Xiaomei Wu

Prevalence, Incidence, and Mortality of Stroke in the Chinese Island Populations: A Systematic Review

Background In China, there are 2.5 million new stroke cases each year and 7.5 million stroke survivors. However, stroke incidence in some island populations is obviously lower compared with inland regions, perhaps due to differences in diet and lifestyle. As the lifestyle in China has changed significantly, along with dramatic transformations in social, economic and environmental conditions, such changes have also been seen in island regions. Thus, we analyzed stroke in the Chinese island regions over the past 30 years. Methods We conducted a systematic review to identify reliable and comparable epidemiologic evidence about stroke in the Chinese island regions between 1980 and 2013. Two authors independently assessed the eligibility and the quality of the articles and disagreement was resolved by discussion. Owing to the great heterogeneity among individual study estimates, a random-effects or fixed-effects model was used to incorporate the heterogeneity among records into a pooled estimate for age-standardized rates. Age-standardized rates were calculated by the direct method with the 2000 world population if included records provided the necessary information. Results During the past three decades, the overall pooled age-standardized prevalence of stroke is 6.17 per 1000 (95% CI 4.56–7.78), an increase from 5.54 per 1000 (95% CI 3.88–7.20) prior to 2000 to 8.34 per 1000 (95% CI 5.98–10.69) after 2000. However, this difference was not found to be statistically significant. The overall pooled age-standardized incidence of stroke is 120.42 per 100,000 person years (95% CI 26.17–214.67). Between 1982 and 2008, the incidence of stroke increased and mortality declined over time. Conclusions Effective intervention and specific policy recommendations on stroke prevention should be required, and formulated in a timely fashion to effectively curb the increased trend of stroke in Chinese island regions.

Methylenetetrahydrofolate reductase C677T polymorphism and type 2 diabetes mellitus in Chinese population: a meta-analysis of 29 case-control studies.

Background Methylenetetrahydrofolate reductase (MTHFR), a key enzyme in folate metabolism, had significant effects on the homocysteine levels. The common functional MTHFR C677T polymorphism had been extensively researched. Several studies had evaluated the relationship between MTHFR C677T polymorphism and type 2 diabetes mellitus (T2DM), but the results were still controversial in the Chinese Han population. This meta-analysis was conducted to evaluate the relationship between MTHFR C677T polymorphism and T2DM in the Chinese Han population. Methods We searched the relevant studies in multiple electronic databases, which published up to December 2013. We reviewed and extracted data from all the included studies on the relationship between MTHFR C677T polymorphism and T2DM in the Chinese Han population. The odds ratios (ORs) and their 95% confidence intervals (95%CIs) were used to evaluate the relationship. Fixed-effects and random-effects meta-analysis were used to pool ORs by the heterogeneity. Publication bias and sensitivity analysis were also examined. Results 29 studies were finally included in our meta-analysis, which contained 4656 individuals with T2DM and 2127 healthy controls. There was a significant relationship between MTHFR C677T polymorphism and T2DM under dominant (OR: 1.70, 95% CI: 1.42–2.02), recessive (OR: 1.48, 95% CI: 1.21–1.80), homozygous (OR: 1.89, 95% CI: 1.47–2.42), heterozygous (OR: 1.58, 95% CI: 1.33–1.87), and additive (OR: 1.46, 95% CI: 1.28–1.68) genetic model in a random-effects model. Subgroup analysis also reached similar results. Sensitivity analysis indicated that the overall result were dependable. Conclusions There was a significant relationship between MTHFR C677T polymorphism and T2DM in the Chinese Han population. The results of our meta-analysis suggested that MTHFR 677T allele might be a risk genetic factor of T2DM in the Chinese Han population.

Comprehensive review of genetic association studies and meta-analysis on miRNA polymorphisms and rheumatoid arthritis and systemic lupus erythematosus susceptibility.

BACKGROUND MicroRNAs (miRNAs), small RNA molecules, play a role in the development and differentiation of immune cells in both innate and adaptive immune responses. Our study was aimed to investigate the association between three miRNA polymorphism and rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE) by using meta-analysis approach. METHODS A PubMed database search was conducted during August 2013 to identify case-control studies of miRNAs and RA or SLE risk. Two authors independently extracted information on the study design, the characteristics of the study participants, exposure and outcome assessments. The fix-effects and random-effects models were used for the risk estimates by Stata 11.0 software. RESULTS Our meta-analysis of six case-control studies involving a total of 998 RA cases and 1493 controls identified no significant association between mir-146a rs2910164 and RA, with an overall OR of 0.843 (95% CI=0.642-1.105; CC vs. GG). No association was observed in three studies with a total of 1532 cases and 2168 controls between miR-146a rs2910164 and SLE risk (OR=0.911, 95% CI=0.710-1.171; CC vs. GG). Three studies with a total of 529 cases and 595 controls evaluated the mir-499 rs3746444 polymorphism and its association with RA. There was a decreased overall risk of RA under the allelic and genotypic models [OR=0.616, 95% CI=0.384-0.981, (T vs. C allele) and OR=0.386, 95% CI=0.226-0.659, (TT vs. CC)]. Two studies with 4826 cases and 4181 controls evaluated miR-146a rs57095329 and its association with SLE. There was a significant association between miR-146a rs57095329 and SLE (OR=1.263, 95% CI=1.136-1.405, G vs. A allele). CONCLUSIONS The present meta-analysis suggests important roles for the mir-499 rs3746444 polymorphism in RA, especially in the Caucasian population and for miR-146a rs57095329 polymorphism in SLE. Further studies with large sample size are needed to confirm these associations.

