Prevalence of and Risk Factors for the Different Stages of Bone Loss in Postmenopausal Women and Elderly Men: A Community-Based Cross-Sectional Study

Abstract

Background: Despite large populations with osteoporosis worldwide, no comprehensive study on the risk factors for different bone loss stages exists. We therefore assessed bone health status and the prevalence of and risk factors for the different bone loss stages. Methods: This cross-sectional study included a representative sample of postmenopausal women and elderly men aged ≥50 years (N=1,412: 1,031 women, 381 men) recruited from eight communities in Guangzhou. All participants underwent measurement of bone mineral density of the lumbar vertebrae and left hip and an assessment of serum bone metabolism parameters. Demographic, clinical, and laboratory data were compared among patients with different bone loss stages. We used univariable and multivariable logistic regression models to explore the risk factors associated with osteopenia or osteoporosis. Findings: The prevalence of osteopenia and osteoporosis was 48·7% and 36·5% in women and 58·3% and 22·3% in men, respectively. For postmenopausal women with normal bone mass, a higher risk of osteoporosis was associated with older age, menstruation duration <35 years, menopause duration ≥10 years, lower education (primary school and lower), higher alkaline phosphatase (ALP), and family history of osteoporosis, whereas a lower risk with a large body mass index (BMI) and waist circumference. For postmenopausal women with osteopenia, a higher risk of osteoporosis was associated with older age, menstruation duration <35 years, higher procollagen I N-terminal peptide (PINP), higher Mg, and family history of osteoporosis, whereas a lower risk with a large BMI. For elderly men with normal bone mass, a higher risk of osteopenia was associated with a higher ALP, higher phosphorus, and higher Mg, while a lower risk with a large BMI and left handgrip strength. A higher risk of osteoporosis was associated with higher phosphorus levels and retirement, while a lower risk with a large BMI. For elderly men with osteopenia, no risk factor was associated with osteoporosis. Interpretation: The incidence of osteoporosis was higher in postmenopausal women than in the elderly men, whereas the incidence of osteopenia was more than 50% in the elderly men, which was significantly higher than that in postmenopausal women. Risk factors vary across bone loss stages in postmenopausal women and elderly men and for postmenopausal women include older age, menstruation duration <35 years, menopause duration ≥10 years, lower education (primary school and lower), higher ALP, higher PINP, higher Mg, family history of osteoporosis, lower BMI, and lower waist circumference, whereas for elderly men include higher ALP, higher phosphorus, higher Mg, lower BMI, lower left handgrip strength, and retirement. Caffeinated beverages and lack of Ca and vitamin D were not risk factors in the population. Hence, accurate prediction and early prevention should be prioritised in China to reduce osteoporotic fracture-related morbidity and mortality. Funding Statement: This study was funded by Special Research Project for the Construction of the National TCM Clinical Research Base of the State Administration of Traditional Chinese Medicine (Grant number: JDZX2015078); National Natural Science Foundation of China (Grant number: 81674000, 81774338, 81904225); and Major Research Project of Guangzhou University of Chinese Medicine. Declaration of Interests: The authors declare no competing interests. Ethics Approval Statement: The study was approved by the ethics committee of the First Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine (NO·ZYYECK [2016]028). We obtained written informed consent from all study participants.