Liver function and distribution of liver fibrosis in older adults aged 65 years and above in 18 longevity areas in China

Objective: To investigate the liver function and the distribution characteristics of liver fibrosis in older adults aged ≥65 years in 18 longevity areas in China. Methods: Based on cross-sectional data from the 2021 China Healthy Ageing and Biomarkers Cohort Study. The information about the demographic characteristics, lifestyles, cognitive function, and disease history of the older adults were collected through face-to-face interviews. Fasting blood samples were taken from the older adults for routine blood tests and liver function tests, including AST, ALT, AST/ALT, total protein (TP), albumin (ALB), globulin (GLOB) tests, and the ratio of ALB to GLOB (A/G) and the Fibrosis-4 index for liver fibrosis were calculated. The skewness-median-coefficient of variation method was used to describe the liver function and the distribution of liver fibrosis of the older adults. The abnormal liver function status of older adults with different risks for advanced liver fibrosis was explored. Results: The study included 5 403 participants with an average age of (85.2±11.6) years, of whom 2 365 (43.8%) were men. In the older adults, the AST, ALT, ALB, TP, and A/G levels showed downward trends with age, while AST/ALT and GLOB levels increased with age. The older adults at high-risk for progressive liver fibrosis accounted for 49.7%. The proportions of those at high risk were 50.0% in men and 49.4% in women. Men aged 65-79, 80-89, and ≥100 years showed higher high risk rates compared with women in same age groups (42.0% vs. 36.9%, 50.0% vs. 45.2% and 69.1% vs. 60.9%). Men had more abnormal liver damage indicators compared with women, such as low AST (9.9% vs. 4.3%) and low ALT (55.7% vs. 51.2%), while women had more abnormal liver synthesis indicators compared with men, including low ALB (25.2% vs. 29.2%) and low A/G (9.2% vs. 11.1%). Conclusions: The risk for advanced liver fibrosis was relatively high in older adults in China, showing an upward trend with age and being higher in men than in women. The abnormality of liver function was characterized by lower level than reference range in older adults. Men showed more liver damage indicators (low AST and low ALT) compared with women, whereas women showed more abnormal liver synthesis indicators (low ALB and low A/G) compared with men.