Obstructive sleep apnea syndrome susceptible genes in the Chinese population: a meta-analysis of 21 case-control studies

Variants of candidate genes associated with the risk of obstructive sleep apnea

BACKGROUND

The researches on the associations between different candidate genes and obstructive sleep apnea (OSA) are inconsistent. Here, we performed a comprehensive qualitative and quantitative analysis to estimate the contribution of variants from candidate genes to the risk of OSA.

METHODS

Qualitative analysis was conducted to find the relationships for all included genes. Then, quantitative analysis of both allele models and genotype models was applied to evaluate the risk variants for OSA. Furthermore, a similar analysis was performed in different ethnic groups.

RESULTS

We included 152 publications containing 75 genes for qualitative analysis. Among them, we included 93 articles containing 28 variants from 16 genes for quantitative analysis. Through allele models, we found 10 risk variants for OSA (rs1801133 of MTHFR, ɛ4 of ApoE, -1438G/A of 5-HT2A, -308G/A of TNF-α, Pro1019Pro of LEPR, rs1130864 and rs2794521 of CRP, D/I of ACE, LPR and VNTR of 5-HTT) with the ORs of 1.21-2.07 in global population. We found that the variant of ɛ2 of ApoE could uniquely decrease the risk of OSA in the East Asian subgroup, while the other 6 variants, including ɛ4 in ApoE, -308G/A in TNF-α, Pro1019Pro in LEPR, D/I in ACE, LPR and VNTR in 5-HTT, could increase the risk of OSA. As for the European subpopulation, we only found that -308G/A in TNF-α could increase the risk for OSA.

CONCLUSIONS

Eleven variants from the candidate genes are associated with the risk of OSA, which also show ethnicity differences in East Asian and European subgroups.

The Association Between Serum/Plasma Leptin Levels and Obstructive Sleep Apnea Syndrome: A Meta-Analysis and Meta-Regression

BACKGROUND

Obstructive sleep apnea syndrome (OSAS) is associated with various adipokines. Leptin, a common adipokine, has attracted considerable attention of many researchers in recent years. So far, there has been little agreement on whether blood leptin levels differ in patients with OSAS. Thus, this meta-analysis examined the relationship between serum/plasma leptin levels and the occurrence of OSAS.

METHOD

WanFang, Embase, CNKI, Medline, SinoMed, Web of Science, and PubMed were searched for articles before March 30, 2021, with no language limitations. STATA version 11.0 and R software version 3.6.1 were used to analyze the obtained data. The weighted mean difference and correlation coefficients were used as the main effect sizes with a random-effects model and a fixed-effects model, respectively. Trial sequential analysis was conducted using dedicated software.

RESULT

Screening of 34 publications identified 45 studies that met the inclusion criteria of this meta-analysis and meta-regression. Our results suggested that plasma/serum leptin levels were remarkably higher in individuals with OSAS than in healthy individuals. Subgroup analyses were performed based on OSAS severity, ethnicity, age, body mass index, assay type, and sample source. The serum and plasma leptin levels were increased in nearly all OSAS subgroups compared to those in the corresponding control groups. Meta-regression analysis indicated that age, BMI, severity, assay approaches, study design, PSG type and ethnicity did not have independent effect on leptin levels. Furthermore, a positive relationship between the serum/plasma leptin level and apnea-hypopnea index (AHI) was found in the meta-analysis. The results of the trial sequential analysis suggested that the enrolled studies surpassed the required information size, confirming that our study findings were reliable.

CONCLUSION

Our study results demonstrate that OSAS patients have higher leptin levels in serum/plasma compared to controls, and the serum/plasma leptin level is positively correlated with AHI, especially in adults.

Association of angiotensin-converting enzyme gene insertion/deletion polymorphism and obstructive sleep apnoea in a Chinese population: A meta-analysis

Introduction:

Many studies have investigated the association between angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and susceptibility to obstructive sleep apnoea (OSA). However, few have confirmed the relationship between ACE and OSA in the Chinese population. We performed a meta-analysis of studies relating the ACE I/D polymorphism to the risk of OSA in a Chinese population.

