OBJECTIVE—We aimed to update the epidemiology of type 1 and type 2 diabetic patients among the incident end-stage renal disease (ESRD) population in Australia and New Zealand (ANZ) and to determine whether outcome is worse for diabetic women, as described in the general population.
RESEARCH DESIGNS AND METHODS—All resident adults of ANZ who began renal replacement therapy (RRT) from 1 April 1991 to 31 December 2005 were included using data from the ANZ Dialysis and Transplant Registry. Incidence rates, RRT, and survival were analyzed. Risk factors for death were assessed using Cox regression.
RESULTS—The study included 1,284 type 1 diabetic (4.5%), 8,560 type 2 diabetic (30.0%), and 18,704 nondiabetic (65.5%) patients. The incidence rate of ESRD with type 2 diabetes increased markedly over time (+10.2% annually, P < 0.0001). In patients aged <70 years, rates of renal transplantation in type 1 diabetic, type 2 diabetic, and nondiabetic patients were 41.8, 6.5 (P < 0.0001 vs. other patients), and 40.9% (P = 0.56 vs. type 1 diabetic patients), respectively. Compared with nondiabetic patients, the adjusted hazard ratio (HR) for death was 1.64 (P < 0.0001) in type 1 diabetes and 1.13 (P < 0.0001) in type 2 diabetes. Survival rates per 5-year period improved by 6% in type 1 diabetic patients (P = 0.36), by 9% in type 2 diabetic patients (P < 0.0001), and by 5% in nondiabetic patients (P = 0.001). In type 2 diabetic patients aged ≥60 years, the adjusted HR for death in women versus men was 1.19 (P = 0.0003).
CONCLUSIONS—The incidence of ESRD with type 2 diabetes increased markedly. Despite high access to renal transplants, type 1 diabetic patients had a poor prognosis after starting RRT. Survival improved significantly in type 2 diabetic patients during the study period. Older type 2 diabetic women had a worse prognosis than older type 2 diabetic men.
Diabetes is associated with high mortality in the general population (1,2). Worse prognosis has also been reported in diabetic women compared with diabetic men (3,4). End-stage renal disease (ESRD) in patients with type 2 diabetes has increased dramatically worldwide during the last few decades, and diabetes is associated with worse survival among patients undergoing dialysis (5–7).
Nevertheless, a study in Denmark showed that the survival rate of patients with ESRD who had type 2 diabetes has improved during the 1990–2005 period (8). Available studies on patients with ESRD who have type 1 and type 2 diabetes have shortcomings because analyses were limited to patients with diabetic nephropathy (6–7), did not differentiate the two types of diabetes (9), were short-term (10), or were based on single-center experiences (11).
The aim of the present study was to examine the epidemiology and long-term survival of patients with incident ESRD by diabetes status (type 1 diabetes, type 2 diabetes, and no diabetes) in Australia and New Zealand (ANZ) and to determine whether outcomes were different between the sexes among patients with diabetes.
RESEARCH DESIGN AND METHODS—
We performed a prospective study including all patients aged ≥16 years who began chronic renal replacement therapy (RRT) in ANZ from 1 April 1991 to 31 December 2005. We used data from the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry (5). Patients were followed until death or 31 December 2005. Data collection consisted of information on patient demographic characteristics, cause of ESRD, comorbidities at start of RRT (presence of type 1 diabetes, type 2 diabetes, coronary artery disease, peripheral vascular disease, cerebrovascular disease, or chronic lung disease; BMI; and smoking status), estimated glomerular filtration rate (eGFR) at the first RRT, details of RRT modality and of renal transplantation (RTx), and date and cause of death. BMI (ratio of weight in kilograms to the square of height in meters at commencement of RRT) was analyzed in categories: underweight <18 kg/m2, normal weight 18–24.9 kg/m2, overweight 25–29.9 kg/m2, and obese ≥ 30 kg/m2. Smoking status at the start of RRT was categorized as never, former, or current smoker. eGFR was determined by the simplified Modification of Diet in Renal Disease formula (12) in patients who began RRT after 1 April 1998 because data on serum creatinine before the first RRT were collected after this date.
