Vascular calcification and osteoporosis are common age-related processes that are prominently displayed on routine lateral lumbar spine radiographs as dense calcium mineral deposits of the aorta that lie adjacent to osteopenic vertebrae. Using a population-based cohort of older men and women, we tested the hypothesis that the progression of vascular calcification of the abdominal aorta should be greatest in those individuals with the greatest amount of bone loss. From the original population-based Framingham Heart Study cohort, 364 women and 190 men had lateral lumbar spine and hand radiographs performed between 1966 and 1970 and repeated between 1992 and 1993. The lateral lumbar films were read for the presence of aortic calcification using a semiquantitative method, and the hand films were read for second metacarpal relative cortical area (MCA). Using multivariate regression techniques, the 25-year progression of the abdominal aortic calcification index was examined in relation to the change in the MCA, while adjusting for recognized risk factors for atherosclerotic cardiovascular disease. During the 25 years of followup, the MCA decreased by 22.4% in women (from 79.6±7.8 (SD) to 61.8±10.3) and by 13.3% in men (from 80.6±6.9 to 69.9±8.3). The aortic calcification score increased over eightfold in women (from 1.2±2.7 (SD) to 9.9±6.7) and sixfold in men (from 1.6±2.8 to 9.6±6.3). There was a significant association between percent change in MCA and change in aortic calcification index (P=0.01) in women after controlling for all potential confounders. No association was observed in men (P=0.50), including the 50% of men with the greatest bone loss. This is the first longitudinal study to show that women with the greatest magnitude of bone loss also demonstrate the most severe progression of abdominal aortic calcification, suggesting that the two processes may be related.