High Diurnal Temperature Range Research Articles

Climate changes altered the citrus fruit quality: A 9-year case study in China

Global climate change has significantly impacted the production of various crops, particularly long-term fruit-bearing plants such as citrus. This study analyzed the fruit quality of 12 citrus orchards (Citrus Sinensis L.Osbeck cv. Bingtang) in a subtropical region in Yunnan, China from 2014 to 2022. The results indicated that high rainfall (>220 mm) and low cumulative temperature (<3150 °C) promoted increases in titratable acidity (>1.8 %) in young fruits. As the fruits further expanded (with a horizontal diameter increasing from 50 to 65 mm), excessive rainfall (300-400 mm), lower cumulative temperature (<2400 °C), and a reduced diurnal temperature range (<10 °C) hindered decreases in titratable acidity. Conversely, low rainfall (<220 mm), high cumulative temperature (>3150 °C), and a high diurnal temperature range (>14 °C) promoted the accumulation of soluble solids in young fruits (9 %) at 120 days after flowering (DAF). Furthermore, low rainfall (<100 mm) favored the accumulation of soluble solids (1.5 %) during fruit expansion (195-225DAF). To quantify the relationship between fruit acidity and climate variables at 120 DAF, we developed a regression model, which was further validated by actual measurements and accurately predicted fruit acidity in 2023. Our findings have the potential to assist citrus growers in optimizing cultivation techniques for the production of high-quality citrus under increasingly variable climatic conditions.

Effects of diurnal temperature range on diarrhea in the subtropical megacity of Dhaka, Bangladesh

IntroductionWhile numerous studies have assessed the association of diarrhea with temperature, few have addressed the relationship between within-day variation of temperature and diarrhea. Materials and methodsWe investigated the association between diurnal temperature range (DTR) and daily counts of hospitalizations for all-cause diarrhea in Dhaka, Bangladesh using time series regression analysis employing distributed lag-linear models. Defining DTRs below 10th, 5th and 1st percentiles as low, very low and extremely low DTR, and DTRs above 90th, 95th and 99th percentiles as high, very high and extremely high DTRs, we additionally analyzed the effects of extreme DTR on diarrhea hospitalization. Effects were assessed for all ages, under-5 children and by gender. ResultsAlthough we did not find any significant effects of overall DTR and large DTRs, we detected significant effects of small DTRs on diarrhea hospitalization in all subgroups. A unit rise in low, very low and extremely low DTR was associated with a 4.9 % (95 % CI: 3.6 – 6.2), 7.1 % (95 % CI: 5.4 – 8.9) and 11.8 % (95 % CI: 8.3 – 15.5) increase in all-cause diarrhea hospitalization in all ages, respectively. A unit increase in low, very low and extremely low DTR was associated with a 4.9 %, 5.1 % and 18.4 % increase in all-cause diarrhea hospitalization in children under 5 years of age, respectively. The impact of extremely low DTR varied by gender (16.2 % in females versus 10.1 % in males). The effect of extremely low DTR was most pronounced in children under 5 years of age. ConclusionLess variation in within-day temperatures is a risk factor for diarrhea hospitalization in Dhaka, Bangladesh. Further research is needed to elucidate the causal pathways and identify the preventive measures necessary to mitigate the impacts of lowering DTRs on diarrhea.

[Effect of Diurnal Temperature Range on the Number of Residents Hospitalized Due to Stroke in Lanzhou].

