Association of glucose transporter 4 genetic polymorphisms with obstructive sleep apnea syndrome in Han Chinese general population: a cross-section study

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 role of biomarkers in the detection of the OSA syndrome. A narrative review of the literature]

INTRODUCTION

Obstructive sleep apnoea (OSA) is a common sleep-related breath disorder associated with cardiovascular and cerebrovascular complications, such as hypertension, arrhythmia, coronary artery disease and stroke. Unfortunately, OSA is underdiagnosed.

BACKGROUND

Because of its clinical and therapeutic variability, OSA could benefit a personalized medicine approach. Diagnosis with polysomnography is expensive and access is limited. Clinical scoring systems allow screening of OSA, but many limitations exist. Because of this, biomarkers could be useful for the detection of OSA.

OUTLOOK

Biomarkers specific to OSA would allow for better mass screening and more personalized treatment of the disease. This narrative review of the literature aims to summarize the biomarkers already described for the diagnosis of OSA and clarify both their advantages and limitations in daily practice.

CONCLUSIONS

Our review of the literature did not actually identify an ideal biomarker even if promising research is ongoing.

Genetic Variation in Human Vitamin C Transporter Genes in Common Complex Diseases

Adequate plasma, cellular, and tissue vitamin C concentrations are required for maintaining optimal health through suppression of oxidative stress and optimizing functions of certain enzymes that require vitamin C as a cofactor. Polymorphisms in the vitamin C transporter genes, compromising genes encoding sodium-dependent ascorbate transport proteins, and also genes encoding facilitative transporters of dehydroascorbic acid, are associated with plasma and tissue cellular ascorbate status and hence cellular redox balance. This review summarizes our current knowledge of the links between variations in vitamin C transporter genes and common chronic diseases. We conclude that emerging genetic knowledge has a good likelihood of defining future personalized dietary recommendations and interventions; however, further validations through biological studies as well as controlled dietary trials are required to identify predictive and actionable genetic biomarkers. We further advocate the need to consider genetic variation of vitamin C transporters in future clinical and epidemiologic studies on common complex diseases.