Objective To evaluate the relationship between body mass index (BMI) and malignant lymphoma by means of Meta-analysis. Methods Such databases as Web of Science, PubMed, EBbase, CNKI, Wanfang, VIP and CBM were searched from the date of their establishment to April 2011 to collect the case control studies on the relationship between BMI and malignant lymphoma. Two researchers independently selected studies, extracted data and assessed the quality according to the inclusive and exclusive criteria, and then conducted Meta-analyses by using RevMan5.0 software for heterogeneity test and pooled OR calculation. Results Seven case control studies involving 8416 malignant lymphoma patients and 14760 other patients were included. The quality of all studies scored 4, indicating reliable quality. Meta-analyses of the low BMI, overweight and obesity population were OR=0.8, 95%CI 0.79 to 0.95, P=0.003; OR=1.04, 95%CI 0.98 to 1.11, P=0.16; and OR=1.22 95%CI 1.04 to 1.43, P=0.01, respectively. The stratified Meta-analysis on histological subtypes showed that obesity was associated with a significantly increased risk of diffuse large B cell lymphoma (OR=1.33 95%CI 1.18 to 1.50, Plt;0.000 01), but was not associated with the follicular lymphoma or small lymphocytic lymphoma/chronic lymphocytic leukemia. Conclusion These findings demonstrate that low BMI is associated with the decrease of malignant lymphoma, and obesity is an increasing risk of malignant lymphoma, especially, the diffuse large B cell lymphoma.
Objective To systematically assess the correlation between smoking and the risk of endometriosis, so as to offer scientific basis to health education and preventing decision. Methods A literature search was performed in The Cochrane Library, Pubmed, Embase, CBM, CNKI and Wanfang database to collect the case control studies on the correlation between smoking and endometriosis. Two reviewers independently screened the literatures according to the inclusion and exclusion criteria, extracted the data, assessed the quality, and then conducted Meta-analyses on the 13 included RCTs by using RevMan 5.0 software, with calculation of the OR value and 95%CI. Results A total of 13 case control studies involving 14260 cases were included, of which 1900 ones were endometriosis. The quality assessment indicated that 2 studies were in quality of Level A, 4 were Level B, 7 were Level C, totally meant low quality. Meta-analyses showed that compared with non-smokers, there was no increasing possibility of endometriosis in smokers (OR= 0.91, 95%CI 0.82 to 1.02). The geographical subgroup analyses showed there was no significant difference in the incidence of endometriosis between the non-smokers and smokers in North America (OR=0.96, 95%CI 0.84 to 1.08), but a significant difference was found between non-smokers and smokers in Europe (OR=0.72, 95%CI 0.54 to 0.97). Conclusion There is no causative relationship between smoking and incidence of endometriosis. However, more high-quality trials are expected for further study because of the heterogeneity and poor quality of the current included studies.
Objective To explore the relationship between periodontitis and postmenopausal osteoporosis.Methods Databases were electronically searched from PubMed (1966 to December, 2010), EMbase (1974 to December, 2010), CBM (1978 to December, 2010), VIP (1989 to December, 2010), CNKI (1979 to December, 2010) and WanFang Data (January, 2007 to December, 2010), and the references listed in all papers were also retrieved. The literature was screened according to the inclusion and exclusion criteria by two reviewers independently; the methodology quality was evaluated after data abstraction; and then the RevMan 5.0 software was used for meta-analyses. Results Four trials were included. Among the total 678 patients involved, 263 were postmenopausal osteoporosis patients, while the other 415 were non-osteoporosis patients. The results of meta-analyses showed that: a) Clinical attachment loss (CAL) of the postmenopausal osteoporosis patients was significantly higher than that of the non-osteoporosis patients (WMD=0.60, 95%CI 0.23 to 0.96); b) The level of gingival recession of the postmenopausal osteoporosis patients was significantly higher than that of the non-osteoporosis patients (WMD=0.78, 95%CI 0.41 to 1.14); c) There were no significant differences in plaque index (PI), gingival index (GI) and periodontal probing depth (PPD) between the two groups (WMD=0.17, 95%CI 0.00 to 0.35; WMD=0.05, 95%CI –0.09 to 0.19; and WMD=–0.08, 95%CI –0.24 to 0.09); d) The results of one study indicated that the rate of periodontitis in the postmenopausal osteoporosis patients was higher than that of the non-osteoporosis patients (OR=2.45, 95%CI 1.38 to 4.34, Plt;0.01); the severe alveolar crest height loss was related to osteoporosis (OR=4.20, 95%CI 1.57 to 11.22, Plt;0.01). Conclusion Postmenopausal osteoporosis patients are more prone to suffer from periodontitis or turn to the worse stage of periodontitis. In consideration of the factors such as small scales and incomplete measure indexes of the included studies, which have influences on the intensity and comprehensiveness of this conclusion, more high-quality studies are required.
