Association of lipid-modifying therapy with risk of obstructive sleep apnea: A drug-target mendelian randomization study.

BACKGROUND: Obstructive sleep apnea (OSA) is considered to be an important contributor of dyslipidemia. However, there lacks observational studies focusing on the potential effect of lipid management on OSA risk. Thus, we aimed to investigate the genetic association of lipid-modifying therapy with risk of OSA. METHODS: A drug-target mendelian randomization (MR) study using both cis-variants and cis-expression quantitative trait loci (eQTLs) of lipid-modifying drug targets was performed. The MR analyses used summary-level data of genome wide association studies (GWAS). Primary MR analysis was conducted using inverse-variance-weighted (IVW) method. Sensitivity analysis was performed using weighted median (WM) and MR-pleiotropy residual sum and outlier (MR-PRESSO) methods. RESULTS: Genetically proxied low-density lipoprotein cholesterol (LDL-C)-lowering effect of cholesteryl ester transfer protein (CETP) was associated with reduced risk of OSA (odds ratio [OR] =0.75, 95% confidence interval [CI]: 0.60-0.94, false discovery rate [FDR] q value = 0.046). A significant MR association with risk of OSA was observed for CETP expression in subcutaneous adipose tissue (OR = 0.94, 95%CI: 0.89-1.00, FDR q value = 0.049), lung (OR = 0.94, 95%CI: 0.89-1.00, FDR q value = 0.049) and small intestine (OR = 0.96, 95%CI: 0.93-1.00, FDR q value = 0.049). No significant effects of high-density lipoprotein cholesterol (HDL-C)-raising effect of CETP inhibition, LDL-C-lowering and triglycerides-lowering effect of other drug targets on OSA risk were observed. CONCLUSIONS: The present study presented genetic evidence supporting the association of LDL-C-lowering therapy by CETP inhibition with reduced risk of OSA. These findings provided novel insights into the role of lipid management in patients with OSA and encouraged further clinical validations and mechanistic investigations.

Associations of systemic inflammation markers with myocardial enzymes in pediatric adenotonsillar hypertrophy: A cross-sectional study.

Objective: The present study aimed to investigate the relationship between systemic inflammation markers and myocardial enzymes in children with adenotonsillar hypertrophy (ATH). Methods: The levels of myocardial enzymes were detected and the systemic inflammatory biomarkers including neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and systemic immune inflammation index (SII) were calculated. Regression analyses were performed and a prediction model for screening myocardial injury was established by receiver operating characteristic (ROC) curve. Results: Finally, a total of 804 children with ATH were included. After adjusting for age, BMI, fasting blood glucose and lipid profiles, both NLR and SII were significantly associated with CK-MB (p = 0.041 and 0.034, respectively) and LDH (p = 0.002 and 0.001, respectively), and PLR was associated with CK-MB (p = 0.008). In addition, NLR, SII were independently associated with hyper-LDH [OR = 1.447, 95%CI (1.063, 1.968); OR = 1.001, 95%CI (1.000, 1.002), respectively] and the associations were more significant in girls. A prediction model for hyper-LDH based on SII was developed with the area under the ROC curve of 0.715 (0.682, 0.746). Conclusion: Systemic inflammation markers were only independently associated with serum hyper-LDH in children with ATH, especially in girls. Further investigation was needed to determine the relationship between systemic inflammation with myocardial enzymes in ATH children.

Assessing causal relationships between sarcopenia and nonalcoholic fatty liver disease: A bidirectional Mendelian randomization study.

