Low childhood high density lipoprotein cholesterol levels and subsequent risk for chronic inflammatory bowel disease.

BACKGROUND AND AIMS: Several genetic and environmental risk factors have been linked to chronic inflammatory bowel disease (IBD). The incidence of IBD has significantly increased in developed countries during last decades. The aim of the present study was to examine childhood risk factors for subsequent IBD diagnosis in a longitudinal cohort study of children and adolescents.

METHODS: A Finnish study population consisting of 3551 children and adolescents originally evaluated as part of the Cardiovascular Risk in Young Finns study in 1980. At baseline, participant BMI, insulin, lipid, C-reactive protein and blood pressure levels, socioeconomic position, dietary habits, and physical activity, were evaluated. In addition, information was gathered on rural residency, severe infections, breast feeding, parental smoking and birth weight. Subsequent IBD diagnosis status was evaluated based on nationwide registries on hospitalisations and drug imbursement decisions.

RESULTS: Altogether, 49 participants (1.4%) had IBD diagnosed during the 34 years of register follow-up, of which 31 had ulcerative colitis, 12 Crohn's disease and 6 undetermined colitis. In univariate analyses, significant correlations were observed between childhood HDL-cholesterol (risk ratio (95% CI) for 1-SD change (0.58 (0.42-0.79)) and CRP concentrations (1.20 (1.01-1.43)) with IBD. The inverse association between HDL-cholesterol and IBD remained significant (0.57 (0.39-0.82)) in a multivariable model including data on age, sex and CRP. In addition, a weighted genetic z-score of 71 single nucleotide polymorphisms associated with elevated HDL-cholesterol levels was significantly lower in IBD patients, P=0.01).

CONCLUSION: Low childhood HDL-cholesterol levels are associated with subsequent IBD diagnosis. In addition, a genetic risk score associated with low HDL-cholesterol levels predict later IBD suggesting that HDL-cholesterol metabolism might have a role in the pathogenesis of IBD.