Objective To explore whether the polymorphism of transforming growth factor β1 (TGF β1) gene at 869T/C and 915G/C loci contributes to the genetic susceptibility to hypertension. Methods Assessed under the same criteria, all case control studies on relationship between the polymorphism of TGF β1 gene and hypertension were searched in both English and Chinese databases. All articles retrieved were screened and evaluated, and meta-analyses were conducted with RevMan 5.1 software. Results A total of 14 case control studies were included. The results of meta-analyses showed TGF β1 gene C allele was related to hypertension (OR=1.37, 95%CI 1.21 to 1.54). It was noted that individuals with CC genotype and TT genotype had a significant increased risk of hypertension (OR=1.43, 95%CI 1.27 to 1.60; OR=0.64, 95%CI 0.53 to 0.78, respectively). And there was no b evidence showing that TGF β1 915G/C genetic polymorphism was related to hypertension. The results from meta-analyses of the studies based on Chinese population on the two loci were in consistent with the outcomes of overall meta-analyses. Sensitivity analyses indicated the results were stable. And publication bias was not present, reflected by P values from Egger’s regression asymmetry test and Begg’s adjusted rank correction test. Conclusions 869T/C polymorphism of TGF β1 gene is associated with hypertension. C allele is potentially one of the genetic risk factors for hypertension. Present studies do not support a direct relationship between 915G/C polymorphism TGF β1 gene and hypertension.
Objective To compare the risk of bone fractures in proton pump inhibitor users and nonusers, so as to evaluate the effects of proton pump inhibitors on the risk of bone fractures. Methods We searched PubMed, MEDLINE and EMbase databases to March 1st 2011 to identify case-control studies or cohort studies evaluating the risk of fracture in proton pump inhibitor users and nonusers. We conducted systematic review and meta-analysis according to the fracture site, duration of exposure, average daily dose and time of last use. Summary odds ratios (OR) and 95% confidence interval (CI) were calculated by RevMan 5.0.25 software. We also calculated and looked for heterogeneity. Results Eleven studies were identified from ten literatures, including seven case-control studies and four cohort studies. In case-control studies, the risk of total fractures increased by 36% in proton pump inhibitor users as compared with nonusers (OR=1.36, 95%CI 1.20 to 1.55). The risk of hip fracture increased by 39% (OR=1.39, 95%CI 1.13 to 1.71). In cohort studies, the risk of total fractures increased by 59% (OR=1.59, 95%CI 1.47 to 1.73). The risk of non-hip fractures increased by 65% (OR=1.65, 95%CI 1.47 to 1.85). As compared with nonusers, fracture risk increased by 41% in current users and by 38% in past users whose last use was at least 1 year ago. There was no significant difference between the two groups. Conclusion Proton pump inhibitors increase the risk of fracture to a certain degree. The effect does not fade away by discontinuation of PPI use for at least one year. Stricter clinical trials are needed to exclude confounding factors.
