Diabetes and renal failure: A southern Italian perspective
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Diabetesand Renal Failure: A Southern Italian Perspective Carlo Catalano, MD ABSTRACT Fiorella Cuzzola, MD Giuseppe Enia, MD Maurizio Postorino, MD Qulrlno Maggiore, MD Centro di Fisiologia Clinica del Consiglio Nazionale delle Ricerche e Divisione Ne frologica, The proportion of diabetics among patients accepted for renal re- placement therapy was 10% (34/338); of the 34 dlabetfc patients, only one was clearly affected by Type I diabetes, 28 had Type II dlabetes, and the classification was uncertain in four patients. Similar relative proportions of Types I and II diabetes were observed among patients referred during the same period for evaluation of chronic renal failure. (The Journal of Diabetic Complications 3;2:124-126, 1989.) Reggio Calabria, Italy INTRODUCTION The authors carried out a retrospective survey assessing the total pro- portlon of diabetic patients and relative proportion of patlents with Type I and Type II diabetes among patients receiving renal replace- ment therapy and those evaluated for chronic renal failure In a south- ern Italian renal unlt during the perlod 1972-1988. The proportion and type of diabetes in a series of patients on Renal Replacement Therapy (RRT) vary widely from country to country.‘-6 According to the EDTA registry, in some northern European countries almost all uremic diabetics are Type I; the proportion of those diag- nosed as Type II increases the further south one goes, although Type I remains highly prevalent.’ Since we had the impression that Type I diabetes was very uncom- mon among patients with chronic renal failure (CRF) in our area, we carried out a retrospective survey to assess the total proportion as well as the specific types of diabetes found among patients referred to our renal unit for evaluation and treatment of chronic renal failure since its opening. METHOOS Our unit, located in Reggio Calabria (southern Italy), provides the sole dialysis facility for a population of about 300,000 and also serves as a referal center for evaluation of patients with CRF coming from a much wider area across Calabria and Sicily. We reviewed the charts of all patients treated with any form of RRT from 1972 to 1986 and the charts of all patients admitted to our unit for evaluation of CRF (serum creatinine >2 mg/dl) from 1972 to 1986. Diabetes was classified according to the patient’s age and mode of treatment at the onset of diabetes. Patients <35 years old at onset, treated with insulin, and with a history of ketosis were considered to be Type I; patients >35 years old treated by diet and/or oral hypo- glycemics were considered Type II. Those who failed to fall distinctly into either definition were considered to be of uncertain type. Reprint requests: C. Catalano, Centro Fi- siologia Clinica CNR, Via Sbarre Inferiori n.39, 89100 Reggio Calabria, Italy. Submitted for publication in December 1987; accepted in revised form in March 1988. RESULTS Patients on RRT In the period under study, 34 of 336 patients (10.0%) accepted for renal replacement therapy were diabetics. Only one was clearly affected by Type I diabetes (2.9%) while 26 were Type II (79%). Four were classified as uncertain but they were probably Type II, because although younger than 35 at onset they had been receiving oral hypoglycemics for an average of 10 years following diagnosis, and their clinical histories did not contain any episodes of ketoacidosis. Two patients (8.8%) developed frank hyperglycemia after 5 and 2 years of renal replacement therapy, respectively. Another patient developed diabetes after kidney transplantation. 124
Transcript of Diabetes and renal failure: A southern Italian perspective
Diabetes and Renal Failure: A Southern Italian Perspective
Carlo Catalano, MD ABSTRACT
Fiorella Cuzzola, MD
Giuseppe Enia, MD
Maurizio Postorino, MD
Qulrlno Maggiore, MD
Centro di Fisiologia Clinica del Consiglio Nazionale
delle Ricerche e Divisione Ne frologica,
The proportion of diabetics among patients accepted for renal re- placement therapy was 10% (34/338); of the 34 dlabetfc patients, only one was clearly affected by Type I diabetes, 28 had Type II dlabetes, and the classification was uncertain in four patients. Similar relative proportions of Types I and II diabetes were observed among patients referred during the same period for evaluation of chronic renal failure. (The Journal of Diabetic Complications 3;2:124-126, 1989.)
Reggio Calabria, Italy INTRODUCTION
The authors carried out a retrospective survey assessing the total pro- portlon of diabetic patients and relative proportion of patlents with Type I and Type II diabetes among patients receiving renal replace- ment therapy and those evaluated for chronic renal failure In a south- ern Italian renal unlt during the perlod 1972-1988.
