.

RESULTS

MR analyses provide evidence of genetically predicted poor overall health rating (odds ratio (OR), 2.82; 95% confidence interval (CI), 1.95-4.08), nap during day (OR, 2.01; 95% CI, 1.37-2.93), high body mass index (BMI) (OR, 1.14; 95% CI, 1.09-1.19), increased body fat mass (OR, 1.83; 95% CI, 1.83-2.05), elevated body water mass (OR, 1.50; 95% CI, 1.31-1.70) and hypertension (OR, 1.81; 95% CI, 1.34-2.45) were associated with higher OSA risk, while high education level (OR, 0.55; 95% CI, 0.40-0.75) correlated with reduced OSA risk. Suggestive evidence was obtained for smoking and waist-to-hip ratio (WHR) with higher OSA odds, and vigorous physical activity, and HDL cholesterol with lower OSA odds. After adjusting for BMI using multivariable MR analysis, the effects of smoking, WHR, vigorous physical activity, and HDL-cholesterol were fully attenuated.

CONCLUSIONS

This MR study indicates that overall health rating, nap during day, BMI, body fat mass, body water mass, hypertension, and education are causally associated with the risk of OSA, which means that these modifiable risk factors are key targets for OSA prevention.

Relationship between slow-wave sleep and serum γ-glutamine transaminase in non-obese men with obstructive sleep apnea-hypopnea syndrome

BACKGROUND

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a disease characterized with intermittent hypoxia and sleep fragmentation. Obesity and gender are major risk factors for the onset of OSAHS. Previous studies on obese men with OSAHS have been performed, while few studies on non-obese men with OSAHS have been carried out. The purpose of this study was to explore the clinical characteristics of polysomnography and blood biochemical indexes in non-obese men with OSAHS and to identify the possible influencing factors.

METHODS

This retrospective study included patients with OSAHS who underwent polysomnography in our hospital. General clinical data such as overnight polysomnography and biochemical indicators were recorded. The patients were divided into two groups according to the apnea-hypopnea index (AHI): mild to moderate OSAHS and severe OSAHS. The differences in biochemical parameters such as the levels of γ-glutamine transaminase (GGT), triglyceride (TG), glucose (GLU), and sleep structure parameters such as N1, N2, slow-wave sleep (SWS), and rapid eye movement (REM) sleep were compared and analyzed. Spearman correlation analysis and logistic regression were used to identify the risk factors of non-obese men with OSAHS. ROC curves were used to evaluate the predictive ability of SWS and GGT on disease severity.

RESULTS

Of 94 non-obese men with OSAHS, 49 had mild to moderate OSAHS and 45 had severe OSAHS. Our data suggested that the levels of low oxygen saturation (L-SaO2), mean oxygen saturation (M-SaO2), SWS, and GGT were significantly changed in the mild to moderate OSAHS group compared with the severe group (p < 0.05). For patients with OSAHS, the proportion of SWS in the group with severe OSAHS was higher than that in the mild to moderate group (p < 0.05), and the serum GGT enzyme levels were significantly elevated in the severe group compared to the mild to moderate group (p < 0.05). Using logistic regression analyses, our data revealed that both SWS and GGT enzyme levels were independent risk factors for AHI (p < 0.05). In addition, the results of correlation analysis indicated that SWS was related to triglyceride (TG), total cholesterol (TC), apolipoprotein E (APOE), and triglyceride glucose (TyG) index (p < 0.05); GGT was related to TG, TC, APOE, and TyG index (p < 0.05). Furthermore, SWS was independently associated with GGT (p < 0.05). The area under the ROC curve plotted with the combined coefficient of SWS and serum GGT was 0.728, which was predictive of the disease severity.

CONCLUSIONS

These results suggest that SWS and GGT are independent associated factors of the severity of the disease. However, TyG index was not an independent associated factor of the severity of disease in non-obese men with OSAHS. In addition, SWS and GGT were negatively correlated. SWS combined with serum GGT may be predictive of the severity of the disease. This study may have added to our understanding of the pathogenesis of OSAHS in non-obese men.

