The insulin-like growth factor-I axis in acute renal failure

Nutrition in acute renal failure

Nutritional status has been considered to be one of the possible determinants of mortality rates in cases of acute renal failure (ARF). However, most studies evaluating possible mortality indicators in ARF cases have not focused on the nutritional status, possibly because of the difficulties involved in assessing the nutritional status of critically ill patients. Although the traditional methods for assessing nutritional status are used for ARF patients, they are not the best choice in this population. The use of nutritional support for these patients has produced conflicting results regarding morbidity and mortality. This review covers the mechanisms and indicators of malnutrition in ARF cases and the types of nutritional support that may be used.

Renal failure after percutaneous coronary intervention is associated with high mortality

Renal failure is a marker of poor outcome in the general population. Renal failure after percutaneous coronary artery intervention (PCI) is associated with an increased hazard of in-hospital mortality. We hypothesized that post-PCI renal insufficiency would be a predictor of long-term mortality in patients undergoing PCI who survive for over 30 days after the procedure. A retrospective analysis was conducted from a registry of 9,067 patients undergoing PCI at our center from 1997 to 2001. A rise in creatinine by 1 mg/dl from baseline was defined as post-PCI renal insufficiency. Vital status was assessed using Social Security Death Index. There were a total of 996 deaths over a mean follow-up period of 3.2 years. In a multivariate analysis, history of recent acute myocardial infarction, older age, insulin-dependent diabetes, baseline creatinine greater than 1.5 mg/dl, and presence of mitral regurgitation were associated with post-PCI renal insufficiency. Developing post-PCI renal insufficiency was associated with a 4.31-fold hazard of mortality in univariate analysis and a 1.77-fold hazard after adjustment for known predictors of mortality after PCI. The 1-year survival in patients with renal failure was 70.3% +/- 3.91%, compared to a survival of 93.6% +/- 0.27% in those without any post-PCI renal insufficiency (P < 0.0001). Acute renal insufficiency after PCI is a strong and independent predictor of long-term mortality in patients who survived for 30 days after the procedure.

GH administration and renal IGF-I system in arthritic rats

Experimental arthritis in rats results in a growth failure and a decrease in circulating and hepatic concentrations of insulin-like growth factor I (IGF-I). Renal damage has also been reported in arthritic rats. The aim of this study was 1) to analyse if alterations in the IGF-I system in the kidney occurs in adjuvant-induced arthritis and 2) to analyse if recombinant human GH (rhGH) administration is able to reverse these effects. Male Wistar rats were injected with complete Freund's adjuvant or vehicle and 22 days later they were killed. Arthritis increased serum creatinine levels, relative kidney weight and IGF-I concentrations in this organ. In a second experiment, arthritic and control rats received rhGH (3 UI/Kg sc) or 250 microl saline from day 14, after adjuvant or vehicle injection, until day 22. IGF-I concentrations were higher in both the renal cortex and medulla of arthritic rats. In contrast, kidney IGF-I mRNA was lower in both areas of arthritic animals. GH treatment significantly decreased serum creatinine levels and IGF-I concentrations in the kidney cortex and medulla of arthritic rats. However, the administration of rhGH to arthritic animals significantly increased the IGF-I gene expression in both the renal cortex and medulla. Serum and kidney concentrations of IGF-I binding proteins (IGFBPs) were increased in arthritic animals and they were reduced by GH administration.

CONCLUSION

These data suggest that experimental arthritis causes renal dysfunction and GH treatment can ameliorate this effect.