Abstract: Objective To investigate the impact of different doses of salmon calcitonin on the levels of osteocalcin(OST), N-terminal propeptide of type I procollagen(PINP) and bone pain, and the safety in the elderly patients with osteoporosis. Methods A total of 106 elderly patients with osteoporosis at Xinjiang Production and Construction Corps Hospital from August 2021 to July 2023 were enrolled in this study. These patients were randomly divided into the low-dose group(n=53) and the high-dose group(n=53) according to the dosage of salmon calcitonin. All patients received alendronate as the standard treatment.The low-dose group received injection of salmon calcitonin, 50 IU every two days in the first 2 weeks of treatment, and 50 IU once a week from the 3rd week. The high-dose group received injection of salmon calcitonin, 50 IU/d for the first 2 weeks of treatment, and 100 IU once a week from the 3rd week. All patients were treated continuously for 3 months. The general clinical characteristics, the levels of OST, PINP, beta-isomer of the C-terminal telopeptides of type Ⅰ collagen(β-CTx) and bone mineral density (BMD) before and after the treatment were compared between the two groups. The improvement in bone pain was assessed using the visual analogue score(VAS), and the clinical effectiveness and the incidence of adverse reactions were compared between the two groups. Results After treatment, the levels of serum OST and β-CTx were significantly decreased, and the level of PINP was significantly increased in both groups, especially in the high-dose group(P<0.05). After treatment, the levels of BMD at femoral neck, lumbar spine and hip were significantly increased in both groups, especially in the high-dose group(P<0.05). After treatment, the VAS score was significantly decreased in both groups, especially in the high-dose group(P<0.05). There were no significant differences in the total effective rate and the incidence rate of adverse between the two groups(P>0.05). Conclusions An increased dosage of salmon calcitonin could enhance the therapeutic effectiveness in treating osteoporosis among the elderly patients, and improve bone metabolism, BMD and bone pain with safety.

Key words: aged, osteoporosis, bone metabolism, salmon calcitonin, bone pain