Objective To analyze the relationship between diurnal temperature range (DTR) and the hospitalization of stroke in Lanzhou,so as to provide a scientific basis for probing into the mechanism of temperature changes in inducing stroke and formulating comprehensive prevention and control measures for stroke by relevant departments.Methods The information of the patients hospitalized due to stroke in Lanzhou during January 2014 to December 2019 and the air pollutants (PM10,SO2,and NO2) and meteorological data in the same period were collected for statistical analysis.Spearman rank correlation analysis was performed to analyze the correlations between air pollutants and meteorological factors.The distributed lag nonlinear model was adopted to fit the relationship between DTR and the number of stroke inpatients,and three-dimensional diagrams and the correlation diagrams of DTR against stroke risk were established.The stratified analysis was performed according to gender and age (< 65 years and ≥65 years).Results From 2014 to 2019,a total of 92 812 stroke patients were hospitalized in Lanzhou,with a male-to-female ratio of 1.35:1.There was a nonlinear relationship between DTR and the number of stroke inpatients in Lanzhou,which presented a lag effect.The low DTR at 4.5 ℃ had the largest RR value of 1.25 (95%CI=1.16-1.35) for stroke inpatients at a cumulative lag of 18 d.The effect of high DTR (18.5 ℃) on the hospitalization of stroke patients peaked at a cumulative lag of 21 d,with an RR value of 1.09 (95%CI=1.01-1.18).The stratified analysis results suggested that low levels of DTR had greater effects on the hospitalization of male stroke patients and stroke patients <65 years.Conclusions Short-term exposure to different levels of DTR had an impact on the number of stroke inpatients,and low levels of DTR had a slightly greater impact on stroke inpatients than high levels of DTR.Importance should be attached to the protection of males and people aged <65 years at low levels of DTR.

[Analysis of the association between diurnal temperature difference and relative humidity and myocardial infarction in Shantou residents].

Objective: To analyze the effect of meteorological conditions on mortality and population susceptibility of patients with acute myocardial infarction (AMI) in the Shantou area and to provide a scientific basis for the local public health system to prevent AMI. Methods: The AMI mortality data recorded in the resident cause of death surveillance database of Shantou from January 1, 2015, to December 31, 2020, were collected and the distribution lag nonlinear model was used to analyze the diurnal temperature range (DTR) and relative humidity (RH) on AMI mortality and the lag effect. Results: There were 13 932 deaths due to AMI in Shantou during the study period, with a male-to-female sex ratio of 1.3∶1. There was a significant association between high diurnal temperature difference exposure and low RH exposure and AMI deaths, with both single-day lag effects appearing and reaching a maximum at lag 2 day (RR=1.019, 95%CI: 1.000-1.039; RR=1.018, 95%CI: 1.003-1.034); the cumulative lag effect was all maximal at lag 0-14 day (RR=1.199, 95%CI: 1.025-1.401; RR=1.279, 95%CI: 1.117-1.465). The elderly (≥75 years) and female populations were susceptible to high DTR exposure and low RH exposure conditions. Conclusions: There was a significant association between DTR and RH and mortality of AMI in Shantou with a significant lag in their effects. Both female and elderly populations ≥75 years old were susceptible populations under high DTR and low RH exposure conditions.

Impact of diurnal temperature range on rhinitis in Lanzhou, China: Accounting for COVID-19 effects

Rhinitis is a global public health issue. A distributed lag non-linear model (DLNM) was used to examine the impact of diurnal temperature range (DTR) on nonallergic rhinitis (NAR) and allergic rhinitis (AR) in Lanzhou, China. Stratified analyses by age, gender, seasons, and the COVID-19 period were conducted, alongside extreme-DTR and attributable risk analyses. Using 37,225 cases, we found:1.The nonlinear DTR-rhinitis relationship: high- and low-DTR acutely impacted AR, while primarily high DTR moderately affected NAR during full and pre-COVID-19 periods.2.COVID-19 transformed the adverse impact of low-DTR into protective effects.3.In full study period, AR showed age heterogeneity, and NAR displayed age and gender differences. In pre-COVID-19 study period, AR had age and gender variations. The age < 18 group, vulnerable to NAR and AR, requires concerns.4.Low-DTR exhibits protective effects during cold seasons, while it poses adverse effects and increased risks in warm seasons.5.Moderate high DTR contributed most to rhinitis outpatients.In conclusion, NAR and AR demonstrate distinct responses to short-term DTR exposure, which may be influenced by COVID-19 and seasonal factors. Future research is essential to assess the long-term impacts of DTR and COVID-19 effects on NAR and AR.

