Background: Bone mineral density (BMD) is a key determinant of fracture risk and functional decline in older adults. Age-related metabolic and vascular dysregulation may contribute to skeletal vulnerability; however, their predictive value for subsequent BMD levels in older men remains unclear. This study aimed to examine whether baseline metabolic indicators and their 4-year changes can predict BMD measured at follow-up in community-dwelling older men. Methods: In this prospective predictive analysis, 86 men aged 65 years and older underwent assessments of physical characteristics and metabolic syndrome-related indicators at baseline and after 4 years. The BMD of the distal forearm was measured at follow-up using dual-energy X-ray absorptiometry. Multiple linear regression analyses were performed to identify baseline and longitudinal metabolic predictors of follow-up BMD. Results: In the baseline predictor model, higher baseline systolic blood pressure was independently associated with lower BMD at follow-up. In the change-inclusive model, a 4-year increase in hemoglobin A1c (HbA1c) was independently associated with lower BMD at follow-up, whereas baseline HbA1c levels were not predictive. Other metabolic indicators did not show significant associations with follow-up BMD. Conclusions: Baseline systolic blood pressure and longitudinal increases in HbA1c levels were independent predictors of lower BMD measured at follow-up in community-dwelling older men. These findings suggest that commonly assessed metabolic indicators may provide useful predictive information for identifying older men at risk of low BMD, highlighting the importance of vascular and metabolic health in skeletal aging.