Background and aims: Sarcopenia has been demonstrated to be closely associated with nonalcoholic fatty liver disease (NAFLD). However, whether there are causal relationships between sarcopenia and NAFLD remains undetermined. Here, we aim to address the question using a two-sample bidirectional Mendelian randomization (MR) analysis approach. Methods: We performed a two-sample bidirectional MR study using summary-level data from genome-wide association studies (GWAS) of the whole body lean mass (n = 38,292), appendicular (arms and legs) lean mass (n = 28,330), and NAFLD (1,483 biopsy-proven NAFLD cases and 17,781 controls). We first conducted MR analysis with five single nucleotide polymorphisms (SNPs) as genetic instruments for whole body lean mass and three SNPs as instruments for appendicular lean mass to estimate the causal effect of genetically predicted sarcopenia on the risk of NAFLD using the inverse-variance weighted (IVW) method. Then we performed reverse MR analysis with four SNPs as instruments to examine the causality of genetically predicted NAFLD with whole body lean mass and appendicular lean mass. Further sensitivity analysis was conducted to testify the reliability of the MR results. Results: Genetic predisposition to decreased whole body lean mass was not associated with NAFLD [IVW-random effects, odds ratio (OR) = 1.054, 95%CI: 0.750-1.482, P = 0.761]. Similar results were observed using genetic instruments of appendicular lean mass (IVW-random effects, OR = 0.888, 95%CI: 0.386-2.042, P = 0.780). Reverse MR analysis revealed that genetically predicted NAFLD using four genetic instruments was not associated with whole body lean mass (IVW, ß = -0.068, 95%CI: -0.179 to 0.043, P = 0.229) and appendicular lean mass (IVW, ß = -0.020, 95%CI: -0.092 to 0.051, P = 0.574). MR analyses using other methods and sensitivity analysis showed consistent results. Conclusion: These results suggested no causal relationships between sarcopenia and NAFLD, indicating that sarcopenia may not be directly involved in the pathogenesis of NAFLD and vice versa.

An effective model for screening moderate-to-severe obstructive sleep apnea based on the STOP-BANG questionnaire.

Background: This study aimed to develop a more effective screening model for moderate-to-severe obstructive sleep apnea (OSA) based on the best tool among Epworth Sleepiness Scale (ESS), NoSAS score and STOP-BANG questionnaire (SBQ). Methods: This study screened 2,031 consecutive subjects referred with suspected OSA from 2012 to 2016, including the test cohort from 2012 to 2014 and the validation cohort from 2014 to 2016. Anthropometric measurements, polysomnographic data, ESS, NoSAS scores and SBQ scores were recorded. Receiver operating characteristic curve analyses were performed and the final predictive models were verified in a validation cohort. Results: A total of 1,840 adults were finally included. The performance of ESS, NoSAS score and SBQ in screening OSA was compared. The diagnostic accuracy of SBQ was superior to ESS and NoSAS. A predictive model based on SBQ yielded an area under the curve (AUC) of 0.931 (95% CI: 0.915-0.946), and the sensitivity and specificity were 84.47 (95% CI: 81.4-87.2) and 87.36 (95% CI: 83.9-90.3) respectively. In the validation cohort, the AUC was 0.955 (95% CI: 0.938-0.969), with a sensitivity and specificity of 86.79 (95% CI: 83.2-89.9) and 90.88 (95% CI: 87.2-93.8) respectively. In addition, the model performed moderately in screening mild OSA with the AUC being 0.771 (95% CI: 0.721-0.815). Conclusions: The SBQ was effective in screening moderate-to-severe OSA. And a SBQ -based predictive model afforded excellent diagnostic efficacy, which could be applied in clinical practice.

Effects of Chronic Intermittent Hypoxia and Chronic Sleep Fragmentation on Gut Microbiome, Serum Metabolome, Liver and Adipose Tissue Morphology.

Chronic intermittent hypoxia (CIH) and chronic sleep fragmentation (CSF) are two cardinal pathological features of obstructive sleep apnea (OSA). Dietary obesity is a crucial risk intermediator for OSA and metabolic disorders. Gut microbiota affect hepatic and adipose tissue morphology under conditions of CIH or CSF through downstream metabolites. However, the exact relationship is unclear. Herein, chow and high-fat diet (HFD)-fed mice were subjected to CIH or CSF for 10 weeks each and compared to normoxia (NM) or normal sleep (NS) controls. 16S rRNA amplicon sequencing, untargeted liquid chromatography-tandem mass spectrometry, and histological assessment of liver and adipose tissues were used to investigate the correlations between the microbiome, metabolome, and lipid metabolism under CIH or CSF condition. Our results demonstrated that CIH and CSF regulate the abundance of intestinal microbes (such as Akkermansia mucinphila, Clostridium spp., Lactococcus spp., and Bifidobacterium spp.) and functional metabolites, such as tryptophan, free fatty acids, branched amino acids, and bile acids, which influence adipose tissue and hepatic lipid metabolism, and the level of lipid deposition in tissues and peripheral blood. In conclusion, CIH and CSF adversely affect fecal microbiota composition and function, and host metabolism; these findings provide new insight into the independent and synergistic effects of CIH, CSF, and HFD on lipid disorders.

Insomnia Moderates the Relationship Between Amyloid-ß and Cognitive Decline in Late-Life Adults without Dementia.

