Improved long-term survival rate of chronic dialysis patients with diabetes mellitus

Nephrology for the people: Presidential Address at the 42nd Regional Meeting of the Japanese Society of Nephrology in Okinawa 2012

The social and economic burdens of dialysis are growing worldwide as the number of patients increases. Dialysis is becoming a heavy burden even in developed countries. Thus, preventing end-stage kidney disease is of the utmost importance. Early detection and treatment is recommended because late referral is common, with most chronic kidney disease (CKD) patients remaining asymptomatic until a late stage. Three-quarters of dialysis patients initiated dialysis therapy within 1 year after referral to the facility. Since its introduction in 2002, the definition of CKD has been widely accepted not only by nephrologists but also by other medical specialties, such as cardiologists and general practitioners. Japan has a long history of general screening for school children, university students, and employees of companies and government offices, with everybody asked to participate. The urine test for proteinuria and hematuria is popular among Japanese people; however, the outcomes have not been well studied. We examined the effects of clinical and laboratory data from several sources on survival of dialysis patients and also predictors of developing dialysis from community-based screening (Okinawa Dialysis Study, OKIDS). At an early CKD stage, patients are usually asymptomatic; therefore, regular health checks using a urine dipstick and serum creatinine are recommended. The intervals for follow-up, however, are debatable due to the cost. CKD is a strong risk factor for developing cardiovascular disease and death and also plays an important role in infection and malignancies, particularly in elderly people. People can live longer with healthy kidneys.

Demographic trends in the Okinawa Dialysis Study (OKIDS) registry (1971-2000)

BACKGROUND

The clinical demographics of chronic dialysis patients are changing worldwide. However, long-term data from regional dialysis registries have not yet been analyzed and reported.

METHODS

The Okinawa Dialysis Study (OKIDS) registry included all chronic dialysis patients treated in Okinawa, Japan, since 1971. Data for the years 1971 to 1990 were analyzed to predict trends for 1991 to 2000. The predicted values were then compared to the actual values and analyzed statistically, with particular attention being paid to relative risk of death. Multivariate Cox proportional hazards analysis was done to analyze the time factors of relative risk of death.

RESULTS

A total of 5246 patients (2981 men and 2265 women) were registered and the total duration of observation was 28,431 patient-years. The prevalence and incidence of dialysis patients expressed per million population were 2320 and 297, respectively, in 2000, values that were significantly higher (P < 0.02 for both) than the predicted values. The gross mortality rate per 1000 patient-years was 118.4 for 1971 to 1980, 63.3 for 1981 to 1990, and 77.7 for 1991 to 2000. The adjusted hazards ratio (95% confidence interval) for mortality was 0.743 (0.650 to 0.862) for 1981-1990 and 0.721 (0.659 to 0.790) for 1991 to 2000 in comparison to the risk of mortality in 1971 to 1980. The decrease in mortality rate was largely due to the drop in cardiac deaths from 71.0 for 1971 to 1980 to 17.2 for 1991 to 2000.

CONCLUSIONS

The incidence and prevalence of chronic dialysis patients increased more than expected over the past decade in Okinawa, Japan. Despite the rapid change in patient demographics, the survival rate did not decrease significantly.