The renal osteodystrophy pattern in Brazil and Uruguay: An overview

Abstract

Background. The prevalence of the types of renal osteodystrophy (ROD) has changed in the last two decades. This study evaluates the prevalence and determining factors of the types of ROD in two countries in South America. Methods. Symptomatic patients who underwent bone biopsies for diagnostic purposes (1985 through 2001) were included in the study. In Brazil, a total of 2340 patients were reviewed, 93.1% on hemodialysis (HD), and 6.9% on continuous ambulatory peritoneal dialysis (CAPD). In Uruguay, 167 patients on hemodialysis were included. Uncalcified bone samples were analyzed in order to diagnose the different types of ROD. Results. Comparing the 1980s to the 1990s, the prevalence of Brazilian patients with hyperparathyroid bone disease (HP) increased from 32.3% to 44.0%, while A1 overload decreased from 61.3% to 42.4%. A logistic regression analysis showed that the main factors associated with HP included female gender, age of less than 40 years, black patients, longer time on dialysis, and absence of A1 overload. In Uruguay, HP also increased over time from 31.8% to 70.5% (P < 0.05), while A1 overload decreased from 42% to 27% (P < 0.05). Conclusion. A better control of A1 overload may lead to a change in histologic pattern, as evidenced by the increasing prevalence of HP.