SERUM AND URINARY LEVELS OF INSULIN-LIKE GROWTH-FACTOR-I IN PATIENTS WITH CHRONIC RENAL-DISEASE AND DIABETES-MELLITUS - ITS CLINICAL IMPLICATION

The aim of this study was to determine the clinical significance of se rum and urinary insulin-like growth factor I (IGF-I) in renal disease and diabetes mellitus. In renal portion, we measured their concentrati ons in patients with chronic renal disease (serum creatinine <2.0 mg/d l) (CRD, n = 22) and those with chronic renal failure (serum creatinin e greater than or equal to 2.0 mg/dl) (CRF, n = 26) and compared with normal healthy controls (C, n = 20). Serum concentrations of growth ho rmone (GH) and IGF-I did not differ among these groups. Urinary IGF-I level was significantly increased in CRF (4.0 +/- 0.5 ng/mg creatinine ) compared with CRD (2.8 +/- 0.6 ng/mg creatinine) and C (1.8 +/- 1.0 ng/mg) creatinine). Urinary IGF-I did not correlate with either serum GH or serum IGF-I. Urinary IGF-I, but not serum IGF-I, demonstrated a significant negative correlation with creatinine clearance. In diabeti c portion, 29 patients with noninsulin dependent diabetes mellitus (NI DDM), whose serum creatinine were within normal range, and age-matched 12 subjects were enrolled. Serum IGF-I in NIDDM (130 +/- 11 ng/ml) wa s significantly lower than that in controls (201 +/- 11 pg/ml). In con trast, urinary IGF-I level in NIDDM (1.93 +/- 0.31 ng/mg creatinine) d id not differ from that in controls (2.00 +/- 0.31 ng/mg creatinine). In NIDDM, urinary IGF-I had poor correlation with both serum IGF-I and albuminuria. The data in renal patients suggest the possible particip ation of renal IGF-I in the progression of renal disease, while in NID DM with normal serum creatinine the role of renal IGF-I may be less in the early diabetic nephropathy.