Methods:

We evaluated eligible published studies from several databases for this meta-analysis. Subgroup analyses were performed for hypertension. Pooled odds ratios and 95% confidence intervals were calculated using a fixed- or random-effects model.

Results:

Ten studies were identified to analyse the association between ACE I/D polymorphism and OSA risk. No marked associations were found in any genetic model (p>0.05). Subgroup analysis showed an association with hypertension (D vs. I, DD vs. II, ID vs. DD+II, DD+ID vs. II, ID vs. II; p<0.05), which was confirmed by sensitivity analyses. No obvious publication bias was found using Egger’s test (p>0.05).

Conclusions:

The ACE I/D polymorphism was not associated with an increased risk of OSA in a Chinese population. However, within the hypertensive subgroup, we detected a significant association between the ACE polymorphism and OSA. More case-control investigations are required.

Relationship between rosacea and sleep

Rosacea is a chronic facial skin disease involved in neurovascular dysregulation and neurogenic inflammation. Behavioral factors such as stress, anxiety, depression and sleep were identified to be associated with other inflammatory skin diseases. Few studies have reported sleep status in rosacea. Aiming to investigate the relationship between rosacea and sleep, a case-control survey was conducted, enrolling 608 rosacea patients and 608 sex- and age-matched healthy controls. Sleep quality was assessed through the Pittsburgh Sleep Quality Index (PSQI) questionnaire. Diagnosis and severity grading of rosacea were evaluated under the standard guidelines of the National Rosacea Society. More rosacea patients (52.3%, n = 318) suffered poor sleep quality (PSQI, >5) than the healthy controls (24.0%, n = 146), displaying a much higher PSQI score (rosacea vs control, 6.20 vs 3.95). There was a strong association between sleep quality and rosacea (odds ratio [OR], 3.525; 95% confidence interval [CI], 2.759-4.519). Moreover, the severity of rosacea was also associated with sleep quality (OR, 1.847; 95% CI, 1.332-2.570). Single nucleotide polymorphisms in hydroxytryptamine receptor 2A and adrenoceptor-β1 genes, which are associated with sleep behaviour, were detected and revealed to be associated with rosacea. Furthermore, the LL-37-induced rosacea-like phenotype and sleep-deprivation mice models were applied, revealing that sleep deprivation aggravated the rosacea-like phenotype in mice, with higher expression of matrix metallopeptidase 9, Toll-like receptor 2, cathelicidin antimicrobial peptide and vascular endothelial growth factor. In conclusion, rosacea patients presented poorer sleep quality, as well as a higher propability of genetic background with sleep disturbance. In addition, poor sleep might aggravate rosacea through regulating inflammatory factors, contributing to a vicious cycle in the progression of disease.

Obstructive Sleep Apnea and Inflammation: Proof of Concept Based on Two Illustrative Cytokines

Obstructive sleep apnea syndrome (OSAS) is a markedly prevalent condition across the lifespan, particularly in overweight and obese individuals, which has been associated with an independent risk for neurocognitive, behavioral, and mood problems as well as cardiovascular and metabolic morbidities, ultimately fostering increases in overall mortality rates. In adult patients, excessive daytime sleepiness (EDS) is the most frequent symptom leading to clinical referral for evaluation and treatment, but classic EDS features are less likely to be reported in children, particularly among those with normal body-mass index. The cumulative evidence collected over the last two decades supports a conceptual framework, whereby sleep-disordered breathing in general and more particularly OSAS should be viewed as low-grade chronic inflammatory diseases. Accordingly, it is assumed that a proportion of the morbid phenotypic signature in OSAS is causally explained by underlying inflammatory processes inducing end-organ dysfunction. Here, the published links between OSAS and systemic inflammation will be critically reviewed, with special focus on the pro-inflammatory cytokines tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6), since these constitute classical prototypes of the large spectrum of inflammatory molecules that have been explored in OSAS patients.