The proportion and type of diabetes in a series of patients on Renal Replacement Therapy (RRT) vary widely from country to country.‘-6 According to the EDTA registry, in some northern European countries almost all uremic diabetics are Type I; the proportion of those diag- nosed as Type II increases the further south one goes, although Type I remains highly prevalent.’
Since we had the impression that Type I diabetes was very uncom- mon among patients with chronic renal failure (CRF) in our area, we carried out a retrospective survey to assess the total proportion as well as the specific types of diabetes found among patients referred to our renal unit for evaluation and treatment of chronic renal failure since its opening.
METHOOS
Our unit, located in Reggio Calabria (southern Italy), provides the sole dialysis facility for a population of about 300,000 and also serves as a referal center for evaluation of patients with CRF coming from a much wider area across Calabria and Sicily.
We reviewed the charts of all patients treated with any form of RRT from 1972 to 1986 and the charts of all patients admitted to our unit for evaluation of CRF (serum creatinine >2 mg/dl) from 1972 to 1986.
Diabetes was classified according to the patient’s age and mode of treatment at the onset of diabetes. Patients <35 years old at onset, treated with insulin, and with a history of ketosis were considered to be Type I; patients >35 years old treated by diet and/or oral hypo- glycemics were considered Type II. Those who failed to fall distinctly into either definition were considered to be of uncertain type.
Reprint requests: C. Catalano, Centro Fi- siologia Clinica CNR, Via Sbarre Inferiori n.39, 89100 Reggio Calabria, Italy. Submitted for publication in December 1987; accepted in revised form in March 1988.
RESULTS
Patients on RRT In the period under study, 34 of 336 patients (10.0%) accepted for renal replacement therapy were diabetics. Only one was clearly affected by Type I diabetes (2.9%) while 26 were Type II (79%). Four were classified as uncertain but they were probably Type II, because although younger than 35 at onset they had been receiving oral hypoglycemics for an average of 10 years following diagnosis, and their clinical histories did not contain any episodes of ketoacidosis. Two patients (8.8%) developed frank hyperglycemia after 5 and 2 years of renal replacement therapy, respectively. Another patient developed diabetes after kidney transplantation.
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DIABETIC NEPHROPATHY IN SOUTHERN ITALY
No diabetic patient started dialysis before 40 years of
age, and about one third began RRT at the age of 60 years or more (mean and median age = 59 years) (Figure 1). At initiation of RRT, 21/31 patients were being treated with insulin.
Patients with Chronic Renal Failure During the years 1972- 1966, 272 diabetic patients were admitted for evaluation of CRF (serum creatinine > 2.0 mg/dl); 11 (4.01) were Type I, 233 (86%) were Type II, and 28 (10.0%) were classified as uncertain. On admission, more than 6OW of these patients were over 60 years old (mean and median age 61) (Figure 2).
Figure 3 shows the fate of diabetic patients admitted with a serum creatinine above 6 mg/dl during the study period. Most of these patients were considered suitable for treatment and RRT was denied at the beginning to only one young Type I patient who was blind and had severe vasculopathy. A further six patients, all over 60 years old,.were excluded from treatment. After 1980, RRT was denied only to a diabetic patient suffering from cancer of the liver.
Two of our diabetic patients were transplanted after 1 and 4 years of hemodialysis, respectively.
DISCUSSION
Our data show that in a series of diabetics with CRF in southern Italy, Type I diabetes is very uncommon. These findings differ strongly from those reported by the EDTA registry.’
Because our data is derived from a retrospective hos- pital survey, we cannot exclude the possibility that the results are biased by our criteria of patient selection and/or by the referral pattern of patients. However, re- viewing the charts of all uremic diabetics, we found that RRT was refused only to one Type I diabetic patient dur- ing the study p;riod. It also seems unlikely that general
practitioners referred only older diabetic uremics to our renal unit, sending the younger patients elsewhere.
Therefore, even allowing for the shortcomings of a ret-
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AGE AT START OF RRT FIG. 1 Age distribution of diabetic patients at initiation of RRT.
