BMD assessment helps pinpoint Asian women at risk of ASCVD

Low bone mineral density (BMD), on its own, is predictive of a heightened risk of atherosclerotic cardiovascular disease (ASCVD) in women, as well as provides an incremental prognostic value over age and other clinical risk factors, as shown in a study from Korea.

The risk could be further stratified according to BMD in a subgroup of relatively young women with no risk factors, according to the investigators. 

“These results … [support] the potential role of BMD as a novel risk marker for future ASCVD in women,” they said. It opens an opportunity for large-scale ASCVD risk assessment without additional cost and radiation exposure, given that dual-energy X-ray absorptiometry (DXA) is widely used to screen for osteopenia and osteoporosis in asymptomatic individuals.

The current approach, namely the 10-year ASCVD risk, makes use of risk-scoring algorithms such as the Pooled Cohort Equation. But this has been shown to have limited accuracy in identifying women at high risk of developing ASCVD. [JAMA 2016;316:2126-2134; J Am Coll Cardiol 2015;65:1633-1639]

“Although the [current] risk prediction could be improved by additional test data, such as the coronary artery calcium score, widespread implementation of coronary artery calcium scanning has been unsuccessful because of the perceived risks of radiation exposure and cost,” the investigators pointed out. [Circulation 2019;139:e1082-1143]

In the study, they examined whether the evaluation of BMD was associated with future ASCVD events in a cohort of 12,681 women (mean age 63.0 years, mean body mass index 24.1 kg/m²) who underwent DXA. None of them had been prescribed hormone replacement therapy for more than 180 days within 6 months before and after the index DXA date.

ASCVD events occurred in 468 women (3.7 percent) over a median follow-up of 9.2 years. This risk was particularly pronounced among those with lower BMD at the lumbar spine, femur neck, and total hip. The corresponding adjusted hazard ratios (HRs) per 1-standard deviation decrease in BMD were 1.16, 1.29, and 1.38 (p<0.001 for all). [Heart 2021;doi:10.1136/heartjnl-2020-318764]

A clinical diagnosis of osteoporosis also showed an independent association with the risk of ASCVD (adjusted HR, 1.79; p<0.001).

The addition of BMD or a clinical diagnosis of osteopenia or osteoporosis to clinical risk factors for ASCVD improved the accuracy of identifying women at risk of developing ASCVD events. BMD at the total hip area specifically provided the strongest improvement in risk stratification. So, the discrimination ability of the model incorporating the said BMD value was significantly better than that of the 10-year ASCVD risk (p<0.001).

“However, further evaluation is required to determine the degree to which BMD refines the risk assessment compared with that with more direct imaging tests of the cardiovascular system, such as carotid ultrasonography or coronary artery calcium imaging,” the investigators acknowledged.

“Additionally, comparison with the predictive value of novel risk markers, such as high-sensitivity C reactive protein or lipoprotein(a), would be valuable, given that these risk markers are also expected to improve the risk stratification for ASCVD,” they added. [JAMA 2012;308:788-795; JAMA Cardiol 2018;3:619-627]

Several potential mechanisms have been proposed to explain a link between atherosclerosis and osteoporosis. For the most part, these two medical conditions share common pathogeneses, such as chronic inflammation and accumulative oxidative stress. Another is oestrogen, a sex hormone that is critical in regulating bone biology and the vasculature. [J Nephrol 2012;25:619-625; Atherosclerosis 2002;165:301-307]

The investigators believe that their study paves the way for an outcome trial to establish whether BMD assessment in women translates into long-term clinical benefits.