The Kidney's Response to Exercise in Heat, and the Impact of Vitamin B3 on This Response

Early Phase 1

Not yet recruiting

• Conditions: Heat Strain; Healthy Volunteer Study; Kidney Dysfunction

• Registration Number: NCT06983730
• Lead Sponsor: Beth Israel Deaconess Medical Center

Brief Summary

The goal of this clinical trial is to learn about the processes occurring in the kidneys while under heat stress in healthy volunteers. The main questions it aims to answer are:

* How do the chemicals produced by the body change under conditions of higher versus lower heat stress?

* What role does a specific area of the body's metabolism, known as NAD+ metabolism, play in the body's response to heat stress, and can this response be modified by taking vitamin B3?

Detailed Description

To answer these questions, researchers will compare the chemical changes in each participant under progressively higher levels of heat stress, and while taking either vitamin B3 or a placebo.

This clinical trial will occur in two stages. Participants may choose participate in stage 1 only, stage 2 only, or both parts of this clinical trial.

During stage 1, participants will exercise using an upper body workout device in a hot and humid environmental chamber for three sessions, each session separated by about a week.

* Each session, they will be asked to work out at a progressively higher intensity with climate conditions kept the same in the chamber.

* More intense exercise produces greater heat stress, resulting in lower, moderate, and higher levels of heat stress exposure across the three sessions.

* Researchers will see how chemicals in the blood and urine, along with physical measurements like heart rate and body temperature, change across these different levels of heat stress.

During stage 2, participants will exercise using the same upper body workout device in the same environmental chamber. They will do this for two sessions, each separated by about a week.

* One of the sessions each participant will take vitamin B3, and the other session each participant will take placebo.

* Heat stress exposure will be the same each session.

* Researchers will again see how chemicals in the blood and urine, along with physical measurements like heart rate and body temperature, change between sessions with vitamin B3 and sessions with placebo

Study Timeline

• Status Verified: 2025-05
• Study First Submitted: 2025-05-14
• Study First Submitted QC: 2025-05-14
• Last Update Submitted: 2025-05-14
• Study First Posted: 2025-05-21
• Last Update Posted: 2025-05-21
• Study Start: 2025-07
• Primary Completion: 2027-10
• Study Completion: 2027-10

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 28

Inclusion Criteria

• Healthy volunteer
• Any race
• Estimated glomerular filtration rate greater than 90 ml/min/1.73m2
• Urine albumin/creatinine ratio less than 30mg/g
• Nonsmoker
• No regular dietary supplements, particularly vitamin B3
• Physically active, defined as doing at least 150 minutes of physical activity in an average week

Exclusion Criteria

• Medical condition preventing safe participation in exercise during heat
• Allergy to Vitamin B3
• Severe food allergies or dietary restrictions that would preclude eating the planned study diet without major modifications

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
Urinary neutrophil gelatinase-associated lipocalin	Pre- and 1 hour post- heat stress exposure	Marker of stress and injury in the kidney

Secondary Outcome Measures

Name	Time	Method
Urine Quinolinate to Tryptophan Ratio	Pre- and 1 hour post- heat stress exposure	Ratio of quinolinate to tryptophan in the urine
Serum creatinine	Pre- and 1 hour post- heat stress exposure	Marker of kidney function

Trial Locations

Locations (2)

Beth Israel Deaconess Medical Center; 🇺🇸 Boston, Massachusetts, United States

Boston University; 🇺🇸 Boston, Massachusetts, United States