Volume regulation and renal function at high altitude across gender

Area of Science:

• Physiology
• Altitude Medicine
• Renal Function

Background:

• High altitude environments pose physiological challenges, affecting fluid balance and kidney function.
• Understanding gender-specific responses to high altitude is crucial for acclimatization and health.

Purpose of the Study:

• To investigate changes in volume-regulating hormones and renal function at high altitudes.
• To examine gender-based differences in these physiological responses.

Main Methods:

• 28 healthy subjects (20 males, 8 females) ascended to 3440m and 5050m.
• Measured plasma and urinary markers, including creatinine, osmolality, plasma renin activity (PRA), aldosterone, antidiuretic hormone (ADH), and atrial natriuretic peptide (ANP).
• Assessed plasma volume loss (PVL) and glomerular filtration rate (GFR) using creatinine clearance (CreaCl).

Main Results:

• Increased urine production in both sexes; significant PVL observed only in males.
• Decreased urinary osmolality, ADH, and PRA at higher altitudes (gender-specific patterns observed).
• GFR decreased at 3440m in both sexes; estimated GFR (eGFR) showed poor correlation with measured CreaCl.

Conclusions:

• High altitude exposure induces significant hormonal and renal function changes, with notable gender differences.
• Current eGFR formulas may not accurately reflect renal function decline at high altitudes.
• Further research is needed to validate GFR estimation methods in high-altitude settings.