Using logic regression to characterize extreme heat exposures and their health associations: a time-series study of emergency department visits in Atlanta

Case-crossover assessment of the modifying effects of home medication use on acute kidney-related morbidity due to elevated ambient heat exposure in Atlanta, GA, from 2013 to 2019

Background

Elevated ambient temperatures increase the risk for acute kidney-related morbidity, and medication use may increase vulnerability to heat exposure. This study examines whether medication use, and combination medication use (ie, polypharmacy), modifies the risk for temperature-related volume depletion (VD) and acute kidney injury (AKI).

Methods

This study uses patient-level emergency department (ED) visit data from four Atlanta-area hospitals during the warm season from 2013 to 2019. ED patient-visits who reported a medication were matched with up to five ED patient-visits without the medication. Medications included angiotensin converting enzymes and angiotensin receptor blockers (ACE/ARBs), anti-depressants, anti-convulsants, β-blockers, diuretics, non-steroidal anti-inflammatory drugs and statins. A case-crossover framework is used to estimate associations between daily maximum temperature, medication use and VD/AKI ED visits.

Results

There were 14 635 VD and 18 716 AKI ED visits in this study. For a change in ambient temperature (lags 0-2) from the 50th to 95th percentiles, patients using antidepressants had a higher risk for AKI (OR 1.28, 95% CI 1.08 to 1.52) compared with antidepressant nonusers (1.03, 95% CI 0.95 to 1.12). Polypharmacy analysis indicated that patients taking statins with ACE/ARBs were at an elevated risk for AKI (OR 1.38, 95% CI 1.02 to 1.86) relative to all other groups. This includes patients taking only an ACE/ARB (OR 1.00, 95% CI 0.82 to 1.21), only a statin (OR 1.10, 95% CI 0.90 to 1.33) or neither medication (OR 1.07, 95% CI 0.93 to 1.23).

Conclusion

Results show that both single and combined medication use are associated with elevated risk for VD and AKI during periods of elevated ambient temperature.

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.

Heatwave Definition and Impact on Cardiovascular Health: A Systematic Review

Objectives: We aimed to analyze recent literature on heat effects on cardiovascular morbidity and mortality, focusing on the adopted heat definitions and their eventual impact on the results of the analysis. Methods: The search was performed on PubMed, ScienceDirect, and Scopus databases: 54 articles, published between January 2018 and September 2022, were selected as relevant. Results: In total, 21 different combinations of criteria were found for defining heat, 12 of which were based on air temperature, while the others combined it with other meteorological factors. By a simulation study, we showed how such complex indices could result in different values at reference conditions depending on temperature. Heat thresholds, mostly set using percentile or absolute values of the index, were applied to compare the risk of a cardiovascular health event in heat days with the respective risk in non-heat days. The larger threshold's deviation from the mean annual temperature, as well as higher temperature thresholds within the same study location, led to stronger negative effects. Conclusion: To better analyze trends in the characteristics of heatwaves, and their impact on cardiovascular health, an international harmonization effort to define a common standard is recommendable.

Association between extreme ambient heat exposure and diabetes-related hospital admissions and emergency department visits: A systematic review

Background and objectives

Diabetes is an increasing public health concern worldwide. The impact of extreme heat exposure on diabetes healthcare utilization such as diabetes-related hospital admissions and emergency department (ED) visits was understudied although extreme temperature exposure was linked with diabetes mortality. In addition, very few systematic reviews have been conducted in this field. This review aims to systematically evaluate the currently available evidence on the association between extreme ambient heat exposure and hospital admissions/ED visits for diabetes and the vulnerable population to heat extremes.

Methods

A systematic literature review was conducted by using the keywords/terms "ambient temperature or heatwave or heat wave or extreme temperature or high temperature effect " and "diabetes morbidity or diabetes hospital admissions or diabetes emergency room visits " for available publications until August 2022. The heat exposure was categorized into four groups using difference definitions. The outcomes were diabetes-related hospital admissions/ED visits. A meta-analysis was performed to estimate the pooled effects of relative risk (RR)/odds ratio (OR) and 95% confidence intervals (CI) for each of the associations of interest.

Results

Eighteen articles were selected from forty full-text, English written papers based on the inclusion and exclusion criteria. The overall pooled effect of excessive heat on diabetes, across all groups, was 1.045 (95% CI 1.024-1.066). The pooled effects for each exposure group were significant/borderline significant. Additionally, the pooled effect of the RR/OR was 1.100 (95% CI: 1.067-1.135) among adults aged 65 years or older. The most controlled confounders were air pollutants. The commonly listed limitation in those studies was misclassification of exposure.

