Cardiovascular Disease (CVD) is the major cause of morbidity and mortality worldwide. It is estimated that up to 50% of deaths are attributed to CVD in the developed world and up to 25% in the developing world i.e., 1 in 3 deaths worldwide. India’s ranking falls in between the two and is fast catching up with the developed world. India has the dubious distinction of being the diabetic capital and the hypertensive capital of the world and is set to achieve another unwanted distinction of being the cardiovascular capital in the next few years.
It is well known and well established by research that the incidence of heart disease is much higher during the winter times compared to the summer months. However, there are a lot of myths and facts intertwined clouding the understanding of the common man and sometimes professionals as well.
Fact 1: Cold weather precipitates angina (chest pain).
The heart is a pump that supplies blood to all organs of the body. The heart also needs energy and oxygen which is supplied by the coronary arteries that are present on the surface of the heart. Cold weather makes these arteries which are made up of specialised smooth muscles vulnerable to spasm (or temporary collapse) leading to a reduction in blood supply and in turn causing angina (chest pain).
Fact 2: BP goes up during cold weather.
Cold weather precipitates constriction of blood vessels and this leads to increased resistance to blood flow and high blood pressure. The elderly are more sensitive to weather changes and manifest with poorly controlled BP which is a major risk factor for heart disease and heart attack.
Fact 3: Change in daylight hours.
As we all know, winter is a time of long dark hours and limited sunlight. This change in the ratio of daylight to dark hours causes a hormonal imbalance, particularly cortisol which can lower the threshold for a cardiovascular event.
Fact 4: Flu causes more heart attacks.
Seasonal flu is typical of the winter months and inflammation can trigger a heart attack. Flu is the major contributor to inflammation during these months and inflammation can make arterial plaque less stable, and may dislodge or block coronaries leading to a heart attack. A flu shot (vaccine) can lower this risk and is recommended for people >65 years and patients with pre-existing heart disease.
Fact 4: Exercise with caution.
There is no doubt that exercise is good for health. However, it is advisable to stay indoors and avoid intense exercise during cold mornings.
Fact 5: Balance your intake with physical activity.
Winter is a time of less physical activity which in turn causes your BP to rise. It is also the festive and holiday season for most and people tend to indulge in unhealthy food habits leading to a rise in high cholesterol and obesity which are all risk factors for CVD.
(The author is a consultant in interventional cardiology.)