Objective To define risk factors of nosocomical pneumonia (NP) in elderly in-patients. Methods Two hundred elderly in-patients were selected in the Geriatric Department of West China Hospital from January 1999 to June 2002. Among them, 100 patients developed NP during their hospital days and the others didn’t have the episodes of NP at the same time. The following factors were analyzed: sex, age, multiple underline diseases and their severity, smoking, activity of daily life, conscious status, aspiration, nasogastrial intubations, antibiotics use and hospitalization. SPSS 10.0 was used for Logistic regression analysis to determine the factors significantly associated with the development of NP. Results The following factors were significantly associated with the development of NP in the logistic regression analysis: aspiration [OR 28.452, 95%CI (3.793 to 213.447)],multiple diseases [OR 17.157, 95%CI (2.734 to 107.651)], multiple antibiotics use [OR 6.396, 95%CI (1.861 to 21.980)], smoking [OR 1.774, 95%CI (1.211 to 2.600)] and prolonged hospitalization [OR 1.134, 95%CI (1.081 to 1.189)]. Conclusions Aspiration, multiple diseases, multiple antitiotics use, smoking and prolonged hospitalization are closely related to NP in elderly in-patients. Cautionary medical measures and shortening hospitalization were the key factors to decrease the incidence of NP for the patients in Geriatric Department.
ObjectiveTo systematically review the association between the level of plasma YKL-40 and obstructive sleep apnea hypopnea syndrome (OSAHS).MethodsWe searched PubMed, EMbase, MEDLINE, CNKI, WanFang Data, VIP database and supplemented by Google academic retrieval to collect case-control studies about the association between the level of plasma YKL-40 and OSAHS from inception to April 2017. Two reviewers independently screened literature, extracted data and evaluated the risk of bias of included studies. And then, meta-analysis was performed by RevMan 5.3 software.ResultsA total of 5 case-control studies were included, involving 755 OSAHS patients and control population. The results of meta-analysis showed that the level of plasma YKL-40 in OSAHS patients was higher than that in control group (SMD=1.20, 95%CI 0.33 to 2.06, P=0.007). The subgroup analysis showed that the level of plasma YKL-40 in OSAHS patients from Asia was significantly higher than that in control group (SMD=1.79, 95%CI 0.83 to 2.75, P=0.000 2). The comparison between different severity of OSAHS showed that the wild-medium group had lower plasma level of YKL-40 than the severe group (SMD=–0.83, 95%CI –1.46 to –0.19, P=0.01).ConclusionYKL-40 may play an important role in the pathogenesis of OSAHS. Due to limited quantity and quality of the included studies, more high quality studies are needed to verify above conclusions.
ObjectivesTo systematically review the relationship between cadmium exposure and the risk of hypertension.MethodsPubMed, EMbase, The Cochrane Library, CBM, WanFang Data, VIP and CNKI databases were searched online to collect studies of cadmium exposure and hypertension from inception to March 2018. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Meta-analysis was then performed by Stata 12.0 software.ResultsA total of 9 studies were included, of which 19 841 cases were patients of hypertension, and 27 578 cases were in the control group. The results of meta-analysis showed that blood cadmium was associated with risk of hypertension (OR=1.23, 95%CI 1.17 to 1.30, P<0.001). However, no significant association was found between urinary cadmium and the risk of hypertension (OR=0.77, 95%CI 0.55 to 1.07,P=0.61). The results of subgroup analysis showed non-smokers (OR=1.19, 95%CI 1.09 to 1.31, P<0.001), males (OR=1.19, 95%CI 1.11 to 1.28,P<0.001), females (OR=1.28, 95%CI 1.18 to 1.40,P<0.001), yellow race (OR=1.26, 95%CI 1.19 to 1.34,P<0.001), and the literatures published after 2010 (OR=1.24, 95%CI 1.17 to 1.31,P<0.001) were associated with risk of hypertension in blood cadmium. The current smokers (OR=0.72, 95%CI 0.56 to 0.93,P=0.013), yellow race (OR=0.65, 95%CI 0.50 to 0.83, P=0.001), and the literatures published before 2010(OR=0.61, 95%CI 0.50 to 0.75, P<0.001) were associated with risk of hypertension in urinary cadmium.ConclusionsBlood cadmium is associated with risk of hypertension and high level of blood cadmium is a risk factor for hypertension. The levels of blood cadmium of non-smokers, males, females, yellow race are associated with risk of hypertension in blood cadmium. Urinary cadmium was not significantly associated with the risk of hypertension. The above conclusions are required to be verified by more high quality studies.