Diabetes mellitus, or as is more commonly called, ‘Diabetes’, is possibly the most alarming pathology affecting the human race today. It is a silent killer in the truest sense of the term. Once regarded as a single disease entity, diabetes is now seen as a heterogeneous group of diseases, characterised by a state of long-term increase in blood sugar levels. It has variable clinical manifestations and progression.
Diabetes is an “iceberg” disease. Although there has been an increase in the number of diabetes cases worldwide, these still represent only a part of the actual population suffering from diabetes or its manifestations. The scourge of diabetes most dramatically affects countries in economic transition – newly industrialised countries and developing countries. In these countries, the onset of diabetes is also at a younger age, hence affecting people in the most productive period of their lives. The WHO (World Health Organisation) had in 2000 estimated the prevalence of diabetes in South-East Asian countries at an alarming 32.7%, and this figure is expected to double by 2025, at the current rate.
Multiple surveys have shown that the Indian population has an increased susceptibility towards diabetes due to multiple factors – diet, lifestyle, body structure and heredity. Our country is hence given the discomfiting title of ‘the diabetes capital of the world’.
Diabetes occurs basically due to defective production or action of insulin, a hormone that controls glucose, fat and amino acid metabolism in our body, and is secreted by the pancreas. The increased blood glucose is accompanied with a decrease in the capacity of body cells to utilise this blood glucose. In long standing diabetes, additional complications occur. These include microvascular, macrovascular and neuropathic disease. The microvascular abnormalities affect small blood vessels in the eye, leading to progressive blindness (diabetic retinopathy), and the kidney, leading to renal failure (diabetic nephropathy). The macrovascular complications are due to accelerated fat accumulation (atherosclerosis) inside the large blood vessels, further leading to stroke and heart attacks.
Diabetes is classified into three major types. Type 1 or Insulin Dependent Diabetes Mellitus (IDDM) is due to an absolute decrease in insulin secretion from the pancreas. This usually affects young populations under the age of 30 years. They hence require an exogenous supply of insulin to effectively regulate metabolic processes. Type 2 or Non-Insulin Dependent Diabetes Mellitus is due to a resistance to the secreted insulin as well as impaired insulin secretion. It is much more common, typically gradual in onset, and occurs mainly in the middle-aged and elderly. A third common entity is the Gestational Diabetes Mellitus, which affects pregnant women during the latter part of pregnancy, and often subsides afterwards.
Diabetes is a multifactorial disease. Factors leading to an increased risk are – overweight and obesity, physical inactivity, a history of diabetes in a parent, increased consumption of saturated and total fats, a high calorie diet, and genetic factors. On the other hand, factors associated with a decreased risk are – voluntary weight loss in overweight and obese people, physical activity, consumption of dietary fibre and foods rich in non-starch polysaccharides (such as wholegrain cereals, vegetables and fruits).
Early detection and effective control of increased blood sugar (hyperglycaemia) in asymptomatic diabetics reduces morbidity due to the disease. Hence it is important to undergo periodic testing after a certain age, especially in high risk populations. These high risk groups include: (i) those in the age group of 40 or over, (ii) those with a family history of diabetes, (iii) the obese, (iv) women who have had a baby weighing more than 4.5 kg, (v) women who show excess weight gain during pregnancy, and (vi) patients with premature atherosclerosis.
The most commonly used test for the diagnosis of diabetes is the standard Oral Glucose test, measuring blood glucose levels after overnight fasting (for eight hours), and two hours following a glucose meal (post prandial sample). Diagnostic values for this test are as follows:
|Fasting||100-125 mg/dL||Impaired Fasting Glucose|
|Fasting||≥126 mg/dL||Diabetes Mellitus|
|2 hours Post Prandial||<140 mg/dL||Normal|
|2 hours Post Prandial||140-199 mg/dL||Impaired Glucose Tolerance|
|2 hours Post Prandial||≥200 mg/dL||Diabetes Mellitus|
Impaired Glucose Tolerance (IGT) and Impaired Fasting Glucose (IFG) describe an intermediate, “at risk” stage.
Another important test for established diabetics is the Glycosylated Haemoglobin test. This should be done at half yearly intervals in diabetic patients. It provides a long term index of glucose control. A glycosylated haemoglobin level of under 5.6% is considered normal.
When diabetes is detected, it must be adequately treated. The aims of treatment are to maintain blood glucose levels as within the normal limits as practicable, and to maintain ideal body weight. Treatment is either based on diet alone, diet and oral antidiabetic drugs, or diet and insulin. Good control of blood glucose protects against the development of complications.
Proper management of the diabetic is most important to prevent complications. Routine checking of blood sugar, of urine for proteins and ketones, of blood pressure, visual function and weight should be done periodically. The feet should be examined for any defective blood circulation, loss of sensation and the health of the skin. Primary health care is of great importance to diabetic patients since most care is obtained at this level.