Dyslipidemia prevalence in nonobese, nondiabetic patients with obstructive sleep apnea: does sex matter?

STUDY OBJECTIVES

Dyslipidemia in obstructive sleep apnea (OSA) has been attributed to confounding obesity and/or diabetes. This study aimed to examine lipid profiles in nondiabetic, nonobese patients with OSA and identify the possible effects of age and sex.

METHODS

We retrospectively evaluated the lipid parameters of 3,050 adults who underwent polysomnography. A total of 2,168 patients were excluded due to obesity (body mass index ≥ 30 kg/m2), diabetes, alcoholism, untreated hypothyroidism, lipid-lowering drug use, missing sleep data, or treatment for suspected OSA.

RESULTS

Of 882 patients (75% males, aged 46.8 ± 12.2 years) included in the study, 88.4% had OSA. Levels of total cholesterol (P = .003), low-density-lipoprotein (LDL) cholesterol (P = .005), non-high-density-lipoprotein (non-HDL) cholesterol (P = .001), and triglycerides (P = .007) were significantly higher in patients with OSA than in those without, whereas HDL-cholesterol levels did not differ. The proportion of patients with hypercholesterolemia and/or elevated non-HDL cholesterol (>  160 mg/dL) was significantly higher in OSA than in non-OSA. Correlation analyses by sex revealed stronger and more significant relationships between lipid parameters and apnea-hypopnea index in women than in men (r = .135, P < .001, vs r = .080, P = .043 for total cholesterol; r = .111, P < .001, vs r = .080, P = .046 for non-HDL cholesterol; r = .122, P < .001, vs r = .061, P = .107 for LDL cholesterol, respectively). In regression analysis, the rate of hypercholesterolemia increased with age (P < .001 for women and P = .031 for men); non-HDL- and LDL-cholesterol levels significantly increased with OSA severity (P = .035 and P = .023, respectively) and age (P = .004 and P = .001, respectively) in women.

CONCLUSIONS

After excluding confounding obesity and diabetes, patients with OSA have an impaired lipid profile including total cholesterol, LDL cholesterol, non-HDL cholesterol, and triglycerides. A significant association between dyslipidemia and OSA severity was observed in women but not in men.

CITATION

Basoglu OK, Tasbakan MS, Kayikcioglu M. Dyslipidemia prevalence in nonobese, nondiabetic patients with obstructive sleep apnea: does sex matter? J Clin Sleep Med. 2023;19(5):889-898.

Association between cold spells and serum lipid levels among the elders: a distributed-lagged effects analysis

Little evidence about the effects of cold spells on serum lipid levels is available. The aim of this study was to explore the association between cold spells and serum lipid levels among the elders in Jinan, China. Data of old adults from health check-up program in Shandong Provincial Qianfoshan Hospital was collected for this study. Linear mixed models combined with distributed lag nonlinear models were used to examine the relationship between cold spells and serum lipid levels, considering the confounding effects of age, sex, blood pressure, body mass index, and other meteorological factors. Subgroup analysis by gender and analysis based on different definitions of cold spells were also conducted. Increased TG levels in lag 0-lag 2 days and decreased TG levels in lag 5-lag 8 days after cold spells were observed among the elders. The largest increase was 0.363 mmol/L (95% CI: 0.184 ~ 0.543) in lag 0 day, while the largest decreased TG levels was 0.083 mmol/L (95% CI: 0.147 ~ 0.019) in lag 6 day. Similar results were obtained in the analysis of different sex and based on different definitions of cold spells. However, no significant association was found between cold spells with TC, LDL-C, and HDL-C. This study indicates that cold spells were significantly associated with serum TG levels in the elders. Effective preventive measures should be implemented around the cold spells to reduce the volatility of serum lipid levels and the occurrence of subsequent cardiovascular diseases.

