Diabetes: A Basic Introduction

Introduction to Diabetes

What is Diabetes?

It is a long term condition that affects the body’s ability to use glucose, which results in the body having high circulating blood glucose levels.

Terms for you to know, to better understand the condition:

Glucose
Insulin
Hyperglycaemia
Hypoglycaemia
Pancreas

Glucose:  An important energy source that is needed by the cells and organs of our bodies. Glucose or sugar comes from the food we eat. Carbohydrates such as fruit, bread pasta and cereals are common sources of glucose. These foods are broken down into sugar in our stomachs, and then absorbed into the bloodstream. The glucose is then transported to cells to provide them with energy. The cells cannot use glucose without the help of Insulin.

Diabetes develops when there is too much glucose in the blood. This can have serious health consequences. However, with careful management, people can continue to lead full, healthy and active lives.

Insulin: A hormone made by the pancreas that allows your body to use glucose from the food that you eat for energy or to store glucose for future use. Insulin helps keeps your blood sugar level from getting too high  or too low.

The cells in your body need glucose for energy. However, glucose cannot go into most of your cells directly. After you eat food and your blood sugar level rises, cells in your pancreas are signalled to release insulin into your bloodstream. Insulin then attaches to and signals cells to absorb sugar from the bloodstream. Insulin is often described as a “key,” which unlocks the cell to allow sugar to enter the cell and be used for energy.

Diabetes

 

Hyperglycaemia: High sugar levels in the blood

Hypoglycaemia: Low sugar levels in the blood

Pancreas: The Pancreas is a gland which lies behind the stomach. It manufactures and secretes enzymes and hormones. One of the hormones it secretes is Insulin.

Diabetes

 

Types of Diabetes

There are three different types: Type1, Type 2 and Gestational Diabetes

Type 1: Insulin-Dependent Diabetes
This is when the body can’t produce enough or any insulin.

Type 1 usually occurs before the age of 40 and accounts for only around 10% of all cases.
It is the most common childhood form of the condition and was previously called juvenile-onset diabetes.

Type 2: Non Insulin dependent diabetes

Type 2 is the most common form of the condition, accounting for 90 – 95% of cases. In type 2, the body does not respond properly to insulin, a condition known as insulin resistance. There are three stages in the progress of type 2 diabetes:

Stage One
The first stage in is when resistance to insulin develops. Normally insulin attaches to receptors on liver and muscle cells and facilitates the movement of blood sugar into the cells. In type 2 diabetes certain mechanisms prevent insulin from moving blood sugar into these cells. Most patients with type 2 produce variable, even normal or high, amounts of insulin. In the beginning, this amount is usually enough to overcome such resistance.

Stage Two
Over time, the pancreas becomes unable to produce enough insulin to overcome resistance. In type 2, the initial effect of this stage is usually an abnormal rise in blood sugar after a meal (called postprandial hyperglycaemia).

Stage Three
Eventually, the cycle of elevated glucose further damages beta cells, thereby drastically reducing insulin production and causing full-blown diabetes. This is made evident by fasting hyperglycaemia, in which glucose levels are high most of the time.

According to the American Cancer Society, Type 2 diabetes increases the risk of certain types of cancer. It is reported that diabetes doubles the risk for developing liver, pancreatic, or endometrial cancer. It is also believed that certain medications used for treating type 2 may possibly increase the risk for some types of cancers. Read more on Type 2 Diabetes.

Gestational Diabetes

Gestational diabetes is a form of type 2, usually temporary, that first appears during pregnancy. It usually develops during the third trimester of pregnancy. After delivery, blood sugar (glucose) levels generally return to normal, although some women develop type 2 within 15 years.

Because glucose crosses the placenta, a pregnant woman with diabetes can pass high levels of blood glucose to the foetus. This can cause excessive foetal weight gain, which can cause delivery complications as well as increased risk of breathing problems.

Children born to women who have gestational diabetes have an increased risk of developing obesity and type 2 of the condition. In addition to endangering the foetus, it can also cause serious health risks for the mother, such as preeclampsia, a condition that involves high blood pressure during pregnancy.

 

References

ACCORD Study Group, Gerstein HC, Miller ME, Genuth S, Ismail-Beigi F, Buse JB, et al. Long-term effects of intensive glucose lowering on cardiovascular outcomes. N Engl J Med. 2011 Mar 3;364(9):818-28.

Alberti KG, Eckel RH, Grundy SM, Zimmet PZ, Cleeman JI, Donato KA, et al. Harmonizing the metabolic syndrome: a joint interim statement of the International Diabetes Federation Task Force on Epidemiology and Prevention; National Heart, Lung, and Blood Institute; American Heart Association; World Heart Federation; International Atherosclerosis Society; and International Association for the Study of Obesity. Circulation. 2009 Oct 20;120(16):1640-5. Epub 2009 Oct 5.

Centers for Disease Control and Prevention. National Diabetes Fact Sheet: National Estimates and General Information on Diabetes and Prediabetes in the United States, 2011. Atlanta, GA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, 2011.

Giovannucci E, Harlan DM, Archer MC, Bergenstal RM, Gapstur SM, Habel LA, et al. Diabetes and cancer: a consensus report. CA Cancer J Clin. 2010 Jul-Aug;60(4):207-21. Epub 2010 Jun 16.

Holman RR, Thorne KI, Farmer AJ, Davies MJ, Keenan JF, Paul S, et al. Addition of biphasic, prandial, or basal insulin to oral therapy in type 2 diabetes. N Engl J Med. 2007 Oct 25;357(17):1716-30. Epub 2007 Sep 21.

Inzucchi SE, Bergenstal RM, Buse JB, Diamant, M, Ferrannini E, Nauck M, et al. Management of hyperglycemia in type 2 diabetes: a patient-centered approach. Position statement of the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD). Diabetes Care. 2012 Apr 19. [Epub ahead of print]

Lee AJ, Hiscock RJ, Wein P, Walker SP, Permezel M. Gestational diabetes mellitus: clinical predictors and long-term risk of developing type 2 diabetes: a retrospective cohort study using survival analysis. Diabetes Care. 2007 Apr;30(4):878-83.

Nathan DM, Buse JB, Davidson MB, Ferrannini E, Holman RR, Sherwin R, et al. Medical management of hyperglycemia in type 2 diabetes: a consensus algorithm for the initiation and adjustment of therapy: a consensus statement of the American Diabetes Association and the European Association for the Study of Diabetes. Diabetes Care. 2009 Jan;32(1):193-203. Epub 2008 Oct 22.

Rosenzweig JL, Ferrannini E, Grundy SM, Haffner SM, Heine RJ, Horton ES, et al. Primary prevention of cardiovascular disease and type 2 diabetes in patients at metabolic risk: an endocrine society clinical practice guideline. J Clin Endocrinol Metab. 2008 Oct;93(10):3671-89. Epub 2008 Jul 29.