CE: Diabetes Mellitus

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Diabetes Mellitus, commonly referred to as Diabetes, is a metabolic disorder caused by impairment of metabolism of glucose. Glucose is metabolised by Insulin, a hormone produced by beta cells of pancreas. Diabetes Mellitus is a result of either a prolonged deficit in production of insulin, or a resistance by the cells of the body to the action of insulin.

About Diabetes In Brief:

Diabetes is the commonest lifestyle related disorder currently ailing the productive age group worldwide, after high cholesterol. By 2020, its expected to affect a whooping 20% of the urban population in India. Diabetes is a silent killer, not producing any significant symptoms in a majority of patients, till multiple organ systems are already affected. As of now, Diabetes Mellitus has no cure. It can only be controlled. Prevention of Diabetes is the best cure.

*The major types of Diabetes are:

Type 1: This type of Diabetes occurs due to failure of the pancreas to secrete Insulin. This type is generally seen in childhood or adolescence and is a result of either viral infection related destruction of pancreatic cells or an autoimmune process. This type of diabetes presents early in its clinical course, generally in form of a potentially fatal complication called Ketoacidosis. This type is known as IDDM (Insulin dependent Diabetes Mellitus)
Type 2: This is the commonest type of Diabetes, occurring as a result of Insulin resistance, as a result of genetic and lifestyle related factors. In this type, the body secretes more insulin in order to counter the resistance. This type of Diabetes rarely produces symptoms and unless diagnosed in routine annual checks, by the time its diagnosed, it already affects multiple organ systems.This type is known as NIDDM (Non Insulin Dependent Diabetes Mellitus)
Other types include MODY (Maturity Onset Diabetes of the Young) which is a Non Insulin dependent diabetes seen at a young age, due to genetic factors and Diabetes Mellitus as a part of multisystem autoimmune and genetic diseases.
Gestational Diabetes: Increase in blood glucose levels of a previously non-diabetic woman, during pregnancy. These women are at a higher risk of type 2 Diabetes later in life.

Risk Factors in Development of Diabetes:

Obesity: This is the single commonest risk factor responsible for a majority of type 2 Diabetes cases. The increased body fat percentage leads to impaired glucose metabolism and increased production of insulin in response.
Sedentary lifestyle: Skeletal muscles are the chief site of glucose utilization. Physical inactivity leads to impairment in this metabolism, consequently leadig to increased production of insulin and insulin resistance.
Diet rich in bad carbohydrates and fats. Diet rich in food with high glycemic index naturally subjects the body to an increased burden of glucose. Coupled with inactivity, this eventually leads to development of initially impaired glucose tolerance and eventually full blown Diabetes Mellitus.
Heredity: With one parent being diabetic, the chance of the offspring developing type 2 Diabetes is almost 40% and with both parents being diabetic, it’s over 60%.
Iatrogenic Diabetes: Certain medications like corticosteroids given for other ailments can produce insulin resistance or Diabetes as a side effect.
Smoking.
Infections such as mumps can lead to type 1 Diabetes.
Pancreatitis/ Pancreatic cancer.
As a part of multiple autoimmune diseases.

Signs and Symptoms of Diabetes:

Polydipsia or increased thirst. A response produced by the body to dilute the concentration increased by high blood glucose
Polyuria or increased urine frequency, especially at night.
Polyphagia or increased appetite.
Weight loss due to muscle catabolism in response to increased metabolic rate to metabolise the raised blood sugar.
Recurrent infections, especially of the skin, external and middle ear etc along with delayed wound healing.
Signs of insulin resistance like pigmentation of skin in the intertriginous areas such as armpits, known as acanthosis nigricans.
Delayed complications like visual impairment due to diabetic retinopathy, tingling and numbness, loss of sensation in limbs due to diabetic neuropathy etc.

Complications of Diabetes:

The vascular complications of Diabetes can be divided into microvascular and macrovascular complications.
A. Microvascular complications like retinopathy, neuropathy, nephropathy.
B. Macrovascular complications like accelerated atherosclerosis leading to coronary and cerebral vascular disease, peripheral vascular disease etc.
Gastrointestinal complications like gastroparesis, constipation
* Erectile Dysfunction in men and loss of libido in women.
*Increased incidence of fatty liver.
*Diabetic ketoacidosis and nonketotic hyperosmolar coma which are emergencies.

Diagnosis of Diabetes:

As per latest guidelines, a fasting blood glucose of < 99 mg/dL or Random blood glucose < 140 is considered normal.
Fasting blood glucose between 100-125 mg/dL is considered impaired fasting glucose and risk of progression to Diabetes.
Fasting blood glucose > 126 or Random sugar > 200 is diagnosed as Diabetes.
Glycosylated Hemoglobin or HbA1C: this is the fraction of hemoglobin which binds blood glucose. A HbA1C reading gives an average estimate of blood glucose over previous 10-12 weeks. HbA1C reading of 5.6-6.4 is considered impaired glucose tolerance. HbA1C > 6.5 is diagnosed as Diabetes.
Gestational diabetes is diagnosed by an oral glucose tolerance test.
Serum insulin levels can help distinguish between type 1 and type 2 diabetes.

Treatment Of Diabetes:

Treatment of diabetes comprises pharmacological and non pharmacological measures, the non pharmacological measures being common irrespective of type or stage if diabetes.

Pharmacological measures:

Oral hypoglycemic agents (OHAs). OHAs are used in NIDDM, strictly in non emergency situations. In pregnancy as well as perioperatively, during infections, kidney involvement, critical states like myocardial infarction or stroke, Insulin is preferred. OHAs are given as single drug or in combinations with other OHAs or insulin based on the glucose level.
Insulin: Indicated in all IDDM cases, later stages of NIDDM and in indications mentioned above. Insulins are long acting, intermediate and short acting and doses are titrated based on individual needs.
Injectable newer drugs like Liraglutide and Exenatide.

Non Pharmacological measures

Non pharmacological measures are the lifestyle modifications recommended at any stage of diagnosis of Diabetes. Impaired tolerance, established diabetes as well as with systemic complications.
The target is to maintain a HbA1C of < 7 by non pharmacological methods alone or in combination with medications.
Diet: A planned diet customized on individual food habits and blood sugar level, based on low glycemic index carbohydrates, balanced protein intake and fat intake free of saturated or trans fats is ideal.
Serum LDL levels < 100 mg/dL and Triglyceride level < 150 mg/dL is the goal.ideal

Aerobic exercise:

This should be a customised plan based on comorbidities, body composition of the individual etc.
It comprises cardiovascular exercises such as running,brisk walking,swimming, dancing, sports etc.

Strength training and weights:

As skeletal muscle is the chief centre of glucose metabolism and insulin activity, weight bearing exercises and strength training, which build the muscle mass,help in glycemic control more effectively. Diabetes itself leads to sarcopenia (depletion of muscle mass) which worsens insulin resistance. This is prevented or reversed by strength training.
*45-60 minutes of combination of various exercises per day,under expert guidance along with diet control, makes glycemic control much easier and prevents many complications of Diabetes.