Association between diurnal temperature range and emergency department visits for multiple sclerosis: A time-stratified case-crossover study

Climate change and disorders of the nervous system

Anthropogenic climate change is affecting people's health, including those with neurological and psychiatric diseases. Currently, making inferences about the effect of climate change on neurological and psychiatric diseases is challenging because of an overall sparsity of data, differing study methods, paucity of detail regarding disease subtypes, little consideration of the effect of individual and population genetics, and widely differing geographical locations with the potential for regional influences. However, evidence suggests that the incidence, prevalence, and severity of many nervous system conditions (eg, stroke, neurological infections, and some mental health disorders) can be affected by climate change. The data show broad and complex adverse effects, especially of temperature extremes to which people are unaccustomed and wide diurnal temperature fluctuations. Protective measures might be possible through local forecasting. Few studies project the future effects of climate change on brain health, hindering policy developments. Robust studies on the threats from changing climate for people who have, or are at risk of developing, disorders of the nervous system are urgently needed.

Association between diurnal temperature range and sperm quality: Evidence from a prospective cohort in Central China

Inter-day temperature variability has been reported to be associated with sperm quality in a city-level exposure assessment study. However, studies exploring the impact of temperature variability within a single day on sperm quality at individual level are still lacking. The present study aims to bridge this research gap by analyzing the linear and non-linear associations between diurnal temperature range (DTR) exposure and sperm quality, utilizing data from the Anhui Prospective Assisted Reproduction Cohort. The study included 15,112 males (totaling 28,267 tests) and assessed individual exposure to various environmental factors (residential greenness, ambient particulate matter, sulfur dioxide, relative humidity, ambient temperature, and DTR) during the 0-90 day period before semen analysis. A combination of a linear mixed model, natural cubic splines, and subgroup analysis was employed. Significant "U"-shaped non-linear associations were observed between DTR exposure and total motility, sperm concentration, sperm count, total motile sperm count, and progressive motile sperm count. Lower DTR levels negatively impacted these parameters, whereas higher DTR levels showed a positive effect. Notably, these associations were more pronounced at ambient temperatures below 16.5 °C, while absent in warmer conditions. Sperm quality demonstrates increased sensitivity to DTR exposure in cooler environments. Therefore, implementing effective individual temperature management strategies is crucial for mitigating decreased sperm quality associated with DTR exposure, highlighting the potential benefits of government policies aimed at achieving carbon neutrality to enhance overall sperm quality in the general population.

Ambient temperature variations and AIDS-related mortality: A time-stratified case-crossover study in 103 counties, China

BACKGROUND

Climate change, characterized by the steady ascent of global temperatures and the escalating unpredictability of climate patterns, poses multifaceted challenges to public health worldwide. However, vulnerable groups, particularly the population affected by HIV/AIDS, have received little attention.

OBJECTIVES

We aimed to examine the impacts of temperature variations on AIDS-related mortality.

METHODS

Data on individuals with HIV/AIDS were collected from the HIV/AIDS Comprehensive Response Information Management System between 2013 and 2019. Temperature variation metrics were constructed by diurnal temperature range (DTR), temperature changes between neighboring days (TCN), and temperature variability (TV0-t). Time-stratified case-crossover design with conditional logistic regression models was used to investigate the associations between ambient temperature variations and AIDS-related mortality.

RESULTS

Each 1 °C elevated in DTR was linked with a 5.28 % [95 % confidence intervals (CIs): 1.61, 9.08] increment in AIDS-related mortality at a lag of 0-6 days. Stronger associations between DTR and AIDS-related mortality were observed in the married than in single, with corresponding excess ORs (%) of 5.33 (95 % CIs: 0.29, 10.62) versus 4.79 (95 % CIs: -0.50, 10.36) for 1 °C increased in DTR at lag 0-6 days. Additionally, we noticed the impact of DTR was more pronounced in the warm season, leading to a 7.32 % (95 % CIs: 0.57, 14.51) elevation in the risks of AIDS-related mortality for 1 °C increase in DTR at lag 0-6 days, while the effect value decreased to 5.16 % (95 % CIs: 0.71, 9.81) in the cold season.

