Diabetes occurs when there is a dis-balance between the demand and production of the hormone insulin. Show
Control of blood sugarWhen food is taken, it is broken down into smaller components. Sugars and carbohydrates are thus broken down into glucose for the body to utilize them as an energy source. The liver is also able to manufacture glucose. In normal persons the hormone insulin, which is made by the beta cells of the pancreas, regulates how much glucose is in the blood. When there is excess of glucose in blood, insulin stimulates cells to absorb enough glucose from the blood for the energy that they need. Insulin also stimulates the liver to absorb and store any excess glucose that is in the blood. Insulin release is triggered after a meal when there is a rise in blood glucose. When blood glucose levels fall, during exercise for example, insulin levels fall too. High insulin will promote glucose uptake, glycolysis (break down of glucose), and glycogenesis (formation of storage form of glucose called glycogen), as well as uptake and synthesis of amino acids, proteins, and fat. Low insulin will promote gluconeogenesis (breakdown of various substrates to release glucose), glycogenolysis (breakdown of glycogen to release gluose), lipolysis (breakdown of lipids to release glucose), and proteolysis (breakdown of proteins to release glucose). Insulin acts via insulin receptors.
Normal Responses to Eating and Fasting
HormonesHormones that raise blood sugar include glucagon, epinephrine and norepinephrine, cortisol, Growth hormone etc. These hormones are released due to stress. Thus during phases of stress like an infection, surgery or pregnancy diabetes control worsens and blood sugar rises. Pathophysiology of type 1 diabetesIn this condition the immune system attacks and destroys the insulin producing beta cells of the pancreas. There is beta cell deficiency leading to complete insulin deficiency. Thus is it termed an autoimmune disease where there are anti insulin or anti-islet cell antibodies present in blood. These cause lymphocytic infiltration and destruction of the pancreas islets. The destruction may take time but the onset of the disease is rapid and may occur over a few days to weeks. There may be other autoimmune conditions associated with type 1 diabetes including vitiligo and hypothyroidism. Type 1 diabetes always requires insulin therapy, and will not respond to insulin-stimulating oral drugs. Pathophysiology of type 2 diabetesThis condition is caused by a relative deficiency of insulin and not an absolute deficiency. This means that the body is unable to produce adequate insulin to meet the needs. There is Beta cell deficiency coupled with peripheral insulin resistance. Peripheral insulin resistance means that although blood levels of insulin are high there is no hypoglycaemia or low blood sugar. This may be due to changes in the insulin receptors that bring about the actions of the insulin. Obesity is the main cause of insulin resistance. In most cases over time the patients need to take insulin when oral drugs fail to stimulate adequate insulin release.
Pathophysiology of gestational diabetesGestational diabetes is caused when there are excessive counter-insulin hormones of pregnancy. This leads to a state of insulin resistance and high blood sugar in the mother. There may be defective insulin receptors. Pathophysiology behind symptoms and complications of diabetes
Further Reading
Last Updated: Feb 26, 2019 Written by Dr. Ananya MandalDr. Ananya Mandal is a doctor by profession, lecturer by vocation and a medical writer by passion. She specialized in Clinical Pharmacology after her bachelor's (MBBS). For her, health communication is not just writing complicated reviews for professionals but making medical knowledge understandable and available to the general public as well. CitationsPlease use one of the following formats to cite this article in your essay, paper or report:
Suggested ReadingWhy does DM cause polydipsia?Polydipsia is also an early symptom of diabetes mellitus and diabetes insipidus. Diabetes mellitus causes polydipsia because your blood sugar levels get too high and make you feel thirsty, regardless of how much water you drink. Diabetes insipidus occurs when your body's fluid levels are out of balance.
What causes polydipsia and polyphagia?Polydipsia, polyuria, and polyphagia are the three Ps of diabetes. These conditions are consistent with increases in hunger, urination, and appetite. The three Ps sometimes occur together, but not always. It is an indication of elevated blood glucose levels than normal and is some of the most common diabetes symptoms.
Is polyphagia a symptom of DM?The main symptoms of diabetes are described as the three polys - polyuria, polydipsia, and polyphagia.
What causes polyuria polydipsia and polyphagia in diabetes?Polyuria or increased frequency of urination is due to excess fluid intake and glucose-induced urination. Weight loss occurs due to loss of calories in urine. Polyphagia or increased hunger due to loss or excess glucose in urine that leads the body to crave for more glucose.
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