Xun Niu

The differences in homocysteine level between obstructive sleep apnea patients and controls: a meta-analysis.

Background Studies have reported inconsistent findings regarding the relationship between obstructive sleep apnea (OSA) and homocysteine (HCY) level. This study aimed to assess the difference in plasma HCY level between OSA patients and controls by conducting a meta-analysis of published studies. Methods Database of PubMed, SCI, and China National Knowledge Internet (CNKI) were comprehensively searched. Eligible studies regarding plasma HCY level in OSA patients were identified by two independent reviewers. RevMan (version 5.2) and STATA (version 12.0) were employed for data synthesis. Results A total of 10 studies involving 432 subjects were included. Meta-analysis showed that plasma HCY levels in OSA group were 3.11 µmol/l higher than that in control group (95% confidence interval: 2.08 to 4.15, P<0.01). Subgroup analysis revealed a more significant differences between OSA patients and controls when average body mass index ≥30 (the total weighted mean difference (WMD) was 3.64), average age<50 (the total WMD was 3.96) and average apnea hypopnea index ≥35 (the total WMD was 4.54). Conclusions In this meta-analysis, plasma HCY levels were found to be higher in OSA patients compared to control subjects.

Association between P16INK4a promoter methylation and HNSCC: a meta-analysis of 21 published studies.

Background The p16INK4a is an important tumor suppressor gene (TSG) and aberrant methylation of promoter is known to be a major inactivation mechanism of the tumor suppressor and tumor-related genes. Aberrant TSG methylation was considered an important epigenetic silencing mechanism in the progression of head and neck squamous cell carcinoma (HNSCC). However, some studies have reported differences in the methylation frequencies of P16INK4a promoter between cancer and the corresponding control group. Therefore, we conducted a meta-analysis to better identify the association. Methods PubMed, Ovid, ISI Web of Science, and EMBASE were searched to identify eligible studies to evaluate the association of p16INK4a promoter methylation and HNSCC. Odds ratio (ORs) and 95% confidence intervals (95%CI) were calculated to evaluate the strength of association between p16INK4a promoter methylation and HNSCC. Results A total of twenty-one studies with 1155 cases and 1017 controls were included in the meta-analysis. The frequencies of p16INK4a promoter methylation in the cancer group were significantly higher than those in the control group (cancer group: median: 46.67%, range = 7.84%-95.12%; control group: median: 18.37%, range = 0–83.33%; respectively). The pooled odds ratio was 3.37 (95%CI = 2.32–4.90) in the cancer group versus the corresponding control group under the random-effects model. Conclusion This meta-analysis of 21 published studies identified that aberrant methylation of p16INK4a promoter was found to be significantly associated with HNSCC.

Reliability and Validity of the Beijing Version of the Montreal Cognitive Assessment in the Evaluation of Cognitive Function of Adult Patients with OSAHS.

Background The patients with obstructive sleep apnea hypopnea syndrome (OSAHS) tend to develop cognitive deficits, which usually go unrecognized, and can affect their daily life. The Beijing version of the Montreal cognitive assessment (MoCA-BJ), a Chinese version of MoCA, has been used for the assessment of cognitive functions of OSAHS patients in clinical practice. So far, its reliability and validity have not been tested. This study examined the reliability and validity of MoCA-BJ in a cohort of adult OSAHS patients. Methods 152 OSAHS patients, ranging from mild, moderate to severe, 49 primary snoring subjects and 40 normal controls were evaluated for cognitive functions by employing both MoCA-BJ and the Mini Mental State Examination (MMSE). Forty of them were re-tested by MoCA-BJ 14 days after the first test. Internal consistency, test-retest reliability, discriminate and concurrent validity of MoCA-BJ were analyzed. Results Internal consistency reliability by Cronbach’s alpha was adequate (0.73). Intra-class correlation coefficient (ICC), an measure of test-retest reliability, was 0.87 (P<0.001). The total MoCA-BJ scores were significant higher in normal controls than in OSAHS groups (p<0.05). The performances of visuospatial ability in severe OSAHS group were significantly weaker than in normal controls and primary snoring group. The performances of executive ability in severe OSAHS patients were weaker than in normal controls. An optimal cut-off between normal controls and non-normal subjects was at 26 points (total MoCA score). Moreover, cut-off between non-severe and severe OSAHS was at 2 points on visuospatial subscale. Analysis of the correlation between MoCA total scores and MMSE total scores revealed a statistically significant, though relatively weak, correlation (r=0.41, P<0.05). Conclusion In conclusion, our study showed that the Beijing version of the MoCA was reliable and stable. The MoCA-BJ was capable of detecting cognitive dysfunction by visuospatial and total MoCA-BJ score.

