Coeliac Disease in the Netherlands

Epidemiologic studies in the past have demonstrated internationally varying prevalence of coeliac disease (CD). To update Dutch data we analyzed the records of members of the Dutch Coeliac Society. At January 1st 1990 1705 unselected members were counted. Twelve hundred thirtythree were at least single-biopsy confirmed coeliacs. Since 1980 1110 new patients have been registered, of which 783 (=701/2%) were biopsy-proven. CD became manifest most frequently in the first de-cade (33%) and in the fourth and fifth decades (35%) of life. Most cases, however, were diagnosed in adults: 62%. An interesting variation was observed in the esti-mate of prevalence rates (per 100.000 inhabitants) in different geographical areas. The overall prevalence rate in the Netherlands was 10.8; the lowest prevalence rate was found in Flevoland (5.9), the highest in Utrecht (17.7). These rates were less in the greater cities (>100.000 inhabitants), than in a selected group of welfaring, smaller cities (<60.00 inhabitants): respectively (mean+SD) 11.7+4.9 vs 20.5+13.7; p<0.05. Incidence rates (per 100.000 inhabitants/yr) increased from 0.13 in 1975, 0.22 in 1980, 0.45 in 1985 to 0.89 in 1989. This increase in coeliac diagnoses outranged the mean increase of the Dutch population over the last decade (+0.5%/yr). We conclude that the number of known coeliacs is low in comparison to neighbouring countries, but in the Netherlands it increases enormously during the last decade. Incidence rates and geographically-varying prevalence rates suggest that other than population factors are causative. To substantiate causes of this increase further analysis is warranted. We hypothesize that medical inattention, in part (still) might explain the low Dutch overall prevalence, as well as the low prevalence in several geographical areas.