High Serum Aspartate Aminotransferase, Underweight, and Weight Loss in Older People: Results of the KITCHEN-4

Abstract

Background: Reduced muscle mass is frequently observed in older people and can lead to being underweight and/or weight loss (WL), but prediction and screening systems utilizing hematological biochemical parameters are limited. High serum aspartatSe aminotransferase in conjunction with normal serum alanine aminotransferase (HASNAL) can reflect systemic muscle damage. HASNAL and the incidence of being underweight concomitant with WL (UWWL) were investigated in the present 6-year community-based cohort study. Methods: Clinical parameters, lifestyle, the incidence of being underweight, ≥5% WL, and UWWL were investigated in 238,536 Japanese people aged 40–68 years who had normal serum alanine aminotransferase. HASNAL was defined as serum aspartate aminotransferase ≥30 U/L and serum alanine aminotransferase <30 U/L. The subjects were divided into a younger group (<55 years) and an older group (≥55 years). Results: After 6 years, overall body weight had increased by 0.4% in the younger group and decreased by 0.4% in the older group. In logistic regression analysis, in the younger group ≥5% WL was significantly associated with baseline HASNAL compared to baseline low serum aspartate aminotransferase (<20 U/L). In the older group, baseline HASNAL was significantly associated with being underweight, ≥5% WL, and UWWL, even after adjustment for potential confounders, and UWWL was inversely associated with regular exercise and daily alcohol consumption—both of which modified the aforementioned associations. Conclusions: Older subjects with HASNAL were at an increased risk of UWWL, possibly via skeletal muscle damage, which may be affected by common lifestyles.

High Aspartate Aminotransferase/Alanine Aminotransferase Ratio May Be Associated with All-Cause Mortality in the Elderly: A Retrospective Cohort Study Using Artificial Intelligence and Conventional Analysis

“…Some previous studies have also shown that high AST activity is associated with mortality [18,19]. In addition, we previously showed that high serum AST activity, accompanied by normal serum ALT activity, is associated with underweight owing to weight loss [20], which are both risks for mortality.…”

“…After the conclusion of a contract between Yamato City and Kanagawa University of Human Services, we received the data, which comprised clinical parameters, nursing care level, and mortality but not the cause of death. The study protocol was approved by the ethics committee of Kanagawa University of Human Services (Approval number [17][18][19][20][21][22][23][24][25][26], and the study conformed with the principles of the Declaration of Helsinki. The requirement for informed consent was waived because it was a retrospective study of anonymized data.…”

High Aspartate Aminotransferase/Alanine Aminotransferase Ratio is the Conventional Biochemical Biomarker that is Most Closely Associated with All-Cause Mortality in Older People

“…Some previous studies have also shown that high AST activity is associated with mortality [18,19]. In addition, we previously showed that high serum AST activity, accompanied by normal serum ALT activity, is associated with underweight owing to weight loss [20], which are both risks for mortality.…”

“…After the conclusion of a contract between Yamato City and Kanagawa University of Human Services, we received the data, which comprised clinical parameters, nursing care level, and mortality, but not the cause of death. The study protocol was approved by the ethics committee of Kanagawa University of Human Services (Approval number [17][18][19][20][21][22][23][24][25][26] and the study conformed with the principles of the Declaration of Helsinki. The requirement for informed consent was waived because it was a retrospective study of anonymized data.…”

“…Institutional Review Board Statement: The study was conducted according to the principles of the Declaration of Helsinki and approved by the Institutional Review Board of the Ethics Committee of Kanagawa University of Human Services (17)(18)(19)(20)(21)(22)(23)(24)(25)(26).…”