BACKGROUND: It is suggested that not all individuals with elevated Aß will develop dementia or cognitive impairment. Environment or lifestyle might modulate the association of amyloid pathology with cognition. Insomnia is a risk factor of cognitive disorders including Alzheimer's disease. OBJECTIVE: To investigate if insomnia moderated the relationship between amyloid-ß (Aß) and longitudinal cognitive performance in non-demented elders. METHODS: A total of 385 Alzheimer's Disease Neuroimaging Initiative participants (mean age = 73 years, 48% females) who completed 4 + neuropsychological evaluations and a [18F] florbetapir positron emission tomography scan were followed up to 8 years. Linear mixed-effects regression models were used to examine the interactions effect between insomnia and Aß on longitudinal cognitive sores, including four domains (memory [MEM], executive function [EF], language [LAN], and visuospatial function [VS]). RESULTS: The Aß-positive status (A+) but not insomnia independently predicted faster cognitive decline in all domains. Furthermore, the relationship between Aß and cognitive decline was moderated by insomnia (MEM: χ2 = 4.05, p = 0.044, EF: χ2 = 4.38, p = 0.036, LAN: χ2 = 4.56, p = 0.033, and VS: χ2 = 4.12, p = 0.042). Individuals with both elevated Aß and insomnia experienced faster cognitive decline than those with only elevated Aß or insomnia. CONCLUSION: These data reinforced the values of insomnia management in preventing dementia, possibly by interacting Aß metabolism. Future efforts are warranted to determine whether sleep improvement will postpone the onset of dementia, specifically among populations in stages of preclinical or prodromal AD.

Eosinophils Are More Strongly Relevant to Allergic Sensitization Than Basophils in Pediatric Adenotonsillar Hypertrophy.

The relationship between eosinophils/basophils and allergic sensitization is not clear in pediatric adenotonsillar hypertrophy (ATH). The objective of this study is to investigate the relationship between eosinophil/basophil counts and peripheral specific IgE levels, and identify the common allergens in children with ATH. We initially screened 1,031 consecutive children who underwent adenotonsillectomy in our department from June 2018 to June 2019, and finally included 676 children. The eosinophil count, basophil count, and levels of specific IgE were collected. Correlations between two quantitative variables were assessed using the Pearson or Spearman coefficient. Logistic regression analyses were performed to evaluate the odds ratios (ORs) for atopy after controlling for age, sex, vitamin D, BMI, and visiting season. Both the eosinophil and basophil counts in atopic participants were significantly higher compared to non-atopic participants. The eosinophil count correlated with the levels of IgE specific to all allergens, and eosinophilia was independently associated with all tested atopy allergens other than atopy to dander after multivariate adjustment. Additionally, the basophil count correlated with the IgE levels specific to A. alternate and food mix, and basophilia was still significantly associated with atopy to food mix after multivariable adjustment. Furthermore, among allergic participants, D. farinae was the most prevalent allergen, followed by food mix, D. pteronyssinus, and A. alternata. In conclusion, eosinophils were more relevant to allergic sensitization than basophils, with eosinophils being significantly associated with all tested atopy allergens apart from dander, and basophils being associated with atopy to food mix. Furthermore, D. farinae was the most prevalent allergen and may be indicative of desensitization therapy.

Association of apnea-hypopnea index during rapid eye movement sleep with insulin resistance in patients with suspected obstructive sleep apnea: a cross-sectional study.

