Background As life expectancy increases, the number of elderly patients with osteoporosis rises as well. Many factors affect the development of osteoporosis, and good physical fitness may contribute to having better social adaptability in older people. So it is very important to pay attention to osteoporosis and ensure physical fitness in this group.
Objective To explore the factors associated with osteoporosis, and analyze physical fitness in elderly men, providing a theoretical basis for preventing osteoporosis, improving physical fitness and developing health management programs for this group.
Methods This study was conducted from January 2018 to December 2020. A total of 250 elderly men who underwent bone mineral density (BMD) examination were selected from Health Management Center, Inner Mongolia People's Hospital, and divided into normal BMD, osteopenia and osteoporosis groups by BMD examination results. Data were collected, including baseline information, laboratory results, physical fitness test results〔 including muscular strength (number of elbow bending within 30 seconds, 30-second sit-to-stand test results) , flexibility (shoulder and arm stretches, sitting flexion test) , balance (stand on one foot with eyes closed) , aerobic capacity (2-minute step test) , agility/mobility (timed up go test with a minimal space of 2.5 meters) 〕.
Results Of the 250 subjects, 76 (30.4%) had normal BMD, 123 (49.2%) had osteopenia, and 51 (20.4%) had osteoporosis. Multivariate Logistic regression analysis demonstrated that abdomen circumference〔OR=0.710, 95%CI (0.566, 0.891) 〕, body mass index 〔OR=0.685, 95%CI (0.474, 0.990) 〕, high-density lipoprotein cholesterol〔OR=74.182, 95%CI (3.738, 1 472.125) 〕, 25 (OH) D3〔OR=0.745, 95%CI (0.619, 0.897) 〕, and estradiol〔OR=0.784, 95%CI (0.665, 0.924) 〕were associated with osteoporosis in elderly men (P<0.05) . All the subjects successfully completed physical fitness tests, without adverse events. The number of repetitions of sit-to-stands within 30 seconds, results of shoulder and arm stretches, sitting flexion test, and 2-minute step test, duration for stand on one foot with eyes closed, as well as time used for timed up go test with a minimal space of 2.5 meters differed significantly across normal BMD, osteopenia and osteoporosis groups (P<0.05) . The number of elbow bending within 30 seconds showed no significant differences across the three groups (P>0.05) .
Conclusion In elderly men, abdomen circumference, body mass index, high-density lipoprotein cholesterol, 25 (OH) D3, and estradiol may independently associated with osteoporosis. Physical fitness indices varied significantly by BMD, especially flexibility, balance, aerobic capacity and agility/mobility.