NAFLD ups glucose intolerance risk despite normal ALT

Fatty liver disease (FLD) is a risk factor for the onset of impaired fasting glucose (IFG) among nonalcoholic adult, a new study has found.

The researchers assessed 8,664 participants who had undergone at least two annual health check-ups. Participants were divided into five groups according to sex-specific alanine aminotransferase (ALT) levels, FLD status, and alcohol consumption; each group was then subdivided according to sex. The study outcome was the onset of IFG, defined as a fasting plasma glucose (FPG) level ≥6.11 nM.

Nonalcoholic men with normal ALT but with FLD were >50-pecent more likely to develop IFG than the reference group (adjusted hazard ratio [HR], 1.54, 95 percent confidence interval [CI], 1.15–2.06). Among nonalcoholic men with FLD and elevated ALT, the excess risk of IFG was almost 80-percent higher (adjusted HR, 1.78, 95 percent CI, 1.33–2.38; p_trend<0.01).

The researchers also saw heightened IFG risks in nonalcoholic men with elevated ALT, but no FLD (adjusted HR, 1.54, 95 percent CI, 1.07–2.23; p<0.01). However, no excess IFG risk was detected in any alcoholic subgroup of men.

In women, multivariate analysis revealed that the only subgroup associated with significantly higher IFG risk was that with nonalcoholic normal ALT levels with FLD (adjusted HR, 1.67, 95 percent CI, 1.03–2.7).

“[T]he present study revealed that FLD in nonalcoholic patients increased the risk of developing glucose intolerance, even if the ALT level was normal,” the researchers said. “Therefore, regardless of their ALT levels, nonalcoholic patients with FLD require care to prevent the onset of prediabetes and reduce the risk of the development of diabetes and cardiovascular disease.”