High-density lipoprotein cholesterol efflux capacity in patients with obstructive sleep apnea and its relation with disease severity

Background

Obstructive sleep apnea (OSA) is linked to an accelerated risk of cardiovascular disease (CVD). Some key CVD risk factors are present in patients suffering from OSA such as hypertension, inflammation, oxidative stress, and dyslipidemia. High-density lipoprotein (HDL) cholesterol efflux capacity (CEC) is proposed as a reliable biomarker of HDL function and the present study aimed to quantify this biomarker in patients with OSA.

Methods

ATP binding cassette subfamily A member 1 (ABCA1), non-ABCA1, and total CEC were determined in 69 polysomnographic-confirmed OSA patients and 23 controls. Moreover, paraoxonase (PON) activities, high-sensitivity C-reactive protein (hsCRP), apolipoprotein B (apo B), and apolipoprotein A-I (apo A-I) circulating levels were quantified in the studied population.

Results: All CEC measures were reduced in the OSA group compared to the control group. Strikingly, ABCA1 CEC was diminished in severe OSA in comparison with mild OSA. Furthermore, PON activities and apo A-I showed lower levels, while hsCRP and apo B were elevated in OSA patients compared to controls. Moreover, ABCA1 CEC showed an inverse association with hsCRP and a positive association with apo A-I, while non-ABCA1 CEC presented an association with HDL-C.

Conclusion

These results suggest the presence of an impaired HDL function in OSA. In particular, ABCA1 CEC was associated with disease severity and inflammation which could be a factor increasing the risk of CVD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-022-01723-w.

Obstructive Sleep Apnoea and Lipid Metabolism: The Summary of Evidence and Future Perspectives in the Pathophysiology of OSA-Associated Dyslipidaemia

Obstructive sleep apnoea (OSA) is associated with cardiovascular and metabolic comorbidities, including hypertension, dyslipidaemia, insulin resistance and atherosclerosis. Strong evidence suggests that OSA is associated with an altered lipid profile including elevated levels of triglyceride-rich lipoproteins and decreased levels of high-density lipoprotein (HDL). Intermittent hypoxia; sleep fragmentation; and consequential surges in the sympathetic activity, enhanced oxidative stress and systemic inflammation are the postulated mechanisms leading to metabolic alterations in OSA. Although the exact mechanisms of OSA-associated dyslipidaemia have not been fully elucidated, three main points have been found to be impaired: activated lipolysis in the adipose tissue, decreased lipid clearance from the circulation and accelerated de novo lipid synthesis. This is further complicated by the oxidisation of atherogenic lipoproteins, adipose tissue dysfunction, hormonal changes, and the reduced function of HDL particles in OSA. In this comprehensive review, we summarise and critically evaluate the current evidence about the possible mechanisms involved in OSA-associated dyslipidaemia.

Rapid eye movement sleep apnea and carotid intima thickness in men and women: a SHE-MUSTACHE cohort study

Rapid eye movement (REM) obstructive sleep apnea might be particularly harmful to the cardiovascular system. We aimed to investigate the association between sleep apnea during REM sleep and signs of atherosclerotic disease in the form of carotid intima thickness in a community-based sample of men and women and possible sex differences in this association. The association between sleep apnea during REM sleep and intima thickness was analysed cross-sectionally in women from the community-based "Sleep and Health in Women" (SHE) study (n = 253) and age- and body mass index (BMI)-matched men from the "Men in Uppsala; a Study of sleep, Apnea and Cardiometabolic Health" (MUSTACHE) study (n = 338). Confounders adjusted for were age, BMI, gender, alcohol, and smoking. All participants underwent a full-night polysomnography, high-resolution ultrasonography of the common carotid artery, anthropometric measurements, blood pressure measurements, and answered questionnaires. There was an association between sleep apnea during REM sleep and thicker carotid intima that remained after adjustment for confounding (adjusted β = 0.008, p = 0.032). The intima was increased by 9.9% in the group with severe sleep apnea during REM sleep, and this association between severe sleep apnea during REM sleep and increased intima thickness remained after adjustment for confounders (adjusted β = 0.043, p = 0.021). More women than men had severe sleep apnea during REM sleep; moreover, in sex-stratified analyses, the association between sleep apnea during REM sleep and intima thickness was found in women but not in men. We conclude that severe REM sleep apnea is independently associated with signs of atherosclerosis. When stratified by sex, the association is seen in women but not in men.

