Prerehabilitation alanine aminotransferase blood levels and one-year mortality rates in older adults following hip fracture

Abstract

Low alanine aminotransferase (ALT) blood levels prior to rehabilitation are associated with poor function in older adults following hip fracture. We hypothesized that low ALT blood levels prior to rehabilitation were also associated with one-year mortality in this population. Included were 456 older adults (age ≥ 60 years, 82.5% women) admitted for rehabilitation following hip fracture. ALT blood levels were documented between one and six months prior to rehabilitation. Excluded were patients with ALT blood levels over 40 IU/L possibly consistent with liver injury. The main outcome was all-cause mortality one year following rehabilitation admission. The study group included 142 (31.1%) patients with low (≤10 IU/L) ALT blood levels and the control group included 314 (68.9%) patients with high-normal (11-40 IU/L) ALT blood levels. Overall, 52 (11.4%) patients died within one year following rehabilitation admission. Compared with the control group, patients with low ALT blood levels had significantly higher 1-year mortality rates [17.6 vs. 8.6%, odds ratio 2.27, 95% confidence interval (CI) 1.27-4.08]. Cox regression analysis showed that low ALT blood levels prior to rehabilitation were associated with one-year mortality (hazard ratio 1.88, 95% CI 1.08-3.28) together with age (hazard ratio 1.06, 95% CI 1.02-1.11), independent of gender. However, this association was no longer significant following adjustment also for peripheral vascular disease, admission and discharge functional independence measure scores, albumin serum levels, and length of rehabilitation. In conclusion, low ALT blood levels prior to rehabilitation are associated with one-year mortality in older adults following hip fracture. They may be used when only age and gender are known.