Time to reach equilibrium deep body temperatures in young and older adults resting in the heat: A descriptive secondary analysis

AJP Regulatory Integrative and Comparative Physiology, Journal Year: 2024, Volume and Issue: 327(3), P. R369 - R377

Published: Sept. 1, 2024

Deep body (rectal) temperature took 3–5 h on average and up to 6–8 at the individual level reach thermal equilibrium in young older adults resting heat. Furthermore, stable rectal temperatures were delayed by 2 relative achievement of heat balance (0 kJ/min rate storage). We provide first quantification temporal profiles strain during extended rest conditions simulating hot weather.

Language: Английский

---

Meta-analysis of heat-induced changes in cardiac function from over 400 laboratory-based heat exposure studies

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: March 14, 2025

Heat waves are associated with increased fatalities from adverse cardiovascular events attributed to the negative effects of heat on cardiac function. However, scientific understanding acute adjustments has come primarily laboratory experiments employing insulated and encapsulated heating modalities, most commonly water-perfused suits. We evaluated whether findings those studies reflect responses during more natural exposures hot ambient conditions simulated in climate-controlled chambers by synthesizing over 400 laboratory-based exposure (6858 participant-exposures) published between 1961–2024. Among all included studies, median (interquartile range) elevations core temperature heart rate baseline end-exposure were 0.9 (0.5–1.3)°C 27 (15–40) beats/min. Multilevel mixed-effects meta-analyses revealed exacerbated rate, output, pressure product (estimate workload) blunted falls systolic participants heated via modalities. Leveraging large dataset, we also provide empirical estimates body a wide range experienced waves. With rising global temperatures, ecologically-minded physiological research is needed improve stress further development robust climate health models evidence-based heat-health guidance. Understanding heat-induced changes function encapsulated, water-based Here, authors show that these overestimate burden compared

Language: Английский

---

An exploratory investigation of heart rate and heart rate variability responses to daylong heat exposure in young and older adults

Applied Physiology Nutrition and Metabolism, Journal Year: 2024, Volume and Issue: 49(12), P. 1783 - 1791

Published: Sept. 10, 2024

Heart rate variability (HRV) has shown potential as a tool for monitoring thermal strain, but there is limited data to support its efficacy in older adults during prolonged heat exposures. We compared HRV between young (19–31 years, n = 20) and (61–78 39) 9 h of exposure (40 °C, 9% RH). also explored whether heart (HR) and/or could be used distinguish who achieved elevated defined either (1) an increase core temperature >1.0 °C (occurring 39%, 15/39) or (2) reduction systolic blood pressure >10 mm Hg 67%, 26/39). Percentage age-predicted maximal HR percentage reserve (HRR) were higher, whereas standard deviation normal RR intervals, the square root mean squared differences successive intervals (RMSSD), high frequency power (HF), cardiac vagal index (CVI) lower ( P ≤ 0.004). In adults, increases correlated with HR, HRR, RMSSD, CVI 0.031), changes not significantly associated indices ≥ 0.327). Receiver operating characteristic curve analysis indicated that had generally poor ability identify strain (area under ≤0.65). Age-related HRV, consistent withdrawal among remained daylong exposure, marked heterogeneity response likely contributed providing discriminatory value identifying adults.

Language: Английский

---

Racial and regional disparities in the risk of noncommunicable disease between sub-Saharan black and European white patients

Journal of Hypertension, Journal Year: 2024, Volume and Issue: 43(3), P. 481 - 491

Published: Nov. 21, 2024

Greater vulnerability of Black vs. White individuals to cardiovascular disease (CVD) and chronic kidney (CKD) is well charted in the United States, but studies involving sub-Saharan blacks are scarce. Baseline data (2021-2024) were collected 168 Blacks 93 European Whites an ongoing clinical trial (NCT04299529), using standardized patient selection criteria. Data included biochemical risk factors, ECG echocardiographic traits, Framingham CVD risk, CKD grades (KDIGO 2024), self-assessed symptoms (WHO questionnaire), urinary proteomic profiles predictive left ventricular dysfunction (LVD) CKD, HF1, CKD273, respectively. Racial comparisons rested on unadjusted multivariable-adjusted analyses. Despite being younger (60.4 68.3 years), had a worse profile, as evidenced by higher diabetes prevalence, BMI, faster heart rate, unfavourable serum cholesterol fractions, lower estimated glomerular filtration microalbuminuria, sedentary lifestyle. This resulted having 10-year age (index vascular ageing with chronological reference), grades. In both races, CKD273 increased grade, HF1 not different race. These observations robust subgroup adjusted study did differentiate host (genetic, molecular, pathogenic) from environmental drivers disease. Nonetheless, findings call for multipronged comprehensive implementation innovative health policies countries. Education, research, empowerment stakeholders, international learned societies connecting experts wide array disciplines should vigorously sustain this effort.

Language: Английский

---

Surviving the 2021 Heat Dome with schizophrenia: A qualitative, interview-based unpacking of risks and vulnerabilities

Social Science & Medicine, Journal Year: 2024, Volume and Issue: 366, P. 117656 - 117656

Published: Dec. 29, 2024

Language: Английский

---