Diabetes mellitus

Type 1 Diabetes

Pathology:                    Absolutelack of insulin secretion > impaired glucose metabolism

Autoimmune destruction of β pancreatic islet cells

Aetiology:                     Primary90% associated with HLD-DR3/4, peak age of onset <25years

                                          Secondarydue to destruction of pancreas

Symptoms:                   Polyuria,polydipsia, weight loss, lethargy, blurred vision, thrush

Signs:                              Acute: Low BMI, dehydration, “peardrop”/fruity odour on breath

Chronic:peripheral neuropathy, decreased vision, lack of hypo awareness

Investigations:          Bloods: Plasma glucose, serum ketones, anti-GADand islet cell antibodies, c-

peptide –ve as noendogenous insulin production

Venous Blood Gas: pH and bicarbonate

Treatment:                  Insulin replacement

                                          Patienteducation

Regular follow-up

Complications:          DKA, retinopathy,nephropathy, neuropathy, PVD, Cardiovascular disease, Autonomic dysfunction(postural hypotension, gastroparesis)

Prognosis:                    Dependson good control. Likely to limit life expectancy by 10-20 years.

Normal

Impaired  glucose tolerance

Diabetes

Fasting  glucose

<6.0

<7.0

>7.0

Oral  glucose tolerance test

<7.8

7.8-11.0

>11.0

Figure 5.1 Diagnostic Glucose Values For Diabetes Mellitus

Type2 Diabetes

Pathology:                    Relative insulin deficit andresistance to insulin action

Aetiology:                     Genetics+ environment (high density food intake, obesity, lack of exercise, chronic pancreatitis,Cushing’s). Peak incidence 50 years

Symptoms:                   Maybe asymptomatic initially, recurrent infections, polyuria, polydipsia, weightloss, HHS

Signs:                              HighBMI, central obesity, acanthosis, foot ulcers, visual defects

Investigations:          Bloods: Plasma glucose, serum ketones, U&E,HbA1C

VenousBlood Gas: pH and bicarbonate

Treatment:                  Lifestyle measures: Diet, exercise,smoking cessation, patient education

                                          Medical: Sulphonylurea,biguanides, glitazones, GLP-1 analogues, and DPP-4

inhibitors, using astepwise approach.

                                          Surveillance: Regularfollow-up and HbA_1c tomonitor glycaemic control and

complications

Complications:          Cardiovasculardisease, DM retinopathy, DM nephropathy, DM neuropathy, peripheral vasculardisease

Prognosis:                    Canbe life limiting due to 4-fold increase in cardiovascular disease, 10-20 yearreduction in life expectancy

‍

Figure 5.2 Common Oral Anti-Diabetic Agents

‍