Diabetes mellitus is a condition where the blood sugar levels are higher than normal, even when the individual has not had any food. It is well recognised as a cause for heart disease.
Diabetes is currently gaining an ‘epidemic’ status in India, with the number of people being diagnosed with the condition rising by the day. It is believed that India currently has over 62 million people who suffer from diabetes. The problem is so huge, that by 2030 it is believed that nearly 80 million people will be affected by this condition. This only means that the incidence of heart disease will also increase.
How does diabetes affect the heart?
Most adults suffer from type 2 diabetes – a condition where the blood sugar levels are high and there is either insufficient insulin in the body or a lack of response to it. People who have type 2 diabetes tend to suffer from heart disease because they often have other clinical conditions associated with them such as
- High blood pressure (hypertension)
- Obesity
- High cholesterol and triglyceride levels
- Poor physical activity
- Smoking – This doubles the risk of heart disease in patients with diabetes.
Around 65% of patients with diabetes die from heart disease and stroke.
Insulin resistance
At the center of type 2 diabetes is a phenomenon called insulin resistance. Insulin resistance is a condition where the insulin that is produced by the pancreas does not work when the sugar levels are high. Insulin is required to move sugar that is present in the blood stream into the cells. However, in insulin resistance, the cells do not respond to insulin, and thus the sugars stay in the blood stream. This results in high blood sugar levels.
A combination of insulin resistance along with other risk factors such as hypertension, obesity and high lipid levels is called ‘metabolic syndrome’. Individuals with metabolic syndrome have a high chance of developing heart disease and stroke.
Endothelial dysfunction
Insulin resistance is also linked to a phenomenon called endothelial dysfunction. The endothelium is a single layer of cells that lines the inner aspect of the blood vessels in our body. They function by releasing certain chemicals that allows a healthy flow of blood to all the organs, including the heart. In other words, they keep the arteries open and prevent them from developing any disease.
In individuals with type 2 diabetes, the endothelial cells do not function normally. As a result, the good chemicals are no longer released, and instead the endothelial surface gets damaged. A damaged endothelium is the site where the process of atherosclerosis begins. This means that where there is endothelial damage, atherosclerosis may occur and the vessel can become narrowed. If this happens in the coronary arteries, this can lead to heart disease.
Endothelial dysfunction can also occur from smoking, obesity, high lipids and high blood pressure.
South Asians i.e. Indians are at a greater risk of endothelial dysfunction. This is primarily due to the fact that we, as Indians, are more prone to becoming insulin resistant. It is in our genes.
Types of heart disease that can result from diabetes
Patients who have diabetes are at a higher risk of developing a heart attack. Some patients may notice chest pain on exertion i.e. angina. However, a large number of diabetic patients do not experience any symptoms, despite having heart disease. In other words, diabetes can silently cause heart disease, especially if it is poorly controlled.
Weakening of the heart muscle i.e. cardiomyopathy can also be seen in patients with diabetes. This is often a consequence of poor circulation to the heart due to coronary artery disease. This can lead to ‘heart failure’ – condition where the heart struggles to pump blood and nutrients to vital organs. Heart failure has a high mortality rate if not treated aggressively.
What can be done?
Firstly, it is important to recognise how serious diabetes is. Doing so will mean that individuals will do their very best to prevent it from developing. Some simple steps include –
- Stop smoking
- Exercise regularly – The AHA recommends at least 150 minutes of cardiovascular exercise per week. A little more will no doubt help as well.
- Eat healthily – Consume low fat, low salt and low sugar foods. Choose to eat plenty of fresh fruits and vegetables, low fat dairy and lean meat and fish.
- Take medication regularly as prescribed – Ask your doctor about taking a small dose of Aspirin everyday
- Visit your doctor regularly to make sure your blood pressure and blood sugar levels are under control.
- Get support from friends and family.
Our 5 step ‘HEART’ plan can guide you further.
References
1. Kaveeshwar, Seema Abhijeet, and Jon Cornwall. “The current state of diabetes mellitus in India.” The Australasian medical journal 7.1 (2014): 45.
2. A great resource for patients with diabetes – National Diabetes Education Program