Climate change and daily outpatient visits for dermatomyositis in Hefei, China: a time-series study.

With the deepening of research on the correlation between meteorological factors and autoimmune diseases, the relationship between climate change and dermatomyositis (DM) has come to our attention. This study aimed to explore the short-term correlation between meteorological factors and DM outpatient visits. Daily records of hospital outpatient visits for DM, air pollutants, and meteorological factor data in Hefei from January 1, 2018 to December 31, 2021 were obtained. The mean temperature (MT), relative humidity (RH), diurnal temperature range (DTR), and temperature change between neighboring days (TCN) were used to quantify environmental temperature and humidity and their variations. And we performed a time series analysis using a generalized linear model (GLM) in combination with a distributed lag nonlinear model (DLNM). Furthermore, gender and age were further stratified for the analysis. The sensitivity analysis was also performed. A total of 4028 DM outpatient visits were recorded during this period. There were statistically significant associations of low temperature (5th, 1.5 °C), low RH (1st, 48.6%), high RH (99th, 99%), high DTR (75th, 12.6°c), and low TCN (10th, -2.7 °C) that were associated with risk of DM outpatient visits, with lag days of 30, 16, 16, 10, and 14, respectively. Moreover, women were more susceptible to high RH exposure and low TCN exposure, while the elderly were more susceptible to low temperature. This study concluded that exposure to low temperature, extreme RH, and temperature changes (especially high DTR and low TCN) was associated with an increased risk of DM outpatient visits.

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.

Spatial variability of diurnal temperature range and its associations with local climate zone, neighborhood environment and mortality in Los Angeles

Urbanization alters the Earth’s emissivity and leads to intraurban differences in temperature variations, including diurnal temperature range (DTR). Despite DTR as a factor of thermal discomfort and mortality risk worldwide, its spatial variability and intraurban associations with local climate zone (LCZ), neighborhood environment and mortality risk have not been investigated. This study first applied the LCZ framework to evaluate associations between climate-sensitive urban design and long-term DTR exposure in Los Angeles, a megacity with the largest DTR in the United States. Using fine-scale daytime and nighttime Landsat thermal imagery to quantify DTR, we found that compact low-rise areas had high DTR, high-rise areas with moderate DTR, and natural areas with the lowest. Young-age, non-white and low-income populations were vulnerable and exposed to high DTR. A spatial Bayesian Poisson regression confirmed that neighborhoods with higher DTR exhibited higher mortality risk after controlling for socioeconomic factors (relative risk: 1.047, 95% credibility interval 1.013–1.082). We did not observe a significant association between mean temperature and mortality in our study. As spatial variability of DTR induces heterogeneous exposure and the evidence that long-term DTR exposure is positively associated with mortality across neighborhoods, planners and policymakers should consider urban landscaping to mitigate large DTR for risk reduction.

[Effect of diurnal temperature range on the number of elderly inpatients with ischemic stroke in Hunan Province].

