Endocrine

• Diabetes Mellitus (DM)


  • Disorder of glucose tolerance & with biochemical & structural consequences
  • Metabolic disorder characterised by hyperglycaemia with disturbances to carbohydrate, fat & protein metabolism
  • Results form defects in insulin secretion, insulin action or both

  
• Types of Diabetes Mellitus

  • Type 1
  • Type 2
  • Pre-diabetes
  • Gestational
• Uncontrolled Diabetes Mellitus


  • Associated with complications such as: Microvascular (retinopathy, nephropathy, neuropathy)
  • Macrovascular (IHD, PVD, Cerebrovascular disease)
  • Metabolic abnormalities
• Pre-diabetes

  Described as impaired glucose tolerance (IGT) when fasting glucose level is between 6.1 – 7.0mmol/L, but rises to 7.8mmol/L after 2 hours from oral administration of glucose (oral glucose tolerance test – OGTT)
• Clinical manifestations of Pre-diabetes


  • Often none
  • Mild polyuria
  • Mild nocturia
  • Mild polydipsia
  • Unexplained weight loss
• Diagnosis of Diabetes Mellitus

  • Random venous plasma glucose ≥11.1 mmol/L
  • Fasting plasma glucose (FPG) ≥ 7.0mmol/L
  • Plasma glucose >11.1mmol/L after an OGTT
• If patient asymptomatic – diagnosis can be complicated & not based on single glucose measurement
• Minimum of a further test must be performed on a different day – can be random, fasting or OGTT
• Second result must be within the range indicative of DM before diagnosis is made
• If the random or fasting are not diagnostic – OGTT result must be used
• UK: standard to measure & report blood glucose for diagnosis – Venous Plasma Sample
• WHO: glycated haemoglobin (HbA1c)


  • Could be used as a diagnostic test
  • HbA1c of 48mmol/L – recommended to diagnose diabetes, levels less than 48mmol/L – do not exclude diabetes diagnosis
  • Measures average amount of glucose carried in patients blood cells in previous 2-3 months
  • Is considered more 'patient friendly' than other tests (OGTT) as no special preparation is required (e.g., fasting)
  • Not suitable if erythrocyte turnover is disturbed or abnormal Hb type

  
• Diagnostic criteria for Diabetes Mellitus

  • Fasting venous plasma glucose (mmol/L) <6.1 - Normoglycaemia
  • Fasting venous plasma glucose (mmol/L) ≥6.1 & <7.0 AND Venous plasma glucose 2 hrs post glucose load (mmol/L) ≤7.8 - Impaired fasting glycaemia (IFG)
  • Fasting venous plasma glucose (mmol/L) <7.0 AND Venous plasma glucose 2 hrs post glucose load (mmol/L) ≥7.8 - Impaired Glucose Tolerance (IGT)
  • Fasting venous plasma glucose (mmol/L) ≥7.0 OR Venous plasma glucose 2 hrs post glucose load (mmol/L) ≥11.1 - Diabetes mellitus
• Treatment aim


  • Dietary plans & exercise programs to prevent or delay development of diabetes, but not cure it
  • If patient returns to previous lifestyle habits diabetes can return
  • Some patients require pharmacological treatment if diet & exercise is insufficient
  • Monitoring blood glucose (BGL) & HbA1c should continue & patient education for self monitoring
• NICE: Do not routinely offer self monitoring of blood glucose levels for adults with T2DM unless: Person is on insulin, Evidence of hypoglycaemic episodes, Person is on oral medications that may increase risk of hypoglycaemia while driving or operating machinery, Person is pregnant or planning to become pregnant
• Type 1 DM


  • Characterised by lack of insulin production due to ß cell defect
  • Can occur at any age, most commonly present in juveniles, but can occur in adult, especially in late 30s & early 40s
  • Common in Caucasians, Africans and Afro Caribbean, but rare in Japanese & Pacific ethnicities
  • Caused by auto immune destruction of pancreatic ß cells
  • High prevalence around the time of puberty which declines after
  • Genetic & environmental factor as can influence T1DM development
  • Environmental factors: Viral infections, Immunisations, Diet (esp. exposure to milk cow at an early age), Vitamin D deficiency, Peri-natal factors (e.g., maternal age, history of neonatal jaundice)

  
• Islet cell antibodies


  • Marker of immune destruction & found to be present in over 70% patients with T1DM in initial diagnosis
  • The antibodies develop slowly & often appearance comes ahead the clinical presentation by 3 years
• Acute event causing sudden stress on body (viral/bacterial infection) can trigger clinical appearance of diabetes when mass of pancreatic ß cells falls below 5-10%

  
• ß-cell destruction leads to insulin deficiency within ~~1 year of presentation/diagnosis

  
• Treatment strategy for Type 1 DM

  • Structured patient education
  • Dietary Management
  • Physical activity
  • Insulin therapy
• Structured patient education


  • Adult patients with newly diagnosed T1DM offer structured patient education programme within 6-12 months after diagnosis
  • Information should be given about condition & management at every opportunity from diagnosis onwards
• Dietary Management


  • Carbohydrate-counting training should be offered to patients with T1DM
  • Low glycaemic index foods & foods marketed as 'diabetic' should not be advised
  • Provide dietary advice & avoid sugary drinks, juices
  • Eating foods low in saturated fat, sugar & salt
  • Control on carbs, & maintainability a normal healthy balanced diet
• Physical activity


