Insulin–glucose infusion given before hemodialysis increases IGF-I in type 2 diabetes patients with chronic kidney disease

Abstract

Objective Hemodialysis is associated with catabolism and one contributing factor could be decreased bioavailable IGF-I. The aim of this investigation was to study the response of IGF-I and IGFBP-1 to a euglycemic hyperinsulinemic clamp before hemodialysis in type 2 diabetes (T2D) with chronic kidney disease on hemodialysis (CKD5D). Stage 5 (Stages 0–5 according to renal function) indicates a GFR less than 15 mL/min/1.73 m 2, D indicates hemodialysis. The response was compared with that in type 1 diabetes (T1D) with normal renal function. Design Five overnight fasted patients with T2D with CKD5D were subjected to an insulin infusion (1.6 mU/kg/h) for 4 h after which they had lunch followed by a four hour hemodialysis session. The results were compared with results from a previous study in seven T1D patients with normal renal function who had received a similar clamp the same insulin dose with the addition of an initial bolus dose. Blood samples were drawn at 15 to 30 min intervals for analysis of IGFBP-1, IGF-I and insulin and at 5 min intervals to determine blood glucose. Results There was no significant change between pre- and postdialysis values of IGF-I but there was a significant 29% increase ( p < 0.05) at the end of hemodialysis compared with the basal levels before insulin infusion in the T2D patients with CKD5D. The fasting mean levels of IGFBP-1 were increased in both T1D with normal renal function (geometric mean: 216 μg/l, range 169–275 μg/l) and in T2D with CKD5D (geometric mean: 112 μg/l , range 78–162 μg/l, p = 0.15 compared with T1D patients) in spite of a high mean insulin level (32 ± 5 mU/l). Insulin caused a similar decrease ( p < 0.05 all groups) in IGFBP-1 mean levels for the first 90 min in the T2D patients with CKD5D (73 ± 7% of basal IGFBP-1 values) and the T1D patients (69 ± 6%) with normal renal function. After 90 min there was a blunted response in the T2D patients with CKD5D whereas IGFBP-1 in the T1D patients with normal renal function continued to decline. After hemodialysis the IGFBP-1 serum levels increased compared with the levels at the end of insulin infusion but the predialysis values remained significantly lower than before the insulin infusion. Conclusion Type 2 diabetes patients with chronic kidney disease requiring hemodialysis (CKD5D) have a high mean basal level of IGFBP-1 in spite of increased insulin levels. The first 90 min response of IGFBP-1 to insulin infusion is similar in T2D patients with CKD5D and T1D patients with normal renal function. After 90 min of insulin infusion a blunted decrease in IGFBP-1 was seen in T2D patients with CKD5D compared with type \\1 diabetes with normal renal function. Insulin infusion before hemodialysis reduced the earlier reported increase in IGFBP-1 and increased IGF-I levels. Insulin infusion before dialysis in patients with CKD5D should be further studied since it could contribute to an anabolic effect with more bioavaialable IGF-I thus reducing the catabolic effect of hemodialysis.