Icodextrin reduces insulin resistance in non-diabetic patients undergoing automated peritoneal dialysis: results of a randomized controlled trial (STARCH)

BACKGROUND

Insulin resistance is a common risk factor in chronic kidney disease patients contributing to the high cardiovascular burden, even in the absence of diabetes. Glucose-based peritoneal dialysis (PD) solutions are thought to intensify insulin resistance due to the continuous glucose absorption from the peritoneal cavity. The aim of our study was to analyse the effect of the substitution of glucose for icodextrin on insulin resistance in non-diabetic PD patients in a multicentric randomized clinical trial.

METHODS

This was a multicenter, open-label study with balanced randomization (1:1) and two parallel-groups. Inclusion criteria were non-diabetic adult patients on automated peritoneal dialysis (APD) for at least 3 months on therapy prior to randomization. Patients assigned to the intervention group were treated with 2L of icodextrin 7.5%, and the control group with glucose 2.5% during the long dwell and, at night in the cycler, with a prescription of standard glucose-based PD solution only in both groups. The primary end-point was the change in insulin resistance measured by homeostatic model assessment (HOMA) index at 90 days.

RESULTS

Sixty patients were included in the intervention (n = 33) or the control (n = 27) groups. There was no difference between groups at baseline. After adjustment for pre-intervention HOMA index levels, the group treated with icodextrin had the lower post-intervention levels at 90 days in both intention to treat [1.49 (95% CI: 1.23-1.74) versus 1.89 (95% CI: 1.62-2.17)], (F = 4.643, P = 0.03, partial η(2) = 0.078); and the treated analysis [1.47 (95% CI: 1.01-1.84) versus 2.18 (95% CI: 1.81-2.55)], (F = 7.488, P = 0.01, partial η(2) = 0.195).

CONCLUSIONS

The substitution of glucose for icodextrin for the long dwell improved insulin resistance measured by HOMA index in non-diabetic APD patients.

Balance between cytokine production by peripheral blood mononuclear cells and reactive oxygen species production by monocytes in patients with chronic kidney disease

Hemodialysis (HD) and peritoneal dialysis are associated with inflammatory events and immunological incompetence. The purpose of this study was to evaluate the effect of both uremia and dialysis modality on the production of cytokines and reactive oxygen species (ROS) by monocytes. four groups of subjects were studied: 28 chronic kidney disease (CKD) patients, 14 chronic HD patients, 14 patients on continuous ambulatory peritoneal dialysis (CAPD) patients, and 14 healthy volunteers, peripheral blood mononuclear cells (PBMC) were isolated from blood samples and incubated for 24 hr with or without lipopolysaccharide (LPS). TNF-alpha and IL-10 production by PBMC and serum levels of these cytokines were quantified by ELISA. Aliquots of whole blood were incubated in vitro and ROS production and phagocytosis were quantified by flow cytometry. Compared to the control group, Staphylococcus aureus-stimulated ROS production by monocytes was significantly lower in the HD group. The highest levels of unstimulated TNF-alpha production in vitro were observed in the HD group. In the CKD group, as well as in the whole population, there were a negative correlation between TNF-alpha production by unstimulated PBMC and ROS production by S. aureus-stimulated monocytes and a positive correlation between PMA-stimulated ROS production by monocytes and unstimulated and LPS-stimulated IL-10 production by PBMC suggesting that the pro-inflammatory state in CKD patients is associated with decreased response to infectious challenges.