Unraveling the Potential of Physical Activity in the Treatment of Familial Hypercholesterolemia: Impact of Exercise on Cardiorespiratory Fitness, Atherosclerosis Progression, and Underlying Mechanisms

Familial hypercholesterolemia (FH) is an inherited disorder characterized by high levels of LDL cholesterol and an increased risk of atherosclerosis and premature cardiovascular disease. From a clinical perspective, FH patients require lifelong management and monitoring of their cholesterol levels and may require multiple medications to control their cholesterol levels, leading to increased healthcare utilization and costs. From an economic perspective, the lifetime costs of managing FH can be significant and can include the cost of medications, diagnostic tests, and hospitalizations for cardiovascular events. In Spain, FH represents a heavy burden for the health care system, with direct costs of 37,299,000 €, indirect costs (due to loss of labor productivity) of 50,049,000 €, and an average of 25 years of life lost adjusted for labor productivity. From a public health perspective, FH affects around 25 million people worldwide that are at an increased risk of premature mortality, making FH a significant public health concern.

Hypercholesterolemia is one of the main vascular risk factors (VRF) related to the development of cardiovascular diseases (CVD), mainly myocardial infarction (MI) and stroke, the main causes of global mortality in the past decades. It is important to note that patients with FH present an increased prevalence of CVD at a very early age (44 years on average) and, in comparison to the general population, patients with FH have a 13.2 times higher risk of developing atherosclerotic CVD; specifically, up to 50% of men and 30% of women with FH will suffer an MI before the age of 60. Atherosclerosis is a complex process that involves endothelial dysfunction, inflammation, or oxidative stress. The presence of atherosclerosis can be assessed with positron emission tomography (PET), which has shown a high ability to predict the development of atherosclerotic plaque and cardiovascular events even after the consideration of classic VRF, so it is used as a method of early diagnosis of subclinical atherosclerosis in patients with chronic proinflammatory diseases. Therefore, the use of PET along with various plasma markers of inflammation in patients with FH (including C-reactive protein, [CRP], interleukin 10 [IL10], oxidized LDL [oxLDL], and the intracellular adhesion molecule 1 [ICAM1]), could allow the detection of atherosclerotic disease in the very early stages. Consequently, understanding novel markers that allow early identification of subclinical atherosclerosis, as well as strategies for reducing the VRF associated with FH, are key targets in these patients.

The treatment of hypercholesterolemia is primarily based on pharmacological therapies such as statins, ezetimibe, and monoclonal antibodies, which can decrease LDL cholesterol levels by up to 60%. However, the rate of achieving LDL cholesterol targets set by clinical practice guidelines is low (30-40%) due to poor tolerance to high doses of statins and other reasons. Importantly, new risk factors such as chronic vascular inflammation and oxidative stress are now considered in the etiology of atherosclerotic CVD beyond LDL cholesterol levels. Consequently, new treatment approaches are needed to address the treatment of FH as an important public health concern.

For all the above, unraveling the role of potential protective factors and interventions that might significantly improve the cardiometabolic profile and reduce the risk of morbi-mortality in this population, as well as the mechanisms involved, is of wide clinical and public health interest.

The UPPA-FH project will unravel the role of physical activity and different exercise interventions on critical health markers in men and women with FH and will study the mechanisms by which these effects are produced. For instance, whether the effects of exercise are mediated by changes in the metabolomic signature related to blood lipids will be explored. This will enable i) international institutions to develop clinical guidelines including exercise as a first-line treatment for the management of FH and ii) to unravel (for the first time) the potential mechanisms behind the effects of exercise in this population.