Is alanine aminotransferase associated with osteopenia in middle-aged and elderly Chinese?

To investigate the association between alanine aminotransferase (ALT) levels and risk of osteopenia in middle-aged and elderly Chinese with ALT within the normal range.

This was a cross-sectional study. A total of 4,890 men and women (pre- and postmenopausal) aged 40 years or older were randomly recruited from Fujian, China. Each participant was required to complete a questionnaire and then undergo anthropometric, biochemical, and bone mineral density measurements.

The odds ratio of osteopenia decreased significantly with increasing ALT level at baseline. The three groups (men, pre- and postmenopausal women) were divided by ALT quartiles. In multiple logistic regression models using the first quartile as the reference, after adjusting for corresponding confounding factors, the odds ratios of osteopenia across the other ALT quartiles were 0.576 (95% confidence interval [CI], 0.390 to 0.851), 0.654 (95% CI, 0.460 to 0.930), and 0.629 (95% CI, 0.427 to 0.926) for premenopausal women, and 0.949 (95% CI, 0.699 to 1.289), 0.733 (95% CI, 0.540 to 0.995), and 0.692 (95% CI, 0.508 to 0.943) for postmenopausal women (not significant for quartile 2). However, no significantly different results were found in men. Multiple linear regression models showed that serum ALT concentrations were positively associated with the homeostasis model assessment of insulin resistance.

Our study of middle-aged and elderly Chinese men and women demonstrates that the prevalence of osteopenia is inversely associated with ALT level when ALT is within the normal range.