BACKGROUND: Obstructive sleep apnea (OSA) is associated with insulin resistance. However, the association between special stages of OSA [rapid eye movement (REM) sleep] and insulin resistance is not clear. This study was designed to assess the association of the frequency of respiratory events during REM sleep with insulin resistance in adults with suspected OSA. METHODS: In this cross-sectional study, 4,062 adult participants with suspected OSA who underwent polysomnography in our sleep center between 2009 and 2016 were screened. Polysomnographic variables, biochemical indicators, and physical measurements were collected. Logistic regression analyses were conducted to determine the odds ratios (ORs) and 95% confidence intervals (95% CIs) for insulin resistance as assessed by the presence of hyperinsulinemia, the homeostasis model assessment of insulin resistance (HOMA-IR) index, the fasting insulin resistance index (FIRI), and Bennett's insulin sensitivity index (ISI). RESULTS: The final analyses included 2,899 adults with suspected OSA. Multivariate adjustments, including the apnea-hypopnea index (AHI) during non-REM sleep (AHINREM), were performed. The AHI during REM sleep (AHIREM) was found to be independently associated with insulin resistance across increasing AHIREM quartiles. For hyperinsulinemia the ORs (95% CIs) followed the order of 1.340 (1.022, 1.757), 1.210 (0.882, 1.660), and 1.632 (1.103, 2.416). For abnormal HOMA-IR, ORs (95% CIs) were 1.287 (0.998, 1.661), 1.263 (0.933, 1.711), and 1.556 (1.056, 2.293). For abnormal FIRI, ORs (95% CIs) were 1.386 (1.048, 1.835), 1.317 (0.954, 1.818), and 1.888 (1.269, 2.807). For abnormal Bennett's ISI, ORs (95% CIs) were 1.297 (1.003, 1.678), 1.287 (0.949, 1.747), and 1.663 (1.127, 2.452). All linear trends were statistically significant (P<0.01). Additionally, the results showed that REM sleep duration was independently associated with hyperinsulinemia (OR =0.777, 95% CI: 0.615-0.982; P<0.05). CONCLUSIONS: AHIREM was independently associated with hyperinsulinemia and an abnormal HOMA-IR, FIRI, and Bennett's ISI in adults with suspected OSA. Additionally, REM sleep duration was independently associated with hyperinsulinemia.

Expression and Prognostic Analyses of ITGA3, ITGA5, and ITGA6 in Head and Neck Squamous Cell Carcinoma.

BACKGROUND The landscape of head and neck cancers has changed with improvements in standard therapy; however, it is necessary to exploit advanced genomic approaches to identify novel diagnostic and prognostic biomarkers for head and neck squamous cell carcinoma (HNSC). ITGA3, ITGA5, and ITGA6, members of the integrin family of proteins, play active roles in cytoskeletal organization and cell migration, proliferation, and survival. However, the expression patterns and prognostic values of ITGA3, ITGA5, and ITGA6 in head and neck squamous cell carcinoma remain unclear. MATERIAL AND METHODS Different expression patterns and prognostic values of ITGA3, ITGA5, and ITGA6 were analyzed in patients with HNSC using various databases, including ONCOMINE, GEPIA, TIMER, HPA, Kaplan-Meier Plotter, GEO, and TCGA. RESULTS Expression levels of ITGA3, ITGA5, and ITGA6 were substantially increased in patients with HNSC. Additionally, higher expression levels of ITGA3, ITGA5, and ITGA6 were associated with worse overall survival in patients with HNSC, and higher levels of ITGA3 correlated with a worse relapse-free survival. CONCLUSIONS ITGA3, ITGA5, and ITGA6 are potential diagnostic and prognostic biomarkers for HNSC. In particular, IGTA5 might be used as a significant independent prognostic factor in this cancer.

[Application of impulse-radio ultra-wideband radar as a non-contact portable monitoring device for the diagnosis of obstructive sleep apnea].

Objective:To compare the effect of impulse-radio ultrawideband（IR-UWB） radar technology and polysomnography（PSG） in sleep assessment. Method:A total of 79 OSA patients were randomly divided into two groups: 40 patients in group A received PSG and IR-UWB, and 39 patients in group B received micromovement sensitive mattress（MSM） and IR-UWB. Pearson correlation and ROC curve were used for statistics. Result:AHI PSG and AHI MSM were significantly correlated with AHI IR-UWB（r=0.91, P＝0.00; r=0.92, P＝0.00）. Bland-Altman analysis showed that AHI IR-UWB value was highly consistent with AHI PSG value（95.00%）, and AHI IR-UWB value（97.44%）. The sensitivity and specificity of AHI IR-UWB compared with PSG were 70.40% and 89.90%, respectively. The area under ROC curve was 0.915. Conclusion:IR-UWB has a high diagnostic value for adult OSA in terms of minimum blood oxygen saturation, average blood oxygen saturation, average number of central sleep apnea, average number of complex sleep apnea, average heart rate, sleep efficiency, REM sleep duration, average AHI, etc. It is an economic and practical sleep evaluation tool.

Association of Adipocytokines With Carotid Intima Media Thickness and Arterial Stiffness in Obstructive Sleep Apnea Patients.