Effect of Continuous Positive Airway Pressure on Leptin Levels in Patients with Obstructive Sleep Apnea A Meta-analysis

Objectives Continuous positive airway pressure (CPAP) is an effective treatment for obstructive sleep apnea hypopnea syndrome (OSAHS), but previous studies assessing the effect of CPAP on leptin in patients with OSAHS yielded conflicting results. In this study, we conducted a meta-analysis to determine whether CPAP therapy could reduce serum leptin levels. Data Sources Databases of PubMed, Elsevier, and SCI were thoroughly searched by 2 independent reviewers. Methods RevMan (version 5.2) was used for data synthesis. Weighted mean difference (WMD) before and after CPAP therapy was calculated to estimate the effects of CPAP therapy. Results A total of 11 studies involving 413 participants were included. Meta-analysis showed that the total WMD for leptin levels was 1.44 units (95% confidence interval: 1.11-1.77, P < .01) before and after CPAP therapy. Subgroup analysis exhibited that leptin was decreased within 3 days after the therapy, and it was further reduced within 1 to 3 months and beyond. Conclusions The results of our meta-analysis showed that CPAP could significantly reduce leptin levels in OSAHS patients without concomitant weight loss.

Impact of Treatment with Metformin on Adipocytokines in Patients with Polycystic Ovary Syndrome: A Meta-Analysis

Background Metformin is effective for the treatment of polycystic ovary syndrome, but conflicting results regarding its effect on adipocytokine levels (adiponectin, resistin, visfatin, and leptin) in patients with polycystic ovary syndrome receiving metformin treatment have been reported. To provide high-quality evidence about the effect of metformin treatment on adipocytokines in patients with polycystic ovary syndrome, relevant studies that assessed the levels of adipocytokines (adiponectin, resistin, visfatin, and leptin) in patients with polycystic ovary syndrome receiving treatment with metformin administration were reviewed and analyzed. Methods A literature search was conducted in the SCI, PUBMED, EMBASE, and Elsevier databases, and personal contact was made with the authors. Standard mean differences and 95% confidence intervals were calculated and combined appropriately. To ensure synthesis of the best available evidence, sensitivity analyses were performed. Results A total of 34 data sets were included in 4 different outcomes, involving 744 women with polycystic ovary syndrome and adipocytokine levels measured both before and after metformin administration. Metformin treatment was associated with significantly elevated serum adiponectin concentrations (standard mean differences [95% confidence interval], −0.43 [−0.75 to −0.11]) and decreased serum leptin concentrations (0.65 [0.26 to 1.04]), whereas no significant difference in resistin level (−0.01 [−0.49 to 0.45]) or visfatin level (−0.04 [−1.55 to 1.46]) was found. Conclusions Metformin administration was associated with increased serum adiponectin concentrations and decreased serum leptin levels. Further study is needed to elucidate whether this apparent effect decreases the incidence of type 2 diabetes and other metabolic diseases in patients with polycystic ovary syndrome later in life.

Aberrant Methylation of RASSF1A Closely Associated with HNSCC, a Meta-Analysis

The RAS association domain family protein 1a (RASSF1A), a tumor suppressor gene at 3p21.3, plays a very important role in various cancers, including the head and neck squamous cell carcinoma (HNSCC). Hypermethylation of CpG islands in the RASSF1A promoter region contribute to epigenetic inactivation. However, the association between RASSF1A promoter methylation and HNSCC remains unclear and controversial. Therefore, a meta-analysis was performed in the study to identify the association. We identified the eligible studies through searching PubMed, EMBASE, Web of Science, and China National Knowledge Infrastructure (CNKI) databases with a systematic searching strategy. The information on characteristics of each study and prevalence of RASSF1A methylation were collected. Pooled odds ratios (ORs) with corresponding confidence intervals (CIs) were calculated. Meta-regression was performed to analyze heterogeneity and funnel plots were applied to evaluate publication bias. A total of 550 HNSCC patients and 404 controls from twelve eligible studies were included in the meta-analysis. Overall, a significant association was observed between RASSF1A methylation status and HNSCC risk under a random-effects model (OR = 2.93, 95% CI: 1.58–5.46). There was no significant publication bias observed. The meta-analysis suggested that there was a significant association between aberrant RASSF1A methylation and HNSCC.

