Low bone mineral density in the hip as a marker of advanced atherosclerosis in elderly women

Abstract

Previous studies indicate that low bone mineral density (BMD) in the hip is a useful predictor of cardiovascular mortality among the elderly. The objective of this study was to investigate whether low hip BMD is directly associated with the severity of atherosclerosis. The per-protocol population consisted of 963 women aged 60-85 years. Study variables were aortic calcification (AC) graded on lateral lumbar radiographs, BMD at various anatomic sites (distal radius, lumbar spine, proximal femur) measured by DXA, information on various risk factors, and medical history. After adjustment for age, BMD at the proximal femur, but not at the radius or spine BMD, showed statistically significant association with the severity of AC (r = -0.12-17, P < 0.001). Age, years since menopause, BMI, level of education, current and previous smoking, and weekly fitness activity were significant common risk factors (all P < 0.05) with contrasting influence on AC and hip BMD. In a multiple regression model, AC contributed significantly and independently to the variation in hip BMD (beta = -0.10, P = 0.004). Impaired blood flow represented by 40 women with documented history of intermittent claudication was not an independent contributor and did not alter the association between AC and hip BMD. However, AC and demineralization in the hip was particularly severe in women with intermittent claudication accompanied by a higher prevalence of coronary heart disease compared with age-matched controls (all P < 0.001). In conclusion, severe osteoporosis in the hip may indicate advanced atherosclerosis and thereby an increased risk for not only hip fractures but also for coronary heart disease. The results further emphasize that osteoporosis in the hip and peripheral vascular disease are linked by common risk factors and pathomechanisms.