Extreme Heat Exposure Linked to Reduced Kidney Function in Older Adults, Especially in Dry Conditions

แนวคิดหลัก

Exposure to extreme heat, especially in dry conditions, can contribute to reduced kidney function in older adults, as evidenced by increased plasma creatinine and cystatin C levels.

บทคัดย่อ

The study investigated the impact of extreme heat exposure on kidney function in 20 young (21-39 years) and 18 older (65-76 years) adults from the Dallas-Fort Worth area. Participants underwent heat exposure in a chamber at 47°C (116°F) and 15% relative humidity (dry setting) and 41°C (105°F) and 40% relative humidity (humid setting) on separate days, while performing light physical activity and staying hydrated.

Key findings:

• In the dry setting, older adults showed a modest increase in plasma creatinine (difference of 0.10 mg/dL at end-heating and 0.17 mg/dL at 2 hours post-exposure) and cystatin C (difference of 0.29 mg/L at end-heating and 0.28 mg/L at 2 hours post-exposure).
• In the humid setting, the increase in plasma creatinine in older adults was much more modest (difference of 0.06 mg/dL at 2 hours post-exposure).
• Young adults did not show any significant changes in cystatin C levels, but had a modest increase in plasma creatinine (difference of 0.06 mg/dL at 2 hours post-exposure).

The authors suggest that the heightened thermal strain in older adults during extreme heat, especially in dry conditions, may contribute to reduced kidney function. The use of plasma-based markers, short laboratory-based exposure, and a small sample size were limitations that could affect the generalizability of the findings.

สถิติ

Older adults in the dry setting showed a 0.10 mg/dL increase in plasma creatinine at end-heating and a 0.17 mg/dL increase at 2 hours post-exposure.
Older adults in the dry setting showed a 0.29 mg/L increase in plasma cystatin C at end-heating and a 0.28 mg/L increase at 2 hours post-exposure.
Older adults in the humid setting showed a 0.06 mg/dL increase in plasma creatinine at 2 hours post-exposure.
Young adults showed a 0.06 mg/dL increase in plasma creatinine at 2 hours post-exposure.

คำพูด

"These findings provide limited evidence that the heightened thermal strain in older adults during extreme heat may contribute to reduced kidney function."

ข้อมูลเชิงลึกที่สำคัญจาก

Heat Waves: A Silent Threat to Older Adults' Kidneys

by Edited Shrab... ที่ www.medscape.com 07-26-2024

https://www.medscape.com/viewarticle/heat-waves-silent-threat-older-adults-kidneys-2024a1000dsb

สอบถามเพิ่มเติม

How do the physiological mechanisms underlying the observed changes in kidney function markers differ between older and younger adults during extreme heat exposure?

During extreme heat exposure, older adults experience more significant changes in kidney function markers compared to younger adults. The physiological mechanisms driving these differences lie in the aging process and the body's ability to regulate temperature and hydration. Older adults have a reduced capacity to dissipate heat due to decreased sweat gland function and lower cardiac output, leading to higher core body temperatures. This thermal strain can impact renal blood flow and glomerular filtration rate, resulting in alterations in kidney function markers like creatinine and cystatin C. Additionally, age-related changes in renal function, such as decreased renal blood flow and tubular function, can exacerbate the impact of extreme heat on the kidneys in older adults.

What are the long-term implications of the observed heat-related kidney function changes in older adults, and how can these be mitigated?

The observed heat-related changes in kidney function in older adults during extreme heat exposure can have long-term implications for their renal health. Prolonged or recurrent heat exposure leading to kidney injury or dysfunction may increase the risk of chronic kidney disease (CKD) or exacerbate pre-existing renal conditions in this population. To mitigate these risks, interventions focusing on hydration, cooling strategies, and environmental modifications are crucial. Older adults should be encouraged to stay well-hydrated, avoid prolonged exposure to extreme heat, and seek cooler environments during heat waves. Healthcare providers should also monitor kidney function in older adults during periods of high heat to detect early signs of kidney injury and provide timely interventions.

What other environmental and individual factors, beyond age and humidity, might influence the impact of extreme heat on kidney function?

Several environmental and individual factors beyond age and humidity can influence the impact of extreme heat on kidney function. These factors include pre-existing medical conditions (e.g., hypertension, diabetes), medications that affect renal function, physical activity levels, and genetic predispositions. Dehydration, electrolyte imbalances, and heat acclimatization status can also play a role in how the kidneys respond to extreme heat. Additionally, air pollution, urban heat island effects, and socioeconomic factors can exacerbate the impact of heat on kidney function in vulnerable populations. Understanding these multifaceted influences is essential for developing comprehensive strategies to protect kidney health during extreme heat events.