Abstract: BACKGROUND: Middle-aged and elderly women have a high risk of osteoporosis, and chronic diseases increase the risk of osteoporosis. Low bone mass is a risk stage before the onset of osteoporosis. There are a small amount of relevant reports on the difference of fracture risk and the tangent value of diagnostic indicators in the population with common chronic diseases.
OBJECTIVE: Through the analysis of fracture risk of middle-aged and elderly women with different chronic diseases, to investigate the correlation between obesity, hypertension, hyperlipemia, diabetes, arteriosclerosis and bone mineral density and identify the cut-off value of low bone mass index, thereby providing reference for the prevention and treatment of osteoporosis. 
METHODS: A total of 203 cases of female adults aged 45-70 years were divided into normal group and chronic disease group. The calcaneal bone density was measured by using an ultrasonic bone densitometer. Brachial-ankle pulse wave velocity was tested by using an arteriosclerotic instrument. Blood sugar and blood lipid were tested by using an automatic biochemical analyzer. Body mass index, fat mass and muscle mass were measured by using a body composition analyzer. 
RESULTS AND CONCLUSION: There were significant differences in body mass index and fracture risk coefficient of women aged 61-70 years and bone strength of women aged 51-60 years and 61-70 years compared with those aged < 50 years (P < 0.05). The fracture risk of diabetes group was significantly higher than that of the other groups, while the fracture risk of arteriosclerosis group was significantly higher than that of normal group and obesity group (P < 0.05). Bone mineral density was negatively correlated with age, left vascular elasticity, right vascular elasticity and triglyceride level, but positively correlated with body mass index (P < 0.05). The area under the receiver operating characteristic curve of body mass density and the above indexes was 0.5-0.7, and the corresponding tangents of low body mass density were 55.5 years old (age), 756.0 cm/s (left vascular elasticity), 789.0 cm/s (right vascular elasticity), 1.115 mmol/L (triglyceride level) and 22.35 kg/m2 (body mass index). To conclude, diabetes and arteriosclerosis increase the risk of fracture in middle-aged and elderly women. Body mass index, vascular elasticity and triglyceride level have a certain early diagnostic value in predicting low bone mass in women.

Key words: middle-aged and elderly women, fracture risk, low bone mass, tangent point prediction