When appropriate, univariate comparisons were performed using a χ2 test or Fisher’s exact test for categorical variables, Student's t test for continuous variables between two groups, and ANOVA for continuous variables across the three groups by diabetes status. We calculated age- and sex-standardized ESRD incidence rates by diabetes status among ANZ populations using direct standardization. For 1991, incidence was projected for the entire year. Data on ANZ populations were provided by the Australian Bureau of Statistics and Statistics New Zealand. The reference populations were the 1991–2005 ANZ populations aged ≥16 years. Calculation of average annual changes in incidence and comparisons between subgroups were performed by Poisson regression, and we checked for overdispersion.
Times to RTx or to death were examined with Kaplan-Meier models and Cox regression for multivariate analyses. RTx outcomes were examined in patients aged <70 years. Cox models to analyze variations in access to RTx by diabetes status per 5-year periods (1991–1995, 1996–2000, and 2001–2005) were adjusted for age, sex, primary renal disease, comorbidities at the first RRT, BMI categories, and smoking status and were stratified on racial origin, state where RRT was started (seven states in Australia and one in New Zealand), and initial RRT modality.
Causes of death were classified into sudden death, cardiovascular, infection, malignancy, and other causes. In survival analyses, death from any cause was the end point. In multivariate survival analysis, diabetes status (type 1 diabetic, type 2 diabetic, or nondiabetic) was the variable of interest. We also examined the evolution of all-cause and cause-specific mortality over 1991–2005 by using the period of the first RRT (1991–1995, 1996–2000, and 2001–2005) as the parameter of interest. Models were adjusted for age, sex, primary renal disease, comorbidities at the first RRT, BMI categories, and smoking status. eGFR at the start of RRT was modeled as a fractional polynomial function (analyses restricted to patients who started RRT from 1 April 1998). Cox regression was stratified on racial origin group, year of the first RRT (1991–2005) with the exception of analysis by period of the first RRT, state where RRT was started, initial RRT modality, and RTx during the study period. We checked for interactions between variables by including multiplicative terms in Cox regression. If significant interactions were found, we performed stratified survival analysis as described above. Validity of the Cox proportional hazard assumption was checked by tests based on Shoenfeld's residuals. All statistical analyses were performed with S-PLUS 6.0 Software Professional Release 2 (Insightful).
RESULTS
Baseline patient characteristics
Type 1 diabetic patients were the youngest, and type 2 diabetic patients were the oldest (P < 0.0001) (Table 1). Rates of cardiovascular disease were higher in diabetic than in nondiabetic patients (P < 0.0001). Type 2 diabetic patients had higher average BMI (P < 0.0001). The proportion of current smokers was higher in type 1 diabetic patients (P < 0.0001).
Proportions of type 1 and type 2 diabetes in Caucasoid, in Australian Aboriginal, and in Maori/Pacific Islander patients were 5.3 and 20.9%, 1.5 and 70.9%, and 2.6 and 64.1%, respectively (P < 0.0001). Sex ratios (male to female) in these groups were 1.5, 0.76, and 1.25, respectively (P < 0.0001). Average ages at the first RRT were 58.8 ± 16, 49.9 ± 11.9, and 53.0 ± 12.9 years, respectively (P < 0.0001).
ESRD incidence rates by diabetes status
Standardized incidence rates of ESRD with associated type 1 diabetes remained stable over time at about 5 per million populations. Average annual change was −0.3% per year (−1.6 to +0.9%), without significant differences between countries, sex, and age (Fig. 1).
Standardized incidence rates of ESRD with associated type 2 diabetes rose from 10.6 per million populations in 1991 to 48.8 per million populations in 2005 in Australia. In New Zealand, they varied between 23.9 per million populations in 1991 and 68.7 per million populations in 2002. Across countries, the average annual change was +10.2% per year (+9.6–+10.8%). For incidence of ESRD at age <60 years with associated type 2 diabetes, the increase was +8.7% (+7.7–+9.7%) in Australia and +5.3% (+3.9–+6.8%) in New Zealand. For ESRD at age ≥60 years with associated type 2 diabetes, the increase was +11.7% (+10.8–+12.6) and +11.5% (+9.7–+13.4%), respectively (P < 0.001 compared with those for patients aged <60 years of the same country).
