Elevated serum aspartate aminotransferase levels concomitant with normal alanine aminotransferase levels in older low body weight people: Preliminary findings from a community-based epidemiological study
BackgroundSerum enzyme levels, including hepatic transaminase, are unknown in older people with low body weight (LBW), who can easily experience sarcopenia. Therefore, we addressed preliminarily this issue in a cross-sectional study of an apparently healthy population. MethodsWe investigated the relationship of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyl transpeptidase (GGT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and total bilirubin levels with body mass index (BMI) and age in 79,623 subjects aged 20-80 years who underwent an annual checkup. ResultsSerum levels of AST, ALP, and LDH levels were significantly higher in older ([≥]50 years) non-obese subjects compared with younger (< 50 years) corresponding subjects. Serum AST levels were significantly higher in older LBW subjects (BMI[≤]18.9 kg/m2) than in those with a reference BMI of 20.9-22.9 kg/m2. Serum AST levels showed a J-shaped curve against BMI, whereas ALT and GGT levels showed a linear relationship, regardless of age. ConclusionElevated serum AST levels concomitant with normal ALT levels, which might reflect systemic damage of skeletal muscle, may be prevalent in older LBW people. Further studies need to determine whether such a condition is equivalent to the etiology of sarcopenia.