Creatinine and Cystatin C

Creatinine (Cr) is often used as a standalone gold standard marker of kidney function. Cystatin C (Cys C) is a less physiologically labile marker of renal function, particularly in certain subgroups. Herein, we analyze trends in cystatin C as compared to creatinine in men on testosterone replacement therapy with varying body mass indices and percent body fat (PBF). This retrospective analysis observes 227 men with testosterone-induced muscle hypertrophy who visited a men’s health tertiary care clinic. All participants were characterized as competitive or recreational athletes. In patients with a normal body mass index (BMI), there was no clinically significant correlation between Cr and Cys C. Slight correlation was seen with overweight ( R 2 = .27) patients ( p 2 = .29) patients ( p 2 = .23) positive correlation between Cys C and Cr ( p = .03). Positive correlation between Cys C and Cr in patients with PBF of 10%–20% was clinically negligible ( R 2 = .17, n = 87), modest ( R 2 = .49) in patients with PBF of 20%–30% ( n = 42), and evident ( R 2 = 1.00) in patients >30% ( n = 3) ( p

Body mass index · Creatinine · Cystatin · Cystatin C · Muscle hypertrophy · Overweight · Population · Renal function · Chronic Kidney Disease and Diabetes · Dialysis and Renal Disease Management · Hormonal and reproductive studies · Medicine · Endocrinology · Internal Medicine · Urology