Standardized incidence rates of ESRD without diabetes increased significantly (+1.5% [+1.1–+1.8%] in Australia and +2.9% [+2.1–+3.8%] in New Zealand).
RRT modalities on the 90th day and access to RTx
Type 1 diabetic patients were more likely to be treated by peritoneal dialysis than type 2 diabetic and nondiabetic patients (P < 0.0001) (Table 1). Type 2 diabetic patients were less likely to receive RTx (P < 0.0001). Over time, rates of RTx were stable in type 1 diabetic patients (adjusted hazard ratio [HR] 1.02 [95% CI 0.91–1.15] per 5-year period, P = 0.72) and in nondiabetic patients (1.00 [0.96–1.03], P = 0.84). Adjusted rates of RTx decreased in type 2 diabetic patients (0.78 [0.68–0.90], P = 0.0005), without a difference between sexes.
Crude survival and causes of death
Unadjusted median (95% CI) survivals from the first RRT in type 1 diabetic, type 2 diabetic, and nondiabetic patients were 72.5 (66.3–82.1), 40.1 (38.8–41.3), and 80.2 (77.7–83.0) months, respectively. Median survivals from birth were 55.7 (54.4–56.7), 70.5 (70.2–70.9), and 74.7 (74.5–74.9) years, respectively (Fig. 2).
Among type 1 diabetic patients, 627 (48.8%) died during the study period. Proportions of sudden death, cardiovascular, infection, malignancy, and other cause as cause of death were in men and in women 27.2, 40.4, 11.3, 3.3, and 17.8% and 18.7, 34.8, 19.5, 2.0, and 25.0%, respectively (P = 0.01). Among type 2 diabetic patients, 4,997 (58.4%) died. Proportions were 17.9, 42.2, 14.7, 4.6, and 20.6% and 15.7, 41.0, 15.9, 3.7, and 23.7%, respectively (P = 0.01). Among nondiabetic patients, 8,393 (44.9%) died. Proportions were 14.9, 35.7, 13.4, 11.5, and 24.5% and 12.2, 35.4, 15.4, 8.7, and 28.3%, respectively (P < 0.0001). Causes of death were significantly different between patient groups by diabetes status (P < 0.0001).
Over time, there was a decrease in adjusted rates of cardiovascular death (adjusted HR 0.96 [95% CI 0.92–0.99] per 5-year period, P = 0.04), death from infectious disease (0.89 [0.83–0.95], P = 0.003), and sudden death (0.88 [0.83–0.94], P < 0.0001), whereas rates of malignancy death increased (1.19 [1.08–1.30], P = 0.0002). These trends were similar in the three patient groups.
Multivariate survival analysis in the whole cohort
Multivariate survival analysis showed that the risk for death after the first RRT was 64% higher in type 1 diabetic (P < 0.0001) and 13% higher in type 2 diabetic (P < 0.0001) than in nondiabetic patients (Table 2).
Multivariate survival analysis by diabetes status
There was a significant interaction between sex and diabetes status (P = 0.0004). Female sex was significantly associated with higher risk for death in type 2 diabetic patients (adjusted HR for death in women versus men 1.08 [95% CI 1.015–1.16], P = 0.02). Sex was not associated with survival in type 1 diabetic (1.12 [0.87–1.46], P = 0.38) and in nondiabetic patients (0.95 [0.91–1.005], P = 0.07).
In type 2 diabetes, there was a significant interaction between sex and age (P < 0.0001). The adjusted HR for death in women versus men was 0.93 (95% CI 0.83–1.04) (P = 0.20) in type 2 diabetic patients aged <60 years (n = 3,762) and 1.19 (1.08–1.30) (P = 0.0003) in type 2 diabetic patients aged ≥60 years (n = 4,798). This last adjusted HR was similar for cardiovascular and noncardiovascular causes of death.
No other significant interactions were found with race, cause of ESRD (diabetic nephropathy versus other causes of ESRD), and BMI. Results were unchanged when follow-up was censored at the time of transplant and/or RRT modality switches and when analyses were adjusted for eGFR.