The impact of sleep apnea syndrome on the altered lipid metabolism and the redox balance

Background

Obstructive sleep apnea (OSA) is a disorder with a significant risk for cardiovascular diseases. Dyslipidemia and redox imbalance belong to potential mechanisms linking OSA with the development of vascular diseases. The main aim of this study was the evaluation of the presence of lipid abnormalities in OSA patients, focusing on small dense low-density lipoprotein (LDL) and high-density lipoprotein (HDL) subfractions and determination of the redox imbalance by evaluating the marker of oxidative damage to plasma lipids - lipoperoxides.

Methods

The study included 15 male subjects with polysomnographically confirmed OSA and 16 male healthy controls. Plasma levels of total cholesterol, LDL and HDL and their subfractions, triacylglycerols and lipoperoxides were determined in all study individuals. Plasma LDL and HDL subfractions were separated by the Lipoprint system which is a polyacrylamide gel electrophoresis. Lipoperoxide levels were determined spectrophotometrically.

Results

OSA patients had significantly higher triacylglycerols, total cholesterol and LDL-cholesterol compared to healthy controls. HDL cholesterol was not significantly different. Of the LDL and HDL subfractions, OSA patients had significantly lower levels of atheroprotective LDL1 and large HDL subfractions and significantly higher levels of atherogenic small dense LDL3–7 and HDL8–10 subfractions. Lipoperoxide levels in patients with OSA were significantly elevated compared to healthy individuals.

Conclusion

The lipoprotein pro-atherogenic phenotype was found in individuals with OSA characterized by increased levels of atherogenic lipoprotein subfractions and reduced levels of atheroprotective subfractions. In addition, a plasma redox imbalance was found in patients with OSA compared to controls by detecting higher oxidative damage to lipids. Abnormalities in lipoprotein levels in patients with OSA, as well as the redox imbalance, could lead to an acceleration of the atherosclerotic process in predisposed individuals and thus represent a significant risk factor for vasular diseases.

Could non-HDL-cholesterol be a better marker of atherogenic dyslipidemia in obstructive sleep apnea?

BACKGROUND/OBJECTIVE

Obstructive sleep apnea (OSA) is independently associated with dyslipidemia, a surrogate marker of atherosclerosis. Low-density lipoprotein (LDL)-cholesterol is accepted as a major independent risk factor for cardiovascular disease. However, non-high-density lipoprotein (HDL)-cholesterol is a better marker of atherogenic dyslipidemia and recommended as a target of lipid lowering therapy. We aimed to assess the prevalence of atherogenic dyslipidemia, and relationship between OSA severity and serum LDL-cholesterol and non-HDL cholesterol levels in OSA patients.

METHODS

We retrospectively evaluated treatment naïve 2361 subjects admitted to the sleep laboratory of a university hospital for polysomnography. All subjects' lipid profile including total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, and non-HDL-cholesterol were measured.

RESULTS

Out of 2361 patients (mean age 49.6 ± 11.9 years; 68.9% male, apnea-hypopnea index 36.6 ± 28.4/h), 185 (7.8%) had no OSA and 2176 (92.2%) had OSA. Atherogenic dyslipidemia prevalence was high (57-66%) in OSA patients, and especially increased in severe OSA compared to other groups (p < 0.05). Though total and LDL-cholesterol did not differ between those with and without OSA, non-HDL-cholesterol (p = 0.020), and triglycerides (p = 0.001) were higher and HDL-cholesterol levels (p = 0.018) were lower in OSA patients than non-OSA. Non-HDL-cholesterol was significantly correlated with OSA severity (p < 0.001) and hypoxia parameters (p < 0.01), whereas LDL-cholesterol showed no correlation.