Conclusions

The body of evidence supports that ambient extreme heat exposure is associated with diabetes-related hospital admissions/ED visits. Additionally, adults 65 years of age or older with diabetes are vulnerable to heat extremes. Future studies should consider controlling for various biases and confounders.

Attributing hypertensive life expectancy loss to ambient heat exposure: A multicenter study in eastern China

Ambient high temperature is a worldwide trigger for hypertension events. However, the effects of heat exposure on hypertension and years of life lost (YLL) due to heat remain largely unknown. We conducted a multicenter study in 13 cities in Jiangsu Province, China, to investigate 9727 individuals who died from hypertension during the summer months (May to September) between 2016 and 2017. Meteorological observation data (temperature and rainfall) and air pollutants (fine particulate matter and ozone) were obtained for each decedent by geocoding the residential addresses. A time-stratified case-crossover design was used to quantify the association between heat and different types of hypertension and further explore the modification effect of individual and hospital characteristics. Meanwhile, the YLL associated with heat exposure was estimated. Our results show that summer heat exposure shortens the YLL of hypertensive patients by a total of 14,74 years per month. Of these, 77.9% of YLL was mainly due to hypertensive heart disease. YLL due to heat was pronounced for essential hypertension (5.1 years (95% empirical confidence intervals (eCI): 4.1-5.8)), hypertensive heart and renal disease with heart failure (4.4 years (95% eCI: 0.9-5.9)), and hypertensive heart and renal disease (unspecified, 3.5 years (95% eCI: 1.8-4.5)). Moderate heat was associated with a larger YLL than extreme heat. The distance between hospitals and patients and the number of local first-class hospitals can significantly mitigate the adverse effect of heat exposure on longevity. Besides, unmarried people and those under 65 years of age were potentially susceptible groups, with average reduced YLL of 3.5 and 3.9 years, respectively. Our study reveals that heat exposure increases the mortality risk from many types of hypertension and YLL. In the context of climate change, if effective measures are not taken, hot weather may bring a greater burden of disease to hypertension due to premature death.

The value of the exertional heat stroke score for the prognosis of patients with exertional heat stroke

OBJECTIVE

This study aims to evaluate the exertional heat stroke score (EHSS) system for the prognosis of exertional heat stroke (EHS) patients.

METHODS

Forty-two EHS patients who had been treated in our hospital between January 2017 and December 2019 were divided into two groups according to their prognosis, a survival group and a non-survival group. All the patients had received comprehensive EHS treatment after admission, and their EHSS parameters were collected within 24 h of admission, including body temperature, hepatorenal function, and coagulation function. A retrospective comparative evaluation was made of the effectiveness of the EHSS, the Acute Physiology and Chronic Health Evaluation II (APACHE II) and the Sequential Organ Failure Assessment (SOFA) in making an EHS prognosis.

RESULTS

Among 42 patients, 28 patients were treated successfully and discharged from the hospital, 5 were given a poor prognosis, and 9 died, amounting to a fatality rate of 21.42%. Univariate analysis showed that within 24 h of admission, the differences were statistically significant (p < 0.05) in the comparison of the following factors: lactate concentration, platelets, prothrombin time, fibrinogen, troponin, aspartate aminotransferase, total bilirubin, urinary creatinine, acute gastrointestinal injury, temperature, and Glasgow coma score. However, no statistically significant difference in blood pH was observed between the two groups of patients (p = 0.117). The EHSS, APACHE II, and SOFA scores of the survival group were significantly lower than those of the non-survival group (p < 0.001). The area under the receiver operating characteristic curve of the EHSS, APACHE II and SOFA scores were the area under the curve (AUC) _EHSS = 0.96 (0.901, 0.990), AUC _{Apache II} = 0.895 (0.802, 0.950), and AUC _SOFA = 0.884 (0.837, 0.964), respectively. Thus, the EHSS diagnostic efficacy of the survival group was significantly higher than that of the other two scores. In addition, the sensitivity and specificity of EHSS were higher than those of the APACHE II and SOFA scores.

CONCLUSION

The EHSS has a good diagnostic efficacy for the prognosis of EHS patients and is significantly higher than that of the APACHE II and SOFA scores. This finding provides a theoretical basis for further increasing the rescue success rate of EHS patients and improving their prognostic quality of life.