The Epidemiological Profile of Inflammatory Bowel Disease in Different Parts of North-West Greece
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434 ANNALS OF GASTROENTEROLOGYE.V. 2005, TSIANOS, 18(4):434-440 et al Original article The epidemiological profile of inflammatory bowel disease in different parts of North-West Greece E.V. Tsianos1, K.H. Katsanos1, D. Christodoulou1, A. Kogevinas2, R.F. Logan3 and the N.W. Greece IBD group* SUMMARY IBD is also suggested. Prevalence of IBD is increasing with Ioannina and Corfu presenting the highest numbers and The epidemiological profile of Inflammatory Bowel Disease being the most industrialized and tourist regions. (IBD) is a topic of great interest because of the differences in incidence, prevalence, sex and age distribution of the This changing profile of Crohns disease strengthens the disease among countries. North-West Greece (NWG) in- hypothesis that some environmental factor(s), probably in cludes 6 prefectures (Ioannina, Arta, Preveza, Thesprotia, correlation with the genetic factor(s), are responsible for Corfu and Lefkas) and it is an area with a great homogene- the expression of IBD. ity in the population because of its geographical morpholo- Key words: Inflammatory bowel disease, Crohns disease, gy. ulcerative colitis, indeterminate colitis, epidemiology, inci- A retrospective epidemiological study was conducted in this dence. area including all hospitals and private doctors and result- ing in the epidemiological registry of 484 patients, the larg- INTRODUCTION est in Greece. The peak age is 35-54 years with a very small number of patients under 25 years. Men are more affected Epidemiological studies of Inflammatory Bowel dis- than women (2:1) and Corfu patients have the most severe ease (IBD) have generally found the incidence to be extraintestinal manifestations. The mean annual incidence higher in Northwest than in South Europe.1-4 Over the of IBD in NWG has an approximate 2-fold (1,86) increase years it has been realized that IBD is a disease with from 1992 to 1997 (7,45x 105 Inhabitants) compared with changing profile and surveys conducted in areas with the years 1982-1991 (3,99 x 105 Inhabitants) with Ioannina homogenous population have shown great interest and and Corfu presenting the greatest increase. In addition the validity. Recently an epidemiological survey troughout gap between ulcerative colitis and Crohns disease is de- Europe showed some differences in several epidemio- creasing because of Crohns more increasing rate. It is also logic parameters of IBD between Northern and South- suggested an East-West (Ioannina, Arta, Preveza, Thespro- ern study centers.5 tia, vs Corfu and Lefkas) or an island-mountain profile of The study of the epidemiology of IBD serves three purposes. It allows first the measurement of the size of the problem that IBD presents in the community, and 1 1ST Department of Internal Medicine, (Section on Hepato- secondly the way in which it is changing in frequency, Gastroenterology), Medical School of Ioannina, 2Gastroenterologist, 3Department of Public Health and Epidemiology, Queens Medical or is associated with specific environmental features. Center, Nottingham, U.K. * N.W. Greece IBD group (1997) Author for correspondence: Dr. Epameinondas V. Tsianos, Professor of Medicine-Gastroenter- D. Christodoulou, I. Familias, S. Georgiou, A. Germanopoulos, ology, Department of Internal Medicine, School of Medicine, K. Katsanos, S. Katsaros, K. Kistis, A. Kogevinas, N. Kostas, K. Masa- University of Ioannina, P.O. Box 1186, 451 10 Ioannina, GREECE las, N. Monastiriotis, G. Mpaltayannis, N. Papadopoulos, N. Tzam- Tel: +30-26510-97500, Fax: +30-26510-97016 bouras, E.V. Tsianos, A. Vlachopoulos The epidemiological profile of inflammatory bowel disease between different parts of North-West Greece 435 Thirdly, it may provide clues to the etiology of the dis- parts of Greece resulting in a very high homogeneity of ease, which is purly understood. Areas of proven or the population; about 80% of the population lives and probable high incidence of IBD include Scandinavia, works in the area of origin. Patients origin was 65% from the UK, North America, Australia and much of North- urban areas, 15% from semi-urban areas and 20% from western Europe in general. Incidence rates are gener- rural areas. ally higher for ulcerative colitis than for Crohns dis- The health care system is of mixed type including both ease. Within Europe incidence rates for ulcerative col- a National Health Service and a private sector. The Na- itis appear to vary by at least five fold, although there tional Health Service consists of health centers, 6 gener- must be unevenness in recording the lesser varieties of al and one University Hospital. However the University disease. The frequency of Crohns disease also appears hospital is the main IBD reference center having the only to vary at least six fold, with the areas of high incidence Hepato-Gastroenterology Division in NW Greece. being the industrialized North-West European and North American countries, as well as Australia and In the private sector there are 8 