In type 1 diabetic patients, survival did not change over time (adjusted HR 0.94 [0.83–1.07] per 5-year period, P = 0.36), whereas it significantly improved by 9% per 5-year period in type 2 diabetic patients (0.91 [0.87–0.95], P < 0.0001) and by 5% in nondiabetic patients (0.95 [0.92–0.98], P = 0.001).
CONCLUSIONS—
This study in ANZ showed a large increase in the incidence rate of ESRD with associated type 2 diabetes from 1991 to 2005, which was especially marked in type 2 diabetic patients aged ≥60 years (+11.5% per year). The incidence of ESRD with associated type 1 diabetes remained stable. After adjustment for age, sex, and risk factors for death, type 1 diabetes had a greater effect on survival in patients with ESRD than in type 2 diabetic patients compared with nondiabetic patients. In each patient group, the proportions of cardiovascular, infection, and sudden death decreased over the study period, whereas rates of malignancy death increased. Female sex was associated with worse outcome than male sex in type 2 diabetic patients aged ≥60 years. This difference did not appear to be explained by the different comorbid conditions, age, race, causes of ESRD, BMI at first RRT, or RRT modalities.
The strength of this analysis is that type 1 diabetes and type 2 diabetes are separately reported in a prospective and population-based study. Previous analyses may have been biased because they only included patients with diabetic nephropathy and because nephropathy may have been misclassified if it was not biopsy proven.
Despite an increase of about +3% per year in the incidence of childhood type 1 diabetes in ANZ during the last decades (13,14), the incidence of RRT with associated type 1 diabetes remained stable between 1991 and 2005. The difference in trends between general and ESRD populations may indicate improvements in care of type 1 diabetic patients due to treatment with ACE inhibitors and aggressive glycemic control available since 1980 (15). High transplant rates, including simultaneous kidney-pancreas transplant, remained stable over time. The higher risk for death in type 1 diabetic than in type 2 diabetic patients was not explained by risk factors in the multivariate analyses. This difference should be accounted for by differences in diabetes duration and severity or glycemic control. These data were not available for analysis, and the result should be interpreted with this limitation in mind.
For type 2 diabetes, the overall 10.2% annual increase in ANZ is consistent with studies in Europe and the U.S. over comparable periods (6,7). The increase was higher in patients aged ≥60 years than in younger patients. Possible explanations for this rise are the increasing incidence and prevalence of overweight, obesity (16), and type 2 diabetes in the general population (17); improved life expectancy in type 2 diabetic patients with earlier stage of kidney disease due in part to better management of cardiovascular diseases (18); and greater access to RRT (5–7).
These results highlighted the specific epidemiology of diabetes and ESRD in the Australasian population. Two-thirds of Australian Aboriginal and Maori/Pacific Islander patients with ESRD had type 2 diabetes at the start of RRT, which was significantly different from the situation in the Caucasoid population (∼20% with type 2 diabetes at the start of RRT). The incidence and prevalence of type 2 diabetes and hypertension are high in Aboriginal population (19). This higher incidence of ESRD with associated type 2 diabetes may be explained in part by genetic susceptibility and higher rates of kidney disease progression than in the Caucasoid population (19).
After the first RRT, overall survival was short in type 2 diabetic patients, with median survival times of <3.5 years, similar to reports from Europe (8,11) and the U.S. (9,12). Less than 10% of type 2 diabetic patients received RTx, as in France (20) and the U.S. (21). Adjusted rates of RTx declined over the study period among type 2 diabetic patients but remained stable in the other two groups. Survival rates improved with a decrease in cardiovascular death. We hypothesize that improvements in dialysis management and in cardiovascular treatments may explain this improvement over time.
Moreover, female sex was significantly associated with death in type 2 diabetic patients aged ≥60 years. Interactions between female sex, diabetes, and excess mortality in the ESRD population compared with the general population have also been noted in France (22). Several dialysis-specific explanations can be proposed, such as sex differences in the effects of the dialysis dose (23) and the importance of glycemic control (12) on survival of patient with ESRD and diabetes.
