Prevalence of and Risk Factors for Hepatic Steatosis and Nonalcoholic Fatty Liver Disease in People With Type 2 Diabetes: the Edinburgh Type 2 Diabetes Study

Abstract

OBJECTIVEType 2 diabetes is an established risk factor for development of hepatic steatosis and nonalcoholic fatty liver disease (NAFLD). We aimed to determine the prevalence and clinical correlates of these conditions in a large cohort of people with type 2 diabetes.RESEARCH DESIGN AND METHODSA total of 939 participants, aged 61–76 years, from the Edinburgh Type 2 Diabetes Study (ET2DS)—a large, randomly selected population of people with type 2 diabetes—underwent liver ultrasonography. Ultrasound gradings of steatosis were compared with magnetic resonance spectroscopy in a subgroup. NAFLD was defined as hepatic steatosis in the absence of a secondary cause (screened by questionnaire assessing alcohol and hepatotoxic medication use, plasma hepatitis serology, autoantibodies and ferritin, and record linkage to determine prior diagnoses of liver disease). Binary logistic regression was used to analyze independent associations of characteristics with NAFLD.RESULTSHepatic steatosis was present in 56.9% of participants. After excluding those with a secondary cause for steatosis, the prevalence of NAFLD in the study population was 42.6%. Independent predictors of NAFLD were BMI, lesser duration of diabetes, HbA1c, triglycerides, and metformin use. These remained unchanged after exclusion of participants with evidence of hepatic fibrosis from the group with no hepatic steatosis.CONCLUSIONSPrevalences of hepatic steatosis and NAFLD were high in this unselected population of older people with type 2 diabetes, but lower than in studies in which ultrasound gradings were not compared with a gold standard. Associations with features of the metabolic syndrome could be used to target screening for this condition.

Global burden of NAFLD and NASH: trends, predictions, risk factors and prevention

“…The two major available studies, conducted on a large cohort of Italian patients with T2DM, reported NAFLD prevalence of 60-70% 33,34 ; data from the UK suggests that NAFLD, detected ultrasonographically, is present in 42.6% of patients with T2DM 35 . Prevalence of NAFLD also increases with BMI, such that in an unselected Italian population sample 91% of patients who were obese (BMI ≥30 kg/m 2 ), 67% of those who were overweight (BMI 25-30 kg/m 2 ) and 25% of individ uals at a normal weight (BMI 18-25 kg/m 2 ) had ultra sonographical evidence of NAFLD 36 .…”

External validation of the fatty liver index and lipid accumulation product indices, using 1H-magnetic resonance spectroscopy, to identify hepatic steatosis in healthy controls and obese, insulin-resistant individuals

“…The predictive models were originally developed using ultrasonography, a semi-quantitative methods capable of defining the degree of steatosis (mild, moderate or severe) (28). 1 H-MRS-derived measures of liver fat can accurately quantify liver fat, validated against liver biopsy specimens (4) with normal liver fat being !5.5% (4).…”

Metformin revisited: A critical review of the benefit–risk balance in at-risk patients with type 2 diabetes

“…In participants from the Edinburgh Type 2 Diabetes Study, unexpectedly, the use of metformin was associated with the presence of hepatic steatosis (compared with those classed as normal/probable normal) on ultrasound scan, independently of BMI and glycemic control (OR=2.19 ; 1.59-3.00) [64]. Because previous studies of the use of metformin in NAFLD have shown a positive or neutral effect in individuals [65], it seems unlikely that there is a causative link between metformin use and NAFLD in that study.…”