110
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NkzE%w ,‘:
50
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:
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1 10 20 30 40 50 60 70 60 90
AGE AT ADMISSION
F/G. 2 Age distribution of diabetic patients admitted for eval-
uation of CRF.
respective survey, we believe that our findings reflect a truly low proportion of Type I diabetes among ure- mic patients in our population. This relative rarity of Type I uremic diabetics could be explained by a low prevalence of the disease in the general population. It is well known that prevalence of Type I diabetes varies widely from country to country: among Northern Euro- pean teenagers, prevalence of Type I diabetes ranges between 1.2 and 3.4/1000 inhabitants, while in Japan it is 0.07/1000.7.8
To our knowledge, no published data are available from southern Italy, but a survey made by the medi- cal service of the Italian army in Sicily and Calabria from 1975 to 1985 found 106 diabetics among more than 258,658 l&year-old recruits from East Sicily and South Calabria. This prevalence of 0.40/1000 is 3-9 times lower than that reported in Northern Europe.9
It must also be stressed that the variation in diagnos- tic criteria can heavily influence the relative frequency of Type I and II diabetes in the published studies. Some- times it is difficult to objectively establish the type of diabetes; the task is even more difficult when diagnosis has to be done after many years of disease, because ret- rospective criteria are not well established. Furthermore,
RENAL REPLACEMENT SENT TO OTHER THERAPY lN OUR UNIT DIALYSIS UNITS
31 \ f
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\ 61 / ‘PATIENTS WITH SCr >8mg/dl ,
6 J I L DEATH IMMEDIATELY V LOST FROM AFTER ADMISSION FOLLOW-UP
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TREATMENT DENIED
FIG. 3 Fate of diabetics admitted with a serum creatinine 28 mgldl.
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there is some confusion in distinguishing between a true insulin-dependent diabetic (Type I) and a Type II patient treated with insulin by physician’s choice. For example, a recent survey covering the dialysis units in the United Kingdom states that 76% of diabetic patients admitted to RRT are Type 1.3This conclusion is based on the sole cri- teria that they are on insulin treatment.35lo Indeed, diag- nosis of diabetes type cannot be based only on whether or not patients were taking insulin at the start of RRT,
because glucose tolerance can vary during the course of chronic renal failure” and physicians tend not to pre- scribe oral hypoglycemics to uremic patients. We betieve that the same criticism applies to the EDTA registry data as well.
In conclusion, our data suggest that the geographical differences in the prevalence of Type I and Type II di- abetes among patients receiving dialysis treatment can be even more marked than previously described by the EDTA registry.
However, prospective, population-based studies are needed to get more accurate information about the true prevalence of Type I and Type II diabetes and the inci- dence of chronic renal failure in patients with these two types of diabetes in the southern Italian population.
ACKNOWLEDGEMENTS
The authors thank Prof. C. Falzon (Messina University) for his help in reviewing the manuscript.
CATALAN0 ET AL.
REFERENCES
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Wing AJ, Brunner FP, Challah S. Fassbinder W. Selwood NH: Diabetic nephropathy causing end stage renal failure and treated by renal replacement therapy in Europe. Xth Int Congr Nephrol Abstract book Ab.n.39a, A.M. Davison (ed) Oxford, Alden Press, 1987. Friedman EA: Clinical strategy in diabetic nephropathy, in Friedman EA, L’Esperance FA Jr (eds), Diabetic Renal- Retinal Syndrome, New York, Grune 8 Stratton, 1986, pp. 31 l-32. Cameron JS, Challah S: Treatment of end stage renal failure due to diabetes in the United Kingdom 1975-84. Lancet ii:1962, 1986. Barcena JA: Prevalence of diabetes mellitus in patients with renal diseases in Mexico. Diabetic Nephropathy 4:97, 1985. Thompson TJ: Diabetic end stage renal failure: 11 years experience (New Zealand). Kidney Int 30:629, 1986. Rettig B, Teutsh SM: The incidence of end stage renal disease in Type I and Type II diabetes mellitus. Diabetic Nephropathy 3:26, 1984. Ekoe JM: Recent trends in prevalence and incidence of diabetes mellitus syndrome in the world. Diab Res C/in P ratice 1:249, 1986. La Porte RE, Naoko T, Akerblom HK: Geographic differ- ences in the risk of insulin-dependent diabetes mellitus: the importance of registries. Diabetes Care 8 (Sl):lOl, 1985. Ragonese F: Prevalence of diabetes mellitus among eighteen-year-old males of eastern Sicily. Personal commu- nication. Friedman EA: Diabetes with kidney failure. Lancet ii:1285 1986. Avram MM, Lauer A, Gonzalez J, Zouabi M, Alvis R: Onset of diabetes after beginning maintenance hemodialysis and the overall reduction in diabetes patients treated for uremia, in Friedman EA, L’Esperance FA Jr (eds), Diabetic Renal- Retinal Syndrome, New York, Grune & Stratton, 1986, pp. 341-348.