Although it remains controversial (24), worse prognosis has also been reported in women than in men in the non-ESRD diabetic population who do not have diabetes (3,4). In diabetic subjects without chronic kidney disease, most studies have found that this difference was not accounted for by traditional risk factors (25). Higher risk for death in women may be related to interactions between cardiovascular risk factors and menopause (26), a stronger inverse association between coronary disease and cholesterol level in women, and differences in coagulation and in patterns of obesity and hyperinsulinemia (2–4,25,26).
In summary, this study confirms that incidences, treatments, and survivals are different between ESRD patients with type 1 and type 2 diabetes. Future studies of patients with ESRD and diabetes should differentiate between these two groups to provide interpretable results. ESRD remains a dreadful complication in patients with type 1 diabetes, and great effort to prevent kidney disease in these young patients is needed. A marked increase in the incidence rate of ESRD with associated type 2 diabetes was seen over the study period. The study emphasizes the burden of ESRD with associated type 2 diabetes in Australian Aboriginal and in Maori/Pacific Islander populations. Prevention of renal impairment (27), nephroprotection in patients with overt nephropathy, early referral to nephrologists (28), and access to RTx (29) may improve the prognosis of type 2 diabetic patients. This study also highlights the poorer prognosis in older type 2 diabetic women compared with older type 2 diabetic men. This finding deserves further explanatory studies.
Age- and sex-standardized ESRD incidence per million population (aged ≥16 years) by diabetes status among the general population in Australia (A, n = 23,417) and in New Zealand (B, n = 5,131). -♦-, patients with type 1 diabetes; -▪-, patients with type 2 diabetes; -▴-, patients without diabetes.
Age- and sex-standardized ESRD incidence per million population (aged ≥16 years) by diabetes status among the general population in Australia (A, n = 23,417) and in New Zealand (B, n = 5,131). -♦-, patients with type 1 diabetes; -▪-, patients with type 2 diabetes; -▴-, patients without diabetes.
Survival curve for national cohorts after birth by diabetes status, computed for mortality rates for the period 1991–2005.
Survival curve for national cohorts after birth by diabetes status, computed for mortality rates for the period 1991–2005.
Baseline characteristics and renal replacement therapy in type 1 diabetic, type 2 diabetic, and nondiabetic patients
. | Type 1 diabetic . | Type 2 diabetic . | Nondiabetic . | P* . |
---|---|---|---|---|
n | 1,284 (4.5) | 8,560 (30.0) | 18,704 (65.5) | |
Male | 733 (57.1) | 4,943 (57.7) | 10,934 (58.5) | 0.002 |
Age at first RRT (years) | 43.1 ± 11.3 | 61.2 ± 11.2 | 56.5 ± 17.0 | <0.0001 |
Racial origin | <0.0001† | |||
