Center of Health Promotion, Bratislava, Slovakia. Address correspondence and reprint requests to Dr. Dagmar Michalkova, Department of. Pediatrics, Comenius ...
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(4,5). Since 1989, Slovak pediatricians have taken part in two internationally coordinated epidemiological research studies: the WHO Multinational Project for Childhood Diabetes-DIAMOND (6) and the EURODIAB ACE Project (7). Social and political changes in KATARINA FANDAKOVA, RND DAGMAR M. MICHALKOVA, MD, DRS Slovakia after division of Czechoslovakia SLOVAK CHILDHOOD DIABETES JOZEF CERNAY, MD, PHD in 1989 so far have not had a substantial EPIDEMIOLOGY STUDY GROUP ANNA DANKOVA, MD influence on the ethnic composition of MARTIN RUSNAK, MD, PHD the various children's age-groups. According to the exact data of the Slovak OBJECTIVE — To provide reliable data on the incidence and prevalence of insulin- Statistical Bureau, 8,365 children aged 0-14 years moved into Slovakia from dependent diabetes mellitus (IDDM) in children in Slovakia. 1989 to 1992, and 8,770 children aged RESEARCH DESIGN A N D M E T H O D S — A total of 754 Slovak children 0-14 years moved out. Of this transfer, with IDDM, aged 0-14 years, were identified during an 8-year study period. There 94% took place between the Czech Rewere 369 boys and 385 girls from an average population of 1,363,499 children. All public and Slovakia; from an ethnic point patients were prospectively recorded. The primary ascertainment was based on notiof view, this does not mean any principal fications by physicians from outpatient departments. The second independent source change. of information was from all hospitals where the diabetic patients were hospitalized. Health care of children with diaThe completeness of ascertainment was based on the capture-recapture procedure. betes in Slovakia has not changed. PaRESULTS — The completeness of the ascertainment was 95%. In 1992, the annual tients are treated by pediatric endocrinolincidence rate of IDDM (per 100,000) in the 0- to 14-year-old age-group was 8.92 for ogists, who are employees of the state. both sexes (7.95 for boys and 9.93 for girls). In the youngest age-group, an increase in Privatization of pediatric physicians has the incidence rates from 2.89 in 1985 to 6.54 in 1992 was observed. Seasonality, with not been carried out yet, and private praca higher incidence in autumn and winter, was observed in children older than 4 years. tice does not exist. After diagnosis, all The prevalence rates of IDDM (per 1,000) were 0.28-0.50% in the 8-year period. children with diabetes are treated in the C O N C L U S I O N S — The incidence of IDDM in Slovak children (0-14 years) is hospital ward and then further monitored similar to what has been found in other Central European countries. In children in children's endocrinology outpatient younger than 4 years of age, in the last 2 years (1991 and 1992) more patients with clinics. Insulin can be obtained only with diabetes were found than in any period during the preceding 6 years. The recent a doctor's prescription. conspicuous increase in the incidence of IDDM among the younger children in SlovaSince 1985, no child at the onset kia urges us to study its mechanisms, so far unknown, and to search for possible means of diabetes has died as a result of delayed of prevention. diagnosis of the illness. Since 1985, only five children with long-lasting diabetes he occurrence of insulin-dependent far (3). The starting points of recent epi- have died because of further complicating diabetes mellitus (IDDM) during demiological studies are demography- diseases. Every death was analyzed. Slochildhood displays a large geo- based national diabetes registers. In Slo- vakia participates in an internationally graphical variability (1,2). The causes of vakia, we established an all-country annotated study on diabetes mortality in geographic differences are unknown so register of children with diabetes in 1985 children under the framework of the F.URODIAB ACE Project. Social and political changes in From the Department of Pediatrics, Comenius University, Children's Hospital, and the National Slovakia may negatively influence paCenter of Health Promotion, Bratislava, Slovakia. tients, especially pregnant women, by Address correspondence and reprint requests to Dr. Dagmar Michalkova, Department of Pediatrics, Comenius University, Center for Slovak Pediatric Diabetology, Limbova Str., Nr. 1, causing stress situations and worsened 833 40 Bratislava, Slovakia. economic conditions. This could be reReceived for publication 25 January 1994 and accepted in revised form 27 October 1994. flected in the rise of diabetes among the IDDM, insulin-dependent diabetes mellitus. youngest age-group of children in recent years.