Objective: To study the effect of diurnal temperature range on the number of elderly inpatients with ischemic stroke in Hunan Province. Method: Demographic and disease data, meteorological data, air quality data, population, economic and health resource data of elderly inpatients with ischemic stroke were collected in 122 districts/counties of Hunan Province from January to December 2019. The relationships between the diurnal temperature range and the number of elderly inpatients with ischemic stroke were analyzed by using the distributed lag non-linear model, including the cumulative lag effect of the diurnal temperature range in different seasons, extremely high diurnal temperature range and extremely low diurnal temperature range. Results: In 2019, 152 875 person-times were admitted to the hospital for ischemic stroke in the elderly in Hunan Province. There was a non-linear relationship between the diurnal temperature range and the number of elderly patients with ischemic stroke, with different lag periods. In spring and winter, with the decrease in diurnal temperature range, the risk of admission of elderly patients with ischemic stroke increased (Ptrend<0.001, Ptrend=0.002);in summer, with the increase in diurnal temperature range, the risk of admission of elderly patients with ischemic stroke increased (Ptrend=0.024);in autumn, the change in the diurnal temperature range would not cause a change in admission risk (Ptrend=0.089). Except that the lag effect of the extremely low diurnal temperature range in autumn was not obvious, the lag effect occurred in other seasons under extremely low and extremely high diurnal temperature ranges. Conclusion: The high diurnal temperature range in summer and the low diurnal temperature range in spring and winter will increase the risk of admission of elderly patients with ischemic stroke, and the risk of admission of elderly patients with ischemic stroke will lag under the extremely low and extremely high diurnal temperature ranges in the above three seasons.

Diurnal temperature range and hospital admission due to cardiovascular and respiratory diseases in Dezful, a city with hot climate and high DTR fluctuation in Iran: an ecological time-series study.

The results of previous studies have indicated the effects of temperature changes on health status. The present study was conducted to investigate the effects of diurnal temperature range (DTR) and hospital admission on cardiovascular and respiratory diseases in Dezful, in Iran. In this ecological time-series study, data related to hospital admissions based on ICD-10, meteorological, and climatological data were gathered over a period of six years from 2014 to 2019. A distributed lag nonlinear model combined with a quasi-Poisson regression was then used to assess the impact of DTR on cardiovascular and respiratory hospital admissions. Potential confounders, including wind speed, air pollution, seasonality, time trend, weekends and holidays, days of week, and humidity were controlled. In extreme low DTRs, the cumulative effects of cardiovascular admissions significantly increased in total, and in warm and cold seasons (Lag0-21, P ≤ 0.05). In addition, in extreme high DTRs, the cumulative effects of cardiovascular significantly decreased in total (Lag0-13 and Lag0-21, P ≤ 0.05), and in warm (Lag0-21, P ≤ 0.05) and cold seasons (Lag0-21, P ≤ 0.05). Moreover, respiratory admissions significantly decreased in total (Lag0-21, P ≤ 0.05) and in warm season (Lag0-21, P ≤ 0.05).Our result indicates that extreme low DTRs could increase the risk of daily cardiovascular admissions, and extreme high DTRs may cause a protective effect on daily respiratory and cardiovascular admissions in some regions with high fluctuations in DTR.

Impact of diurnal temperature range on other infectious diarrhea in Tongcheng, China, 2010-2019: a distributed lag non-linear analysis.

Our study aimed to quantify the exposure-lag-response effects of the diurnal temperature range (DTR) on other infectious diarrhea (OID) in Tongcheng city and examine the vulnerable populations. Distributed lag non-linear model (DLNM) and generalized additive model (GAM) were applied jointly to quantify the association between DTR and the daily number of OID cases compared with the median DTR. Stratified analysis was performed by gender, age, and seasons of onset. There are a total of 8231 cases during this decade. We observed a j-shaped relationship between DTR and OID, with a peak point at the maximum DTR (RR: 2.651, 95% CI: 1.320-5.323) compared to the median DTR. As DTR increased from 8.2 to 10.9°C, we found the RRs started to decrease and then rise from day 0, and the minimum value occurred on day 7 (RR:1.003, 95% CI: 0.996-1.010). From stratified analysis, we observed that females and adults are more likely to be affected by high DTR significantly. In addition, the influence of DTR was different in cold and warm seasons. High DTR in warm seasons affects the number of OID daily cases, but no statistical significance was identified in cold seasons. This study suggests a significant relationship between high DTR and the incidence risk of OID.

Diurnal temperature range impacts on outpatients department visits for allergic rhinitis in Lanzhou, China.