Aberrant Methylation of MGMT Promoter in HNSCC: A Meta-Analysis.

Background O6-methylguanine-DNA methyl-transferase (MGMT) gene, a DNA repair gene, plays a critical role in the repair of alkylated DNA adducts that form following exposure to genotoxic agents. MGMT is generally expressed in various tumors, and its function is frequently lost because of hypermethylation in the promoter. The promoter methylation of MGMT has been extensively investigated in head and neck squamous cell carcinoma (HNSCC). However, the association between the promoter methylation of MGMT and HNSCC risk remains inconclusive and inconsistent. Therefore, we performed a meta-analysis to better clarify the association between the promoter methylation of MGMT and HNSCC risk. Methods A systematical search was conducted in PubMed, Web of Science, EMBASE, and Ovid for studies on the association between MGMT promoter methylation and HNSCC. Odds ratio (ORs) and 95% confidence intervals (CI) were calculated to estimate association between MGMT promoter methylation and risk of HNSCC. The meta-regression and subgroup analysis were undertaken to explore the potential sources of heterogeneity. Results Twenty studies with 1,030 cases and 775 controls were finally included in this study. The frequency of MGMT promoter methylation was 46.70% in HNSCC group and 23.23% in the control group. The frequency of MGMT promoter methylation in HNSCC group was significantly higher than the control group (OR = 2.83, 95%CI = 2.25–3.56). Conclusion This meta-analysis indicates that aberrant methylation of MGMT promoter was significantly associated with the risk of HNSCC, and it may be a potential molecular marker for monitoring the disease and may provide new insights to the treatment of HNSCC.

Association between promoter methylation of DAPK gene and HNSCC: A meta-analysis

Background The death-associated protein kinase (DAPK) is a tumor suppressor gene, which is a mediator of cell death of INF-γ–induced apoptosis. Aberrant methylation of DAPK promoter has been reported in patients with head and neck squamous cell carcinoma (HNSCC). However, the results of these studies are inconsistent. Hence, the present study aimed to evaluate the association between the promoter methylation of DAPK gene and HNSCC. Methods Relevant studies were systematically searched in PubMed, Web of Science, Ovid, and Embase. The association between DAPK promoter methylation and HNSCC was assessed by odds ratio (ORs) and 95% confidence intervals (CI). To evaluate the potential sources of heterogeneity, we conducted the meta-regression analysis and subgroup analysis. Results Eighteen studies were finally included in the meta-analysis. The frequency of DAPK promoter methylation in patients with HNSCC was 4.09-fold higher than the non-cancerous controls (OR = 3.96, 95%CI = 2.26–6.95). A significant association between DAPK promoter methylation and HNSCC was found among the Asian region and the Non-Asia region (Asian region, OR = 4.43, 95% CI = 2.29–8.58; Non-Asia region, OR = 3.39, 95% CI = 1.18–9.78). In the control source, the significant association between DAPK promoter methylation and HNSCC was seen among the autologous group and the heterogeneous group (autologous group, OR = 2.71, 95% CI = 1.49–4.93; heterogeneous group, OR = 9.50, 95% CI = 2.98–30.27). DAPK promoter methylation was significantly correlated with alcohol status (OR = 1.85, 95% CI = 1.07–3.21). Conclusion The results of this meta-analysis suggested that aberrant methylation of DAPK promoter was associated with HNSCC.

