Diabetes Mellitus - How to Approach a Patient with Diabetes Mellitus in the Long Case Examination (History Taking)

Diabetes Mellitus (DM) is a common entity nowadays and therefore it should be well known by every healthcare practitioner particularly the clinicians. 

Similarly, diabetes mellitus is also a common appearance in the medical examinations. They may appear in various forms e.g.  target organ damage, complications related to treatment, as well as psychosocial issues surrounding the condition itself. 

For the undergraduate final examinations, students can expect to encounter cases where a patient presents with a particular complaint related to a target organ damage. For example the patient may present with numbness affecting the feet or even blurred vision affecting one or both eyes. The student is expected to get a competent and complete history pertaining to the presenting complaint as well as establish the diagnosis of diabetes mellitus and whether there are presence of other target organ damage occurring concomitantly with the presenting complaint.

So, let us refresh our memories with regards to diabetes mellitus and its complications.

Diabetes mellitus are broadly categorised into 2 types (for the undergraduate level, at least):

Type 1 - Autoimmune cause, due to premature loss of pancreatic beta islet cells

Type 2 - Acquired cause, usually due to insulin resistance as a result of increased adipocity, hormonal dysregulation etc.

There are other types as well e.g Maturity Onset of Diabetes in the Young (MODY), Gestational diabetes, Double Diabetes (mixture of both Types 1 and 2 in the same patient) etc. But those are for another topic and discussion as it can be complex. 

In general, the differentiating factor between Types 1 and 2 Diabetes Mellitus is age of onset. Type 1 typically occur in the young, usually pre adolescent age whereas Type 2 diabetes occur in adulthood (in general). However this distinctive factor is no longer clearcut and we are seeing younger patients with Type 2 diabetes due to lifestyle and the ever increasing waistline among youngsters. 

After tackling the presenting complaint, you can add the following information within the history of presenting illness (HOPI) segment. 

Enquire and explore regarding complications resulting from diabetes mellitus:

MACROVASCULAR:

• Coronary artery disease
• Ask about chest pains (categorise according to Canadian Cardiovascular Society classification), dyspnoea (categorise according to New York Heart Association classification), pedal oedema, orthopnoea, paroxysmal nocturnal dyspnoea etc
• Cerebrovascular disease
• Ask about facial assymetry, unilateral limb weakness, speech impairment, dysphagia, memory impairment (vascular dementia)
• Peripheral arterial disease
• Claudication pains, resting pains, digital cyanosis or gangrene

MICROVASCULAR:

• Retinopathy
• Ask about scotomas, blurred vision, floaters, visual field defects
• Nephropathy
• Ask about frothy urine, pedal oedema, facial puffiness, periorbital oedema, dyspnoea, uremia (nausea/ vomiting/ anorexia/ chest pains (pericarditis) / abdominal pains (uremic peptic ulceration)/ altered sensorium or seizures (uremic encephalopathy), dialysis, renal transplantation)
• Neuropathy - somatic and autonomic
• Ask about numbness affecting extremities especially the foot, pressure ulcers, digital gangrene, foot deformities, postural giddiness, recurrent vomiting (gastroparesis)
• Sexual dysfunction - erectile dysfunction (a sensitive issue due to the taboo among Asian customs, but if approached professionally and you are able to obtain information regarding this issue, many patient's will be grateful and of course, impress the examiners)

METABOLIC:

• Hyperglycemia
• Ask about polyuria, polydipsia, unintentional weight loss, nocturia (not to be mistaken with prostatism - diabetic polyuria have good amd large volume urine stream due to osmotic diuresis whereas prostatism nocturia have weak urine stream with the usual lower urinary tract symptoms e.g. terminal dribbling, hesitancy etc). 
• Diabetic ketoacidosis (DKA) or hyperosmolar hyperglycemic syndromes (HHS)
• Ask about symptoms of hyperglycemia plus dyspnoea (may suggest acidotic breathing), sweet fruity breath smell (ketone breath), altered sensorium (HHS) or involuntary limb movements (hemichorea hemiballismus due to HHS) ** diabetic emergencies will not appear for exams, rest assured 😏
• Hypoglycemia
• Ask about hand tremors, hunger pangs, diaphoresis, agitation/ anxiety/ restlessness, syncope and coma (unlikely to appear in the exams as you wont be able to clerk the patient!!) 

In the review of systems segment, can explore regarding any health problems from head to toe which may be the cause of diabetes mellitus e.g. connective tissue disorders e.g. SLE/  rheumatoid arthritis or chronic lung disease (asthma/COPD) (chronic steroid usage), acromegaly, Cushing's syndrome. If the patient is young, presence of concomitant connective tissue disease (s) may suggest an autoimmune cause of DM. 

In the family history segment, explore about strong family history of DM. 

For past medical history or surgical history segment, enquire about history of pancreatitis, pancreatic tumours or pancreatic surgery. Also about any pituitary tumour resection (pituitary Cushing's or Acromegaly), adrenal tumour (Adrenal Cushing's) resections. 

In the drug history section, can check with the patient regarding their medication list and compliance. Patients may know the medications they are on and the dosages. Alternatively, patients may be provided a prescription slip and will be instructed to show the medical student upon request. If there is element of non-compliance, be sure to enquire the reason behind the behaviour. Very often, the patient may inform of some adverse side effects as a result of taking that particular medication which causes the non-compliance. For example, the patient may be non-compliant to metformin because of bloating or frequent loose stools. 

Physical examination of the patient with diabetes mellitus requires a comprehensive approach from head to toe similar to history taking. There will be many areas to cover and therefore, it will be covered in the next post "Diabetes Mellitus - How to Approach a Patient with Diabetes Mellitus in the Long Case Examination (Physical Examination)". 

CCE.