Abstract
Both non-alcoholic fatty liver (NAFL) and alcoholic fatty liver (AFL) are strongly associated with obesity, metabolic syndrome, and type 2 diabetes mellitus (T2DM). Recently, also the vitamin D level has been associated with these and may also be associated with fatty liver (FL). Liver function tests (LFTs) are insensitive markers of FL, but use of scores may help in identifying subjects with FL. We studied how LFTs and the FL score predict the development of T2DM in subjects with AFL versus NAFL and low versus high vitamin D levels.
A cohort study based on 4,517 participants, aged 40-79, from the representative Mini-Finland Health Survey was carried out. During a follow-up of 15 years, 217 T2DM cases occurred. LFTs were determined from serum samples, and the FL score was formed using BMI, fasting glucose, HDL cholesterol, and GGT concentrations.
The risk of T2DM incidence in the highest versus lowest quartile was twofold for the LFTs and ninefold for the FL score. A total of 77 % (95 % confidence interval: 57-87 %) of the T2DM cases could have been prevented if all individuals' FL scores had been at the level of the first quartile. Heavy alcohol consumption and low serum vitamin D concentrations were associated with an increased risk of T2DM among individuals with high FL scores.
The FL score is a useful tool for diagnosing FL in epidemiological studies. A high FL score predicts increased risk of T2DM, especially when combined with heavy alcohol consumption or low vitamin D levels.