Hepatology 1995;22:833C6. statement being a current smoker (OR for current versus by no means 0.36 (95% CI 0.14C0.90)) than EMA unfavorable participants. EMA positivity was associated with an 8% reduction in mean serum cholesterol (0.5 mmol/l; p 0.01) and reductions in mean haemoglobin (0.3 g/dl; p 0.01), total protein (1.0 g/l; p 0.05), and corrected serum calcium (0.02 mmol/l; p 0.05). There was an increased risk of osteoporosis in EMA positive participants (OR 3.1 (95% CI 1.3C7.2)) and of moderate anaemia (OR 4.6 (95% CI 2.5C8.2)) compared with EMA negative participants. Conclusions: Undetected coeliac disease is likely to affect approximately 1% of the population of England aged 45C76 years, a value similar to several other countries. Those affected statement better health but they do have an increased risk of osteoporosis and moderate anaemia. In contrast, they have a favourable cardiovascular risk profile that may afford protection from ischaemic heart disease and stroke. ray absorptiometry, using the Hologic QDR-1000 densitometer (Hologic, Waltham, Massachusetts, USA). Blood samples were obtained by venepuncture and serum lipids were measured in new samples at the Hinchingbrooke Hospital biochemistry laboratory. All participants have been flagged at the Office of National Statistics for mortality and have CHMFL-BTK-01 been followed up to the end of May 2001. Death certificates were coded CHMFL-BTK-01 according to the 9th Revision of the International Classification of Diseases. We were unable to gain access to participants for the purposes of duodenal biopsy. The study was approved by the CHMFL-BTK-01 Cambridge District Local Research Ethics Committee. Serology We used IgA class antiendomysial antibody (EMA) as our marker of undetected coeliac disease as it has a reported specificity of 99%.17 As there is the possibility of false positive results, we used a second serological marker, human antitissue transglutaminase antibody (tTGA), to validate the positive samples. All sera (n=7550) were investigated for the presence of EMA using indirect immunofluorescence on commercial monkey oesophagus sections (The Binding Site, Birmingham, UK), using a 1 in 10 serum dilution. A positive control was included with every batch of 40 samples. Samples positive for EMA were further tested for tTGA using a commercially available quantitative ELISA kit (Celikey; Pharmacia Diagnostics AB, Freiburg, Germany). We considered results of 3 U/ml to be negative based on the experience in our laboratory. We measured total serum IgA in all sera and considered results of 0.05 g/l to indicate selective IgA deficiency. Definitions We defined undetected coeliac disease as those participants without self reported coeliac disease that were EMA positive. Definitions for the presence or absence of coeliac disease in participants are given in fig 1 ?. Open in a separate window Physique 1 Overview of study participants. *Participants with probable coeliac disease (treated)those who reported taking a gluten free diet and using a medical condition coded as malabsorption (including coeliac disease) and who were antiendomysial antibody (EMA) unfavorable. ?Participants with probable coeliac disease (untreated)those who reported using a medical condition coded as malabsorption (including coeliac disease) but did RCCP2 not report taking a gluten free diet, and who were EMA positive. ?Participants with possible coeliac diseasethose who also reported taking a gluten free diet but did not report using a medical condition coded as malabsorption (including coeliac disease) and who were EMA negative. Participants not previously diagnosed with coeliac diseasethose that did not report being on a gluten free diet, or having any other medical condition coded as malabsorption (including coeliac disease). This group was further subdivided into those who were EMA unfavorable (no evidence of coeliac disease) and those who were EMA.