This study aims to investigate the association between the diurnal temperature range (DTR) and allergic rhinitis (AR) outpatient visits in Lanzhou, China, utilizing more than 7years of participant surveys. Our study used the distributed lag non-linear model (DLNM) aimed to evaluate the association between DTR and AR outpatient visits. We also performed subgroup analyses in order to find susceptible populations by gender and age groups. In 2013-2019, DTR in Lanzhou demonstrates a non-linear correlation with outpatient visits for AR, which is S-shaped. In addition, when DTR was located in the 0.9-5.3°C and 12-20°C compared with 12°C, the risk of outpatient visits for AR increased. Moreover, males appeared to be more vulnerable to the DTR effect than females, the risk of children visits exceeded both the adult and the elderly groups at the higher DTR. Our study adds to the evidence that DTR is a possible risk factor for outpatient visits for AR; therefore, the public health sector and medical staff should take DTR into account when it comes to preventing AR onset.

715: CLIMATE AND WEATHER AS RISK FACTORS FOR PEDIATRIC ASTHMA EXACERBATIONS: A SCOPING REVIEW

Introduction: Climate change is leading to more weather events and swings in outdoor temperature. The relationship between asthma and such events is understudied, especially accounting for pollution, pollen, and viral illnesses. With higher respiratory rates, children are uniquely vulnerable to climate change, therefore this literature gap needs to be urgently addressed to identify interventions. The aims of this scoping review are (1) identify previously described relationships of weather/climate with asthma, (2) summarize the evidence on timing of exposure to exacerbation and (3) map the current body of international literature. Methods: Using the Joanna Briggs Institute’s Preferred Reporting Items for Scoping Review, a review of the full-text literature was conducted. PubMed, Scopus, Web of Science and EMBASE were used to search the concepts of (1) asthma, (2) weather or climate, and (3) emergency department or hospitalization for studies before February 2022. Results: Of the 12,692 studies identified, a total of 66 relevant studies were selected based on criteria of age < 18 years. Of the 66 studies, 88% looked at daily temperature via daily mean, max, min or diurnal temperature range. Of the 66 studies, 71% accounted for pollution, 14% for pollen, 9% for viral illnesses, and 8% for weather events such as thunderstorms. Most studies reported positive associations between high diurnal temperature range and asthma-related admissions or ED visits. Most studies reported the lower the daily minimum temperature the more likely an asthma exacerbation to occur. Results were mixed for high daily maximum temperature and asthma exacerbations. Few studies attempted to ascertain the timing between exposure and exacerbation, although most studies only considered asthma exacerbations within 2 weeks of an exposure. Finally, most studies used airport temperature sensors to assume the patient’s exposure and none geocoded patient data to assess more local exposure. Conclusions: Future studies are needed to understand the timing of asthma exacerbations from known climate change-related weather events such as large diurnal temperature range and thunderstorms– especially how they vary by neighborhood. Future studies need to identify key times to intervene in pediatric asthma when trigger events can be predicted.

The relationship between ecological factors and commercial quality of high-quality foxtail millet “Jingu 21”

The commercial quality of foxtail millet grain (Setaria italica L.) includes appearance quality, functional quality, and cooking and eating quality, which directly determine whether consumers will purchase the product. We studied the relationship between ecological factors and commercial quality attributes of foxtail millet “Jingu 21” from twelve production areas. The results showed that altitude, latitude, and diurnal temperature range were negatively correlated with b*, total flavones content (TFC), setback (SB), consistence (CS) and pasting temperature (PTM), but positively correlated with L/B and breakdown (BD). In contrast, average temperature, average precipitation, average humidity, available nitrogen, phosphorus, and potassium had positive effects on 1,000-grain weight (KGW), b*, TFC, CS, and PTM and had a negative impact on L/B and BD. Climate factors had a greater effect on the commercial quality of foxtail millet than soil factors, and the influence of climatic factors was particularly obvious in the early and middle growth periods. The multivariate equation between ecological factors and the comprehensive score of foxtail millet commercial quality is Y = 1,159.745–4.496X1 (altitude) + 19.529X5 (≥10℃ effective accumulated temperature) − 166.327X10 (organic matters). In conclusion, high temperature and precipitation are conducive to high quality appearance and the accumulation of functional substances, while a high diurnal temperature range and high soil nutrients are conducive to the formation of cooking and eating quality. The impact of ecological factors on foxtail millet quality is complicated and it is essential to select a cultivation site that is matched to the intended use of the foxtail millet being produced.

