The Impact of Cold Spells on the Incidence of Infectious Gastroenteritis and Relapse Rates of Inflammatory Bowel Disease: A Retrospective Controlled Observational Study

Short-term effects of ambient temperature on acute exacerbation of inflammatory bowel disease: A nationwide case-crossover study with external validation

Inflammatory bowel disease (IBD) is an idiopathic inflammatory disorder characterized by chronic and relapsing manifestations. Several environmental factors are known as triggers for exacerbation of IBD. However, an association between exacerbation of IBD and ambient temperature is uncertain. This study aimed to estimate the risk of acute exacerbation of IBD due to ambient temperature. We performed a bidirectional case-crossover study using a nationwide claim data from South Korea. The external validation was conducted with a large prospective cohort in the United Kingdom. We confirmed significant associations between acute exacerbation of IBD and the short-term ambient temperature changes toward severe temperatures, in the cold weather (-19.4°C-4.3°C) (odd ratio [OR] = 1.13, 95% confidence interval [CI]: 1.13-1.14) and in the hot weather (21.3°C-33.5°C) (OR = 1.16, 95% CI: 1.15-1.17). However, the association was not significant in the moderate weather (4.3°C-21.3°C). The external validation suggested consistent results with additional elevation of acute exacerbation risk in the colder weather (-13.4°C to 2.6°C) (OR = 1.90, 95% CI: 1.62-2.22) and in the hotter weather (15.7°C-28.4°C) (OR = 1.41, 95% CI: 1.32-1.51). We observed and validated that the short-term ambient temperature changes were associated with acute exacerbation of IBD in the cold and hot weathers. Our findings provide evidence that temperature changes are associated with the acute exacerbation of IBD.

Effects of temperature, weather, seasons, atmosphere, and climate on the exacerbation of inflammatory bowel diseases: A systematic review and meta-analysis

BACKGROUND

Exacerbation of inflammatory bowel disease (IBD) is common. Identification of the exacerbating factors could facilitate interventions for forecastable environmental factors through adjustment of the patient's daily routine. We assessed the effect of natural environmental factors on the exacerbation of IBD.

METHODS

In this systematic review and meta-analysis, studies published from January 1, 1992 to November 3th, 2022 were searched in the MEDLINE, Embase, CINAHL Complete and Cochrane Library databases. We extracted data related to the impact of environmental variations on IBD exacerbation, and performed a meta-analysis of the individual studies' correlation coefficient χ2 converted into Cramér's V (φc) with 95% confidence intervals (CI).

RESULTS

A total of 7,346 publications were searched, and 20 studies (sample size 248-84,000 cases) were selected. A meta-analysis with seven studies was performed, and the pooled estimate of the correlation (φc) between the seasonal variations and IBD exacerbations among 4806 cases of IBD exacerbation was 0.11 (95% CI 0.07-0.14; I2 = 39%; p = 0.13). When divided into subtypes of IBD, the pooled estimate of φc in ulcerative colitis (six studies, n = 2649) was 0.07 (95% CI 0.03-0.11; I2 = 3%; p = 0.40) and in Crohn's disease (three studies, n = 1597) was 0.12 (95% CI 0.07-0.18; I2 = 18%; p = 0.30).

CONCLUSION

There was a significant correlation between IBD exacerbation and seasonal variations, however, it was difficult to synthesize pooled results of other environmental indicators due to the small number of studies and the various types of reported outcome measures. For clinical implications, additional evidence through well-designed follow-up studies is needed.

PROTOCOL REGISTRATION NUMBER (PROSPERO)

CRD42022304916.

The association between ambient temperature and clinical visits for inflammation-related diseases in rural areas in China

BACKGROUND

The association between temperature and mortality has been widely reported. However, it remains largely unclear whether inflammation-related diseases, caused by excessive or inappropriate inflammatory reaction, may be affected by ambient temperature, particularly in low-income areas.

OBJECTIVES

To explore the association between ambient temperature and clinical visits for inflammation-related diseases in rural villages in the Ningxia Hui Autonomous Region, China, during 2012─2015.

METHODS

Daily data on inflammation-related diseases and weather conditions were collected from 258 villages in Haiyuan (161 villages) and Yanchi (97 villages) counties during 2012─2015. A Quasi-Poisson regression with distributed lag non-linear model was used to examine the association between temperature and clinical visits for inflammation-related diseases. Stratified analyses were performed by types of diseases including arthritis, gastroenteritis, and gynecological inflammations.

