DXA imaging may inform atherosclerotic vascular disease risk in older women
Abdominal aortic calcification scores assessed using densitometric lateral spine images at the time of bone mineral density testing may identify older women at higher risk for atherosclerotic vascular disease-related events or death, according to findings published in the Journal of Bone and Mineral Research.
“As large numbers of elderly women are already undergoing routine bone densitometry, the use of these lateral spine images to identify women with subclinical cardiovascular disease who are at a higher risk for future cardiovascular events may help to inform future treatment decisions,” Joshua R. Lewis, PhD, of the School of Medical and Health Sciences at Edith Cowan University in Joondalup, WA, Australia, and colleagues wrote in the study background. “Additionally, using these images may form the basis of low-cost, routine, community-based initiatives to improve current CVD prevention strategies, such as weight loss, improved diet and increased physical activity, as well as drug therapy with statins.”
Lewis and colleagues analyzed data from 1,052 ambulatory white women aged at least 70 years who underwent baseline BMD testing via DXA in 1998 or 1999 as part of the Calcium Intake Fracture Outcome study, a 5-year, prospective, randomized controlled trial of oral calcium supplements. Participants also provided fasting blood samples to assess total cholesterol, HDL cholesterol, LDL cholesterol and triglyceride levels, and provided medical history for baseline CV risk assessment. Women with history of prior myocardial infarction or revascularization procedures were excluded. Researchers estimated 10-year Framingham general CV risk scores using both BMI data and lipid profile data and 14.5-year atherosclerotic vascular disease-related hospitalizations and deaths, using linked health records. Researchers used Cox regression analyses to estimate the association of low, moderate or high abdominal aortic calcification observed on DXA scans with incident atherosclerotic vascular disease events.
Within the cohort, 471 women had low abdominal aortic calcification severity (score 0-1), 387 had moderate severity (score between 2-5) and 194 had high severity (score between 6-18); the median score was 2. Over 14.5 years, 335 women experienced an atherosclerotic vascular disease event, and 206 women died from an atherosclerotic vascular disease-related event.
Researchers found that women with a high abdominal aortic calcification score were more likely to be hospitalized or die from an atherosclerotic disease event when compared with women who had a low abdominal aortic calcification score (HR = 1.51; 95% CI, 1.18-1.94), with results persisting after adjustment for Framingham risk scores and treatment.
In examining atherosclerotic disease-related death, researchers found that women with both moderate and high levels of abdominal aortic calcification were at higher risk for death vs. women with low severity scores, with HR 1.47 (95% CI, 1.07-2.01) and 1.93 (95% CI, 1.35-2.76), respectively. Risk persisted after adjustment for Framingham risk scores.
In additional analyses, researchers stratified the cohort by abdominal aortic calcification status, assessing the association with CV events and all-cause mortality for women who had no abdominal aortic calcification (n = 287) and any abdominal aortic calcification (n = 765).The researchers noted that most women who underwent BMD testing had evidence of abdominal aortic calcification, with advanced or severe scores in one in five women.
“Our study highlights that bone density machines can be used to not only tell women about their risk of fracture, but also as a safe, low-cost test of their long-term risk of cardiovascular disease,” Lewis told Endocrine Today.
Lewis called the findings encouraging, but added that important features of calcification may not be adequately captured by the current scoring methods.
“New scoring methodology using these scans needs to be developed and validated in large prospective cohort studies,” Lewis said. “Next, studies with longitudinal scans every 2 or 3 years are needed to determine whether the change in calcification or ‘active’ disease is more important than the amount of calcification, which can be evidence of historical disease or active disease. Third, we need to know whether patient and physician knowledge of abdominal aortic calcification will lead to real change in clinical decisions and patient behavior.”– by Regina Schaffer
For more information:
Joshua R. Lewis, PhD, can be reached at the School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Dr, Joondalup WA 6027, Australia; email: firstname.lastname@example.org.
Disclosures: One of the study authors reports he is an employee of Hologic, Inc., and holds multiple densitometer imaging and reporting patents in the U.S. and worldwide.