High cholesterol, a significant contributor to heart attack and stroke, can affect individuals regardless of their weight, diet, or exercise habits, according to a leading cardiologist. The condition often progresses silently, increasing cardiovascular disease risk even in those who appear healthy.
Dr. Zoe Astroulakis, a consultant cardiologist at New Victoria Hospital in London, explained that a person's cholesterol levels cannot be determined by their physical appearance alone. "You cannot tell what your blood cholesterol is without a blood test," she stated. "You may have had high cholesterol levels all your life, and yet wouldn’t show any signs of it."
Cholesterol, a fatty substance in the blood, is measured in millimoles per litre (mmol/L). Healthy adults should aim for an overall level of 5 mmol/L or less, with low-density lipoprotein (LDL), often termed 'bad' cholesterol, no more than 3 mmol/L. High-density lipoprotein (HDL), or 'good' cholesterol, should be above 1 mmol/L. LDL can accumulate in artery walls, narrowing blood vessels and restricting blood flow, while low HDL levels can hinder the body's ability to clear excess cholesterol.
Inherited and Lifestyle Factors
One primary reason for high cholesterol in seemingly healthy individuals is genetic predisposition. Familial hypercholesterolaemia (FH), a common yet underdiagnosed inherited condition affecting about one in 250 people globally, significantly elevates LDL cholesterol from an early age. Individuals with FH face a 10 to 20-fold increased risk of heart and artery problems. Without testing, many remain unaware until a major cardiovascular event occurs.
Even without FH, genetics play a substantial role. The British Heart Foundation estimates that 40-60% of the variation in LDL cholesterol levels is inherited. Doctors advise individuals with close relatives who experienced early heart disease or have multiple family members with high cholesterol to undergo testing, even if under 40.
Another factor is the "thin outside, fat inside" (TOFI) phenomenon, where individuals with a slim frame carry visceral fat around their internal organs. This type of fat can disrupt cholesterol processing and is often linked to diets high in calories, excessive alcohol intake, and conditions like diabetes, kidney, or liver disease.
Beyond Total Cholesterol
Cardiologists consider a full lipid profile, not just the overall cholesterol number. This profile includes "good" HDL, "bad" LDL, and triglycerides, another type of blood fat that contributes to cardiovascular risk even if LDL levels are normal. These data are used in risk calculators to estimate the likelihood of a heart attack or stroke within ten years, guiding treatment decisions.
Cholesterol testing is offered by the NHS to all adults aged 40 and over. Earlier or free testing is available for those with a family history, who are overweight, smoke, or have high blood pressure. Private testing can also be obtained at pharmacies.
Gender and Menopause
Gender also plays a role. While estrogen offers women protection against heart disease before menopause, this benefit diminishes afterward. Post-menopause, LDL levels can increase by over 20%, and HDL levels can decrease, leading to a higher risk of heart disease that approaches that of men within a decade.
Women experiencing early menopause or those with a history of pre-eclampsia or gestational diabetes may face an elevated cardiovascular risk, underscoring the importance of early monitoring.
Physical Warning Signs
Despite its silent nature, high cholesterol can sometimes present with visible signs. Xanthelasma, characterized by soft, yellow fatty deposits around the eyelids, can be associated with high cholesterol, diabetes, or other fat metabolism disorders. A gray or white ring around the cornea, known as corneal arcus, can also signal high cholesterol if it appears before age 45.
Tendon xanthomas, firm lumps on the Achilles tendon or the tendons of the hands, are another indicator, particularly common in individuals with familial hypercholesterolaemia.
Treatment Options
For those diagnosed with high cholesterol, statins are a highly effective treatment. Dr. Astroulakis highlighted that statins can reduce the risk of heart attacks and strokes by 25-30%. They work by lowering LDL cholesterol in the blood and may also help stabilize existing plaques, reducing the risk of blood clots. The benefits of statin therapy, she noted, substantially outweigh the small risk of serious side effects.
