Department of Healthcare Epidemiology, School of Public Health in the Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Center for Gastroenterology, Teine Keijinkai Hospital, Sapporo, Japan.
J Gastroenterol Hepatol. 2019 Oct;34(10):1793-1799. doi: 10.1111/jgh.14631. Epub 2019 Feb 27.
Alanine aminotransferase (ALT) is an important enzyme for amino acid metabolism and gluconeogenesis, and low ALT is an indicator of vitamin B6 deficiency. However, it is unknown whether individuals with low ALT are likely to develop loss of independence (LOI) or death. We investigated the association of low ALT with LOI or death in the elderly.
Between 2008 and 2010, 2,484 elderly individuals (≥ 65 years old) without functional dependency from the Locomotive Syndrome and Health Outcomes in the Aizu Cohort Study were enrolled. Based on baseline ALT values, the participants were divided into the following groups: ALT < 10 (n = 73), 10-20 (n = 1,372), 20-30 (reference, n = 734), 30-40 (n = 201), and ≥ 40 (n = 104) U/L groups. LOI was defined as requiring complete support for basic activities of daily living, which is care levels 3-5 in Japanese long-term care insurance certifications. The hazard ratios of LOI or death were estimated by Cox proportional hazard models adjusted for potential confounders.
During the median follow-up period of 5.75 (interquartile range 4.85-5.83) years, LOI or death occurred in 195 participants (7.85%). Compared with ALT 20-30 U/L, low ALT was associated with LOI or death (multivariable adjusted hazard ratios [95% confidence intervals]: 3.02 [1.57-5.81] and 1.55 [1.07-2.24] in ALT < 10 and 10-20 U/L groups, respectively), while high ALT was not (1.29 [0.72-2.31] and 1.49 [0.68-3.25] in ALT 30-40 and ≥ 40 U/L groups, respectively).
Clinicians should be aware of not only high ALT, indicating liver injury, but also low ALT associated with LOI or death.
丙氨酸氨基转移酶（ALT）是氨基酸代谢和糖异生的重要酶，低 ALT 是维生素 B6 缺乏的指标。然而，目前尚不清楚低 ALT 的个体是否容易发生丧失独立性（LOI）或死亡。我们研究了低 ALT 与老年人 LOI 或死亡的关系。
2008 年至 2010 年，纳入了来自 Locomotive Syndrome 和 Aizu 队列研究的 2484 名无功能依赖的老年人（≥65 岁）。根据基线 ALT 值，参与者被分为以下几组：ALT<10（n=73）、10-20（n=1372）、20-30（参考值，n=734）、30-40（n=201）和≥40（n=104）U/L 组。LOI 定义为需要完全支持日常生活的基本活动，这是日本长期护理保险认证中的护理水平 3-5。通过 Cox 比例风险模型估计 LOI 或死亡的风险比，并调整了潜在混杂因素。
在中位随访期 5.75 年（四分位距 4.85-5.83）期间，195 名参与者（7.85%）发生 LOI 或死亡。与 ALT 20-30 U/L 相比，低 ALT 与 LOI 或死亡相关（多变量调整后的风险比[95%置信区间]：ALT<10 和 10-20 U/L 组分别为 3.02[1.57-5.81]和 1.55[1.07-2.24]，而高 ALT 则没有（ALT 30-40 和≥40 U/L 组分别为 1.29[0.72-2.31]和 1.49[0.68-3.25]）。
临床医生不仅要注意高 ALT，提示肝损伤，还要注意低 ALT 与 LOI 或死亡有关。
