Gonadal Steroids and Body Composition, Strength, and Sexual Function in Men

To the Editor: The meta-analysis by Shlipak et al. (Sept. 5 issue)(1) shows that a cystatin C-based estimated glomerular filtration rate (eGFR) offers improvements in predicting risks of death and end-stage renal disease across diverse populations. In their editorial, Ingelfinger and Marsden(2) caution that results cannot be applied to Asian and Hispanic patients except by extrapolation. Also, diabetes was underrepresented in the sample of patients with chronic kidney disease; it was present in only 9% of participants. Further, more information is still needed about the use of cystatin C in pregnant women, patients who have undergone renal transplantation, and children. ...