Impact of increasing alanine aminotransferase levels within normal range on incident diabetes

J Formos Med Assoc. 2012 Apr;111(4):201-8. doi: 10.1016/j.jfma.2011.04.004. Epub 2012 Mar 23.


Background/purpose: Abnormal alanine aminotransferase level (ALT) levels might be associated with type 2 diabetes, but whether higher ALT levels within the normal range predict the risk is unknown.

Methods: We followed a community-based cohort of 3446 individuals who were ≥35 years old without diabetes and hepatitis B or C in southern Taiwan for 8 years (1997-2004) to study the risk for type 2 diabetes with different normal ALT levels.

Results: Among the 337 incident diabetes cases, 16.0% were from those with ALT levels <10 IU/L, 44.5% with ALT levels 10-19 IU/L, 30.0% with ALT levels 20-39 IU/L, and only 9.5% with ALT levels ≥40 IU/L. A cumulative hazard function test showed that the higher the ALT levels, the greater the cumulative incidence rate of diabetes (p < 0.001, log-rank test). A multiple Cox proportional hazards analysis showed that increasing age, lower educational levels, higher body mass index levels (≥25 vs. <25), and higher ALT levels (vs. the reference group, ALT <10 IU/L), from hazard ratio (HR) = 1.8, for ALT = 10-19, HR = 3.7 for ALT = 20-39, to HR = 4.5 for ALT ≥40, were significant factors for developing diabetes (p < 0.001). The hazard ratios of higher ALT levels in the participants without alcohol consumption were similar to or higher than those in the total cohort.

Conclusion: Higher ALT levels, even within the normal range, are strong predictors of type 2 diabetes independently of body mass index levels with a dose-response relationship.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age Factors
  • Aged
  • Alanine Transaminase / blood*
  • Body Mass Index
  • Case-Control Studies
  • Cohort Studies
  • Diabetes Mellitus, Type 2 / blood*
  • Diabetes Mellitus, Type 2 / complications
  • Diabetes Mellitus, Type 2 / diagnosis
  • Diabetes Mellitus, Type 2 / epidemiology*
  • Female
  • Follow-Up Studies
  • Glucose Tolerance Test
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Proportional Hazards Models
  • Reference Values
  • Risk Factors
  • Socioeconomic Factors
  • Surveys and Questionnaires
  • Taiwan / epidemiology


  • Alanine Transaminase