Retrospective Analysis of Factors Related with Renal Outcomes in Elderly Type 2 Diabetic Patients Including Advanced Diabetic Nephropathy

Kim, Na Ri; Choi, Soo Jeong; Lee, Kwan Hyen; Park, Moo Yong; Lee, Wan Bok; Song, Min Soo; Kim, Jin Kuk; Hwang, Seung Duk

Abstract

BACKGROUND
Recently, the prevalence of diabetes mellitus in elderly people is increasing in Korea because of an increase in longevity. With advancing age, also a greater proportion of end-stage renal disease (ESRD) patients with complex medical co-morbidity contributes to the higher mortality seen in patients receiving dialysis. Diabetic nephropathy has become the most important cause of ESRD worldwide. More intensive therapeutic manipulation is needed to prevent the progression of diabetic nephropathy, but there are few studies about this subject in type 2 diabetes. The aim of this study is to predict renal outcomes of elderly people with type 2 diabetes and investigate risk factors related with the deterioration of renal function and the development of ESRD. METHODS: Study subjects were 67 elderly patients (over 65 years old) with type 2 diabetes. We retrospectively analyzed risk factors for the end points of doubling of serum creatinine or the development of ESRD (dialysis or transplantation). RESULTS: 17 patients (26.4%) reached the end points during the follow-up period. 16 patients of 43 patients with decreased renal function reached the end points and only one of 24 patients with preserved renal function reached the end points. A univariate analysis revealed significant correlations between renal outcomes and duration of diabetes, anemia, hypoalbuminemia, BUN, baseline serum creatinine, GFR, serum calcium, phosphorus, uric acid levels and the degree of proteinuria. In our multivariate analysis, proteinuria and baseline serum creatinine level were significantly independent risk factors. The risk of doubling of serum creatinine or development of ESRD among patients with baseline urinary protein excretion rate >or=1g/24h was six times higher compared with the risk among those with urinary protein excretion rate <1g/24h. CONCLUSION: Proteinuria and the degree of baseline kidney dysfunction are significant risk factors that contribute to the deterioration of renal function and the development of ESRD in elderly patients with type 2 diabetes. Proteinuria is the most powerful independent predictor of renal outcomes.