A new research presented in JAMA says to have identified proof to support a causal link between high levels of “bad” cholesterol and aortic valve stenosis – a type of aortic valve condition in which the valve is narrowed, reducing blood flow from the heart.
With respect to the study team, which includes Dr. George Thanassoulis, aortic valve disease is the very frequent type of heart valve disease in North America and Europe. It is also the very frequent cause for sufferers to need an aortic valve replacement.
Previous studies have connected raised low-density lipoprotein (LDL) cholesterol – well-known as the “bad” cholesterol – with development of aortic valve stenosis.
But Dr. Thanassoulis and co-workers note that scientists monitoring the consequences of cholesterol-lowering medicines in sufferers who presently have aortic valve disease have was unable to show decreased disease progression.
“Nonetheless,” the researchers add, “if LDL cholesterol has a normal role in the earlier stages of aortic valve disease, this could have essential effects for prevention.”
Examining genetic difference to recognize biomarkers of aortic valve disease
With the goal of developing a better knowing of the connection between LDL cholesterol and aortic valve disease, the researchers applied a approach known as “Mendelian randomization.”
The method enables scientists to use genetic difference to differentiate biomarkers that lead to disease from those that do not. “This approach has been effectively used to examine for causality of various biomarkers with various clinical end points,” the researchers note.
In this research, the scientists examined the connection between members’ genetic risk score – an estimate of genetic predisposition to high lipid levels in the blood – and aortic valvre disease.
They considered this connection among more than 35,000 people who were portion of research in the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE): the Framingham Heart Research, the Multi-Ethnic Study of Atherosclerosis, the Age/Gene Environment Study and the Malmö Diet and Cancer Study.
The scientists examined calcium levels in the aortic valves of individuals using computed tomography (CT) scans. A calcium buildup in the valve – recognized as aortic valve calcification – is a recognized cause for aortic valve stenosis.
The team also evaluated the occurrence and diagnoses of new aortic valve stenosis among individuals, along with aortic valve replacement occurrence.
Results ‘support causal role of LDL cholesterol in development of aortic stenosis’
The scientists identified that the existence of aortic valve calcium was more dominant in individuals who were genetically susceptible to increased levels of LDL cholesterol.
Individuals genetically susceptible to high LDL cholesterol levels in the Malmö Diet and Cancer Research were more probably to have a new diagnosis of aortic valve stenosis. In addition, in a sub-group of this research who had their lipid fractions calculated, increased LDL cholesterol at baseline was connected to new diagnoses of aortic valve stenosis.
Leaving comments on these results, the research authors say:
“Our outcomes link a genetically mediated increase in plasma LDL cholesterol with early subclinical valve disease, as calculated by aortic valve calcium and incident clinical aortic stenosis, offering supportive proof for a causal role of LDL cholesterol in the progression of aortic stenosis.
These data recommend that, in addition to the recognized threats for myocardial infarction and other vascular illnesses, raises in LDL cholesterol are also related with enhanced risk for aortic stenosis.”
The scientists conclude that additional research is warranted to figure out whether early intervention methods to decrease LDL cholesterol levels could prevent aortic valve disease.