• Enquire about erectile dysfunction in men

• Ask about postural hypotension, sweating, diarrhoea and vomiting in

all patients

10.5 Causes of secondary diabetesa

Cause of diabetes Examples Clinical features

Pancreatic disease Pancreatitis Abdominal pain

Trauma/pancreatectomy Surgical scar

Neoplasia Weight loss

Cystic fibrosis Chronic cough, purulent sputum

Haemochromatosis Skin pigmentation (‘bronze diabetes’)

Endocrinopathies Acromegaly, Cushing’s syndrome p. 202

Drugs Glucocorticoids (e.g. prednisolone)

Antipsychotics (e.g. olanzapine)

Features of Cushing’s syndrome (see Fig. 10.11)

Immunosuppressants (e.g. ciclosporin, tacrolimus) Gum hypertrophy may be seen with ciclosporin use

Pregnancy Gestational diabetes may develop in the third trimester Gravid uterus

Monogenic defects in

beta-cell function

Glucokinase deficiency Glucokinase deficiency is present from birth with

stable mild hyperglycaemia

Genetic syndromes associated

with diabetes

Down’s syndrome p. 36

Turner’s syndrome p. 36

a

Based on classification by the American Diabetes Association.

The physical examination • 207

10

The diabetic foot

Up to 40% of people with diabetes have peripheral neuropathy and

40% have peripheral vascular disease, both of which contribute

to a 15% lifetime risk of foot ulcers (Fig. 10.16).

Early recognition of the ‘at-risk’ foot is essential. There are

two main presentations:

• Neuropathic: neuropathy predominates but the major

arterial supply is intact.

• Neuroischaemic: reduced arterial supply produces

ischaemia and exacerbates neuropathy.

Infection may complicate both presentations.

Examination sequence

• Look for hair loss and nail dystrophy.

• Examine the skin (including the interdigital clefts) for

excessive callus, skin breaks, infections and ulcers. Look

for any discoloration. Distal pallor can suggest early

ischaemia, while purple/black discoloration suggests

gangrene.

• Ask the patient to stand so that you can assess the foot

arch; look for deformation of the joints of the feet.

• Feel the temperature of the feet.

• Examine the dorsalis pedis and posterior tibial pulses. If

absent, arrange Doppler studies and evaluate the

ankle:brachial pressure index (p. 69).

• Test for peripheral neuropathy: use a 10-g monofilament

to apply a standard, reproducible stimulus. The technique

Routine review of a patient with diabetes

Examination sequence

• Weigh the patient: weight gain in type 2 diabetes is likely

to be associated with worsening insulin resistance while

weight loss in type 1 diabetes often suggests poor

glycaemic control and inadequate insulin dosage.

• For patients on insulin, examine insulin injection sites for

evidence of lipohypertrophy (which may cause

unpredictable insulin release), lipoatrophy (rare) or signs of

infection (very rare).

• Measure the pulse and blood pressure.

• Test visual acuity and perform fundoscopy (p. 164; see

Fig. 8.16).

• Examine the feet (see the next section).

• Perform routine biochemical screening (Box 10.7).

A

B

C

Fig. 10.15 Diabetes and the skin. A Acanthosis nigricans.

B Necrobiosis lipoidica. C Eruptive xanthomata.

10.7 Investigations in diabetes

Investigation Indication/comment

Diagnostic investigations

Fasting glucose, random

glucose, oral glucose

tolerance test

To make a diagnosis of diabetes.

Patients will also monitor capillary blood

glucose to adjust their treatment

HbA1c Can be used for diagnosis of type 2

diabetes and to assess glycaemic burden

Urine or blood ketone

measurement

Ketones suggest insulin deficiency,

which occurs in type 1 diabetes and in

diabetes due to pancreatic pathology

Pancreatic antibodies

(anti-GAD and islet cell)

To confirm a diagnosis of autoimmune

diabetes

Annual review investigations

HbA1c An important measure of glycaemic

control over the preceding 3 months;

predicts risk of complications

Urea and electrolytes To assess for the presence of diabetic

nephropathy

Lipid profile To aid estimation of cardiovascular risk

and guide treatment with lipid-lowering

therapy

Thyroid function tests To screen for the commonly associated

hypothyroidism

Urine albumin : creatinine

ratio

To assess for early signs of diabetic

nephropathy (microalbuminuria)

Digital retinal photography

or fundoscopy

To screen for diabetic retinopathy and/or

maculopathy

GAD, glutamic acid decarboxylase.

208 • The endocrine system

and the best sites to test are shown in Fig. 10.17. Avoid

areas of untreated callus. Sensory loss typically occurs in

a stocking distribution.

• Assess dorsal column function by testing vibration and

proprioception.

• Undertake a foot risk assessment to guide management

(Box 10.8).

Hair loss and nail dystrophy occur with ischaemia. Feet are

warm in neuropathy and cold in ischaemia. Ischaemic ulcers are

typically found distally: at the tips of toes (see Fig. 10.16B), for

example. There may be skin fissures or tinea infection (‘athlete’s

foot’). Loss of sensation to vibration (p. 143) and proprioception

(p. 144) are early signs of diabetic peripheral neuropathy. Sensory

neuropathy is present if the patient cannot feel the monofilament

on the sites shown in Fig. 10.17. This suggests loss of protective

pain sensation and is a good predictor of future ulceration.

With significant neuropathy, the foot arch may be excessive or

collapsed (rocker-bottom sole). Both conditions cause abnormal

pressures and increase the risk of plantar ulceration (see Fig.

10.16C), particularly in the forefoot. Charcot’s arthropathy is

disorganised foot architecture, acute inflammation, fracture and

bone thinning in a patient with neuropathy. It presents acutely

as a hot, red, swollen foot and is often difficult to distinguish

clinically from infection.

10.8 Risk assessment of the diabetic foot

Level of risk Definition Action required

Low No sensory loss, peripheral vascular disease or other risk factors Annual foot screening can be undertaken by any trained

healthcare professional

Moderate One risk factor present, e.g. absent pulses or reduced sensation Annual foot screening should be undertaken by a podiatrist

High Previous ulceration or amputation, or more than one risk factor

present

Annual screening should be undertaken by a specialist

podiatrist

Active foot disease Ulceration, spreading infection, critical ischaemia or an

unexplained red, hot, swollen foot

Prompt referral to a multidisciplinary diabetic foot team is

required

A

B

C