Clinical trials

The goal of this clinical study is to learn how different temperature and humidity conditions affect breathing, lung function, exercise capacity, symptoms, and other physical responses in children and youth aged 11 to 18 years with asthma, compared with age- and sex-matched children and youth without asthma. The main questions it aims to answer are: * How do different temperature and humidity conditions affect lung function, breathing symptoms, exercise capacity, and physiological responses in children and youth with asthma? * Do children and youth with asthma respond differently to these environmental conditions than children and youth without asthma? * Do sex and gender influence these responses? Researchers will compare children and youth with asthma to age- and sex-matched children and youth without asthma to see if temperature and humidity exposures have different effects on breathing, exercise performance, symptoms, and physiological responses. Participants will: * Attend two study visits in a climate-controlled chamber. * Be exposed to hot, cold, and varying humidity conditions for short periods of time. * Complete breathing tests and exercise testing before, during, and after each exposure. * Have symptoms, physical activity, and physiological responses monitored throughout the study.

People with end-stage kidney disease who receive hemodialysis are often told to strictly limit foods high in potassium, such as fruits, vegetables, legumes, nuts, and whole grains. This advice is intended to prevent high blood potassium levels (hyperkalemia), which can cause dangerous heart rhythm problems. However, these restrictions can make eating difficult, reduce diet quality, and lower quality of life. New research suggests that not all sources of potassium affect the body in the same way. Potassium added to highly processed foods is more easily absorbed than potassium naturally found in whole foods like fruits and vegetables. Large studies have found little evidence that eating potassium-rich whole foods increases blood potassium levels in people on dialysis. Clinical guidelines are beginning to shift, but no high-quality clinical trial has tested whether a more flexible, food-based approach is safe for people receiving hemodialysis. This study will compare two dietary approaches in 148 adults on hemodialysis: the usual low potassium diet and a "liberalized" potassium diet that encourages minimally processed foods while limiting highly processed foods with potassium additives. Participants will receive dietitian support and grocery assistance for 12 weeks. The investigators will closely monitor blood potassium levels to ensure safety. The investigators will also examine whether the liberalized diet is as safe as standard care, and whether it improves diet quality and quality of life. The investigators will also study factors that influence the participant's ability to follow the diet in real-world settings. If safe, this approach could reduce unnecessary food restrictions, improve diet quality, and enhance quality of life for people receiving hemodialysis, while maintaining patient safety.