No microalbuminuria or other adverse effects of long-standing hyperfiltration in humans with one kidney

Hypertrophy and hyperfiltration are characteristic features of single kidneys and kidneys of patients with insulin-dependent diabetes mellitus (IDDM). In both cases the hyperfiltration has been suggested to be involved in the pathogenesis of renal functional deterioration. We studied the effect of long-standing hyperfiltration on kidney function in 29 subjects with one kidney, three of whom were insulin-dependent diabetics. Four groups were studied: (1) uninephrectomized less than 10 years since uninephrectomy (UN) (n = 7; age, 30 +/- 6 years); (2) uninephrectomized greater than or equal to 10 years since UN (19 +/- 11 years, 10 to 52); n = 14; age, 38 +/- 15 years; (3) congenital unilateral renal agenesis (n = 5, age, 39 +/- 16 years); and (4) IDDM patients with one kidney (n = 3; age, 28 to 52 years; diabetes duration, 8 to 31 years; years with one kidney, 18 to 30). Glomerular filtration rate (GFR) and renal plasma flow (RPF) were measured by the constant infusion technique, kidney volume (KV) by ultrasonic scanning, and urinary albumin excretion rate (UAE) by radioimmunoassay. In all subjects GFR, RPF, and KV were within the normal range, representing a single kidney hyperfiltration of approximately 70% and hypertrophy of approximately 100%. Only one of the subjects with renal agenesis had an elevated UAE (117 micrograms/min); the remainder had a normal UAE, ie, less than 10 micrograms/min, and the diabetics were below the risk level of 20 micrograms/min. Serum creatinine was normal and BP was slightly elevated in only three subjects.(ABSTRACT TRUNCATED AT 250 WORDS)