CONCLUSIONS

Atherogenic dyslipidemia is highly prevalent and non-HDL-cholesterol levels are significantly increased, predominantly in severe OSA patients. Non-HDL-cholesterol but not LDL-cholesterol, is significantly correlated with OSA severity and hypoxia parameters. Therefore, it could be better to use non-HDL-cholesterol, which is a guideline recommended target of lipid therapy, as a marker of atherosclerotic cardiovascular risk in OSA patients.

Circulating levels of ghrelin, galanin, and orexin-A orexigenic neuropeptides in obstructive sleep apnea syndrome

PURPOSE

The orexigenic peptides, ghrelin, galanin, and orexin-A, have an important role in food intake and energy homeostasis and regulate the higher brain functions including the sleep-wake state. Although the interactions of these neuropeptides affect neuroendocrine systems resulting in obesity, a major risk factor for obstructive sleep apnea syndrome (OSAS), the mechanism has not been fully elucidated. The objective of this study was to evaluate the association of serum ghrelin, galanin, and orexin-A levels with OSAS.

METHODS

In this cross-sectional study, patients who underwent one-night polysomnography and conformed to the inclusion criteria were asked to participate. A blood sample was obtained from all participants on the morning of the sleep test to evaluate the serum levels of ghrelin, galanin, and orexin-A using the enzyme-linked immunosorbent assay (ELISA) method. Demographic characteristics, polysomnography data, and serum levels of the participants were recorded and analyzed. Comparison between the OSAS groups was performed by independent sample t-test, Mann-Whitney U test, and Kruskal-Wallis test with post hoc K-W test using SPSS 20.0.

RESULTS

Of 272 patients, those in the OSAS group (n=210) were older than patients in the non-OSAS group (n=62), p < 0.003, and had increased BMI, p < 0.006. Patients with, serum ghrelin, galanin, and orexin-A levels were significantly elevated in patients with OSAS (635.9 pg/mL vs. 420.7 pg/mL, 91.0 pg/mL vs. 60.0 pg/mL, 600.3 pg/mL vs. 485.6 pg/mL, respectively) and found to be higher in patients with severe OSAS than mild and moderate cases (p < 0.01). In multinomial logistic regression to predict the OSAS severity, levels of serum ghrelin (OR = 1.016 [1.010-1.021]; p < 0.001), galanin (OR = 1.050 [1.020-1.081]; p < 0.001), and orexin-A (OR = 1.021 [1.012-1.030]; p < 0.001) were significantly associated only with a moderate level of OSAS.

CONCLUSION

The orexigenic neuropeptides were found to be an independent determinant of the presence of OSAS and correlate with the severity of OSAS. Increased levels of ghrelin, galanin, and orexin-A were associated with the presence of moderate OSAS.

Triglyceride-Glucose Index in Non-Diabetic, Non-Obese Patients with Obstructive Sleep Apnoea

Obstructive sleep apnoea (OSA) is associated with increased insulin resistance. Triglyceride-glucose index (TyG) is a simple marker of insulin resistance; however, it has been investigated only by two studies in OSA. The aim of this study was to evaluate TyG in non-diabetic, non-obese patients with OSA. A total of 132 patients with OSA and 49 non-OSA control subjects were included. Following a diagnostic sleep test, fasting blood was taken for the analysis of the lipid profile and glucose concentrations. TyG was calculated as ln(triglyceride [mg/dL] × glucose [mg/dL]/2). Comparison analyses between OSA and control groups were adjusted for age, gender, body mass index (BMI) and smoking. TyG was higher in men (p < 0.01) and in ever-smokers (p = 0.02) and it was related to BMI (ρ = 0.33), cigarette pack-years (ρ = 0.17), apnoea–hypopnoea index (ρ = 0.38), oxygen desaturation index (ρ = 0.40), percentage of total sleep time spent with oxygen saturation below 90% (ρ = 0.34), and minimal oxygen saturation (ρ = −0.29; all p < 0.05). TyG values were significantly higher in OSA (p = 0.02) following adjustment for covariates. OSA is independently associated with higher TyG values which are related to disease severity in non-obese, non-diabetic subjects. However, the value of TyG in clinical practice should be evaluated in follow-up studies in patients with OSA.

