Renal Vascular Control During Normothermia and Passive Heat Stress in Healthy Younger Men and Women

Details

• Personal Author:
  Baker TB ; Chapman CL ; Freemas JA ; Gabler MC ; Goss CS ; Hess HW ; Johnson BD ; Schlader ZJ ; Worley ML
• Description:
  Men are likely at greater risk for heat-induced acute kidney injury compared with women, possibly due to differences in vascular control. We tested the hypothesis that the renal vasoconstrictor and vasodilator responses will be greater in younger women compared with men during passive heat stress. Twenty-five healthy adults [12 women (early follicular phase) and 13 men] completed two experimental visits, heat stress or normothermic time-control, assigned in a block-randomized crossover design. During heat stress, participants wore a water-perfused suit perfused with 50 degrees C water. Core temperature was increased by approx. 0.8 degrees C in the first hour before commencing a 2-min cold pressor test (CPT). Core temperature remained clamped and at 1-h post-CPT, subjects ingested a whey protein shake (1.2 g of protein/kg body wt), and measurements were taken pre-, 75 min, and 150 min post-protein. Beat-to-beat blood pressure (Penaz method) was measured and segmental artery vascular resistance (VR, Doppler ultrasound) was calculated as segmental artery blood velocity ÷ mean arterial pressure. CPT-induced increases in segmental artery VR did not differ between trials (trial effect: P = 0.142) nor between men (heat stress: 1.5 +/- 1.0 mmHg/cm/s, normothermia: 1.4 +/- 1.0 mmHg/cm/s) and women (heat stress: 1.4 +/- 1.2 mmHg/cm/s, normothermia: 2.1 +/- 1.1 mmHg/cm/s) (group effect: P = 0.429). Reductions in segmental artery VR following oral protein loading did not differ between trials (trial effect: P = 0.080) nor between men (heat stress: -0.6 +/- 0.8 mmHg/cm/s, normothermia: -0.6 +/- 0.6 mmHg/cm/s) and women (heat stress: -0.5 +/- 0.5 mmHg/cm/s, normothermia: -1.1 +/- 0.6 mmHg/cm/s) (group effect: P = 0.204). Renal vasoconstrictor responses to the cold pressor test and vasodilator responses following an oral protein load during heat stress or normothermia do not differ between younger men and younger women in the early follicular phase of the menstrual cycle. NEW & NOTEWORTHY: The mechanisms underlying greater heat-induced acute kidney injury risk in men versus women remain unknown. This study examined renal vascular control, including both vasodilatory (oral protein load) and vasoconstrictor (cold presser test) responses, during normothermia and heat stress and compared these responses between men and women. The results indicated that in both conditions neither renal vasodilatory nor vasoconstrictor responses differ between younger men and younger women. [Description provided by NIOSH]
• Subjects:
  Heat Stress Disorders Hot Temperature Occupational Health Safety Sex Characteristics
• Keywords:
  Author Keywords: Heat Stress Body Temperature Heat Stress Kidney Function Oral Protein Load Renal Vasoconstriction Renal Vasodilation Sex Differences Sex Factors
• ISSN:
  1931-857X
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Indiana ; Massachusetts ; New York ; Ohio ; OSHA Region 1 ; OSHA Region 2 ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  326
• Issue:
  5
• NIOSHTIC Number:
  nn:20069441
• Citation:
  Am J Physiol Renal Physiol 2024 May; 326(5):F802-F813
• Contact Point Address:
  Zachary J. Schlader, Department of Kinesiology, Indiana University Bloomington, Bloomington, IN, United States
• Email:
  zschlade@iu.edu
• Federal Fiscal Year:
  2024
• Performing Organization:
  Indiana University, Bloomington
• Peer Reviewed:
  True
• Start Date:
  20190901
• Source Full Name:
  American Journal of Physiology: Renal Physiology
• End Date:
  20240831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:4a2df68fc2231cf7a27056470c08e10c429da7b3c5a1db7f487ebc4c877e7e3839958c247d2715d91d1accc6d37d51ba473301fd3033f52ecd3c9518dd31985f
• Download URL:
  https://stacks.cdc.gov/view/cdc/207895/cdc_207895_DS1.pdf
• File Type:
  [PDF - 2.83 MB ]