Page 325 - fbkCardioDiabetes_2017

Cardio Diabetes Medicine 2017 301

Diabetic Cardiomyopathy: Mechanisms,

Diagnosis and Treatment

Dr. A.K. Das
(Professor and Head of Dept of Endocrinology, Pondicherry Institute of Medical Sciences)
Dr. Kevin T. John
(Senior Resident, Department of General Medicine, Pondicherry Institute of Medical Sciences)

Introduction The epidemic of obesity and sedentary lifestyle is
The incidence of diabetes mellitus is increasing projected to result in over 300 million people with
worldwide and rapidly assuming epidemic propor- diabetes mellitus by 2025. Cardiovascular disease is
tions. India is no exception, and currently 25 million responsible for 80% of deaths among diabetic pa-
Indians are estimated to be suffering from diabe- tients much of which has been attributed to CAD
tes. Further projections indicate that India will have (coronary artery disease). However, there is an in-
maximum number of diabetic patients by the year creasing recognition that diabetic patients suffer
2025. The life span of patients with diabetes has im- from an additional cardiac insult termed ‘diabetic
1
proved with newer insulins and oral hypoglycaemic cardiomyopathy’.This entity was originally described
agents. Unfortunately chronic complications of the in 1972 on the basis of observations in four diabetic
disease show a rising trend among diabetics living patients who presented with HF (heart failure) with-
longer. Diabetes, formerly thought of as a problem out evidence of hypertension, CAD,valvular or con-
of glucose metabolism, actually produces most of its genital heart disease. The increasing recognition of
harm by its effects on the cardiovascular system. 2 this additional cardiac insult is supported by data
from epidemiological, molecular and more refined
Patients with diabetes are characterised by an in- gnostic studies.
creased likelihood for congestive heart failure reflect-
ing the contribution of diabetes to coronary artery Epidemiology
disease (CAD) and its association with hypertension. Diabetes mellitus has reached an epidemic level
Even in the absence of CAD and hypertension, dia- worldwide, with a prevalence of 4% in 1995 and an an-
betics remain vulnerable to CHF. In the Framingham ticipated prevalence of 5.4% in 2025, corresponding
cohort, after adjustment for age, blood pressure, cho- to 300 million adults with diabetes worldwide. Car-
5
lesterol level, obesity, and history of CAD, the pres- diovascular diseases represent the primary cause of
ence of diabetes quadrupled the risk for CHF in men death in this population, due to coronary artery dis-
35 - 64 years old and doubled it in men 65 years or ease or associated hypertension, but also because
older; in women 35 - 64 years of age, it entailed an of a direct adverse effect of diabetes mellitus on
eightfold increase in CHF and fourfold increase in the heart, the so called diabetic cardiomyopathy. In
risk in older women. 3
diabetic patients the prevalence of diabetic cardio-
Over the last three decades, a number of epidemi- myopathy is 12% and reaches 22% in people over 64
ological, clinical and autopsy studies have proposed years old.
the presence of diabetic heart disease, as a distinct
clinical entity. However, the existence of diabetic car- As was demonstrated in the Framingham Heart
4
diomyopathy referring to myocardial disease in dia- Study, diabetes is a strong and independent risk fac-
betic subjects that cannot be ascribed to hyperten- tor for developing heart failure, leading this group of
sion, CAD, or any other known cardiac disease has patients to a worse prognosis. The risk of heart failure
remained controversial. In this review, we will discuss was 2.4-fold and 5-fold higher in diabetic men and
the evidences regarding the existence of this specific women, respectively, than in non-diabetic subjects.
entity, alongwith its pathophysiology and manage- The incidence of heart failure in diabetic patients is
ment. still increased even after adjustment for age, hyper-

Cardio Diabetes Medicine