Objective:To analyze the changes in biochemical markers of bone turnover and bone mineral density (BMD) with age and interrelationships in elderly people.Methods:A cross-sectional study was conducted.Community-dwelling elderly people who underwent health examinations at the Health Management Center of the Third People's Hospital of Chengdu from March 2022 to December 2024 were randomly selected.They were divided into groups according to their age: 60-69 years old (174 cases), 70-79 years old (181 cases), ≥80 years old (184 cases).Bone alkaline phosphatase(BALP)and type I collagen carboxy-terminal peptide (CTX)measured by enzyme-linked immunosorbent assay, and BMD of the lumbar spine and hip was measured by quantitative computed tomography.The changes in BALP, CTX, and BMD with age and the correlation between bone biochemical markers and BMD of each part were analyzed.Results:There were no significant differences in sex ratio, height, weight, and body mass index (BMI) among the subjects at different ages (all P>0.05); With increasing age, at the age of over 80 years, the BMD loss of lumbar spine femoral neck, Ward's triangle and hip was higher than those at 60 to 69 years and 70 to 79 years ( F=4.052, 5.563, 16.365, 4.710, all P<0.001); BALP and CTX had no statistically significant differences between subjects of different ages( F=0.290, 0.256, both P>0.05); the results of Pearson correlation analysis showed that overall BMD in lumbar spine, femoral neck, Ward's triangle, and hip were negatively correlated with age ( r=-0.150, -0.427, -0.569, -0.258, all P<0.05).The results of the Pearson correlation analysis showed that BALP was negatively associated with lumbar spine, femoral neck, Ward's triangle, and overall BMD of hip( r=-0.224, -0.169, -0.221, -0.157, all P<0.05); CTX was negatively associated only with the lumbar spine and the overall BMD of the hip ( r=-0.150, -0.106, all P<0.05). Conclusions:The bone turnover status of elderly people can be reflected by BALP and CTX with age.The relationship between BALP and BMD is negatively correlated; CTX is negatively correlated with the overall BMD in lumbar spine and hip.Monitoring BALP and CTX is of great significance for the prevention and treatment of osteoporosis in the elderly people.

Objective:To analyze the changes in biochemical markers of bone turnover and bone mineral density (BMD) with age and interrelationships in elderly people.Methods:A cross-sectional study was conducted.Community-dwelling elderly people who underwent health examinations at the Health Management Center of the Third People's Hospital of Chengdu from March 2022 to December 2024 were randomly selected.They were divided into groups according to their age: 60-69 years old (174 cases), 70-79 years old (181 cases), ≥80 years old (184 cases).Bone alkaline phosphatase(BALP)and type I collagen carboxy-terminal peptide (CTX)measured by enzyme-linked immunosorbent assay, and BMD of the lumbar spine and hip was measured by quantitative computed tomography.The changes in BALP, CTX, and BMD with age and the correlation between bone biochemical markers and BMD of each part were analyzed.Results:There were no significant differences in sex ratio, height, weight, and body mass index (BMI) among the subjects at different ages (all P>0.05); With increasing age, at the age of over 80 years, the BMD loss of lumbar spine femoral neck, Ward's triangle and hip was higher than those at 60 to 69 years and 70 to 79 years ( F=4.052, 5.563, 16.365, 4.710, all P<0.001); BALP and CTX had no statistically significant differences between subjects of different ages( F=0.290, 0.256, both P>0.05); the results of Pearson correlation analysis showed that overall BMD in lumbar spine, femoral neck, Ward's triangle, and hip were negatively correlated with age ( r=-0.150, -0.427, -0.569, -0.258, all P<0.05).The results of the Pearson correlation analysis showed that BALP was negatively associated with lumbar spine, femoral neck, Ward's triangle, and overall BMD of hip( r=-0.224, -0.169, -0.221, -0.157, all P<0.05); CTX was negatively associated only with the lumbar spine and the overall BMD of the hip ( r=-0.150, -0.106, all P<0.05). Conclusions:The bone turnover status of elderly people can be reflected by BALP and CTX with age.The relationship between BALP and BMD is negatively correlated; CTX is negatively correlated with the overall BMD in lumbar spine and hip.Monitoring BALP and CTX is of great significance for the prevention and treatment of osteoporosis in the elderly people.