Caucasoid | 1,136 (88.5) | 4,493 (52.5) | 15,882 (84.9) | |
Australian Aboriginal | 31 (2.4) | 1,444 (16.9) | 562 (3.0) | |
Maori/Pacific Islander | 71 (5.5) | 1,784 (20.8) | 930 (5.0) | |
Other people | 46 (3.6) | 839 (9.8) | 1,327 (7.1) | |
Primary renal disease | <0.0001† | |||
Diabetes | 1,205 (93.8) | 6,345 (74.1) | 0 (0) | |
Renal vascular disease | 15 (1.2) | 572 (6.7) | 3,114 (16.6) | |
Glomerular nephropathy and related disease | 36 (2.8) | 775 (9.1) | 7,699 (41.2) | |
Polycystic | 2 (0.1) | 89 (1.0) | 1,842 (9.8) | |
Other | 26 (2.1) | 779 (9.1) | 6,049 (32.4) | |
Biopsy-proven nephropathy | 162 (12.6) | 1,421 (16.6) | 7,032 (37.6) | <0.0001 |
Comorbid conditions at first RRT | ||||
Chronic lung disease | 84 (6.5) | 1,496 (17.5) | 2,728 (14.6) | <0.0001 |
Coronary artery disease | 435 (33.9) | 4,802 (56.1) | 5,550 (29.7) | <0.0001 |
Peripheral vascular disease | 555 (43.2) | 3,694 (43.2) | 2,989 (16.0) | <0.0001 |
Cerebrovascular disease | 153 (11.9) | 1,692 (19.8) | 2,134 (11.4) | <0.0001 |
BMI (kg/m2) | 25.0 ± 4.7 | 28.6 ± 6.4 | 25.2 ± 5.3 | <0.0001 |
<18 | 29 (2.3) | 128 (1.5) | 844 (4.5) | <0.0001b |
18–24 | 727 (56.6) | 2,574 (30.1) | 9,633 (51.5) | |
25–29 | 368 (28.7) | 2,878 (33.6) | 5,495 (29.4) | |
≥30 | 160 (12.5) | 2,980 (34.8) | 2,832 (15.1) | |
Cigarette smoking | ||||
Never | 676 (52.6) | 3,725 (43.5) | 9,135 (48.8) | <0.0001† |
Former | 384 (29.9) | 3,720 (43.5) | 7,131 (38.1) | |
Current | 224 (17.5) | 1,115 (13.0) | 2,438 (13.1) | |
Serum creatinine at first RRT (μmol/l)‡ | 686 ± 263 | 735 ± 306 | 795 ± 339 | <0.0001 |
eGFR at first RRT (ml/min)‡§ | 8.5 ± 3.8 | 7.5 ± 4.0 | 7.0 ± 3.6 | <0.0001 |
90-day RRT modality | <0.0001† | |||
Haemodialysis | 531 (41.3) | 4,971 (58.1) | 10,860 (58.1) | |
Peritoneal dialysis | 639 (49.8) | 3,554 (41.5) | 6,992 (37.4) | |
Renal transplantation | 114 (8.9) | 35 (0.4) | 852 (4.5) | |
Details of RTx | ||||
n | 1,257‖ | 6,551‖ | 10,860‖ | |
Waiting list registration | 522 (41.5) | 724 (11.1) | 5,069 (36.7) | <0.0001 |
Preemptive renal transplantation | 85 (6.8)¶ | 18 (0.3) | 502 (3.6) | <0.0001 |
Living donor renal transplantation | 89 (7.1)# | 111 (1.3) | 2,024 (14.6) | <0.0001 |
Cadaveric renal transplantation | 436 (34.7)** | 340 (5.2) | 3,638 (26.3) | <0.0001 |
Median times to RTx (months) | 18.3 (16.7–20.9) | 48.8 (45.7–55.9) | 26.0 (24.9–26.9) | <0.0001 |
. | Type 1 diabetic . | Type 2 diabetic . | Nondiabetic . | P* . |
---|---|---|---|---|
n | 1,284 (4.5) | 8,560 (30.0) | 18,704 (65.5) | |
Male | 733 (57.1) | 4,943 (57.7) | 10,934 (58.5) | 0.002 |
Age at first RRT (years) | 43.1 ± 11.3 | 61.2 ± 11.2 | 56.5 ± 17.0 | <0.0001 |
Racial origin | <0.0001† | |||
Caucasoid | 1,136 (88.5) | 4,493 (52.5) | 15,882 (84.9) | |
Australian Aboriginal | 31 (2.4) | 1,444 (16.9) | 562 (3.0) | |
Maori/Pacific Islander | 71 (5.5) | 1,784 (20.8) | 930 (5.0) | |
Other people | 46 (3.6) | 839 (9.8) | 1,327 (7.1) | |
Primary renal disease | <0.0001† | |||
