Comorbidity and mortality in peritoneal dialysis: a comparative study of type 1 and 2 diabetes versus nondiabetic patients. Peritoneal dialysis and diabetes.

We conducted a retrospective study with 750 peritoneal dialysis (PD) patients in a Spanish multicenter registry between 1993 and 1999 to analyze comorbidity and mortality in type 1 diabetes (T1D), type 2 diabetes (T2D) and nondiabetic (ND) patients. 163 patients (21.7%) were diabetic--96 T1D (58.8%) and 67 T2D (42.2%)--while 587 were not (78.3%). Different comorbidity factors such as the presence of cardiovascular disease, age over 70 and dyslipidemia at the start of PD were analyzed as well as the incidence of peritonitis, the peritonitis-free interval, need for hospitalization, mortality rate, early mortality rate, survival curves (log rank) and the impact factor (Cox) on mortality for the different variables. The comorbidity index (number of comorbidity factors when starting the treatment) and the peritonitis incidence were higher for T2D. Hospitalization rates were similar, but mortality rates were higher for T2D and early mortality rates (death during the 1st year of treatment) were higher for T1D. The actuarial survival curves showed a higher mortality for T2D with no differences between ND and T1D after adjustment for age. The mortality odds ratio was 1.78 for T2D and 1.13 for T1D, differences which were not significant after adding age over 70 and cardiovascular disease to the variables analyzed. Our results show that associated comorbidity is the most important difference between ND, T1D and T2D. While cardiovascular comorbidity is responsible for the higher percentage of early mortality found in T1D when compared to ND, both age and cardiovascular disease are responsible for the higher comorbidity and mortality found in T2D.