RESULTS

During the study period, there were 724,788 and 288,965 clinical visits for inflammation-related diseases in Haiyuan and Yanchi, respectively. Both exposure to low (RR: 2.045, 95% CI: 1.690, 2.474) and high temperatures (RR: 1.244, 95% CI: 1.107, 1.399) were associated with increased risk of total inflammation-related visits in Haiyuan county. Low temperatures were associated with increased risks of all types of inflammation-related diseases in Yanchi county (RR: 4.344, 95% CI: 2.887, 6.535), while high temperatures only affected gastroenteritis (RR: 1.274, 95% CI: 1.040, 1.561). Moderate temperatures explained approximately 26% and 33% of clinical visits due to inflammation-related diseases in Haiyuan and Yanchi, respectively, with the burden attributable to cold exposure higher than hot exposure. The reference temperature values ranged from 17 to 19 in Haiyuan, and 12 to 14 in Yanchi for all types of clinical visits.

CONCLUSIONS

Our findings add additional evidence for the adverse effect of suboptimal ambient temperature and provide useful information for public health programs targeting people living in rural villages.

The association between cold spells and admissions of ischemic stroke in Hefei, China: Modified by gender and age

BACKGROUND

Some studies have discovered that low ambient temperatures were associated with increased risk of the incidence of ischemic stroke. Although the frequency of extreme weather events is increasing, few studies have studied the effects of cold wave on ischemic stroke.

OBJECTIVE

The purpose of this study was to explore the association between cold waves and ischemic stroke onset and further to explore how this association was modified by cold spell characteristics and individual-level factors.

METHODS

A Poisson regression with a distributed lag nonlinear model was used to investigate the association between cold spells under 9 different definitions and daily admissions of ischemic stroke in 2013-2015 in Hefei.

RESULTS

By comparing the attribution risk and the results of the sensitivity analysis of different models, the local optimal cold spell was defined as the day between November to March when daily mean temperature was less than 10th for 2 or more consecutive days (backward attributable risk fraction (b-AF) = 4.19%, 95% empirical confidence intervals (eCI): 0.87%, 6.66%, backward attributable number (b-AN) = 278). On the basis of optimal model, the single-day effect of cold waves on ischemic stroke occurred on 5th day after exposure and continued until 17th day, and the maximum effect appeared on the 5th day with relative risk (RR) = 1.050 (95% confidence interval (CI) = 1.008, 1.094). The significant cumulative effect lasted from day 9 after exposure to cold spells to day 21. The maximum cumulative effect was observed on the 21st day with RR = 2.378 (95% CI = 1.304, 4.337). The female and the young and middle-aged people were susceptible to the local cold waves.

CONCLUSION

This study suggests that cold spell is a risk factor for ischemic stroke in Hefei, and there is a certain lag effect. Targeted measures should be taken to protect susceptible populations during cold spell days, including women and young and middle-aged people.

Temperature Variability and Gastrointestinal Infections: A Review of Impacts and Future Perspectives

The objectives of this research are to review and assess the current state of knowledge of the association between environmental temperature and gastrointestinal (GI) infections. A review of the published literature was undertaken using standard approaches. Initially, four electronic databases including Embase, Medline, Scopus, and Web of Science were chosen to retrieve studies published from 1 January 2006 to 31 December 2017 based on selected keywords used in the primary search. After the elimination of duplicates, the titles were reviewed for relevance to the principal research question. Secondly, the abstracts of titles deemed to be relevant were reviewed for significance and finally the articles were reviewed in their entirety to identify their contribution to the principal research question. Initially, 8201 articles were identified, and eight studies finally met the inclusion criteria. A secondary phase involving scrutiny of the references of key identified articles found three further studies. Consequently, 11 papers were selected for the final review. Current literature confirms a significant association between temperature and infectious gastroenteritis worldwide. Also, a most-likely non-linear correlation between rainfall and GI infections has been identified in that the rate of such infections can be increased with either high or low precipitation. Finally, some studies suggest high relative humidity may not increase the rate of GI infections and some have found it may decrease it. These findings help inform predictions of risk, particularly under future climate change scenarios.