Keizo Nishime

Impact of the initial levels of laboratory variables on survival in chronic dialysis patients

Besides the age at start of dialysis and the presence of diabetes mellitus, serum albumin has been shown to be a significant predictor of survival in prevalent dialysis patients. However, this was not evaluated in incipient dialysis patients. The initial biochemical variables were retrieved for a large dialysis population (N = 1,982) who were started on chronic dialysis in Okinawa, Japan from 1971 to 1990. Biochemical data that included blood urea nitrogen, serum creatinine, serum electrolytes (sodium, potassium, calcium, and phosphate), total cholesterol, triglyceride, total protein, serum albumin, and hematocrit obtained just before the first dialysis session were available for 1,491 (75.2%) patients. Six hundred sixty-four (43.2%) patients died by the end of 1993. Cox proportional analysis adjusted for sex, age, year of start of dialysis, presence of diabetes mellitus, and the laboratory variables was performed to examine the significance of the initial biochemical data on survival. The risk ratio was 0.577 (P = 0.0025) in serum albumin, 1.291 (P = 0.0138) in serum potassium, and 0.966 (P = 0.0202) in serum sodium. The study results support the notion that nutritional status is important for survival in chronic dialysis patients. Causes of hypoalbuminemia, hyperkalemia, and hyponatremia should be evaluated carefully at initiation of dialysis.

Increased Risk of Cardiovascular Disease with Erythropoietin in Chronic Dialysis Patients

Recombinant human erythropoietin is widely used in chronic dialysis patients. However, the long-term effect, especially on the incidence of cardiovascular disease, has not been critically evaluated. We observed the annual incidence of stroke and acute myocardial infarction from April 1988 through March 1993 in Okinawa, Japan. Until April 1990, erythropoietin was not generally used. Therefore, we have two periods: pre-erythropoietin, April 1988 through March 1990, and post-erythropoietin, April 1990 through March 1993. Two thousand one hundred and sixteen patients (1,219 males and 897 females) were on chronic dialysis during the study period by March 31, 1993. Every case of stroke and acute myocardial infarction during the study period was registered. The odds ratio was calculated using the data of the general population in each sex and age class obtained in the same area. A total of 86 cases of stroke and 15 cases of acute myocardial infarction were registered during the study period. The annual incidence, per 1,000 patient-years, of stroke was 12.5 (1988), 10.5 (1989), 12.7 (1990), 14.0 (1991), and 17.5 (1992). The incidence of stroke was increased in the post-erythropoietin period compared to the pre-erythropoietin period, odds ratio 1.22 and 95% confidence interval (95% CI 1.06-1.41, p < 0.01). The annual incidence of acute myocardial infarction was 1.0 (1988), 1.8 (1989), 0.8 (1990), 2.9 (1991) and 4.7 (1992). The incidence of acute myocardial infarction was increased significantly in the post-erythropoietin period compared to the pre-erythropoietin period, odds ratio 1.87 (95% CI 1.66-2.10, p < 0.01). The odds ratio of stroke to the general population was 4.25 (95% CI 3.10-5.82) in the pre-erythropoietin and 4.58 (95% CI 2.14-9.80) in the post-erythropoietin period. In acute myocardial infarction, it was 2.98 (95% CI 2.84-3.12) and 3.81 (95% CI 3.18-4.56). The odds ratio of acute myocardial infarction was significantly increased (p < 0.01). The introduction of erythropoietin was associated with an increased risk of cardiovascular disease, especially acute myocardial infarction. Erythropoietin may unmask the sclerotic lesion in chronic dialysis patients.

