Edith Simmons

BACKGROUND: Chronic kidney disease patients have a high prevalence of inflammation and oxidative stress, and this has been associated with the excess cardiovascular morbidity and mortality observed in this population. Because maintenance hemodialysis is ineffective in controlling these factors, we hypothesized that restoration of kidney function by transplantation would be required to improve uremic inflammation and oxidative stress. METHODS: This was a prospective cohort study evaluating time-dependent changes in biomarkers of inflammation and oxidative stress before and after renal transplantation. Nineteen end-stage renal disease (ESRD) patients (age 38.3+/-13.7 years, 58% male, 95% white, 21% diabetic) undergoing living-donor renal transplantation were enrolled. C-reactive protein (CRP), interleukin (IL)-6, IL-10, tumor necrosis factor (TNF)-alpha, protein-associated carbonyl content, and F2-isoprostanes were assessed at 1 week pretransplantation and at 1 week and 2 months posttransplantation. RESULTS: Pretransplant levels of the pro-inflammatory proteins IL-6, TNF-alpha, and CRP, as well as the oxidative stress markers plasma protein carbonyls and F2-isoprostanes, were significantly elevated in ESRD patients compared with healthy control subjects. We observed rapid and significant declines in all of these biomarkers after transplantation that persisted for 2 months. CONCLUSIONS: Our findings indicate that restoration of renal function by transplantation improves the chronic inflammation and increased oxidative stress associated with uremia, which may contribute to the improved survival afforded to ESRD patients by renal transplantation.

Mortality in critically ill patients with acute renal failure (ARF) remains high. Hyperglycemia associated with insulin resistance has been associated with adverse outcomes in critically ill intensive care unit (ICU) patients but has not been examined specifically in patients with ARF. We used data from a subcohort (n = 90) of the Program to Improve Care in Acute Renal Disease (PICARD), an observational study of 618 adult ICU patients with ARF in whom nephrology service consultation was obtained. We obtained simultaneous measurements of serum glucose, insulin, insulin-like growth factor (IGF)-I, and IGF-1 binding proteins (IGFBP) in 90 patients. Daily glucose determinations were obtained from a larger fraction of the PICARD cohort (n = 509). Among the 90 patients with intensive metabolic monitoring, glucose concentrations in survivors were significantly lower than in nonsurvivors throughout the 5-wk period (P = 0.008, adjusted P = 0.013). In the larger PICARD cohort (n = 509), hyperglycemia was also significantly associated with in-hospital mortality. Mean insulin concentrations were significantly higher (431 +/- 508 vs. 234 +/- 189 pmol/l, P = 0.03), mean homeostasis model of insulin resistance levels were significantly higher (24.1 +/- 30.0 vs. 11.7 +/- 12.5, P = 0.04), and IGFBP-3 concentrations were significantly lower (1,190 +/- 498 vs. 1,470 +/- 581 microg/l, P = 0.02) among nonsurvivors compared with survivors. Insulin resistance as defined by hyperglycemia in the setting of higher insulin concentrations may be associated with mortality in critically ill patients with ARF. The IGF-IGFBP axis may play an important role in this process.