Understanding Diabetes for Rural Patients: Pathophysiology

What is Diabetes?

Diabetes is a disease where the body is not able to use the energy and fat from the food properly. A hormone or chemical called Insulin is produced by the pancreas which is situated behind the stomach in the body. Insulin helps in proper utilization of the absorbed energy from the food. Diabetes occurs when the body produces less or no insulin. It can also occur despite normal production of insulin if the insulin does not work well due to resistance to it. Very few people [less than 5% of diabetics] have what is called Type 1 Diabetes or Juvenile diabetes where insulin is not produced. Others have Type 2 or adult onset diabetes.

What happens in Diabetes?

The body needs energy and the food we eat is broken down and absorbed as Glucose from the intestines. The blood vessels carry the Glucose to all the cells that use them or need them. The excess can be converted to fat and stored. Insulin is necessary to let the Glucose enter the cells that need them.

When there is deficiency of insulin the Glucose is unable to go to the cells and the levels stay high in the blood producing the state called hyperglycemia or high blood sugar levels. High blood sugar level is the cause of many of the problems of Diabetes.

What is the etiology of diabetes?

The Beta cells of the pancreas produces insulin. Beta cell dysfunction is the most important cause. It can be genetic or occurs in families. This combined with the so called Diabetogenic lifestyle causes Diabetes. The Diabetogenic lifestyle is essentially increased caloric intake, inadequate expenditure of calories and obesity. In other words, people are born with a certain reserve of ability of pancreas to produce insulin depending on their genetic makeup. If they use it up quickly they develop Diabetes early.

What is described above is a very simplistic way of understanding. However, there are as many as 40 different chemicals involved in predisposing to Diabetes. Other hormones like Glucagon, insulinotropic polypeptide, post prandial glucagon like peptide are some of them.

In recent times more of the young are diagnosed with Diabetes and it is called MODY or Maturity Onset Diabetes in Youth. Till date about eleven different genetic variations are linked to this.

What are the symptoms of Diabetes?

Most of the time, especially in early stages, the disease is symptomatic or there is no significant abnormality. However, the following could be present:

  1. CLASSICAL SYMPTOMS: These are due to high blood sugar levels and are i) Frequent urination, ii) Increased thirst and hunger and iii) weight loss. Body decreases the blood sugar by putting out the sugar in urine which leads to increased frequency. The resulting dehydration causes thirst and despite the high blood sugars since the tissues do not get sufficient energy there is hunger and weight loss.
  2. SYMPTOMS DUE TO INFECTION: Wound healing is poor and there is dry and itchy skin especially in the groin due to fungal infections. In men infection in the tip of the penis called Balanoposthitis might be the first one to present or notice.
  3. OTHER VAGUE SYMPTOMS: Sometimes unexplained weight loss, weakness, numbness or just not feeling well might be the presenting symptom.

How is Diabetes Diagnosed?

Blood tests are necessary to diagnose Diabetes. The following criteria are used

  1. Fasting blood sugar level of over 126 mg/dl
  2. Two random blood sugars that are greater than 200 mg / dl
  3. Two-hour post food blood sugar is greater than 200 mg / dl
  4. Hemoglobin A1c or Glycosylated Hemoglobin which gives the three monthly average blood sugar is greater than 6.5%

A diagnosis of Pre-Diabetes is made if the values are not normal but less than abnormal.

diabetes-numbers-table

These values are from American Diabetic Association.

What are the risk factors for Diabetes or who should have the tests?

Since the disease is asymptomatic in many it is better for anyone especially over 40 years of age to have regular testing to diagnose silent disease. The following group need greater index of suspicion.

  • Family history of diabetes
  • Being overweight
  • Having high blood pressure
  • Having abnormal cholesterol or triglyceride levels
  • Smokers and alcoholics
  • Women who had diabetes during pregnancy
  • Those with autoimmune disease
  • Those on medication like steroids
  • Women with Polycystic ovarian syndrome

What are the complications and why do they develop?

The complications of diabetes are often due to hyperglycemia or high blood sugar levels. The good news is that with proper control these are preventable. The complications are divided into two groups namely Microvascular complications and Macrovascular complications. There are other complications too.

The cardiovascular risk in diabetes is related to insulin resistance. This leads to increased lipid or fat accumulation in the liver. In the blood it reflects are elevated levels of LDL or low-density Lipoprotein Cholesterol and high levels of triglycerides. The high-density or HDL cholesterol is low. These changes often occur much earlier than the elevated blood sugars and hence elevation of these levels is considered as a risk factor for diabetes in the earlier section.

One simple way of looking at complications of diabetes is that the small blood vessels in the body are affected and blocked. These are present in all the systems of the body and causes disease. In the eye it causes what is called retinopathy that can lead to blurred vision, spots and discomfort. They are more prone to cataracts and glaucoma too. In the kidneys, diabetes causes nephropathy and it is one of the most important causes for chronic renal failure and end-stage renal disease. In the brain it can lead to stroke and affection of the nerves causes neuropathy. Peripheral neuropathy damages peripheral nerves and cause numbness and tingling, internal nerve damage can cause postural hypotension or blood pressure becoming low with sudden change in position. The movement of food through the stomach can be slow and is called Gastroparesis. Severe diarrhea is also possible. Several factors contribute to complications in the feet.

gnanaraj Dr. J. Gnanaraj MS, MCh [Urology], FICS, FARSI, FIAGES is a urologist and laparoscopic surgeon trained at CMC Vellore currently working as Director of Medical Services of the charitable organization SEESHA and Adjunct Professor in Karunya University. He has special interest in rural surgery and during the last three decades of service in rural areas helped 23 rural hospitals start minimally invasive surgeries. Karunya is now recognized as center for excellence in innovation for rural surgery by Lancet Commission on Global Surgery. He has over 200 publications. He received the Barker Memorial award from the Tropical Doctor for the work regarding surgical camps in rural areas. He is also the recipient of the Innovations award of Emmanuel Hospital Association for health insurance programs in remote areas and the Antia Finseth innovation award for Single incision Gas less laparoscopic surgeries. Recently, he was awarded the Lockheed Martin innovations award by the Department of Science and Technology of Indian Government and the Lockheed Martin Group (USA)

References (click to show/hide)

  1. http://my.clevelandclinic.org/health/diseases_conditions/hic_Diabetes_Basics
  2. http://www.hopkinsmedicine.org/gim/core_resources/Patient%20Handouts/Handouts_May_2012/Diabetes%20Mellitus%20Type%202.pdf
  3. http://emedicine.medscape.com/article/117853-overview