Diabetes | 1,205 (93.8) | 6,345 (74.1) | 0 (0) | |
Renal vascular disease | 15 (1.2) | 572 (6.7) | 3,114 (16.6) | |
Glomerular nephropathy and related disease | 36 (2.8) | 775 (9.1) | 7,699 (41.2) | |
Polycystic | 2 (0.1) | 89 (1.0) | 1,842 (9.8) | |
Other | 26 (2.1) | 779 (9.1) | 6,049 (32.4) | |
Biopsy-proven nephropathy | 162 (12.6) | 1,421 (16.6) | 7,032 (37.6) | <0.0001 |
Comorbid conditions at first RRT | ||||
Chronic lung disease | 84 (6.5) | 1,496 (17.5) | 2,728 (14.6) | <0.0001 |
Coronary artery disease | 435 (33.9) | 4,802 (56.1) | 5,550 (29.7) | <0.0001 |
Peripheral vascular disease | 555 (43.2) | 3,694 (43.2) | 2,989 (16.0) | <0.0001 |
Cerebrovascular disease | 153 (11.9) | 1,692 (19.8) | 2,134 (11.4) | <0.0001 |
BMI (kg/m2) | 25.0 ± 4.7 | 28.6 ± 6.4 | 25.2 ± 5.3 | <0.0001 |
<18 | 29 (2.3) | 128 (1.5) | 844 (4.5) | <0.0001b |
18–24 | 727 (56.6) | 2,574 (30.1) | 9,633 (51.5) | |
25–29 | 368 (28.7) | 2,878 (33.6) | 5,495 (29.4) | |
≥30 | 160 (12.5) | 2,980 (34.8) | 2,832 (15.1) | |
Cigarette smoking | ||||
Never | 676 (52.6) | 3,725 (43.5) | 9,135 (48.8) | <0.0001† |
Former | 384 (29.9) | 3,720 (43.5) | 7,131 (38.1) | |
Current | 224 (17.5) | 1,115 (13.0) | 2,438 (13.1) | |
Serum creatinine at first RRT (μmol/l)‡ | 686 ± 263 | 735 ± 306 | 795 ± 339 | <0.0001 |
eGFR at first RRT (ml/min)‡§ | 8.5 ± 3.8 | 7.5 ± 4.0 | 7.0 ± 3.6 | <0.0001 |
90-day RRT modality | <0.0001† | |||
Haemodialysis | 531 (41.3) | 4,971 (58.1) | 10,860 (58.1) | |
Peritoneal dialysis | 639 (49.8) | 3,554 (41.5) | 6,992 (37.4) | |
Renal transplantation | 114 (8.9) | 35 (0.4) | 852 (4.5) | |
Details of RTx | ||||
n | 1,257‖ | 6,551‖ | 10,860‖ | |
Waiting list registration | 522 (41.5) | 724 (11.1) | 5,069 (36.7) | <0.0001 |
Preemptive renal transplantation | 85 (6.8)¶ | 18 (0.3) | 502 (3.6) | <0.0001 |
Living donor renal transplantation | 89 (7.1)# | 111 (1.3) | 2,024 (14.6) | <0.0001 |
Cadaveric renal transplantation | 436 (34.7)** | 340 (5.2) | 3,638 (26.3) | <0.0001 |
Median times to RTx (months) | 18.3 (16.7–20.9) | 48.8 (45.7–55.9) | 26.0 (24.9–26.9) | <0.0001 |
Data are n (%), mean ± SE, or median (95% CI).
Comparisons across the three groups.
Comparisons in categorical variables (racial origin, primary renal disease, BMI categories, cigarette smoking status, 90-day RRT modality).
Analysis restricted to patients who started RRT after 1 April 1998: n = 17,809; type 1 diabetic, n = 694; type 2 diabetic, n = 6,176; nondiabetic, n = 10;939; for conversion to milligrams per deciliter divide by 88.4.
Estimated by the simplified Modification Diet in Renal Disease formula (12).
Analyses restricted to patients aged <70 years.
Including 15 living donor renal transplantations, 5 single cadaveric renal transplantations, and 65 simultaneous kidney-pancreas transplantations.
Including 15 preemptive renal transplantations.
Including 159 single renal transplantations and 277 simultaneous kidney-pancreas transplantations.
