Endocrine e-book Flashcards
Diabetes mellitus is defined as
Diabetes mellitus is defined as a persistent state of hyperglycaemia due to the body’s inability to properly utilise glucose.
Glucose is an essential part of the diet- it is the fuel for all of the cells within the human body, and is essential for cells to be able to function.
In order for us to be able to utilise the glucose we ingest in our diets the glucose needs to be able to enter the cells. The entrance of glucose into the cells is facilitated by the hormone insulin which is produced by the pancreas.
In patients with diabetes the glucose is unable to enter the cells and therefore remains in the bloodstream where it cannot be used as energy
2 types of DM
There are two main different types of diabetes mellitus- type 1 and type 2, which are defined by the reason for the glucose being unable to be utilised.
Type 1 diabetes is caused when the pancreas does not produce any insulin. This occurs when the β-cells in the pancreas are destroyed- this may be autoimmune T-cell mediated destruction or idiopathic.
Type 2 diabetes is caused by a relative insulin deficiency and/or insulin resistance.
Type 2 DM is commonly associated with obesity, physical inactivity, hypertension, dyslipidaemia and a tendency to develop thrombosis; therefore it increases cardiovascular
risk. It is associated with long term microvascular and macrovascular complications, together with reduced quality of life and life expectancy.
Type 1 is most commonly diagnosed in people under the age of 30 and especially in childhood. Type 2 usually develops in people over the age of 40. However, there is now an increasing incidence of type 2 in younger patients who are obese.
Signs and symptoms
Polyuria Nocturia Polydipsia Lethargy Unexplained weight loss
Reasons behind the symptoms
Patients may experience polyuria, nocturia and polydipsia as a result of osmotic diuresis secondary to the hyperglycaemia.
Lethargy is a result of the body’s inability to utilise the glucose to provide energy.
Unexplained weight loss is caused by the breakdown of body protein and fat as alternative energy sources as the glucose is unavailable.
Whilst the symptoms are the same for both types of diabetes mellitus the intensity at which a patient may experience their symptoms can vary.
Type 1 and 2 DM symptom variations
Type 1 DM- Symptoms are usually experienced at a more severe level and the onset is usually faster.
Type 2- DM- Symptoms are usually more ‘vague’ in their presentation and they may develop over a longer period of time and in some cases even years.
Treatment of type 1 diabetes mellitus
As type 1 DM is caused by a destruction of the insulin producing cells in the pancreas the treatment requires the replacement of the insulin.
The aim of treatment is to achieve as optimal a level of blood glucose control as is feasible, while avoiding or reducing the frequency of hypoglycaemic episodes.
Good control of type I DM will reduce the risk of both short term and long term complications.
There are different types of insulin available;
Short acting
Intermediate
Long acting
Ultralong acting
There are some common insulin regimens that are used and these are
Multiple daily injection basal-bolus insulin regimens
Short acting insulin or rapid acting insulin analogue bolus doses before meals with intermediate or long acting insulin once or twice daily as the basal insulin.
An advantage of a basal-bolus regimen is that it offers more flexibility over when meals are taken and also allows doses to be varied in response to different carbohydrate quantities in meals.
Mixed (biphasic) regimen
Insulin injections given twice a day consisting of short acting insulin mixed with intermediate-acting insulin. In type I DM this may be suitable for patients who have a
consistent day to day routine. This type of regimen allows some flexibility for adjusting doses but not as much as a basal-bolus regimen.
Continuous Subcutaneous insulin infusions
The use of a continuous subcutaneous insulin infusion is a relatively recent addition to the treatment regimens that are available to patients with type I diabetes mellitus. Pumps are popular with patients as they reduce the need for multiple insulin injections daily.
A continuous subcutaneous insulin infusion allows the patient to receive a continuous basal infusion of rapid or short acting insulin via a portable infusion pump and the patient will also administer bolus doses at mealtimes.
There are strict criteria that patients must meet if they are to be considered for the use of such a device, the patients need to be highly motivated to manage their diabetes, they need to be able to monitor their blood glucose concentrations accurately and they must be under the supervision of a healthcare team who are experienced in the management of diabetes.
-People with type I DM may be offered Insulin pump therapy if despite being highly motivated to manage their condition they have struggled to keep blood glucose levels under control on a multiple daily injection regimen
Side effects of insulins
These are some of the most common side effects that can be associated with the use of insulins;
Local reactions at the injection site
Hypoglycaemia (if too much insulin is administered)
Rarely; hypersensitivity reactions.
Treatment of type 2 diabetes mellitus
As type 2 DM is characterised by a resistance to the insulin that is naturally produced by the body and also insufficient production of insulin by the pancreas which occurs progressively over time treatment is initiated to allow the body to use the insulin that is produced naturally more effectively.
The first stage when a patient is diagnosed as having type 2 diabetes is to recommend nonpharmacological management.
Treatment of type 2 diabetes mellitus - Non-pharmacological management
Patients should be offered lifestyle advice; this should include advice on restricting the amount of energy and carbohydrates that they ingest and increasing the amount of physical activity that the patient undertakes (this must be on an individual patient basis and take account of other patient factors). At this stage patients often refer to themselves as having ‘diet-controlled’ diabetes.
Treatment of type 2 diabetes mellitus - diet
Weight loss is often the first thing that is suggested to patients with type 2 DM. If patients are overweight, losing weight can help to improve insulin sensitivity.
Patients should be encouraged to reduce calorie intake, however it is important that this is done in a way that is sustainable for them long term. Energy dense foods such as bread, rice, pasta and potato based foods are usually advised to be limited in a patients diet, particularly if they are not very active. Patients should also be advised to increase the amount of vegetables in their diet as vegetables provide a variety of nutrients while having a
relatively low calorie count, in addition to this vegetables contain soluble fibre which helps people to feel fuller for longer.
If patients are not overweight they should be encouraged to eat a balanced diet to help keep blood glucose levels under control.
Treatment of type 2 diabetes mellitus - exercise
Increasing the amount of exercise that a person undertakes is beneficial in lowering blood glucose levels in two ways.
Firstly, when muscles are used they require glucose from the blood, liver and muscles.
When the exercise is finished the body replenishes its stores of glucose by taking in available glucose from the blood- thus lowering blood glucose levels.
Secondly, exercise utilizes the energy (calories) from food so if exercise levels are increased and calorie intake maintained (or reduced as part of a healthy diet) patients will lose weight which will help to manage the diabetes mellitus
Treatment of type 2 diabetes mellitus - other advise
Patients should be encouraged to stop smoking and reduce alcohol intake to help diabetes control and general health.
If these lifestyle advice measures fail, patients should be commenced on oral antidiabetic agents; these should be used alongside the dietary and physical activity changes NOT instead of them
There are many classes of oral antidiabetic drugs available
Biguanides; e.g. Metformin Sulfonylureas; e.g. Gliclazide Inhibitor of intestinal alpha glucosidases; e.g. Acarbose DPP-4 inhibitors; e.g. Sitagliptin Thiazolidinediones; e.g. Pioglitazone GLP-1 mimetics; e.g. Exenatide Meglitinides; e.g Repaglinide SGLT2 inhibitors; e.g. Dapagliflozin