Genetic polymorphism of MMP family and coronary disease susceptibility: A meta-analysis

The issue that genetic polymorphism of matrix metalloproteinase (MMP) family is in association with coronary disease is controversial. So we did a meta-analysis to clarify it clearly. We made a literature search of PubMed, the Web of Science, and Cochrane Collaborations database to identify eligible reports. The methodological quality of each included studies was assessed. We calculated the pooled ORs with their 95%CI for each genetic polymorphism in STATA 11 software. Separate analysis was performed to address the consistency of results across the subgroup with different continents. A total of 39 studies were included, with a sample of 42269 individuals. This meta-analysis provided evidence that genetic polymorphism of MMP1-1607 1G/2G, MMP3-Gly45lys, MMP3-376 G/C, MMP3-1171 5A/6A, MMP9-1562 C/T and MMP9-R279Q have a small to medium effect on incidence of coronary disease. There was no evidence that MMP1-519 A/G, MMP1-340 T/C and MMP2-1306 C/T polymorphism could increase risk of coronary disease. Results from subgroup analysis supported a relation between MMP3-1711 5A allele, MMP9-1562 C allele and coronary disease especially in Asian population. The results provide moderate association between the six common genetic polymorphism of matrix metalloproteinase family and coronary disease. However, the challenge for researcher is identifying separate effect on different races.

The pooled incidence of post-stroke seizure in 102 008 patients

Background: Post-stroke seizures and epilepsy may worsen the recovery and increase the disability of stroke patients during their daily lives. However, few meta-analysis studies have been conducted on post-stroke seizures incidence. We carried on a meta-analysis on the incidence rate of post-stroke seizures and associated factors. Methods: We searched the Medline, Embase, Web of Science, Science Citation Index, and Cochrane Library electronic databases (1990–2013) to identify observational studies of post-stroke seizures. Two authors independently extracted the related information from all included studies. We calculated the pooled incidence by meta-analysis using the software R version 12.3. Results: A total of 34 longitudinal cohort studies involving 102 008 patients were included in our meta-analysis. The pooled incidence rate of post-stroke seizures was found to be 0.07 [95% confidence interval (CI), 0.05–0.09] while the rate of post-stroke epilepsy (PSE) was 0.05 (95% CI, 0.04–0.06). The incidence of post-stroke seizures in hemorrhagic stroke (0.10, 0.08–0.13) was much higher than in ischemic stroke (0.06, 0.04–0.08) and when the cortical region was involved (0.15, 0.10–0.21). Conclusions: Our meta-analysis showed that seizures occurred in about 6.93% of people with stroke. Seizures occurred more commonly after hemorrhagic stroke and when stroke occurred in the cortical region.

Infarction of the Corpus Callosum: A Retrospective Clinical Investigation

Objectives The aim of this study was to investigate patients with ischemic infarctions in the territory of the corpus callosum to advance our understanding of this rare stroke subtype by providing comprehensive descriptive and epidemiological data. Methods From January 1, 2010 to June 30, 2014, all cases of acute ischemic stroke diagnosed by clinical manifestation and diffusion weighted imaging in Dalian Municipal Central Hospital were investigated. The patients presenting with corpus callosum infarctions were selected and further allocated into genu and/or body and splenium infarction groups. Proportion, lesion patterns, clinical features, risk factors and etiology of corpus callosum infarction were analyzed. Results Out of 1,629 cases, 59 patients (3.6%) with corpus callosum infarctions were identified by diffusion weighted imaging, including 7 patients who had ischemic lesions restricted to the corpus callosum territory. Thirty six patients had lesions in the splenium (61.0%). Corpus callosum infarction patients suffered from a broad spectrum of symptoms including weakness and/or numbness of the limbs, clumsy speech, and vertigo, which could not be explained by lesions in corpus callosum. A classical callosal disconnection syndrome was found in 2 out of all patients with corpus callosum infarctions. Statistical differences in the risk factor and infarct pattern between the genu and/or body group and splenium group were revealed. Conclusion Corpus callosum infarction and the callosal disconnection syndrome were generally rare. The most susceptible location of ischemic corpus callosum lesion was the splenium. Splenium infarctions were often associated with bilateral cerebral hemisphere involvement (46.2%). The genu and/or body infarctions were associated with atherosclerosis. The most common cause of corpus callosum infarction probably was embolism.