CONCLUSIONS

Our findings indicated that DTR might be a significant risk factor for AIDS-related deaths among ambient temperature variation indicators, and underscored the importance of considering temperature variability in public health interventions aimed at mitigating this risk of AIDS-related mortality.

The effects of diurnal temperature range on mortality and emergency department presentations in Victoria state of Australia: A time-series analysis

State of Victoria, Australia (SVA) has a wide variation of diurnal temperatures (DTR). DTR has been reported to be associated with risk of mortality and morbidity. We examined the association between exposure to DTR and risk of all-cause mortality and emergency department (ED) presentations in the SVA. We obtained data on daily counts of deaths and ED presentations, and weather data from 1 st January 2000─2019. We applied a quasi-Poisson time-series regression analysis to examine the association between daily DTR exposures and risk of mortality and ED presentations. The analyses were queried by age, sex, seasons, ED presentations triages, and departure status. Risk of mortality and ED presentation increased by 0.33% (95% CI: 0.24%-0.43%), and 0.094% (95% CI: 0.077%-0.11%) in relation to one degree increase in the daily DTR. The association between DTR and ED presentations was stronger in children (0-15 years) (0.38% [95% CI: 0.34%-0.42%]) and the elderly (75+ years) (0.34% [95% CI: 0.29%-0.39%]). Resuscitation, which was consistently accounted for the highest vulnerability to DTR variation, increased by 0.79% (95% CI: 0.60%-0.99%). This study suggests that the risk of mortality and ED presentations associates with the increase of DTR. Children, the elderly, and their caregivers need to be made aware of the health risk posed by DTR.

Augmented temperature fluctuation aggravates muscular atrophy through the gut microbiota

Large temperature difference is reported to be a risk factor for human health. However, little evidence has reported the effects of temperature fluctuation on sarcopenia, a senile disease characterized by loss of muscle mass and function. Here, we demonstrate that higher diurnal temperature range in humans has a positive correlation with the prevalence of sarcopenia. Fluctuated temperature exposure (10-25 °C) accelerates muscle atrophy and dampens exercise performance in mid-aged male mice. Interestingly, fluctuated temperature alters the microbiota composition with increased levels of Parabacteroides_distasonis, Duncaniella_dubosii and decreased levels of Candidatus_Amulumruptor, Roseburia, Eubacterium. Transplantation of fluctuated temperature-shaped microbiota replays the adverse effects on muscle function. Mechanically, we find that altered microbiota increases circulating aminoadipic acid, a lysine degradation product. Aminoadipic acid damages mitochondrial function through inhibiting mitophagy in vitro. And Eubacterium supplementation alleviates muscle atrophy and dysfunction induced by fluctuated temperature. Our results uncover the detrimental impact of fluctuated temperature on muscle function and provide a new clue for gut-muscle axis.

Impacts of Climate Change and Air Pollution on Neurologic Health, Disease, and Practice: A Scoping Review

BACKGROUND AND OBJECTIVES

Although the international community collectively seeks to reduce global temperature rise to less than 1.5°C before 2100, irreversible environmental changes have already occurred, and as the planet warms, these changes will continue to occur. As we witness the effects of a warming planet on human health, it is imperative that neurologists anticipate how the epidemiology and incidence of neurologic disease may change. In this review, we organized our analysis around 3 key themes related to climate change and neurologic health: extreme weather events and temperature fluctuations, emerging neuroinfectious diseases, and pollutant impacts. Across each of these themes, we appraised and reviewed recent literature relevant to neurologic disease and practice.

METHODS

Studies were identified using search terms relating to climate change, pollutants, and neurologic disease in PubMed, OVID MEDLINE, EMBASE, PsycInfo, and gray literature. Studies published between 1990 and 2022 were included if they pertained to human incidence or prevalence of disease, were in English, and were relevant to neurologic disease.

RESULTS

We identified a total of 364 articles, grouped into the 3 key themes of our study: extreme weather events and temperature fluctuations (38 studies), emerging neuroinfectious diseases (37 studies), and pollutant impacts (289 studies). The included studies highlighted the relationships between neurologic symptom exacerbation and temperature variability, tick-borne infections and warming climates, and airborne pollutants and cerebrovascular disease incidence and severity.