Atherogenic Index of Plasma in Obstructive Sleep Apnoea

Background: Dyslipidaemia is well recognised in obstructive sleep apnoea (OSA) and could contribute to the development of cardiovascular disease (CVD). Atherogenic index of plasma (AIP) predicts cardiovascular morbidity and mortality better than the individual lipid levels. The aim of this study was to investigate the AIP in patients with OSA in relation with disease severity. Methods: Four hundred sixty-one patients with OSA and 99 controls participated in this study. AIP was assessed in the morning following a diagnostic sleep study. The association between lipid values and OSA were adjusted for age, gender, and body mass index. Results: Patients with OSA had higher AIP and triglyceride, and lower high-density lipoprotein cholesterol (HDL-C) levels (all p < 0.05). AIP significantly correlated with the Epworth Sleepiness Scale score (ρ = 0.19), the apnoea-hypopnoea index (ρ = 0.40) and oxygen desaturation index (ρ = 0.43, all p < 0.05). However, there was no relationship between the AIP and markers of sleep quality such as total sleep time, sleep period time, sleep efficiency, arousal index or percentage of REM sleep (all p > 0.05). AIP was not a better predictor for self-reported cardiovascular disease or diabetes than HDL-C. Conclusions: AIP is elevated in OSA and is related to disease severity. However, it does not seem to have an additional clinical value compared to HDL-C.

The Association of Obstructive Sleep Apnea and Nocturnal Hypoxemia with Lipid Profiles in a Population-Based Study of Community-Dwelling Australian Men

OBJECTIVE

To determine the association of obstructive sleep apnea and nocturnal hypoxemia with serum lipid profiles in unselected community-dwelling men.

METHODS

Cross-sectional data from participants of the Men Androgen Inflammation Lifestyle Environment and Stress (MAILES) study (n=753) who underwent full in-home polysomnography (Embletta X100) was used. Triglycerides, high- (HDL), low-density lipoprotein (LDL), and total cholesterol were assessed on a fasting morning blood sample. Multivariable linear regression analyses assessed associations between lipids and continuous measures of nocturnal hypoxemia (oxygen desaturation index (3%) (ODI), apnea-hypopnea index (AHI), and rapid eye movement sleep apnea-hypopnea index (REM-AHI)), adjusted for chronic conditions, risk behavior and sociodemographic factors. Sensitivity analyses examined the effect of lipid lowering therapies on reported estimates. Effect modification was examined through stratification by waist circumference groups.

RESULTS

In 753 participants with mean (SD) age of 60.8 (10.9) years and waist circumference: 99.3 (11.6) cm, the prevalence of OSA (AHI≥10) was 52.6%. Overall, no significant associations between OSA metrics and lipid measures were found. Similarly, sensitivity analysis excluding lipid lowering therapies showed no significant associations. In analysis stratified by waist circumference (<95cm, 95-100cm, >100cm), ODI (3%, unstandardized B: 0.027, 95% CI: 0.015-0.040), AHI (0.023, 0.012-0.033) and AHI_REM (0.012, 0.001-0.022) were positively associated with serum triglycerides in participants with a normal waist circumference (<95cm).

CONCLUSION

Obstructive sleep apnea metrics were positively associated with serum triglyceride levels in men with a normal waist circumference. Healthy weight individuals with OSA require clinical attention to improve cardiometabolic risk profiles.

