Diabetes Mellitus

Diabetes mellitus is a chronic, metabolic disease more aptly fuel metabolism disorder that primarily shows hyperglycemia leading to several long-term complications. It has been reported that about 422 million people suffer from diabetes globally, and the majority of them are from low-and middle-income countries. Among these, 1.6 million deaths are directly related to diabetes every year.

The number of cases as well as the prevalence of diabetes has been gradually rising over the past few decades. Diabetes mellitus is broadly classified into 2 groups based on the requirement of insulin for treatment, viz., insulin-dependent diabetes mellitus (IDDM) and non-insulin-dependent diabetes mellitus (NIDDM). Type I diabetes or juvenile-onset diabetes or IDDM is primarily observed in children of 12 -15 years of age. IDDM is observed in about 10 to 20 % of diabetics. In this disease, almost total insulin deficiency is seen because of β-cell destruction in the pancreas caused by drugs, viruses, or autoimmunity.

The IDDM patient is dependent on insulin therapy. Whereas, NIDDM or type II diabetes, or adult-onset diabetes, is the most common and covers 80 to 90 % of the diabetic population. NIDDM occurs in adults (generally above 35 years) and its severity is less than IDDM.

The cause of NIDDM is genetic and environmental. NIDDM is mostly seen in obese individuals. Obesity acts as a diabetogenic factor in genetically predisposed individuals by increasing the resistance to the action of insulin. The NIDDM individual may have either normal or even increased insulin levels. Such individuals are not dependent on insulin. Another type of diabetes is gestational diabetes observed in 5–10% of pregnant women.

The typical symptoms of diabetic patients are unintentional weight loss, polyuria (increased urination), polydipsia (increased thirst), and polyphagia (increased hunger). Symptoms may advance rapidly (weeks or months) in type 1 diabetes, whereas type 2 diabetes generally advances slowly and may be elusive or absent. Diabetes increases the risk of long-term complications which generally develop after 10-20 years. This is the reason that diabetes is known as a slow poison. The major long-term complications relate to damage to blood vessels. Diabetes doubles the risk of cardiovascular disease and about 75% of deaths in people with diabetes are due to coronary artery disease. Other macrovascular diseases include stroke and peripheral artery disease.

The main reason for complications in diabetes is damage to small blood vessels of the eyes, kidneys, and nerves. Damage to the eyes is called diabetic retinopathy, which is caused by damage to the blood vessels in the retina of the eye, and can result in gradual vision loss and eventual blindness. Diabetes also augments the chances of glaucoma, cataracts, etc. Damage to the kidneys is called diabetic nephropathy which can result in tissue scarring, urine protein loss, and ultimately chronic kidney disease, occasionally causing dialysis or kidney transplantation. Damage to the nerves of the body is called diabetic neuropathy which shows symptoms of numbness, tingling, pain, and altered pain sensation that can lead to damage to the skin. Diabetes-related foot problems (such as diabetic foot ulcers) may occur, and can be difficult to treat, occasionally requiring amputation. Additionally, proximal diabetic neuropathy causes painful muscle atrophy and weakness.

Diagnosis of diabetes is done by checking plasma glucose levels (fasting, random, postprandial), glucose tolerance test (GTT), and Glycated hemoglobin (HbA_1C). Diabetes management concentrates on keeping blood sugar levels as close to normal, without causing low blood sugar. This can usually be accomplished with dietary changes, exercise, weight loss, use of appropriate medications (insulin, oral medications), regular screening and treatment for complications.