DISCUSSION

Temperature extremes and variability both associated with stroke incidence and severity, migraine headaches, hospitalization in patients with dementia, and multiple sclerosis exacerbations. Exposure to airborne pollutants, especially PM2.5 and nitrates, associated with stroke incidence and severity, headaches, dementia risk, Parkinson disease, and MS exacerbation. Climate change has demonstrably expanded favorable conditions for zoonotic diseases beyond traditional borders and poses the risk of disease in new, susceptible populations. Articles were biased toward resource-rich regions, suggesting a discordance between where research occurs and where changes are most acute. As such, 3 key priorities emerged for further study: neuroinfectious disease risk mitigation, understanding the pathophysiology of airborne pollutants on the nervous system, and methods to improve delivery of neurologic care in the face of climate-related disruptions.

Health effect of temperature change on respiratory diseases in opposite phase in semi-arid region

The impact of temperature variation on health has attracted increasing attention under global climate change. A distributed lag non-linear model (DLNM) was performed to estimate the risk of two indicators of temperature change (diurnal temperature range (DTR) and temperature change between neighboring days (TCN)) on respiratory hospital visits in Lanzhou, a semi-arid climate city in western China from 2012 to 2018. The whole year is divided into two different temperature change periods according to the TCN of each solar term. The results showed that extreme high DTR can apparently enlarge respiratory risk, and it indicated strong cumulative relative risk (RR) in the temperature drop period. Extreme low TCN had strong adverse effects on respiratory diseases especially in temperature rise period, with the greatest RR of 1.068 (95% CI 1.004, 1.136). The effect of extreme high TCN was more obvious in temperature drop period, with a RR of 1.082 (95% CI 1.021, 1.148) at lag 7. Females were more affected by extreme temperature changes. Young people were more vulnerable to DTR, while TCN has a greater impact on the elderly.

Seasonal variation in association between temperature change and emergency department visits: A multi-site study in China

BACKGROUND

There is limited evidence of effects and seasonal variation of temperature change on emergency department visits (EDVs).

OBJECTIVE

To investigate the association between diurnal temperature range (DTR), temperature change between neighboring days (TCN) and a comprehensive collection of cause-specific EDVs in China.

METHODS

We collected EDVs, weather, and air pollution data in 20 sites in China from 2014 to 2018. We applied a quasi-Poisson regression with distributed lag nonlinear model to evaluate DTR- and TCN-EDVs association. We used meta-analysis to pool site-specific estimates. We also conducted seasonal analysis and assess effects of modifiers.

RESULTS

A 1 °C increase of DTR and TCN was associated with 0.29% [95% confidence interval (CI): 0.07%, 0.51%)] and 1.44% (95% CI: 0.93%, 1.96%) increase of total EDVs, respectively. People aged 18-44 were sensitive to DTR and TCN, while the elderly population was sensitive to TCN only in spring and autumn. In seasonal analysis, effects of temperature change on total EDVs were lower in summer. TCN increased risks of genitourinary diseases in summer, respiratory diseases in winter, injury in autumn, and mental diseases in spring. DTR increased the risk of respiratory diseases in autumn.

CONCLUSION

Exposure to DTR and TCN was associated with elevated risk of EDVs but with great seasonal variations. Our results provided potential time and target populations for adaptive strategies and preventive measures.

Seasonal and monthly variation in multiple sclerosis relapses: a systematic review and meta-analysis

BACKGROUND

Multiple Sclerosis (MS) relapses are episodes of transient disease exacerbation. There are contradictory findings regarding seasonal variation in MS relapses. In this systematic review and meta-analysis, we aimed to investigate the seasonal and monthly variation in relapse rates among patients with MS.

METHODS

We systematically queried PubMed, Scopus, and Web of Science for published papers until February 30, 2022.

RESULTS

A total of 24 studies were included in this systematic review and meta-analysis with a total of 29,106 patients with MS. We found that the relapse rate was significantly lower in fall compared to the average relapse rate in other seasons with a risk ratio (RR) of 0.97 (95% CI 0.95-0.98). Furthermore, patients with MS experienced a higher number of relapses in April (RR: 1.06, 95% CI 1.01-1.11) and March (RR: 1.08, 95% CI 1.00-1.16) compared to other months. Also, the risk of relapse was lower in August (RR: 0.92, 95% CI.85-0.98), September (RR: 0.97, 95% CI.94-0.99), October (RR: 0.92, 95% CI.89-0.96), and November (RR: 0.93, 95% CI.89-0.97).

