Geographical Differences of Risk of Asthma and Allergic Rhinitis according to Urban/Rural Area: a Systematic Review and Meta-analysis of Cohort Studies.

Several studies have demonstrated an association between the risk asthma/allergic rhinitis and the environment. However, to date, no systematic review or meta-analysis has investigated these factors. We conducted a systematic review and meta-analysis to assess the association between urban/rural living and the risk of asthma and allergic rhinitis. We searched the Embase and Medline databases for relevant articles and included only cohort studies to observe the effects of time-lapse geographical differences. Papers containing information on rural/urban residence and respiratory allergic diseases were eligible for inclusion. We calculated the relative risk (RR) and 95% confidence interval (CI) using a 2 × 2 contingency table and used random effects to pool data. Our database search yielded 8388 records, of which 14 studies involving 50,100,913 participants were finally included. The risk of asthma was higher in urban areas compared to rural areas (RR, 1.27; 95% CI, 1.12-1.44, p < 0.001), but not for the risk of allergic rhinitis (RR, 1.17; 95% CI, 0.87-1.59, p = 0.30). The risk of asthma in urban areas compared to rural areas was higher in the 0-6 years and 0-18 years age groups, with RRs of 1.21 (95% CI, 1.01-1.46, p = 0.04) and 1.35 (95% CI, 1.12-1.63, p = 0.002), respectively. However, there was no significant difference in the risk of asthma between urban and rural areas for children aged 0-2 years, with a RR of 3.10 (95% CI, 0.44-21.56, p = 0.25). Our study provides epidemiological evidence for an association between allergic respiratory diseases, especially asthma, and urban/rural living. Future research should focus on identifying the factors associated with asthma in children living in urban areas. The review was registered in PROSPERO (CRD42021249578).

Presenilin 2 N141I mutation induces hyperactive immune response through the epigenetic repression of REV-ERBα.

Hyperimmunity drives the development of Alzheimer disease (AD). The immune system is under the circadian control, and circadian abnormalities aggravate AD progress. Here, we investigate how an AD-linked mutation deregulates expression of circadian genes and induces cognitive decline using the knock-in (KI) mice heterozygous for presenilin 2 N141I mutation. This mutation causes selective overproduction of clock gene-controlled cytokines through the DNA hypermethylation-mediated repression of REV-ERBα in innate immune cells. The KI/+ mice are vulnerable to otherwise innocuous, mild immune challenges. The antipsychotic chlorpromazine restores the REV-ERBα level by normalizing DNA methylation through the inhibition of PI3K/AKT1 pathway, and prevents the overexcitation of innate immune cells and cognitive decline in KI/+ mice. These results highlight a pathogenic link between this AD mutation and immune cell overactivation through the epigenetic suppression of REV-ERBα.

Changes in DNA methylation after 6-week exercise training in colorectal cancer survivors: A preliminary study.

AIM: Behavioral interventions such as exercise may induce epigenetic changes. Only few studies investigated the effects of exercise on epigenetic alterations in colorectal cancer survivors. The aim of this study was to explore the changes of genome-wide DNA methylation after 6-week exercise training in colorectal cancer survivors. METHODS: This preliminary study used a subset of data from a randomized controlled trial in 15 colorectal cancer survivors. Participants were randomized either to the 6-week exercise group or control group. The exercise intervention consisted of a weekly, group-based, supervised resistance exercise program and a home-based same resistance exercise plus walking six times per week. Blood samples were collected at baseline and after the intervention and data from eight subjects were analyzed for genome-wide DNA methylation on 865,918 CpG sites. RESULTS: Compared to the control group, the exercise group shows notable methylation changes in 756 CpG sites (22.7-25.2%). Gene ontology and disease annotation analysis showed that the genes targeting 81 CpG sites in promoter region with significant group-difference were linked in biological process such as immune response and transcription and related to metabolic and immune diseases. Also, hypermethylation on genes related to disease prevention seemed to be inhibited in the exercise group compared to the control group, indicating a likelihood of transcriptional activity of these genes. CONCLUSION: We found a preliminary evidence of the positive effects of exercise intervention on epigenetic markers in colorectal cancer survivors. Larger scale randomized controlled trials are warranted to further investigate our findings.

Exercise participation, barriers, and preferences in Korean prostate cancer survivors.

Objective: To identify patterns of physical activity (PA) participation, exercise preference, and barriers of stage 2-3 prostate cancer survivors across cancer trajectories based on selected demographic and medical variables.Design: The current study is a descriptive cross-sectional study which included data from a total of 111 prostate cancer survivors, at Shinchon Severance Hospital, Seoul, Korea. The survey includes PA levels before and after prostate cancer diagnosis, exercise barriers, and preferences.Results: Moderate- to vigorous-intensity PA levels were significantly lower after cancer diagnosis (vigorous PA:41.9 ± 123.1 min/week vs. 4.6 ± 29.8 min/week, p < 0.001; moderate PA: 159.9 ± 240.0 min/week vs. 56.8 ± 129.7 min/week, p < .001) compared to their PA level before cancer diagnosis. Perceived exercise barriers were distinctly different according to participants' age and time since surgery. The two most prevalent exercise barriers among prostate cancer survivors <65 years were lack of time (28.6%) and poor health (26.5%), whereas the exercise barriers for prostate cancer survivors aged ≥65 years were lack of exercise facilities (21.4%) and lack of exercise information (17.9%). Furthermore, within 6 months after surgery, prostate cancer survivors perceived poor health (29.5%) and pain at the surgery site (29.5%) to be the two most prevalent exercise barriers. 6 months after surgery, prostate cancer survivors perceived lack of time (21.3%) and poor health (14.8%) to be the two most prevalent exercise barriers. Walking, pelvic floor and Kegel exercises were three most preferred exercises among prostate cancer survivors in our study, which uniquely differ according to time since surgery.Conclusion: This study showed significant reduction in PA levels among prostate cancer survivors and their perceived exercise barriers were distinct according to their age and time since surgery. Therefore, PA and exercise recommendation should be specific to their personal characteristics such as age and time since surgery.

Handgrip Strength as a Predictor of All-Cause Mortality in Patients With Chronic Kidney Disease Undergoing Dialysis: A Meta-Analysis of Prospective Cohort Studies.

The aim of this study was to conduct a meta-analysis of the association between handgrip strength (HGS) and all-cause mortality in patients with chronic kidney disease undergoing dialysis. We evaluated eligible studies by searching PubMed and EMBASE databases up to December 2, 2018. A total of 9 prospective cohort studies were included in this meta-analysis. When we compared patients with low HGS to those with high HGS, the summary risk ratio of all-cause mortality was 1.88 (95% confidence interval 1.51-2.33; P < .001). In addition, the summary risk ratio of all-cause mortality associated with a 1-kg unit increase in HGS was 0.95 (95% confidence interval 0.93-0.97; P < .001). This quantitative synthesis showed that low HGS was associated with increased risk of all-cause mortality in patients with chronic kidney disease undergoing dialysis. Our study suggests that HGS may be a simple and useful predictor of prognosis in this patient population.