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 serum and urinary insulin-like growth factor I (IGF-I) in renal disease and diabetes mellitus. In renal portion, we measured their concentrations in patients with chronic renal disease (serum creatinine < 2.0 mg/dl) (CRD. n = 22) and those with chronic renal failure (serum creatinine > or = 2.0 mg/dl) (CRF, n = 26) and compared with normal healthy controls (C. n = 20). Serum concentrations growth hormone (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 diabetic portion, 29 patients with noninsulin dependent diabetes mellitus (NIDDM), whose serum creatinine were within normal range, and age-matched 12 subjects were enrolled. Serum IGF-I in NIDDM (130 +/- 11 ng/ml) was significantly lower than that in controls (201 +/- 11 pg/ml). In contrast, urinary IGF-I level in NIDDM (1.93 +/- 0.31 ng/mg creatinine) did 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 participation of renal IGF-I in the progression of renal disease, while in NIDDM with normal serum creatinine the role of renal IGF-I may be less in the early diabetic nephropathy.