Objective: Obstructive sleep apnea (OSA) results in increased carotid intima-media thickness (IMT) and arterial stiffness; however, the association between adipocytokines and IMT/arterial stiffness in OSA patients is unclear. Methods: We enrolled 95 normal weight and overweight, not obese, participants from May 2018 to December 2018 in this study. All subjects underwent a carotid artery ultrasound examination and polysomnography. Blood samples were used to determine serum chemerin, adiponectin, SFRP5, and apelin levels. Correlations between two quantitative variables were assessed using the Pearson or Spearman coefficient. Stepwise models of multiple linear regression analysis were performed to assess the independent relationships. Result: IMT in OSA patients was significantly higher than in the non-snorers. There were significant differences in the arterial stiffness parameters such as distensibility coefficient (DC), compliance coefficient (CC), and pulse wave velocity (PWV). SFRP5 level was lower in OSA patients than in non-snorers. Adiponectin correlated with CC, DC, and PWV among OSA patients; however, the relationship disappeared after a multivariable adjustment. Age was independently associated with all quantitative IMT and stiffness indices. AHI and minimum oxygen saturation (Mini SaO2) were independently related to arterial stiffness. Conclusion: The quantitative IMT and carotid arterial elasticity were significantly worse among OSA patients. Age was the main independent factor correlated with quantitative IMT and arterial stiffness, and AHI and mini SaO2 were associated factors. There were no relationships between aforementioned adipocytokines and quantitative IMT/carotid arterial stiffness.

The use of visceral adiposity variables in the prediction of obstructive sleep apnea: evidence from a large cross-sectional study.

PURPOSE: The purposes of this study were to evaluate the ability of visceral adiposity variables [the lipid accumulation product (LAP), the visceral adiposity index (VAI), and the triglyceride-glucose index (TyG)] in predicting obstructive sleep apnea hypopnea syndrome (OSAHS) and to determine the effect of sex on the prediction. METHODS: A total of 5539 subjects admitted to the sleep center for suspected OSAHS were consecutively recruited from 2007 to 2016. Anthropometric measurements, biological indicators, Epworth sleepiness scale score, and polysomnographic variables were collected. Prediction models for diagnosing OSAHS were established in the test group by logistic regression and verified in the validation group by receiver operating characteristic (ROC) curves. RESULTS: A total of 4703 patients were included in total. LAP and TyG were of moderate diagnostic accuracy for OSAHS, with the diagnostic efficiency differing between men and women. A prediction model was developed that combined visceral adiposity indicators with waist circumstance and the lowest SpO2. The sensitivity of those indicators were both 84% in men and women, respectively, and their specificity were both 90%. In addition, the model was confirmed in the validation group with a sensitivity and specificity of 83% and 85% in men and 85% and 84% in women. CONCLUSIONS: LAP and TyG were of moderate efficiency in screening for OSAHS. The prediction model provides a simple and practical screening tool for OSAHS.

Sleep problems and risk of all-cause cognitive decline or dementia: an updated systematic review and meta-analysis.

OBJECTIVES: To conduct an updated systematic review and meta-analysis of association between sleep and all-cause cognitive disorders. METHODS: PubMed and EMBASE were searched from inception to 18 February 2019. Cohort studies exploring longitudinal associations of sleep with cognitive decline or dementia were included. The multivariable-adjusted effect estimates were pooled by random-effects models, with credibility assessment. The robust error meta-regression model was used to conduct the dose-response meta-analysis for sleep duration. RESULTS: 11 155 reports were searched and 51 eligible cohorts with 15 sleep problems were included for our meta-analyses. Ten types of sleep conditions or parameters, including six (insomnia, fragmentation, daytime dysfunction, prolonged latency, rapid eye movement sleep behaviour disorder and excessive time in bed) with moderate-to-high levels of evidence, were linked to higher risk of all-cause cognitive disorders. Furthermore, a U-shaped relationship was revealed for the associations with sleep duration. CONCLUSIONS: Sleep management might serve as a promising target for dementia prevention.

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.

The Relationship between Simple Snoring and Metabolic Syndrome: A Cross-Sectional Study.