Short-term effects of meteorological factors on childhood atopic dermatitis in Lanzhou, China.

Atopic dermatitis (AD) is one of the leading burdens of skin disease in children globally. Meteorological factors are involved in the onset and development of AD. Several studies have examined the effects of meteorological factors on AD, but their results are inconsistent, and the understanding of the link between AD and meteorological factors remains inadequate. In this study, a total of 19,702 children aged 0 to 14 visited the outpatient clinic for AD from 2015 to 2019 in Lanzhou, China. A distributed lag nonlinear model (DLNM) applies to evaluate effects of meteorological factors on childhood AD in Lanzhou, China, and further explored age and gender differences. It was found that extremely high or low temperatures, extremely high diurnal temperature range (DTR), extremely low relative humidity (RH), and extremely high wind speed (WS) increased the risk of outpatient visits for childhood AD. Effects of extremely high DTR and extremely high WS were more intense, with maximum cumulative risks of 2.248 (95% CI 1.798, 2.811) and 3.834 (95% CI 3.086, 4.759) at lag 0-21, respectively. Furthermore, the combination of low temperature and low RH can also contribute to the higher risk of childhood AD. For extreme temperatures, children aged 7-14years were more vulnerable. For extremely low RH, extremely high DTR and WS, boys and children aged 0-3years were more vulnerable. Public health departments should strengthen publicity and education about how meteorological factors affect childhood AD and develop sex- and age-specific preventative measures.

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.

Impact of diurnal temperature range on hospital admissions for cerebrovascular disease among farmers in Northwest China

Diurnal temperature range (DTR) is an appropriate indicator for reflecting climate change. Many previous studies have examined the relationship between DTR and mortality. Cerebrovascular disease (CVD) have a higher mortality than other diseases, with mortality from CVD higher in rural areas than in urban areas. A distributed lag non-linear model (DLNM) was used to analyze the exposure-effect relationship between DTR and hospital admissions for CVD from 2018 to 2020 in the population living in rural areas of Tianshui, Gansu Province, China. We investigated the effects of extreme DTR in groups stratified according to gender and age. A U-shape relationship was observed between DTR and hospital admissions for CVD. Both high DTR (19 °C) and low DTR (3 °C) were significantly associated significantly with CVD hospital admissions. When the lag period was 0–21 days, the impact of high DTR (1.595 [95% CI 1.301–1.957]) was slightly more significant than that of a low DTR (1.579 [95% CI − 1.202 to 2.075]). The effect of DTR on CVD varied in different populations. Males and adults were more sensitive to DTR than females and elderly people. It is necessary to make preventive measures to protect vulnerable populations from the adverse effects of extreme DTR.

Relationship between meteorological factors and mortality from respiratory diseases in a subtropical humid region along the Yangtze River in China.