  • T1DM patients have increased risk of CVD
  • Risk is reduced in medium & long term physical activity
• Insulin therapy

  • New onset of T1DM lifelong insulin therapy must be initiated
  • Administered subcutaneous injection using an insulin insulin pen device or syringe
  • Some circumstances – may be given as IV infusion
  • Hospital admission due to severe hyperglycaemia or diabetic ketoacidosis (DKA)
  • Therapy can commence on hospital & managed in outpatient setting with support in diabetes education
  • Inpatient setting allows immediate education about safe use of insulin including: Safe dose adjustment, Controlled reduction in blood glucose, Safe use of insulin – regimen, injection delivery device, provision of advice, Recognising hypo- hyper- glycaemia, Self-management strategies, Achieving blood glucose levels
  • Patients with T1DM often have endogenous insulin production at early diagnosis, slowly reducing to none
• Types of insulin


  • Animal (porcine or bovine)
  • Human (synthetically produced by modification of porcine insulin or recombinant DNA technology to mimic human insulin)
  • Analogues (insulin lispro – levemir®, insulin glargine – lanctus® & insulin aspart)
• Insulin analogues


  • Control insulin release by strengthening or weakening natural tendency of insulin forming complexes in SC injection sites
  • Strengthening complexes – delays release without carrier substances (e.g. protamine)
  • Weakening complexes – gives rapid release, faster than normal human insulin by SC injection
• Considerations when prescribing, dispensing or administering insulin

  • Often prescribe by brand name, or avoid confusion for HCP & maintain compatibility with devices
  • Biological medicines should be prescribed & dispensed by brand to avoid switching
  • 6 rights of Insulin: Right person, Right insulin, Right dose, Right device, Right injecting way, Right time
• Overdose of insulin due to misunderstood abbreviations or incorrect device is a 'never event' by Department of Health
• Overdose refers to: Patient receives a 10x or greater overdose of insulin because a prescriber abbreviates words 'unit' or 'international units', HCP fails to use a specific insulin administration device i.e. does not use insulin syringe or insulin pen to measure insulin
• Patients should be shown the container of the insulin to confirm that is the version they are required to take
• Patients on insulin should receive an insulin booklet & insulin passport
• Insulin should never be extracted from pen devices
• Insulin storage & disposal of needles & lancets

  • Use of sharps bin for used needles, sharps lancets & clippers usually from a FP10 prescriptions
  • Used needles must not be bent or broken before disposal & never recap a needle
  • A needle clipper can be used to snap off a needle or sharp part of a syringe – needle stays in the clipper
  • Clippers not used to remove lancet needles (needles used for diabetes to check blood glucose)
  • The contents of the bin must not exceed the line on the bin
  • Keep out of reach from children & others
  • Do not put used needles in general waste, recycling as blood-borne viruses can be passed to others (HIV, Hep B/C)
• Self-monitoring of blood glucose

  • Home testing of blood glucose by parties with diabetes to determine the amount of glucose in the blood
  • This should be taught when initiating insulin
  • Patients requires blood glucose monitor/meter, finger pricking device, lancets & test strips
• Hypoglycaemia


  • Main ADR of insulin therapy is hypoglycaemia- blood glucose levels less than 3.5 mmol/L
  • Symptoms: hunger, anxiety, irritability, palpitations, sweating or tingling lips, to convulsions, loss of consciousness & coma
  • Severe hypoglycaemia where a person has a reduced level of consciousness, IM glucagon given by another person is recommended
• Glucagon


  • Pancreatic alpha cells of Islet of Langerhans, produce glucagon, polypeptide hormone – opposite effects of glucose
  • Glucagon elevates blood glucose levels by inhibiting glycogen synthesis & enhance formation of glucose from non-carbohydrate sources (proteins & fats) (gluconeogenesis)
  • Glucagon indicated for severe hypoglycaemic episodes in patients with diabetes treated with insulin
  • Dose of 1 mg IM/SC/IV, if no IV glucose given, repeated every 20min x1-2 - giving glucose if there is still no response
  • Administration of supplemental carbohydrate to replenish glycogen stores is required when patient gains consciousness

  
• Type 2 Diabetes Mellitus

  • Reduced insulin production or body's resistance to intrinsic insulin
  • T2DM is common over 40s, but is increasing in children & adolescents
  • Patients not dependent on insulin supplementation for survival

  
• Risk factors for T2DM

  • Weight greater than 120% of desirable body weight
  • Family history of T2DM in a 1st-degree relative
  • HTN (>140/90 mm Hg) &/or dyslipidaemia
  • History of gestational diabetes
  • Polycystic ovarian syndrome (results in insulin resistance)
  • Medications e.g. antipsychotics & oral corticosteroids
• Diagnosis of T2DM


  • symptoms (if present) such as polyuria, polydipsia & unexplained weight change, plus: Random venous plasma glucose ≥ 11.1mmol/L or; Fasting plasma glucose (FPG) ≥ 7.0mmol/L or; Plasma glucose ≥ 11.1mmol/L after an oral glucose tolerance test (OGTT)

  
• If patient asymptomatic, the diagnosis is more complicated & never based on single glucose reading