PURPOSE: This cross-sectional study was performed to assess the relationship between simple snoring and metabolic syndrome (MetS). METHODS: A total of 5635 participants including 300 healthy volunteers without snoring allegedly were initially included from 2007 to 2016. Polysomnographic variables, anthropometric measurements, and biochemical indicators were collected. The polynomial linear trend test was used to assess the linear trend across snoring intensity for metabolic score, and logistic regression was used to evaluate the odds ratios (ORs) for MetS after controlling for age, sex, obesity, smoking status, and alcohol consumption. RESULTS: The final study population consisted of 866 participants. Simple snorers showed more severe metabolic disorders and higher prevalence of MetS than nonsnorers. A significant linear trend was observed between snoring intensity and metabolic score. Simple snoring was significantly associated with increased odds for MetS among all participants (OR = 2.328, 95% CI: 1.340-4.045) and female participants (OR = 2.382, 95% CI: 1.136-4.994) after multivariable adjustment. With regard to MetS components, simple snoring was significantly associated with increased odds for hypertension (OR = 1.730, 95% CI: 1.130-2.650), abdominal obesity (OR = 1.810, 95% CI: 1.063-3.083), and hyper-triglycerides (TG) (OR = 1.814, 95% CI: 1.097-2.998) among all participants, with hypertension (OR = 3.493, 95% CI: 1.748-6.979) among males and with abdominal obesity (OR = 2.306, 95% CI: 1.245-4.270) and hyper-TG (OR = 2.803, 95% CI: 1.146-6.856) among females after multivariable adjustment. CONCLUSIONS: After excluding the influence of repeated apnea and hypoxia, simple snoring was still significantly associated with MetS, especially in women. Furthermore, the associations were more obvious for hypertension among males and for abdominal obesity and hyper-TG among females. In addition to OSA, simple snoring also should be valued.

Effect of the Interaction between Obstructive Sleep Apnea and Lipoprotein(a) on Insulin Resistance: A Large-Scale Cross-Sectional Study.

Both obstructive sleep apnea (OSA) and decreased serum lipoprotein(a) (Lp(a)) concentrations are associated with insulin resistance. However, their interaction effect on insulin resistance has never been investigated. Therefore, we performed a cross-sectional study on OSA-suspected Chinese Han participants. Laboratory-based polysomnographic variables, biochemical indicators, anthropometric measurements, and medical history were collected. Linear regression and binary logistic regression analyses with interaction terms were used to investigate the potential effects of the interaction between the severity of OSA (assessed by the apnea-hypopnea index (AHI)) and Lp(a) concentrations on insulin resistance (assessed by the homeostasis model assessment of insulin resistance (HOMA-IR)), after adjusting for potential confounders including age, gender, body mass index, waist-to-hip circumference ratio, mean arterial pressure, smoking status, drinking status, and lipid profiles. A total of 4,152 participants were enrolled. In the OSA-suspected population, AHI positively correlated with insulin resistance and serum Lp(a) concentrations independently and inversely correlated with insulin resistance. In addition, the interaction analysis showed that the linear association between lgAHI and lgHOMA-IR was much steeper and more significant in subjects with relatively low Lp(a) concentrations, suggesting a significant positive interaction between lgLp(a) and lgAHI on lgHOMA-IR (P = 0.013). Furthermore, the interaction on a multiplicative scale also demonstrated a significant positive interaction (P = 0.044). A stronger association between AHI quartiles and the presence of insulin resistance (defined as HOMA-IR > 3) could be observed for participants within lower Lp(a) quartiles. In conclusion, a significant positive interaction was observed between OSA and decreased Lp(a) with respect to insulin resistance. This association might be relevant to the assessment of metabolic or cardiovascular disease risk in OSA patients.

Abdominal Obesity Is More Strongly Correlated with Obstructive Sleep Apnea than General Obesity in China: Results from Two Separated Observational and Longitudinal Studies.

BACKGROUND: Previous studies have reported that obesity can result in or worsen obstructive sleep apnea (OSA). However, whether abdominal or general obesity indices or visceral adiposity indicators have a stronger association with OSA remains unclear. METHODS: This cross-sectional study included 4344 patients who underwent polysomnography (PSG) due to suspicion of OSA. We also performed a longitudinal study on 86 patients who underwent bariatric surgery to confirm the relationship between OSA and obesity. Data on overnight PSG parameters, biochemical biomarkers, and multiple anthropometric obesity indices were collected. RESULTS: In the cross-sectional study, waist circumference (WC) and body mass index (BMI) were independently associated with the apnea-hypopnea index (AHI) after adjusting for potential confounding factors (additional R2 = 0.232, standardized beta coefficient [Beta] = 0.210; and additional R2 = 0.015, Beta = 0.183, respectively). Logistic regression analysis showed similar results, as did stratified analysis of adult males aged ≤ 55 years. Restricted cubic spline (RCS) analysis revealed a linear dose-response relationship between OSA and obesity. In the longitudinal study, no significant relationship was found between remission of OSA and improvement in WC and BMI (r = 0.252, p = 0.098; and r = 0.132, p = 0.395, respectively), whereas the change in the visceral adiposity indicator (lipid accumulation calculated according to WC and fasting triglycerides) was significantly correlated with ΔAHI (r = 0.322, p = 0.033). CONCLUSIONS: Abdominal obesity, rather than general obesity, appears to play a more important role in OSA.