Incidence and Prevalence of Childhood Diabetes in Slovakia (1985-1992)
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Table 1—Incidence rates of IDDM in children younger than age 15 (per 100,000 population) in Slovakia during 1985-1992
Years Boys 1985 1986 1987 1988 1989 1990 1991 1992 Girls 1985 1986 1987 1988 1989 1990 1991 1992 Children 1985 1986 1987 1988 1989 1990 1991 1992
Population size
No. with IDDM
Incidence
95% confidence interval
695,900 699,451 700,030 697,102 690,979 683,105 674,929 641,607
41 39 45 50 51 41 51 51
5.89 5.58 6.43 7.17 7.38 6.00 7.56 7.95
4.09-7.70 3.83-7.33 4.55-8.31 5.18-9.16 5.36-9.41 4.16-7.84 5.48-9.63 5.77-10.13
667,549 671,081 671,773 669,075 662,935 654,920 646,692 614,063
51 38 46 40 49 38 62 61
7.64 5.66 6.85 5.98 7.39 5.80 9.59 9.93
5.54-9.74 3.86-7.46 4.87-8.83 4.13-7.83 5.32-9.46 3.96-7.65 7.20-11.97 7.44-12.43
1,363,449 1,370,532 1,371,803 1,366,177 1,353,914 1,338,025 1,321,621 1,255,670
92 77 91 90 100 79 113 112
6.75 5.62 6.63 6.59 7.39 5.90 8.55 8.92
5.37-8.13 4.36-6.87 5.27-8.00 5.23-7.95 5.94-8.83 4.60-7.21 6.97-10.13 7.27-10.57
from hospitals. These questionnaires also contained data on treatment and clinical status. Both sources represented 95% of the patients. The data were stored separately in two auxiliary registers and were regularly brought into conformity and statistically processed. The significance of differences in the incidence of IDDM between the years 1985 and 1991-1992 was statistically tested with the ^ test. The 95% confidence intervals were estimated assuming a Poisson distribution. The seasonality of incidence of IDDM during individual months of the year was followed up in 749 patients (367 boys and 387 girls). Fisher's periodogram was used for statistical evaluation. RESULTS— In Table 1, the underlying population, the number of patients suffering from diabetes in individual years, and the yearly incidence (per 100,000) with a 95% confidence interval are reported. The annual incidence of IDDM in patients 0-14 years old, divided into boys and girls, is shown in Fig. 1. The annual incidence of IDDM in patients 0-4 years old is shown in Fig. 2.
In this study, we measured the incidence and prevalence of IDDM among children 0-14 years old.
RESEARCH DESIGN AND METHODS— The incidence and prevalence of IDDM in Slovakian children was prospectively followed since 1985 by collecting information on the situation in the whole country from two sources. The completeness of ascertainment was based on the model that assumes independent ascertainment of the same population by two alternative sources, the capture-recapture procedure. The first source of data was notification on special forms by physicians from outpatient departments. The second source of information was notification
316
1988
1989
1990
1991
1992
Figure 1—Annual incidence of IDDM in 754 Slovak children aged 0-14 years, divided into 369 boys 3 In Fig. 4, the manifestation of TJ "o IDDM by individual months is shown for .£ 2 a group of 749 patients (367 boys and 382 girls). In these patients we found seasonality with a maximum of new cases of diabetes in the colder autumn and winter 1985 1988 1987 1988 1989 1990 1991 months. No differences were found beyears tween the sexes. Figure 2—Annual incidence oj IDDM in 123 Slovak children aged 0-4 years, divided into 58 boys In Table 3, the seasonal variations V
0-
t
.. _ _ - — .. .. .. ..
•
j
A 0
1
t
3
4
10
11
11
1» 14
age Figure 3—Mean incidence oj IDDM (1985-1992) in boys (HI) and girls ( • ) in Slovakia by individual years oj age (0-14 years). , Children.