As the health impacts of climate change take on a more serious form, this study for the first time investigates the effect of meteorological factors on the risk of death from respiratory diseases (RD) in Wuhu, a representative city along the Yangtze River in subtropical humid region. Daily meteorological element data and RD deaths in Wuhu City were collected from 2014 to 2020. Time series analysis was conducted using distributed lagged nonlinear model (DLNM) combined with generalized additive model (GAM), and stratified by age and gender. In 7years, a total of 8016 RD death cases were collected in Wuhu, China. The results demonstrated that the maximum impacts of short-term exposure to exceedingly low temperatures mean (Tmean) were at lag 9, with the maximum relative risk (RR) of 1.044 (lag 1, 95% CI: 1.001, 1.098). The risk of exceedingly high Tmean reached its maximum at lag 0 (RR = 1.070, 95% CI: 1.018, 1.125). Low relative humidity (RH) was negatively associated with the risk of RD death, with the lowest RR values occurring at lag 12 (RR = 0.987, 95% CI: 0.975, 0.999). No significant correlation was found for diurnal temperature range (DTR). Stratified analysis showed that Tmean exposure remained statistically significant for male, female and elderly, while RH and DTR only seemed to increase the mortality risk in the young. In a word, short-term exposure to extreme temperatures may increase the RD mortality risk in the population, and young people needed to be aware that exposure to exceedingly high RH and DTR also increased the risk.

The effects of temperature variability on mortality in patients with chronic obstructive pulmonary disease: a time-series analysis in Hangzhou, China.

Chronic obstructive pulmonary disease (COPD) is a leading cause of death in people aged over 60years old. Research has been reported that ambient temperature and diurnal temperature range (DTR), as representative indices of temperature variability, are contributors to the development and exacerbation of COPD. However, few studies are available in Chinese population. In this study, we aimed to assess the associations of temperature variability on COPD mortality in a fast developing city in China. Using the mortality surveillance system, we obtained a total of 7,863 deaths attributed to COPD from 2014 to 2016. Quasi-Poisson generalized linear regression with distributed lag non-linear model was applied to explore the associations between temperature variability and COPD deaths, after controlling for the potential confounders, including relative humidity, day of week, public holiday, and long-term trend. A J-shaped association of DTR and a reversely J-shaped association of temperature for COPD mortality were observed. Risk estimates showed that the relative risks (RRs) of COPD mortality with extreme high DTR at lag 0 and 0-7days were 1.045 (95% CI: 0.949-1.151) and 1.460 (95% CI: 1.118-1.908), and the extreme high temperature at lag 0 and 0-7days were 1.090 (95% CI: 0.945-1.256) and 1.352 (95% CI: 1.163-1.572). Our findings suggest that short-term exposure to extreme temperature was associated with mortality for COPD in Hangzhou. The evidence has implications for policy decision-making and targeted interventions.

Association between weather and utilisation of physical therapy in patients with osteoarthritis: a case-crossover study

BackgroundDuring varied weather conditions, patients with osteoarthritis experience different severity of symptoms and signs. However, weather may also cause barriers or incentives for patients to seek medical services. These factors may result in changes in medical utilisation; however, no studies have investigated whether the probability of physical therapy utilisation among patients with osteoarthritis is associated with changes in meteorological factors.MethodBy using a secondary data of NHID in Taiwan, we conducted a population-based, retrospective study with case-crossover design for patients initially diagnosed with osteoarthritis between 2000 and 2013. The meteorological factors of months with the lowest treatment rate were used as patients’ own control periods and compared with the parameters of months with high treatment frequency. The risk of exposure to different meteorological factors, including mean temperature, daily highest temperature, daily minimum temperature, diurnal temperature range, relative humidity, and barometric pressure, was estimated and represented by odds ratios (ORs) and 95% confidence intervals (CIs).ResultsA total of 8,130 patients were recruited. Regardless of univariate or multivariable analysis, increased daily highest temperature enhanced the frequency of physical therapy (OR: 1.04; 95% CI: 1.02–1.05; p < 0.01; OR: 1.07; 95% CI: 1.04–1.10; p < 0.01). When the weather was hotter (> 23 °C), higher diurnal temperature range and humidity resulted in an increase in the utilisation of physical therapy. However, when the weather was colder (< 23 °C), reverse effects were observed.ConclusionsAn increase in temperature increases the probability of physical therapy resource use. Therefore, temperature, along with other meteorological factors, may play a key role in the utilization of physical therapy among patients with osteoarthritis.