The Association Between Passive Smoking and Type 2 Diabetes A Meta-Analysis

The number of people with diabetes has been exponentially increasing. A number of reports in the literature have suggested that exposure to passive smoke may play a key role in the development of diabetes; however, the association has not been jointly summarized yet. In this meta-analysis, 2 databases were searched to identify studies, and the references of these studies were scanned for further studies. Fourteen studies on the relationship between passive smoking and diabetes were included. After all the studies were pooled, the results showed that passive smoking was significantly associated with an increased risk of type 2 diabetes in a random model. The subgroup analysis results were consistent with overall results regardless of type of study design, age, gender, adjustment of dependent variables, area, or study quality. Sensitivity analysis indicated that the overall results were reliable. There was no publication bias observed in the selected studies.

Trends in the Prevalence of Hypertension in Island and Coastal Areas of China: A Systematic Review With Meta-Analysis

BACKGROUND With the economic development in recent years, there has been a dramatic increase in the prevalence of hypertension in some coastal cities of China; however, the number of reports regarding the prevalence of hypertension based on a nationwide study of island and coastal areas of China is limited. We estimated the prevalence and described the trends of hypertension during the last 3 decades in these specific areas. METHODS Authoritative databases were searched for cross-sectional studies reporting the prevalence of hypertension in island and coastal areas of China published in the past 3 decades, and 37 studies that involved 760,428 individuals representing 22 different locations were identified and included in our analysis. RESULTS The estimated prevalence of hypertension was 9.8% (95% confidence interval (CI) = 6.3%-14.9%) in the 1980s, 18.5% (95% CI = 13.6%-24.8%) in the 1990s, and 30.0% (95% CI = 26.7%-33.6%) in the 2000s (χ(2) for trend: P = 0.00). In the 2000s, adjusted prevalence estimate of hypertension was 21.6% according to the national standard population composition in 1990, and the pooled prevalence estimate for the northern region in coastal areas of China was significantly higher than the southern region (36.2% vs. 26.2%; P = 0.002). Thus, the prevalence of hypertension in the island and coastal areas of China appears to have increased 21.5% in the last 3 decades; the increasing trend was observed in men and women. CONCLUSIONS Our findings highlight the urgent need for public health strategies with more emphasis on improvement of primary health care in the island and coastal areas of China.

Prognostic role of copeptin with all-cause mortality after heart failure: a systematic review and meta-analysis

Background As the C-terminal section of vasopressin precursor, copeptin has been recently suggested as a new prognostic biomarker after heart failure (HF). Thus, the aim of this study was to evaluate the prognostic value of plasma copeptin level with all-cause mortality in patients with HF. Methods Comprehensive strategies were used to search relevant studies from electronic databases. Pooled hazard ratios (HRs) and standardized mean differences (SMDs) together with their 95% confidence intervals (CIs) were calculated. Subgroup analysis and sensitivity analysis were performed to find the potential sources of heterogeneity. Results A total of 5,989 participants from 17 prospective studies were included in this meta-analysis. A significant association was observed between circulating copeptin levels and risk of all-cause mortality in patients with HF (categorical copeptin: HR =1.69, 95% CI =1.42–2.01; per unit copeptin: HR =1.03, 95% CI =1.00–1.07; log unit copeptin: HR =3.26, 95% CI =0.95–11.25). Pooled SMD showed that copeptin levels were significantly higher in patients with HF who died during the follow-up period than in survivors (SMD =1.19, 95% CI =0.81–1.57). Subgroup analyses also confirmed this significant association, while sensitivity analyses indicated that the overall results were stable. Conclusion This study demonstrated that circulating copeptin seemed to be a novel biomarker to provide better prediction of all-cause mortality in patients with HF.

Gene polymorphism of XRCC1 Arg399Gln and cervical carcinoma susceptibility in Asians: a meta-analysis based on 1,759 cases and 2,497 controls.

Many epidemiological studies in Asian populations have investigated associations between the Arg399Gln gene polymorphism of X-ray repair cross complementing gene 1 (XRCC1) and risk of cervical carcinoma, but no conclusions have been available because of controversial results. Therefore a meta-analysis was conducted for clarification. Relevant studies were identified by searching the Pubmed, Embase, the Web of Science, Cochrane Collaborations database, Chinese National Knowledge Infrastructure (CNKI), Wanfang database and China Biological Medicinse (CBM) until September, 2012. A total of eight studies were included in the present meta- analysis, which described 1,759 cervical carcinoma cases and 2,497 controls. Odds ratios (ORs) and corresponding 95% confidence intervals (95%CIs) as effect size were calculated by fixed-effect or random-effect models. The overall results indicated that the XRCC1-399G/A polymorphism was marginally associated with cervical carcinoma in Asians: OR (95%CI): 1.16 (1.07, 1.26) in the G/A vs G/G inheritance model, 1.24 (0.87, 1.76)in A/A vs G/G inheritance model, 1.13 (1.01, 1.27) in the dominant inheritance model and 1.18 (0.94, 1.47) in the recessive inheritance model. Subgroup analyses on sample size showed no significant correlation in the small- sample size group but the large-sample size group was consistent with the outcomes of overall meta-analysis. In the subgroup analysis by regions, we only found significant association under the G/A vs G/G inheritance model in the Chinese population. For the non-Chinese populations, no correlation was detected in any genetic inheritance model. In the Asian populations, XRCC1-399G/A gene polymorphism was implied to be associated with cervical carcinoma.