Diabetes puts heart at risk – fact check

Diabetes is one of the leading causes of cardiovascular problems. In our country current trend shows one in three persons to be diabetic. Diabetes occurs due to deficiency of Insulin production by pancreas thereby causing high blood sugar levels. Diabetes is defined as Fasting Sugar more than 126mg%, Post meal sugar of more than 160 mg%, Random Sugar more than 200 mg% or HbA1C more than 6.5. Diabetes does not cause any symptoms other than classical triad of “increased thirst, increased appetite and increased urination”.  Persistently high blood sugar level damages blood vessels over a period which in turn leads to heart complications. Patients with diabetes have a two to fourfold increase in risk of coronary heart disease, brain stroke and up to three – fold increase in mortality.

Patients with diabetes may not manifest any organ specific symptoms as diabetes slowly and progressively damages the tissues of heart, brain, kidney, eyes and blood vessels. When the manifestations start it is too late – early indicators are very mild and nonspecific symptoms like weight loss or weight gain, shortness of breath, fatigue, pedal edema, frothy urination, visual problems, tingling and numbness of limbs, calf pain on walking and in men erectile dysfunction.  These symptoms need to be addressed early on as they may be caused by other diseases also. Hence the need for certain basic investigations such as urine for proteins, serum creatinine, ECG and 2d Echo, Doppler studies, eye examination etc. Co-existing risk factors like high blood pressure, high cholesterol, obesity, smoking, alcoholism compound the problems in patients with diabetes.

Diabetes causes several problems such as coronary artery disease, heart attacks, heart failure, vascular disease in addition to causing brain stroke, kidney failure, neuropathy and myopathy. It is important to note that the duration of diabetes of more than 10 years even though well controlled can cause above problems. These problems may occur earlier and in a more exaggerated manner in uncontrolled diabetes.

How does diabetes cause the vascular injury? It is by disrupting the inner lining of blood vessels called “endothelium”, thereby allowing cholesterol particles to get deposited inside the vessel wall. Gradually the plaque volume increases and causes obstruction to blood flow to vital organs. Diabetes increases blood clotting tendency and leads to formation of clots inside the vessels causing heart attack, brain stroke, limb gangrenes etc., When the plaques rupture, it is associated with abrupt clot formation and cessation of blood flow to distal part and causes infarction – in heart – myocardial infarction or heart attack, in brain – cerebrovascular accident or brain stroke, in eyes – retinal infarcts, in lower limbs -gangrene. It is an important cause for loss of daily life activities and morbidity.

Apart from vascular problems, Diabetes causes heart muscle weakening called “cardiomyopathy” directly (diabetic cardiomyopathy) or indirectly after heart attack leading to heart failure and rhythm disturbances (ischemic cardiomyopathy). Most importantly diabetes can cause sudden cardiac arrest by producing heart attack or by creating disturbances in cardiac electrical activity. Diabetes is notorious to cause silent heart attacks. As continuously high blood sugar decreases nerve sensitivity to pain, diabetics may not experience angina. Instead of angina, they may experience shortness of breath as Angina Equivalent.

Patients with blockages in heart arteries are treated by Stents, or Bypass surgery to clear the blockages. Diabetic patients who undergo Stents or Bypass surgery are prone to   early bypass graft failure and stent failures thereby leading to repeat intervention procedures. Therefore, it is important for this subset of patients to undergo tests such as CT Angiogram or standard Angiogram in 5- 10 years after the index procedure. Progression of new blockages can be detected with high degree of accuracy and appropriate therapeutic measures can be undertaken.

Duration of diabetes is a key factor for cardiovascular and CHD risk in diabetes. Age more than 40 years, diabetes duration of more than 10 years,  history of heart attack in young age in first degree relatives, male gender, high blood pressure, LDL cholesterol more than 100 mg/dl, low kidney function, loss of protein in urine, presence of non-alcoholic fatty liver disease, obstructive sleep apnoea, erectile dysfunction and  metabolic syndrome, chronic high blood sugar are some conditions that increase cardiovascular risk.

Diabetes is known as a silent killer. It affects the nerves that controls the heart functioning and leads to silent heart attacks that does not show any prior symptoms or mild symptoms. In view of these diabetes related complications, it is very important to detect diabetes early on by checking Fasting sugar, post meal sugar and three monthly average HbA1C. Home blood glucose monitoring is very useful to achieve optimal control thereby preventing the diabetes related complications. Cardiac symptoms like chest pain, shortness of breath, syncope, leg swelling, and palpitations need evaluation by cardiologist. Tests such as ECG, ECHO, Exercise Tests, CT Coronary Angio or Angiogram are necessary in selected patients. Control the ABC to keep CVDs at bay:

  • To measure your average blood sugar over two to three months, have a regular A1C test; try to maintain as much of your blood sugar within the target range as you can.
  •  Attempt to maintain a blood pressure of less than 140/90 mm Hg (or the target your doctor sets).
  •  Keep your cholesterol under control especially Low-Density Cholesterol

Several new diabetes medications are available with cardiac vascular benefits and will help to decrease heart attack and heart failure risks. These are many oral formulations with novel mechanism of action and newer injectable insulins.



Views expressed above are the author’s own.