CONCLUSIONS— This study has demonstrated a slow increase of the incidence of IDDM in Slovakia, especially in the youngest age-group (0-4 years) of children during the last 2 years. The incidence of IDDM in 1992 in the entire sample of children aged 0-14 years was 8.92/ 1 0 \ The incidence of IDDM in the youngest boys reached 6.89/105 and in the youngest girls reached 6.18/105. The increase in the number of
children with diabetes in the youngest age-group has been previously recorded (8). Thus, Slovakia can be classified with other Central European countries—Austria (9), Hungary (10), Poland (11), and Germany (12)—that have an intermediately high incidence of diabetes in children. An increase in the incidence of IDDM in childhood in Europe in several countries (13,14) during the last 25 years has been observed. The lowest European
Acknowledgments— On behalf of the WHO DIAMOND Project and the EURODIAB ACE Study Group, we acknowledge the help of Dr. A. Raisova for the statistical evaluations. We also thank the members of The Slovak Childhood Diabetes Epidemiology Study Group for cooperation and acknowledge the technical assistance of J. Bratink. APPENDIX— The Slovak Childhood Diabetes Epidemiology Study Group: principal investigator: D. Michalkova, MD; local investigators: L\ Barak, MD; M. Bastrnakova, MD; A. Caradska, MD; M. Debreova, MD; K. Halova, MD; M. Hlavacova, MD; M. Hudakova, MD; L'. Hunak, MD; E.Jancova, MD;J.Javorkova, MD; V. Karvaj, MD; M. Kecerova, MD; M. Kusekova, MD; M. Lukacovic, MD; J. Marcok, MD; V. Matheova, MD; B. Milosovicova, MD; M. Paskova, MD; G. Nagyova, MD; S. Ninajova, PhD; M. Repkova, MD; D. Reptisova, MD; J. Strnova, MD; V. Sajdikova, MD; A. Sarisska, MD; Z. Simekova, MD; E. Spanitzova, MD; A. Sufliarska, MD; and D. Trezova, MD.
References 1. Diabetes Epidemiology Research International Group: Geographic patterns of months childhood insulin-dependent diabetes Figure 4—Manifestation of IDDM by individual months in patients (n = 749) aged 0-14 years (HI, mellitus. Diabetes 37:1113-1119, 1988 2. Karvonen M, Tuomilehto J, Lib man I, Laboys, n = 367; • , girls, n = 382; , children) followed 1985-1992.
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Table 3—Seasonal variation oflDDM onset by sex and age-groups of children in Slovakia during 1985-1992 Age 0-4 years
Age 5-9 years
Age 10-14 years
Age 0-14 years
Month
Boys
Girls
Both
Boys
Girls
Both
Boys
Girls
Both
Boys
Girls
Both
1 2 3 4 5 6 7 8 9 10 11 12 Sum
11 3 3 6 6 4 5 4 4 5 4 3 58
4 6 5 5 7 3 5 6 8 4 3 9 65
15 9 8 11 13 7 10 10 12 9 7 12 123
17 10 17 6 7 9 8 10 17 15 11 10 137
16 12 10 8 13 9 11 13 12 13 10 9 136
33 22 27 14 20 18 19 23 29 28 21 19 273
18 12 17 15 8 11 10 15 17 13 23 13 172
18 14 12 11 11 17 9 16 23 17 16 17 181
36 26 29 26 19 28 19 31 40 30 39 30 353
46 25 37 27 21 24 23 29 38 33 38 26 367
38 32 27 24 31 29 25 35 43 34 29 35 382
84 57 tv+ 51 52 53 48 64 81 67 67 61 749
Porte R: A review of the recent epidemio6. logical data on the worldwide incidence of type 1 (insulin-dependent) diabetes mellitus. Diabetologia 36:883-892, 1993 7. WHO DIAMOND Project Group of Epidemics: Childhood diabetes, epidemics, and epidemiology: an approach for con8. trolling diabetes. Am J Epidemiol 135: 803-816, 1992 CernayJ, Rusnak M, MichalkovS D, Raisova A: Centr&lny register diabetes mellitus u deti v SR. Estonia Pediatr 44:385388,1989 9. Michalkova D, CernayJ, Rusnak M, Raisov& A, Fand&kova M: The incidence of childhood diabetes mellitus type 1 in Slovakia 10. (Abstract). Diabetologia 35:A131, 1992