Association between P16INK4a Promoter Methylation and Ovarian Cancer: A Meta-Analysis of 12 Published Studies

Background Ovarian cancer is the primary cause of death in women diagnosed with gynecological malignancies worldwide. Absence of early symptoms prevents prompt diagnosis or successful therapeutic intervention. P16INK4a is a well-known tumor suppressor gene (TSG). Aberrant methylation of TSG promoter is an important epigenetic silencing mechanism leading to ovarian cancer progression. Studies have reported differences in methylation frequencies of the p16INK4a promoter between ovarian cancer and the corresponding control group. However, the association between p16INK4a promoter methylation and ovarian cancer remains unclear and controversial. Therefore, a meta-analysis was conducted to clarify the relationship between p16INK4a promoter methylation and ovarian cancer. Methods PubMed, Web of Science, EMBASE and CNKI were searched to identify eligible studies for the evaluation of the association between p16INK4a promoter methylation and ovarian cancer. Odds ratio (ORs) and 95% confidence intervals (95%CI) were calculated to determine the strength of association between p16INK4a promoter methylation and ovarian cancer. Results A total of 612 ovarian cancer patients and 289 controls from 12 eligible studies were included in the meta-analysis. Overall, a significant association was observed between p16INK4a methylation status and ovarian cancer risk using a fixed-effects model (OR = 2.02, 95% CI = 1.39–2.94). Conclusion The results of our meta-analysis show that aberrant methylation of p16INK4a promoter was significantly associated with ovarian cancer. It may represent a promising molecular marker to monitor the disease and provides new insights into the treatment of human ovarian cancer.

Serum sex hormone levels in different severity of male adult obstructive sleep apnea-hypopnea syndrome in East Asians.

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a serious health issue, which can impact the hormone secretion. The aim of this study is to analyze the relationship between serum sex hormone concentrations and different severity degree of OSAHS, and to evaluate the influence of OSAHS on sex hormone levels. We enrolled 116 subjects who were subjected to polysomnography (PSG). They were divided into three groups: control group (n=10) [apnea hypopnea index (AHI) <5/h], mild-moderate OSAHS group (n=15) (5≤AHI<30/h), and severe OSAHS group (n=91) (AHI≥30/h). The patients in OSAHS group were subdivided into obesity and non-obesity subgroups. The parameters such as AHI, body mass index (BMI), lowest oxygen saturation (LSaO2), and mean oxygen saturation (MSaO2) were recorded. Serum levels of testosterone, polactin, estradiol, follicle stimulating hormone (FSH) and luteinizing hormone (LH) were determined in the morning immediately after waking up. Mean levels of hormones were compared among groups. The correlation between hormone levels and sleep-breathing parameters was analyzed. No significant differences in serum sex hormone levels were found among control, mild-moderate OSAHS, and severe OSAHS groups (P>0.05). There was no correlation between AHI and sex hormone levels (P>0.05). Testosterone was significantly negatively correlated with BMI (P<0.05). These results suggested that BMI might have a direct effect on testosterone level, and it might be an important factor affecting testosterone level in male OSAHS patients, and there may be no correlation between severity of OSAHS and sex hormones levels.SummaryObstructive sleep apnea-hypopnea syndrome (OSAHS) is a serious health issue, which can impact the hormone secretion. The aim of this study is to analyze the relationship between serum sex hormone concentrations and different severity degree of OSAHS, and to evaluate the influence of OSAHS on sex hormone levels. We enrolled 116 subjects who were subjected to polysomnography (PSG). They were divided into three groups: control group (n=10) [apnea hypopnea index (AHI) <5/h], mild-moderate OSAHS group (n=15) (5≤AHI<30/h), and severe OSAHS group (n=91) (AHI≥30/h). The patients in OSAHS group were subdivided into obesity and non-obesity subgroups. The parameters such as AHI, body mass index (BMI), lowest oxygen saturation (LSaO2), and mean oxygen saturation (MSaO2) were recorded. Serum levels of testosterone, polactin, estradiol, follicle stimulating hormone (FSH) and luteinizing hormone (LH) were determined in the morning immediately after waking up. Mean levels of hormones were compared among groups. The correlation between hormone levels and sleep-breathing parameters was analyzed. No significant differences in serum sex hormone levels were found among control, mild-moderate OSAHS, and severe OSAHS groups (P>0.05). There was no correlation between AHI and sex hormone levels (P>0.05). Testosterone was significantly negatively correlated with BMI (P<0.05). These results suggested that BMI might have a direct effect on testosterone level, and it might be an important factor affecting testosterone level in male OSAHS patients, and there may be no correlation between severity of OSAHS and sex hormones levels.