Screen-Detected Coeliac Disease in a Nationally Representative Cohort: Health Indicators, Long-Term Outcomes and Mortality.

BACKGROUND: Population-based screening for coeliac disease could reduce underdiagnosis, but benefits and harms remain debated. AIM: We studied health outcomes in screen-detected coeliac disease patients at diagnosis and following a long-term gluten-free diet. METHODS: Data were collected from Health 2000 and 2011 studies representing the Finnish population. Coeliac disease was screened in 6339 individuals by transglutaminase and endomysial antibodies, with dual seropositivity as the diagnostic criterion, histologically validated in this cohort. Survey-weighted analyses enabled population-level results. The follow-up cohort comprised those participating in both time points. Mortality was assessed between 2000 and 2017. RESULTS: At screening, 92 (1.5%) undiagnosed coeliac disease patients and 6216 non-coeliac controls were identified. Patients were less often smokers (11% vs. 22%, p = 0.014), more often had a history of pre-eclampsia (13% vs. 5%, p = 0.037) and anaemia (14% vs. 6%, p = 0.012), and lower ferritin (29 vs. 68 ng/mL, p < 0.001), with an altered lipid profile including lower total cholesterol, LDL-C, and ApoB but higher atherogenic ratios. At 11-year follow-up, mental health, quality of life, and cardiometabolic markers were comparable between treated coeliac disease patients (n = 50) and non-coeliac controls (n = 3226). Mortality did not differ after adjustment for age and sex (HR 0.77, 95% CI 0.45-1.33). CONCLUSIONS: Nationally screened adults with undiagnosed coeliac disease showed iron deficiency and anaemia. Long-term dietary treatment did not adversely affect quality of life or cardiometabolic health and may prevent complications. Furthermore, mortality was comparable to the general population. The results suggest a favourable benefit-harm balance for population-based screening.