Background: Patients with chronic renal insufficiency, especially those undergoing continuous ambulatory peritoneal dialysis (CAPD), normally have insulin resistance due to deficiencies in insulin secretion and degradation, as well as tissue resistance to insulin at both receptor and postreceptor levels.
Objective: The aim of this study was to investigate the effectiveness and tolerability of rosiglitazone on insulin resistance and body composition in patients without diabetes mellitus (DM) undergoing CAPD.
Methods: This pilot study included a pretest and posttest with a repeated-measure design in a small number of patients. CAPD patients without DM received rosiglitazone 2-mg tablets BID for 12 weeks. Homeostasis Model Assessment Index of Insulin Resistance (HOMA-IR) and bioelectrical impedance analysis (BIA) were used to assess insulin resistance and body composition, respectively. Tolerability was assessed using laboratory analyses as well as physical examination findings to evaluate peripheral edema. Peripheral edema was assessed by the study investigators.
Results: Thirteen Thai patients (mean [SD] age, 54.17 [11.42] years [range, 35–85 years]; body mass index [BMI], >20 to <30 kg/m2; fasting blood glucose [FBG] concentration, <5.39 mmol/L) were included in the study. One patient was withdrawn due to illness unrelated to the study. No significant difference was found in FBG concentration between baseline and posttreatment (after 12 weeks of treatment) (5.45 [0.59] vs 5.24 [0.51] mmol/L), but fasting plasma insulin concentrations (28.50 [23.70] vs 10.15 [4.22] μIU/mL; P = 0.005) and HOMA-IR score (6.70 [5.23] vs 2.40 [1.15]; P = 0.011) were significantly lower. There were no significant changes in weight or BMI from baseline to posttreatment. Seven subjects (58.3%) experienced weight gain at week 4, while 2 patients (16.7%) still had weight gain after 12 weeks of treatment. A significant increase was found between baseline and posttreatment in total body water (38.03 [4.55] vs 42.44 [5.99] L; P = 0.018), extracellular fluid (20.24 [3.75] vs 26.22 [8.69] L; P = 0.005), plasma fluid (4.29 [0.80] vs 5.20 [0.93] L; P = 0.005), and interstitial fluid (14.99 [2.78] vs 17.68 [3.07] L; P = 0.040). Using BIA, no significant changes were observed in intracellular fluid, fat mass, or liver function. After 12 weeks of rosiglitazone administration, 2 patients (16.7%) had mild edema.
Conclusions: Rosiglitazone 2 mg BID for 12 weeks was associated with significantly improved insulin resistance in this small group of nondiabetic Thai patients undergoing CAPD. There was a significant increase in total body water and extracellular fluid after administration of rosiglitazone for 12 weeks. There were no significant changes in FBG, weight, or BMI.