Background: Non-alcoholic fatty liver disease (NAFLD) is principally a disease of middle and old age. Previous studies reported it to be benign in old age, however more recent studies suggest an increased mortality in the >60-year-olds.

Objectives: To define the prevalence of risk factors and the laboratory and histological differences between different age groups with NAFLD, in order to confirm/refute findings in previous smaller studies.

Methods: Retrospective, cohort study set in a tertiary liver clinic in the UK. 351 consecutive patients with biopsy-proven NAFLD were divided into an older (> or =60), a middle-aged (> or =50 to <60) and a younger (<50) group. Blood pressure, body mass index, serum lipids, glucose, HbA1C, albumin, liver enzymes, bilirubin, mean cell volume (MCV), platelets, and insulin resistance were recorded. In addition, liver biopsy was analyzed for steatosis, inflammation and fibrosis.

Results: Older patients had significantly more risk factors (hypertension, obesity, diabetes, hyperlipidaemia). Albumin, alanine aminotransferase (ALT), ALT/aspartate aminotransferase ratio and platelets significantly reduced with advancing age. MCV and alkaline phosphatase significantly increased with increasing age. Older patients had significantly greater fibrosis on biopsy with less percentage fat, with the cirrhotic patients being significantly older than non-cirrhotics. Insulin resistance was similar in younger and older groups.

Conclusion: NAFLD affects mainly the middle-aged and the elderly. With advancing age come more risk factors for its development. Older patients show more severe biochemical, haematological and histological changes, with cirrhotics having a significantly greater age than those with milder disease.