The Burden of Associated Comorbidities in Patients with Obstructive Sleep Apnea-Regional Differences in Two Central-Eastern European Sleep Centers

Background: Obstructive sleep apnea (OSA) is usually associated with cardiovascular and cerebrovascular disease, metabolic syndrome and depression. Data on relevant OSA-associated comorbidities in Central–European populations are scarce. The aim of this study was to compare the prevalence of comorbidities in two OSA cohorts from Hungary and Romania. Methods: Data from 588 (282 from Hungary, 306 from Romania) untreated patients with OSA were retrospectively analyzed. The prevalence rates of hypertension, diabetes, dyslipidemia, allergic rhinitis, asthma, chronic obstructive pulmonary disease (COPD), osteoporosis, cerebrovascular and cardiovascular disease, arrhythmia and depression were compared between the two populations following adjustment for demographics, body mass index, smoking history, comorbidities and sleep parameters. Results: The prevalence rates of hypertension, arrhythmia, cerebrovascular and cardiovascular disease, diabetes and COPD in the whole study population were directly related to the severity of OSA. We found an inverse correlation between the prevalence of osteoporosis and OSA severity (all p < 0.05). Following adjustment, the prevalence of dyslipidemia was higher in the Hungarian cohort, whilst the prevalence of asthma, cardiovascular and cerebrovascular diseases was higher in the Romanian cohort (all p < 0.05). Conclusions: There was no difference in the prevalence rate of most comorbidities in patients with OSA from the two cohorts, except for dyslipidemia, asthma, cardiovascular and cerebrovascular disease.

Broken sleep predicts hardened blood vessels

Why does poor-quality sleep lead to atherosclerosis? In a diverse sample of over 1,600 individuals, we describe a pathway wherein sleep fragmentation raises inflammatory-related white blood cell counts (neutrophils and monocytes), thereby increasing atherosclerosis severity, even when other common risk factors have been accounted for. Improving sleep quality may thus represent one preventive strategy for lowering inflammatory status and thus atherosclerosis risk, reinforcing public health policies focused on sleep health.

Why does poor quality sleep correlate with cardiovascular disease? A large population-based study suggests that fragmented sleep contributes to atherosclerosis in humans by increasing inflammatory-related activity of white blood cells.

Obstructive sleep apnea in obese adolescents referred for bariatric surgery: association with metabolic and cardiovascular variables

BACKGROUND

obstructive sleep apnea syndrome (OSA) is a well-described disease entity in adults, with a higher prevalence in severely obese individuals, while at the same time associated with several comorbidities independently of BMI. Literature regarding OSA in severely obese adolescents is qualitatively and quantitatively limited, possibly resulting in suboptimal diagnosis and treatment.

METHODS

polysomnographic, demographic, anthropometric, and comorbidity-related data were prospectively collected in 56 adolescents with morbid obesity refractory to conservative treatment who presented for surgical therapy. Differences between adolescents with no/mild (apnea-hypopnea index (AHI) 0-4.9) and moderate/severe OSA (AHI ≥ 5.0) were evaluated using independent-samples t, chi-square or Fisher's exact tests. Multivariable linear regression analysis was performed to evaluate the association of several variables with AHI, corrected for BMI z-score.

RESULTS

of the 53 included subjects, 48 (90.6%) showed some degree of sleep disordered breathing and 20 (37.7%) had moderate/severe OSA. Patients with moderate/severe OSA had on average a higher neck circumference (42.4 versus 40.1 cm, p = 0.008), higher BMI z-score (3.7 versus 3.4, p = 0.003), higher plasma triglyceride level (2.2 versus 1.5 mmol/L, p = 0.012), and lower IGF (29.6 versus 40.2 mmol/L, p = 0.010) than those with no/mild OSA. BMI z-score and plasma triglyceride levels were independently related to AHI.

CONCLUSIONS

OSA is highly prevalent amongst morbidly obese adolescents and is strongly associated with BMI z-score. Elevated plasma triglyceride levels are associated with AHI, independent of BMI z-score.