Adjusted HR of death of any cause in the whole cohort, patients not censored at renal replacement modality switches or renal transplantation
. | HR (95% CI) . | P . |
---|---|---|
Diabetes status | ||
Patients without diabetes* | 1 | |
Patients with type 1 diabetes | 1.64 (1.47–1.84) | <0.0001 |
Patients with type 2 diabetes | 1.13 (1.06–1.20) | <0.0001 |
Male versus female | 1.0 (0.96–1.04) | 0.89 |
Age at first RRT (+1 year) | 1.024 (1.022–1.026) | <0.0001 |
Primary renal disease | ||
Diabetes | 1.21 (1.12–1.31) | <0.0001 |
Renal vascular disease | 1.10 (1.04–1.17) | 0.002 |
Glomerular nephropathy and related disease* | 1 | |
Polycystic | 0.76 (0.69–0.83) | <0.0001 |
Myeloma, light chain deposit, and amyloid | 3.0 (2.72–3.32) | <0.0001 |
Renal cancer | 1.67 (1.4–2.0) | <0.0001 |
Other | 1.07 (1.02–1.13) | 0.01 |
Lung disease | 1.24 (1.18–1.29) | <0.0001 |
Coronaropathy | 1.22 (1.17–1.27) | <0.0001 |
Peripheral vascular disease | 1.21 (1.15–1.26) | <0.0001 |
Cerebrovascular disease | 1.16 (1.11–1.22) | <0.0001 |
BMI (kg/m2) | ||
<18 | 1.33 (1.21–1.45) | <0.0001 |
18–24* | 1 | |
25–29 | 0.89 (0.86–0.93) | <0.0001 |
≥30 | 0.91 (0.87–0.96) | 0.0005 |
Cigarette smoking | ||
Never* | 1 | |
Former | 0.99 (0.95–1.03) | 0.72 |
Current | 1.10 (1.04–1.17) | 0.001 |
. | HR (95% CI) . | P . |
---|---|---|
Diabetes status | ||
Patients without diabetes* | 1 | |
Patients with type 1 diabetes | 1.64 (1.47–1.84) | <0.0001 |
Patients with type 2 diabetes | 1.13 (1.06–1.20) | <0.0001 |
Male versus female | 1.0 (0.96–1.04) | 0.89 |
Age at first RRT (+1 year) | 1.024 (1.022–1.026) | <0.0001 |
Primary renal disease | ||
Diabetes | 1.21 (1.12–1.31) | <0.0001 |
Renal vascular disease | 1.10 (1.04–1.17) | 0.002 |
Glomerular nephropathy and related disease* | 1 | |
Polycystic | 0.76 (0.69–0.83) | <0.0001 |
Myeloma, light chain deposit, and amyloid | 3.0 (2.72–3.32) | <0.0001 |
Renal cancer | 1.67 (1.4–2.0) | <0.0001 |
Other | 1.07 (1.02–1.13) | 0.01 |
Lung disease | 1.24 (1.18–1.29) | <0.0001 |
Coronaropathy | 1.22 (1.17–1.27) | <0.0001 |
Peripheral vascular disease | 1.21 (1.15–1.26) | <0.0001 |
Cerebrovascular disease | 1.16 (1.11–1.22) | <0.0001 |
BMI (kg/m2) | ||
<18 | 1.33 (1.21–1.45) | <0.0001 |
18–24* | 1 | |
25–29 | 0.89 (0.86–0.93) | <0.0001 |
≥30 | 0.91 (0.87–0.96) | 0.0005 |
Cigarette smoking | ||
Never* | 1 | |
Former | 0.99 (0.95–1.03) | 0.72 |
Current | 1.10 (1.04–1.17) | 0.001 |
Whole cohort: n = 28,548. Results were unchanged when patients were censored at time of transplant and/or RRT modality switches, when analyses were adjusted for eGFR, or when analyses were performed only in patients starting RRT with hemodialysis or in patients starting with peritoneal dialysis.
Reference group in categorical variables.
Article Information
We acknowledge all registry participants, especially the nephrologists and professionals who collected the data and conducted the quality control studies. The ANZDATA Registry is funded by the Australian Government Department of Health of Ageing, by the New Zealand Ministry of Health, and by Kidney Health Australia. The Registry has also received contributions from various pharmaceutical and dialysis companies on an unrestricted basis. E.V. is supported by research grants from the Hospices Civils de Lyon and from Novartis and Roche.
References
Published ahead of print at http://care.diabetesjournals.org on 11 September 2007. DOI: 10.2337/dc07-0895.
Sponsors have not been involved in any way in the study design, data interpretation, and manuscript editing. The interpretation of reported data are the responsibility of the authors and in no way should be seen as an official interpretation of the ANZDATA Registry.
A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.
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