Independent relationships between cardinal features of obstructive sleep apnea and glycometabolism: a cross-sectional study.

BACKGROUND: Obstructive sleep apnea (OSA) is associated with abnormal glycometabolism; however, the cardinal features of OSA, such as sleep fragmentation (SF) and intermittent hypoxia (IH), have yet to show clear, independent associations with glycometabolism. METHODS: We enrolled 1834 participants with suspected OSA from July 2008 to July 2013 to participate in this study. Polysomnographic variables, biochemical indicators, and physical measurements were collected for each participant. Multiple linear regression analyses were used to evaluate independent associations between cardinal features of OSA and glycometabolism. Logistic regressions were used to determine the odds ratios (ORs) for abnormal glucose metabolism across microarousal index (MAI) and oxygen desaturation index (ODI) quartiles. The effect of the interaction between MAI and ODI on glycometabolism was also evaluated. RESULTS: The MAI was independently associated with fasting insulin levels (ß = 0.024, p = 0.001) and the homeostasis model assessment of insulin resistance (HOMA-IR; ß = 0.006, p = 0.002) after multiple adjustments of confounding factors. In addition, the ORs for hyperinsulinemia across higher MAI quartiles were 1.081, 1.349, and 1.656, compared with the lowest quartile (p = 0.015 for a linear trend). Similarly, the ODI was independently associated with fasting glucose levels (ß = 0.003, p < 0.001), fasting insulin levels (ß = 0.037, p < 0.001), and the HOMA-IR (ß = 0.010, p < 0.001) after adjusting for multiple factors. The ORs for hyperglycemia across higher ODI quartiles were 1.362, 1.231, and 2.184, compared with the lowest quartile (p < 0.05 for a linear trend). In addition, the ORs for hyperinsulinemia and abnormal HOMA-IR across ODI quartiles had the same trends. There was no interaction between MAI and ODI with respect to glycometabolism. CONCLUSION: SF was independently associated with hyperinsulinemia, and IH was independently associated with hyperglycemia, hyperinsulinemia, and an abnormal HOMA-IR. We found no interaction between SF and IH with respect to OSA-related abnormal glycometabolism.

[Preparation and optimization of polymer-based monolithic stationary phase for high performance liquid chromatography].

Unstirred in-situ polymerization was employed to directly produce glycidyl methacrylate-ethylene dimethacrylate copolymer (poly(GMA-co-EDMA)) monoliths. Mercury intrusion method was adopted to measure some parameters of the monoliths, such as pore size distribution, porosity and specific surface area. Effects of key variables such as composition of pore-forming solvent mixture, temperature and content of cross-linking reagent, divinyl monomer on porous structure of monoliths were studied. The optimization of preparation conditions was achieved. Homogeneous micro porous structure was observed in the monoliths by scanning electron microscope. The effect of flow rate on back pressure was investigated, and good permeability of the monolithic stationary phase was obtained. The monolithic column was also used for the separation of goat serum and five oligonucleotides, and the results proved that the monolithic column is suitable for the separation of biopolymers.

[Separation of proteins by gradient pressurized capillary electrochromatography].

The separation of four proteins including RNase A, cytochrome C, lysozyme and myoglobin was investigated by reversed-phase gradient pressurized capillary electrochromatography (p-CEC) with 1.5 microm non-porous silica C18 stationary phase. This mode was compared with micro-high performance liquid chromatography (mu-HPLC) and the effects of applied voltage, stationary phase and concentration of ion-pairing agent (trifluoroacetic acid, TFA) on the gradient p-CEC were also studied. This separation was performed rapidly on a new CEC instrument Trisep 2010 GV. The results showed that the retention mechanism of proteins in p-CEC mode is based on both chromatographic partitioning and electrophoretic migration. The results also demonstrated that p-CEC may have great potential for fast and efficient separation of proteins.