Associations of Serum Homocysteine with Bone Mineral Density and Osteoporosis Incidence in Chinese Middle-Aged and Older Adults: A Retrospective Cohort Study

Objective: This research investigated the prospective association of serum homocysteine with lumbar bone mineral density (BMD) and the risk of osteoporosis in the Chinese population. Methods: In this cohort, 2551 Chinese individuals aged ≥50 years underwent annual health examinations. Among them, 2551, 1549, and 926 completed two, three, and more than three examinations, respectively. We used generalized estimating equations to analyze the connection between serum homocysteine and lumbar BMD. Additionally, we assessed the connection between serum homocysteine and the incidence of osteoporosis using Cox proportional hazard models. Subgroup analyses based on covariates were performed to identify important at-risk populations. Results: Participants with higher homocysteine levels showed decreased lumbar BMD compared to those with lower homocysteine levels (p-trend < 0.05). Specifically, lumbar BMD decreased by −0.002 (−0.003, −0.001) g/cm2 for every standard deviation increase in log-transformed serum homocysteine. Compared to the lowest quartile of homocysteine levels, lumbar BMD decreased by −0.006 (−0.010, −0.002) g/cm2 in the highest quartile in men. In smokers, lumbar BMD decreased by −0.007 (−0.012, −0.003) g/cm2 in the highest quartile. During the follow-up period, 175 incidences of osteoporosis were recorded. Serum homocysteine was linked to an increased risk of osteoporosis (p-trend < 0.05). Furthermore, for every standard deviation rise in log-transformed homocysteine, the HR for osteoporosis was 1.33 (95% CI, 1.12–1.58). Conclusions: Elevated homocysteine levels may be responsible for reduced lumbar BMD in middle-aged and older Chinese people, especially men and smokers. In addition, elevated homocysteine levels may be a risk factor for the development of osteoporosis.