Reevaluating the causal link between liver fat and hyperglycaemia.

Area of Science:

• Metabolic disorders
• Hepatology
• Genetics

Background:

• Liver fat accumulation, or hepatic steatosis, is increasingly linked to diabetes.
• The precise causal relationship between liver fat and glycemic control remains unclear.

Purpose of the Study:

• To investigate the potential causal effect of liver fat on key glycemic traits.
• To determine if targeting liver fat with medications improves glycemic control.

Main Methods:

• A two-sample Mendelian randomization (MR) analysis utilized genome-wide association study (GWAS) data from 37,358 individuals.
• A meta-analysis of 13 randomized controlled trials (RCTs) involving 2,482 participants examined the impact of liver fat-targeted drugs on glycemic parameters.

Main Results:

• MR analysis showed no causal effect of liver fat on fasting glucose, HbA1c, postprandial glucose, fasting insulin, or HOMA-IR.
• Meta-analysis of RCTs revealed no significant differences in fasting blood glucose or HbA1c levels between drug-treated and control groups.
• Meta-regression analysis indicated no linear relationship between liver fat reduction and changes in fasting blood glucose or HbA1c.

Conclusions:

• The study found no evidence of a causal relationship between hepatic steatosis and glycemic traits.
• These findings suggest that hyperglycemia in metabolic dysfunction-associated steatotic liver disease may be driven by mechanisms other than liver fat accumulation.