CONCLUSION

Our systematic review and meta-analysis confirm the temporal fluctuations in the relapse of MS through a comprehensive review of the existing literature, with a lower relapse rate during late summer and fall and a higher relapse rate during early spring.

The association between diurnal temperature range and clinic visits for upper respiratory tract infection among college students in Wuhan, China

The effects of daily mean temperature on health outcomes have been discussed in many previous studies, but few have considered the adverse impacts on upper respiratory tract infection (URTI) due to variance of temperature in one day. Diurnal temperature range (DTR) was a novel indicator calculated as maximum temperature minus minimum temperature on the same day. In this study, generalized additive model (GAM) with quasi-Poisson distribution was used to investigate the association between DTR and the number of daily outpatient visits for URTI among college students. Data about meteorological factors and air pollutants were provided by Hubei Meteorological Bureau and Wuhan Environmental Protection Bureau, respectively. Outpatient visits data were collected from the Hospital of Wuhan University from January 1, 2016, to December 31, 2018. Short-term exposure to DTR was associated with the increased risk of outpatient for URTI among all college students. Per 1 °C increased in DTR was associated with 0.73% (95%CI: 0.24, 1.21) increased in outpatient visits of all college students for URTI at lag 0 day. The greatest effect values were observed in males [1.35% (95%CI: 0.33,2.39)] at lag 0-6 days, and in females [0.86% (95%CI: 0.24, 1.49)] at lag 0-1 days. DTR had more adverse health impact in autumn and winter. Public health departments should consider the negative effect of DTR to formulate more effective prevention and control measures for protecting vulnerable people.

Heat Exposure and Multiple Sclerosis-A Regional and Temporal Analysis

Multiple sclerosis (MS) is a neurological disorder that progressively distorts the myelination of axons within the central nervous system (CNS). Increased core body temperature or metabolism as a result of exercise are common causes of short-term exacerbations of neurological symptoms in MS. About 60–80% of patients with MS experience a worsening of their symptoms when exposed to heat. In comparison, less data are available on the relationship between ambient meteorological conditions (e.g., temperature and relative humidity (RH)) and fluctuations in such variables in relation to MS symptoms. Thus, this study examined associations between time-lagged exposure to meteorological conditions and risk of a clinic visit due to MS among US veterans between 2010 and 2013. This study leveraged data from the Veterans Affairs (VA) and National Climactic Data Center (NCDC) for the continental US, partitioned into eight climate zones. We used a case crossover design to assess the risk of a MS clinic visit with respect to several meteorological conditions. Location-specific time-lagged daily (ambient) exposure to temperature, RH, and temperature variations (standard deviation (SD) of temperature) were computed (up to 30 days) for each case (i.e., day of MS visit) and control (a randomly assigned date ± 90–270 days prior to visit). Statistical analyses were conducted to examine independent associations between the selected meteorological conditions and risk of MS visits at the national and regional levels. A total of 533,066 patient visits received a MS diagnosis (International Classifications of Diseases (ICD)-9 code = 340). The Northeast (NE) and Upper Midwest (UMW) regions reported the highest frequency of clinic visits due to MS. Clinic visits were 9% more likely to occur in the spring, summer, and fall months (March–October) than in the winter (OR = 1.089; 95% CI = 1.076–1.103; p < 0.01). In the univariate analyses, the SD of temperature, temperature, and temperature–RH interaction were positively associated with an elevated risk of a MS clinic visit, while the RH was negatively associated with the risk for a clinic visit. In multivariate analyses, the strongest association of a MS clinic visit was observed with the SD of the temperature (OR = 1.012; 95% CI 1.008–1.017; p < 0.01). These associations between MS clinic visits and meteorological conditions varied across climate regions, with the strongest associations being observed in the LMW, UMW, DSW, and NE zones. The SD of the temperature was again the strongest associated predictor when examined regionally. Temperature variations and temperature–RH interactions (a proxy of the heat index) showed significant associations with MS clinic visits. These associations varied across climate regions when examined geographically. Our findings have implications for the management of MS in severe or recurrent cases, especially considering the impending changes in the daily temperature variations and intensity of the heatwaves expected with the intensification of global warming.