Epidemiologic Analysis of Diabetic Patients on Chronic Dialysis

We retrospectively surveyed all of the available medical records of 404 (191 females and 213 males) chronic dialysis patients, of whom 16 (4%) had insulin-dependent diabetes mellitus (IDDM) and 388 (96%) non-insulin-dependent diabetes mellitus (NIDDM). The patients were among 2,214 dialysis patients in Okinawa, Japan, of whom 443 were diabetic. The patients entered a large population-based dialysis registry. The mean duration from the diagnosis of diabetes mellitus (DM) to dialysis was 181.6 months in the IDDM patients and 150.4 months in the NIDDM patients. The NIDDM patients were classified into four subgroups according to their status when DM was first suspected. The duration from the diagnosis of DM until the onset of dialysis treatment was significantly shorter than in any other subgroup or in the IDDM subgroup with major vascular disease (131.9 months). Otherwise, the course of renal disease in NIDDM patients was similar to that in IDDM individuals. Most of our dialysis patients with DM had NIDDM. In most of the NIDDM patients, the diagnosis had been delayed for several years for unknown reason. However, if diagnosed early, NIDDM shows a clinical time course until dialysis similar to that of IDDM. Whether NIDDM patients contract chronic renal disease at an equal incidence to that of IDDM patients and the fraction of all diabetic patients accepted for chronic dialysis remain to be determined.

Effect of renal diseases and comorbid conditions on survival in chronic dialysis patients

International and geographical differences in the survival rates of chronic dialysis patients can be explained by differences in primary renal disease, in the acceptance rate of elderly patients, and in predialysis comorbid conditions. Several studies have shown the effects of these factors on survival. However, in most studies, a large number of patients may leave for renal transplantation or transfer to other centers, so that precise analysis becomes impossible. Although the number of patients in our registry is not so large (n = 1,982), we have few such problems and were able to examine the effects of the above-mentioned factors on patient survival using the Cox proportional hazard model. Hazard ratios (HR) and 95% confidence intervals were 0.739 and 0.366-1.491 in patients with polycystic kidney disease (n = 38), 2.669 and 1.513-4.708 in patients with systemic lupus erythematosus (n = 39), 1.245 and 0.935-1.660 in patients with nephrosclerosis (n = 122), 1.815 and 1.447-2.229 in patients with diabetes mellitus (n = 374), and 1.595 and 1.201-2.117, respectively, in patients with other renal diseases (n = 146) when the HR in patients with chronic glomerulonephritis (n = 1,263) was taken as 1.00. HR and 95% confidence intervals were 1.222 and 1.016-1.470 in patients with one comorbid condition (n = 217) and 1.494 and 1.033-2.160, respectively, in patients with two comorbid conditions (n = 24) when the HR of patients with no predialysis comorbid conditions (n = 1,741) was taken as 1.00. Our data demonstrate the effects of renal diseases and number of predialysis comorbid conditions on the survival in chronic dialysis patients.(ABSTRACT TRUNCATED AT 250 WORDS)

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

AbstractBackground. The survival rate of diabetic dialysis patients has been poor. However, it is uncertain whether the survival rate of these patients has been improving. Methods. Using the Okinawa Dialysis Study (OKIDS) registry, in which the records of all chronic dialysis patients in Okinawa, Japan, are filed, we compared the prognosis of dialysis patients with diabetes mellitus (DM) and that of dialysis patients with chronic glomerulonephritis (CGN). Using Cox proportional hazard analysis, we examined the effect of the start year of dialysis on survival after adjusting for confounding variables such as age, sex, and predialysis comorbid conditions. Results. Between 1976 and 1998, a total of 1256 DM patients and 2101 CGN patients started dialysis. In the DM patients who started dialysis between 1976 and 1990, the survival rate was 80.4% at 12 months and 42.1% at 60 months, and among those who started dialysis between 1991 and 1998, the survival rate was 87.9% at 12 months and 55.8% at 60 months. In both disease groups, the relative risk of death was significantly lower in patients who started dialysis between 1991 and 1998 than in those who started dialysis between 1976 and 1990. The adjusted relative risk (95% confidence interval [CI]) was 0.65 (95% CI 0.54–0.77). The relative risk of death of DM to CGN was 2.23 (95% CI, 1.91–2.60) when comparing those treated between 1976 and 1990, and 2.00 (95% CI, 1.62–2.46) when comparing those treated between 1991 and 1998. Conclusions. While the prognosis of diabetic dialysis patients in both categories improved significantly with time, that of DM patients was still worse than that of CGN patients.