gastroenterologists South Africa. Areas of probable low incidence are working in NW Greece who are affiliated with the Uni- Greece, Japan, Israel, Spain and Italy and many other versity department of Gastroenterology for IBD research. areas, although dependebility about hospital databases The study was performed retrospectively. Each gastro- in case identification makes confident assertions diffi- enterogist was asked in January 1997 to complete a spe- cult. Herein we present the first population based study cial epidemiological card for every IBD patient he was for IBD in a well defined area of Greece (North-West responsible for. Meanwhile all the archives of our Hepa- Greece). to-Gastroenterology Section were revised. Only cases that met the diagnostic criteria (Table 1) METHODS at least twice in a time span of six months or more were included in this study. For patients with ulcerative colitis A retrospective epidemiological survey was conduct- (UC) the extent was recorded at the time of maximal ed in Northwest (NW Greece) for the years 1982-1997. colonic involvement; (1) pancolitis (entire colon affect- NW Greece has 6 prefectures Ioannina, Arta, Preveza, ed or involvement proximal to transverse colon), (2) left Thesprotia, Lefkas and Corfu, the last two of them be- colitis (no involvement proximal to the splenic flexure), ing famous tourist islands and the first four consisting (3) proctitis (no involvement proximal to the rectum or the region of Epirus. This region (NWG) is very well sep- the first 15 cm). arated geographically by mountains and sea from other Table 1. Inclusion criteria for ulcerative colitis and Crohns disease Ulcerative colitis Crohns disease History Patients with diarrhea or rectal Patients with diarrhea or bleeding, or both for more than 2 rectal bleeding, or both and weeks or repeated episodes weight loss for more than 4 weeks, or repeated episodes Laboratory tests Exclusion of infectious diseases Exclusion of infectious diseases Radiological signs Ulcerations with or without Stenoses and prestenotic speculated granulated inner surface dilatations in the small or large of the return or colon, or both bowel, segmental findings, burrowing ulcerations, stictures or the formation of fistulas Endoscopy Typical sigmoidoscopic or «Cobblestone» appearance of colonoscopic picture with affected segments of the bowel granulated, friable mucosa or or aphthoid ulcers, or both ulcerations or both, of the surface mucosa Histology Inflammatory changes indicative of Signs of inflammatory changes ulcerative colitis indicative of Crohns disease or epithelial granulomata, or both 436 E.V. TSIANOS, et al The severity of UC was classified according to the For IND the highest incidence rate was 0,82/10000 in- criteria of Truelove and Witts6 and of Crohns disease habitants (Prefecture of Ioannina and the lowest in the according to the criteria of Harvey and Bradshaw.7 All island of Lefkas 0,0/100.000 inhabitants. For UC the high- patients with ulcerative colitis had at least one colonos- est incidence was 5,47 (Pref of Ioannina) and the lowest copy done throughout these years while all patients with in the island of Lefkas with 1,66/100.000 inhabitants. Crohns disease had at least one colonoscopy and ente- Furthermore UC has a higher incidence in Epirus than roclysis at the same period. in the Ionian Islands. For CD in Ionian Islands the high- The referral population was estimated according to est incidence was 1,0/100.000 (Pref of Corfu) and the low- the 1981 and 1991 census (446.004 and 468.431 inhabit- est in Lefkas 0,0/100.000. ants respectively, National Statistical Organisation). The The incidence of CD in the Ionian Islands (Corfu and study was divided into two periods: 1982-1991 and 1992- Lefkas) was almost double than that of Epirus. In num- 1997 in order to compare the epidemiologic parameters. bers this is 0,83 for Ionian Islands to 0,44 for Epirus per A similar study for IBD epidemiology was conducted in 100.000 inhabitants (Table 2). Generally IBD is slowly the prefecture of Ioannina for the years 1982-1991 by increasing all over NW Greece affecting 3,99/105 inhab- 8 our Section on Hepato-Gastroenterology and was used itants for the years 1982-1991 and 7,45/105 for the years for comparison. 1992-1997 (Table 2, Figures 1,2,3). The highest preva- lence is 82,58/105 inhabitants (Pref of Ioannina) and the STATISTICAL ANALYSIS lowest is Lefkas with 2,39/105 inhabitants (Table 3). Confidence intervals were calculated at the 95% lev- el of significance using the form of the normal distribu- tion or an exact method based on the Poison distribu- tion when the number of cases was equal or less than 20. The referral population was calculated for every pre- fecture and for every year using annual estimated num- bers derived from the 1981 and 1991 census. All num- bers were calculated for every 105 inhabitants and includ- ed annual incidence, prevalence and specific incidence of sex and age distribution for every prefecture, for Epi- rus (Prefectures of Ioannina, Arta, Preveza and Thes- protia) for Ionian Islands (Corfu and Lefkas) and for the whole of NW Greece.9 Fig.