World Stroke Day 2024: Addressing the Top Preventable Causes of Stroke - Dr Jayakrishnan C

The current century is the century of brain and genetics. The final frontiers in modern medicine, where all the heavenly mysteries of human physiology lay. The era also showed the rise of non-communicable disease.

The top five non-communicable diseases causing significant morbidity to human beings are Diabetes, Hypertension, Heart disease, Cancer and Stroke. The top three killers among the non-communicable diseases are heart disease, cancer and stroke.

As the population ages, the chances of getting a non-communicable disease also increases. Among the Neurological illnesses, the ones which cause the maximum morbidity and a top sizable cause of mortality are Stroke, Epilepsy and Dementia.

Stoke is a neurological illness caused by the abrupt disruption of blood flow to the brain. The events that cause stroke can be due to sudden blockage of the lumen of the blood vessel to the brain leading to an Ischaemic stroke or due to weakness of the walls of the blood vessel, which then leaks of suddenly and ruptures, causing a local bleed and the related damage to the neurons called a haemorrhagic stroke. The latter one is a more catastrophic event and constitutes about 15 % of all the strokes.

Now, it's important to understand that ischaemic stroke (which constitutes about 85 % of all strokes), is a disease of the blood vessels.

The lumen of the blood vessel is lined by the vascular endothelial cells, and the blood inside the vessel lumen has a chemistry that it will not clot, the moment the endothelium is damaged, and the underlying subendothelial tissue is exposed, it activates the process of blood clotting and the resultant coagulum, will block the lumen of the vessel.

There is a perpetual yin -yang like configuration of pro and anti coagulant chemicals in the blood, which accordingly will manage the unwanted clots, and retain the one which are needed.

Now, it's very important to understand that the Vascular Endothelial tissue is the one major or probably the most important tissue responsible for the healthy blood vessel, an all the current major killers of human population by the top three non-communicable disease (Heart attacks, Stroke and cancer) works in a way by damaging or disrupting the function of this endothelial tissue. So, stroke is an Endothelial Tissue Disorder.

Diabetes, High blood pressure, bad cholesterol, smoking, obesity, lack of exercise are the main causes of Heart attacks, which is also an endothelial tissue damage associated disease, so they are also the main causes of ischaemic stroke.

A good control of Diabetes, as marked by a HbA1c value less than 7 %, is favourable for stroke prevention. The high or poorly controlled blood sugars create an environment causing endothelial damage and a pro atherosclerotic chemical milieu inside the blood vessel, leading to more and more damage to small and medium-sized blood vessels.

All the complications due to Diabetes are due to damage to blood vessels. When the large blood vessels are damaged you have heart attacks, stroke and peripheral vascular occlusive disease (PVOD).

When the small blood vessels are damaged you have retinal disease, diabetic kidney disease and nerve disease due to diabetes. So a good control of the sweet killer is a must for good prevention of Stroke too. A healthy diet, regular exercise and pharmacological measures to keep diabetes under check is also a prevention for stroke.

Hypertension or high BP is a silent killer of human beings. Of all the High BP people diagnosed 90 percent more are undetected in the population, of that 90 % more is poorly controlled, so you can realize how big the problem is, difficult to detect and difficult to control.

Now, the high BP also causes endothelial damage and creates an environment favouring the atherosclerotic damage to blood vessels. For a good control of BP weight reduction, control of obesity, low salt diet, regular exercises and a good balanced diet are cornerstones for optimal control of this risk factor.

High cholesterol, especially the bad (LDL/ TGL) cholesterol, favours the damage to the endothelial tissues. The subendothelial deposition of bad cholesterol, leads to the growth and later occlusion of the blood vessels.

The atherosclerotic plaque as it is known is like a bomb waiting to explode. The surface of this plaque is often composed of a thin damaged layer of endothelium with calcium deposition, they have cracks on them and the underlying gruel of bad cholesterol is waiting to come out.

Under shear stress from the blood flowing in the lumen, especially where there is branching or forking of blood vessel the turbulence will rip the surface of these plaques, setting in motion the sudden activation of the clotting process and the entire vessel is filled up with the clot, leading to acute myocardial infarction and to acute stroke (both atherothrombotic and athero embolic kinds).

The patient may be doing brisk exercise like a round of badminton game, or a sprint in the ground and then collapses to the ground. Good control of cholesterol is by appropriate diet, exercise, control of obesity and medicines (statin) when needed. The target is to reduce the LDL cholesterol to less than 70 mg/DL.

Obesity is a new epidemic that the Indian Urban is suffering from. We now have better standards of living, and we have in a way changed our eating culture to mirror the US eating pattern. The fast pace of life has reduced the time for regular exercise.

All the surgery, fat and processed/ ultra processed food is dumped in the adipose tissue in and around the abdomen and waist.

Fat or adipose tissue is an inflamed tissue, all the time triggering the pro inflammatory agents in the body, choking the organs of their blood supply, clogging the blood vessels and ripping the endothelial tissue off the blood vessel, all the current major killers (Coronary heart disease, Cancer and Stroke) have proven strong epidemiological links with obesity. Eating mindfully, a balanced fibre rich, preferably plant based diet has shown to be protective.

Regular exercise and being mindful of the need for exercise and educating the future generation about the need for going out and moving the muscles is an important thing that all of us should do.

Smoking and or use of any tobacco products, is going to cause damage to the endothelial tissue and promote the top three killers of humankind (CAD, Cancer and stroke).

The process of passive smoking is also proven to be harmful, so your loved ones like the wife/ children of a smoker man, if he smokes inside the house would have to pay for his sins of smoking. Cessation of smoking or use of tobacco has proven to be helpful in prevention of stroke.

So to conclude the top preventable causes of stroke are Diabetes Mellitus, Systemic Hypertension, Dyslipidemia, Obesity and Smoking, if they are kept under good control, the stroke epidemic can also be kept under control.