Background and objective: Recently, several studies have investigated the prevalence of chronic obstructive pulmonary disease (COPD) at high altitude (>1,500 m). However, much remains to be understood about the correlation between altitude and COPD. We aimed to summarize the prevalence of COPD at high-altitudes and find out if altitude could be a risk factor for COPD. Methods: We searched PubMed/Medline, Cochrane Library, Web of Science, SCOPUS, OVID, Chinese Biomedical Literature Database (CBM) and Embase databases from inception to April 30th, 2019, with no language restriction. We used STATA 14.0 to analyze the extracted data. A random-effect model was used to calculate the combined OR and 95% CI. Heterogeneity was assessed by the I 2 statistic versus P-value. We performed a subgroup analysis to analyze possible sources of heterogeneity. The Egger's test and the Begg's test were used to assess any publication bias. Results: We retrieved 4,574 studies from seven databases and finally included 10 studies (54,578 participants). Males ranged from 18.8% to 49.3% and the population who smoked ranged from 3.3% to 53.3%. The overall prevalence of COPD at high-altitude was 10.0% (95% CI [0.08-0.12], P < 0.001). In a subgroup analysis, based on different regions, the results showed that the prevalence in Asia was higher than that in Europe and America. Seven studies compared the relationship between the prevalence of COPD at high-altitudes and the lowlands. The results showed that altitude was not an independent risk factor for the prevalence of COPD (ORadj = 1.18, 95% CI [0.85-1.62], P = 0.321). There was no publication bias among the studies. Conclusions: Our study found a higher prevalence of COPD at high-altitudes than those from average data. However, altitude was not found to be an independent risk factor for developing COPD (PROSPERO Identifier: CRD42019135012).

Extracorporeal shock wave therapy (ESWT) as a new adjuvant therapy has shown a potential capability to promote diabetic foot ulcer (DFU) healing. The purpose of this study was to assess the efficacy and safety of ESWT on the healing of DFUs. The Cochrane Library, PubMed, Embase, Web of Science, China Biology Medicine and reference lists were searched for studies published up to December 2018. Randomized controlled trials of any design, including ESWT for patients with DFU, were included. Two reviewers extracted data, including the wound surface area (WSA), percentage of re-epithelialization, population of complete cure and unchanged and other related outcomes. Eight randomized controlled trials (N=339) were included. ESWT was found to be associated with a greater reduction of WSA by 1.54 cm2, and increase of re-epithelialization by 26.31%. A greater population with complete cure was found at the end of treatment (risk ratio [RR] = 2.22; 95% confidence interval [CI], 1.46 to 3.40); however, there was no statistically significant difference at the end of follow up (p=0.052). It can also reduce treatment inefficiency by 4.8-fold (95% CI, 0.12 to 0.37). In addition, ESWT also showed a higher superiority than hyperbaric oxygen therapy in the population for complete cure and unchanged ulcer (RR=1.83; 95% CI, 1.14 to 2.94 and RR=0.25; 95% CI, 0.13 to 0.48, respectively). ESWT is a feasible adjuvant treatment for DFUs. It can effectively improve the complete cure rate, shorten the healing period of DFUs and significantly reduce treatment ineffectiveness. This can provide new therapeutic ideas for clinical practice of intractable and recurrent DFUs.

Background: Chronic kidney disease (CKD) has become a global public health problem with a high prevalence and mortality. There is no sensitive and effective markers for chronic kidney disease. Previous studies proposed suPAR as an early predict biomarker for chronic kidney disease, but the results are controversial. Therefore, the purpose of the current meta-analysis is to evaluate the association between suPAR and CKD. Methods: We searched the PubMed, Embase, Cochrane Library databases, and Web of Science before May 1, 2019. The search was based on the key words including suPAR and CKD. Data are extracted independently according to standard format, and quality analysis is performed. We extracted the concentration of suPAR and hazard rate (HR) values of mortality, cardiovascular disease, and end-stage renal disease. Results: There were 14 studies fulfilling the criteria. The concentration of suPAR was higher in patients with CKD than that in the control group (P < 0.001; SMD: -2.17; 95% CI: -2.71, -1.63; I 2 = 67.4%). SuPAR had a higher risk of mortality (P=0.001; HR: 1.72; 95% CI: 1.24, 2.39; I 2 = 68.0%). The higher suPAR level increased the risk of cardiovascular disease (P < 0.001; HR: 3.06; 95% CI: 2.21, 4.22; I 2 = 0.0%) and the risk of end-stage renal disease (P < 0.001; HR: 1.40; 95% CI: 1.22, 1.60; I 2 = 0.0%). Conclusions: Monitoring suPAR concentrations may be used for early diagnosis and prognosis for patients with CKD, and the higher suPAR increased the risk of mortality, cardiovascular events, and end-stage renal disease.

Background: Chronic renal failure (CRF) is a serious disease that has become a burden on global and local economics and public health. In addition, non-thyroidal illness syndrome (NTIS) has become increasingly more prevalent in CRF patients. Materials and methods: A data search was conducted on the PubMed/Medline, Cochrane Library, Web of Science, Embase, and CBM databases to identify studies up to November 1st, 2018, that compared low T3 and normal T3 levels in patients with CRF. Data analysis was done by calculating the relative risks (RR) and 95% confidence intervals (95% CI) and continuous variables were described by weighted mean difference (WMD) and 95% CI. The efficacy outcomes included renal function and mortality. The Newcastle-Ottawa Scale and Agency for Healthcare Research and Quality scale were used to assess the quality of the cohort and cross-sectional studies, respectively. A funnel plot was used to identify publication bias. Results: Seventeen studies with a total of 4593 patients were finally included in the analysis. Among the 17 studies, 11 reported the mortality of CRF patients with low T3 and normal T3 levels. Subgroups were assigned according to different follow-up times and different methods of treatment. The mortality rate in the low T3 group was much higher than in the normal T3 group. 11 studies reported creatinine (Cr) results in patients with low T3 and normal T3 levels and our analysis found no significant differences between the two groups (95%CI: 0.46-0.25; P-heterogeneity = 0.000; P = 0.559). Five studies reported uric acid results and we found no significant differences between the two groups (95%CI: 0.08-0.22; P-heterogeneity = 0.438; P = 0.377). Five studies reported the urea levels in the two groups and our analysis found no significant differences (95%CI: 1.60-1.23; I2 = 0.0%; P-heterogeneity = 0.498;P = 0.798). Conclusion: Low T3 had a greater impact on the short-term prognosis of patients with CRF than on the long-term prognosis. NTIS did not cause substantial kidney damage.