WHO DIAMOND Project: WHO multinational project for childhood diabetes. Diabetes Care 13:1062-1068, 1990 Green A, Gale EM, Patterson C: Incidence of childhood onset insulin-dependent diabetes mellitus: the EURODIAB ACE study. Lancet 33:905-909, 1992 Michalkova D, Cernay J, Kost'Sl M, PetroviCova A, TomeckovS E: Diabetes mellitus in pre-school children (Abstract). 1SGD Bull: Diabetes in the Young 28:
A17, 1992 Schober E, Frisch H: Incidence of childhood diabetes mellitus in Austria (19791984). Ada Paediatr Scand 77:299-302, 1988 Soltesz G, Madaczy L, Bekefi D, Darko I:
Rising incidence of type 1 diabetes in Hungarian children (1978-1987). Diabetic Med 7:111-114, 1990 11. Rewers M, LaPorte RE, Walczak M, Dmo chowski K, Bogaczynska K: Apparent epidemic of insulin-dependent diabetes mellitus in midwestern Poland. Diabetes 36:106-113,1987 12. Michaelis D, Jutzi E, Hcinke P: 30-jahrige Inzidenz-und Prevalenz-Trend des juvenilen type 1 Diabetes in der ostdeutschen Bevolkerung. Diabetes Stoffwechsel 2:245- •
250,1993 13. Nystrom L, Dahlquist G, Rewers M, Wall S: The Swedish Childhood Diabetes Study: an analysis of the temporal variation in the diabetes incidence 1978-
Table 4—Prevalence rates oflDDM in children younger than age 15 (per 1,000 population) in Slovakia during 1985-1992 Boys
Girls
Children
Population size
No. with IDDM
Prevalence (%)
Population size
No. with IDDM
Prevalence (%)
Population size
No. with IDDM
Prevalence
Years 1985 1986 1987 1988 1989 1990 1991 1992
695,900 699,451 700,030 697,102 690,979 683,105 674,929 641,607
177 204 235 261 282 279 285 299
0.25 0.29 0.34 0.37 0.41 0.41 0.42 0.47
667,549 671,081 671,773 669,075 662,935 654,920 646,692 614,063
199 220 250 265 278 271 305 324
0.30 0.33 0.37 0.40 0.42 0.41 0.47 0.53
1,363,449 1,370,532 1,371,803 1,366,177 1,353,914 1,338,025 1,321,621 1,255,670
376 424 485 526 560 550 590 623
0.28 0.31 0.35 0.39 0.41 0.41 0.45
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0.50
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1987. J Epidemiol 19:141-146, 1990 betes mellitus in Finland: background of 14. Levy-Marchal C, Papoz L, DeBeaufort C, nationwide study of type 1 diabetes mellitus. Diabetologia 35:70-76, 1992 Doutreix J, Froment V, Voirin J, Collingnon A, Garros B, Schleret Y, Czernichow 17. Green A, Andersen PK, Svendsen AJ, P: Incidence of juvenile type 1 (insulinMortensen K: Increasing incidence of dependent) diabetes mellitus in France. early onset type 1 (insulin-dependent) diDiabetologia 33:465-469, 1990 abetes mellitus: a study of Danish male cohorts. Diabetologia 35:178-182, 1992 15. Kocova M, Trucco M, Konstantinova M, Dorman JS: A cold spot of IDDM inci- 18. Dahlquist G, Blom L, Tuveno T, Nystrom L, Wall S: The Swedish childhood diabedence in Europe. Diabetes Care 16:1236tes study: results from a nine-year case 1240,1993 register and a one-year case-referent 16. Tuomilehto J, Lounamaa R, Tuomilehtostudy indicating that type 1 (insulinWolf E, Reunanen A, Virtala E, Akerblom dependent) diabetes mellitus is associated HK: Childhood Diabetes in Finland Study with both type 2 (non-insulin-depenGroup: Epidemiology of childhood dia-
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dent) diabetes mellitus and autoimmune disorders. Diabetologia 32:2-6, 1989 19. Fishbein HA, LaPorte RE, Orchard TJ, Drash AL, Kuller LH, Wagener DK: The Pittsburgh Insulin-Dependent Diabetes Mellitus Registry: seasonal incidence. Diabetologia 23:83-85, 1982 20. Ludvigsson J, Afoke AO: Seasonality of type 1 (insulin-dependent) diabetes mellitus: values of C-peptide, insulin antibodies and haemoglobin A u . show evidence of a more rapid loss of insulin secretion in epidemic patients. Diabetologia 32:84-91, 1989
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