Renal Disease in Hypertensive Blacks: MRFIT

To the Editor. —The article by Walker et al 1 is one of several studies to address the issue of the effect of blood pressure control on renal function and comparison of this effect in black and nonblack patients. Although their study has a large database (463 black and 5061 nonblack patients), it is unclear how many of the patients enrolled had preexisting renal disease. Their conclusion that blood pressure control was not efficacious in stabilizing or improving renal function in black patients may be due to the fact that more of the black patients in their study had underlying parenchymal renal disease than did the nonblack patients. The fact that there was no significant difference between average baseline serum creatinine level in the black and in the nonblack cohorts does not necessarily mean that there were equal proportions of patients with renal dysfunction in the two groups. In a