Diabetes

1. ENDOCRINE CAUSES OF DIABETES MELLITUS
DR SAQIB ALI FRCPI
CONSULTANT ENDOCRINOLOGY & DIABETES
King Salman Hospital, Riyadh
The Kingdom of Saudi Arabia

2. ENDOCRINE CAUSES OF DIABETES
• CUSHING SYNDROME
• ACROMEGALY
• HYPERTHYRDOISM
• GLUCAGONOMA
• SOMATOSTATINOMA
• PHEOCHROMOCYTOMA

3. Cushing Syndrome Scenario:
• This female patient has been gaining weight
and has noticed difficulty in getting out of a
chair
• Talk to the patient and examine her?

4. History:
Symptoms
• Difficulty rising from seated position (proximal
myopathy)
Drug history
• Exogenous vs endogenous steroid
Associated problems
• Visual problems: Bitemporal hemianopia
• Skin hyperpigmentation
• Diabetes mellitus

5. Examination:
Spot diagnosis
• Face: moon‐shaped, hirsute, with acne
• Skin: bruised, thin, with purple striae
• Back: ‘buffalo hump’
• Abdomen: centripetal obesity
• Legs: wasting (‘lemon on sticks’ body shape) and
edema
Complications
• Hypertension (BP)
• Diabetes mellitus (random blood glucose)
• Osteoporosis (kyphosis)
• Cellulitis
• Proximal myopathy (stand from sitting)

6. DD & Causes:
Differential diagnosis:
• Ethanol excess: pseudo‐Cushing’s
Causes:
• Exogenous: signs of chronic condition (e.g.
RA, COPD) requiring steroids
• Endogenous: Bitemporal hemianopia and
hyperpigmentation (if ACTH ↑)

7. Investigation: step 1 screening
1. Confirm high cortisol ( 2/5 +)
• 24‐hour urinary collection
• Low dose (for 48 hours) or
• overnight dexamethasone suppression test
• Midnight cortisol
• Salivary cortisol
• Suppressed cortisol:
alcohol/depression/obesity (‘pseudo‐Cushing’s’)

8. Investigation: step2 Look for source
• 2. If elevated cortisol confirmed, then identify
cause:
• ACTH level
• High: ectopic ACTH secreting tumor or pituitary
adenoma
• Low: adrenal adenoma/carcinoma
• High‐dose dexamethasone suppression test may
help >50% suppressed cortisol: Cushing’s disease
• MRI pituitary fossa ± adrenal CT ± whole body
CT to locate lesion

9. Investigations: step 3 for ACTH dependent Cushing
• Bilateral inferior petrosal sinus vein
sampling (IPSS)
• (best test to confirm pituitary vs ectopic origin;
may also lateralize pituitary adenoma)

10. Discussion
• Cushing’s disease: glucocorticoid excess due
to ACTH secreting pituitary adenoma
• Cushing’s syndrome: the physical signs of
glucocorticoid excess

11. Treatment:
• Surgical:
• Trans‐sphenoidal approach to remove pituitary tumors.
• Adrenalectomy for adrenal tumors
• Nelson’s syndrome:
• bilateral adrenalectomy (scars) to treat Cushing’s disease, causing
massive production of ACTH (and melanocyte‐stimulating hormone),
due to lack of feedback inhibition, leading t hyper‐pigmentation and
pituitary overgrowth
• Pituitary irradiation
• Medical: Metyrapone

12. Prognosis:
• Untreated Cushing’s syndrome:
• 50% mortality at 5 years
• (usually due to accelerated ischemic heart disease
secondary to diabetes and hypertension)

13. Causes of proximal myopathy:
• Inherited:
• Myotonic dystrophy
• Muscular dystrophy
• Endocrine:
• Cushing’s syndrome
• Hyperparathyroidism
• Thyrotoxicosis
• Diabetic amyotrophy
• Inflammatory:
• Polymyositis
• Rheumatoid arthritis
• Metabolic:
• Osteomalacia
• Malignancy:
• Paraneoplastic
• Lambert–Eaton myasthenic syndrome
• Drugs:
• Alcohol
• Steroids

14. Thank You
• Thank You