Increasing prevalence of coeliac disease over time S. LOHI*, K. MUSTALAHTI*, K. KAUKINEN*,  , K. LAURILA*, P. COLLIN  , H. RISSANEN à , O. LOHI*,§, E. BRAVI – , M. GASPARIN – , A. REUNANEN à & M. MA ¨ KI*,§ *Paediatric Research Center, Medical School, University of Tampere, Tam- pere, Finland;  Department of Gastro- enterology and Alimentary Tract Surgery, Tampere University Hospital, Tampere, Finland; àDepartment of Health and Functional Capacity, National Public Health Institute, Helsinki, Finland; §Department of Paediatrics, Tampere University Hospital, Tampere, Finland; –Eurospital S.p.A, Diagnostic Division, Trieste, Italy Correspondence to: Dr M. Ma ¨ki, Coeliac Disease Study Group, Pediatric Research Center, Medical School, Building FM3, FIN- 33014 University of Tampere, Finland. E-mail: markku.maki@uta.fi Publication data Submitted 4 June 2007 First decision 21 June 2007 Resubmitted 16 August 2007 Accepted 29 August 2007 SUMMARY Background The number of coeliac disease diagnoses has increased in the recent past and according to screening studies, the total prevalence of the disorder is around 1%. Aim To establish whether the increased number of coeliac disease cases reflects a true rise in disease frequency. Methods The total prevalence of coeliac disease was determined in two population-based samples representing the Finnish adult population in 1978–80 and 2000–01 and comprising 8000 and 8028 individuals, respectively. Both clinically–diagnosed coeliac disease patients and pre- viously unrecognized cases identified by serum endomysial antibodies were taken into account. Results Only two (clinical prevalence of 0.03%) patients had been diagnosed on clinical grounds in 1978–80, in contrast to 32 (0.52%) in 2000–01. The prevalence of earlier unrecognized cases increased statistically signifi- cantly from 1.03% to 1.47% during the same period. This yields a total prevalence of coeliac disease of 1.05% in 1978–80 and 1.99% in 2000– 01. Conclusions The total prevalence of coeliac disease seems to have doubled in Finland during the last two decades, and the increase cannot be attributed to the better detection rate. The environmental factors responsible for the increasing prevalence of the disorder are issues for further studies. Aliment Pharmacol Ther 26, 1217–1225 Alimentary Pharmacology & Therapeutics ª 2007 The Authors 1217 Journal compilation ª 2007 Blackwell Publishing Ltd doi:10.1111/j.1365-2036.2007.03502.x