Mammograms have, so far, had the single role of identifying potentially cancerous tumours in the breast. However, could they also help doctors identify women at risk of heart disease and heart failure?
Some researchers believe that mammograms could also help doctors identify women with a high risk of heart failure.
Mammograms work by using low energy X-rays to “scan” breast tissue for irregularities and abnormalities that may be signs of cancer. They are the first port of call when it comes to diagnosing breast cancer in its early stages.
In 2016, the United States Preventive Services Task Force recommended that women aged 50–74 years — the age range in which women’s risk of breast cancer increases — should undergo breast cancer screening once every 2 years.
Mammograms do not only detect potential cancerous tumours, though. As it turns out, they also show the formation of breast arterial calcifications, which are calcium buildups inside the arteries in the breast.
Breast arterial calcification is often associated with coronary artery calcium — a dangerous buildup of calcium sediment in the arteries that transport oxygenated blood to the heart — particularly in women.
Coronary artery calcium is, in itself, a strong predictor of cardiovascular disease, and doctors will use computed tomography scans to screen for these buildups in people whom they believe to be at risk. Dr. Bui and colleagues argue that breast arterial calcification can help identify women who may be at risk of cardiovascular problems, including heart attack, stroke, and heart failure, in which the heart is unable to pump blood effectively. In particular, the investigators argue that mammograms — which women over a certain age will often undertake as a regular screening procedure anyway — could help doctors detect not just cancer but also the risk of heart disease. They explain that these tests could do this by highlighting the presence of calcium buildups in breast arteries.
In their study, the investigators analyzed data from the medical records of 278 female participants with a mean age of about 61 years. These records covered the period of 2006–2016.
All of these participants had undergone both a mammogram and a coronary CT scan within the same year.
Meanwhile, Doctors commonly prescribe metformin to help people with type 2 diabetes lower their blood sugar levels. The drug increases insulin sensitivity through its effects on glucose metabolism.
Metformin may hold surprising benefits in the fight against age-related illness.
However, although there is clear evidence of metformin’s effectiveness, scientists do not fully understand how it interacts with cells and tissues at the molecular level. Using cell cultures and mice, the researchers identified numerous biochemical switches for turning various cell and molecular processes on and off.
The findings shed light not only on metformin’s mechanism of glucose control, but also on a surprising number of other reactions and pathways.
Large-scale clinical trials of metformin are already under way to test the drug’s effectiveness in extending life span and health span — that is, the proportion of a person’s life span that they spend in good health. However, the underlying biochemistry has been unclear. Teams from three research centres worked on the study: the Salk Institute for Biological Studies, the Scripps Research Institute — both in La Jolla, CA — and Weill Cornell Medical College in New York.
“These results,” says Reuben J. Shaw, one of the study’s corresponding authors, “provide us with new avenues to explore in order to understand how metformin works as a diabetes drug, along with its health-span-extending effects.”
“These are pathways that neither we, nor anyone else, would have imagined,” he adds.
Shaw is a professor of molecular and cell biology at the Salk Institute and director of the Salk Cancer Centre.
More recently, scientists have found that metformin may be effective in a number of other conditions, including obesity, cancer, metabolic syndrome, polycystic ovary syndrome, and nonalcoholic fatty liver disease.
Other recent research has also suggested that metformin may have anti-aging effects Trusted Source and an ability to protect bone, especially during the early phases of rheumatoid arthritis.
Until the new study, scientists’ understanding of the biochemical effects of metformin was limited to knowing that the drug activates a signalling pathway called AMPK. This pathway plays a key role in balancing energy levels in cells.
Prof. Shaw had also discovered that when nutrients levels are low, the AMPK pathway holds back cell growth and alters metabolism. Researchers have seen this effect in cancer. Knowing this led Prof. Shaw and colleagues to wonder if metformin might also work through other pathways.
For the new study, the teams used a “quantitative proteomics platform” to screen kinases. These are signalling proteins that can switch cell processes on and off.
The researchers found hundreds of kinases whose switching activity responds rapidly to metformin with potential impact on healthy aging. Many of the signalling pathways work independently of AMPK.
Scientists were already aware of two of the pathways — protein kinase D and MAPKAPK2 — and that they concern cellular stress. This could explain the link with healthy aging and the impacts on extending life span and health span.