Association of a lifestyle index with MRI-determined liver fat content in a general population study

Background In prior studies, lifestyle indices were associated with numerous disease end points, but the association with fatty liver disease (FLD), a key correlate of cardiometabolic risk, is unknown. The aim was to investigate associations between a lifestyle index with liver fat content. Methods Liver fat was quantified by MRI as liver signal intensity (LSI) in 354 individuals selected from a population-based cohort from Germany. Exposure to favourable lifestyle factors was quantified using an additive score with each factor modelled as a dichotomous trait. Favourable lifestyle factors were defined as waist circumference below 102 (men) or 88 cm (women), physical activity ≥3.5 h/week, never-smoking and a favourable dietary pattern, which was derived to explain liver fat variation. In a cross-sectional study, multivariable adjusted linear and logistic regression was applied to investigate the association between the lifestyle index (range 0–4, exposure) and LSI (modelled as a continuous trait or dichotomised as a FLD indicator variable, respectively). Results Individuals with four favourable lifestyle factors (n=9%) had lower LSI values (s −0.40; 95% CI −0.61 to −0.19) and a lower OR (0.09; 95% CI 0.03 to 0.30) for FLD compared with individuals with zero favourable lifestyle factors (n=10%). Conclusions A healthy lifestyle pattern was associated with less liver fat. Prospective studies are warranted.