12.15 Endocrine Hypertension

Question 1

Secondary hypertension

Answer 1

• Renovascular disease (including primary renal disease or primary vascular abnormalities such as renal artery stenosis, vasculitis… Most common correctable cause of secondary hypertension
• Pheochromocytoma
• Primary hyperaldosteronism
• Other endocrine disorders (associations)
  ➡️Cushing’s syndrome
  ➡️Hypothyroidism & hyperthyroidism
  ➡️Hyperparathyroidism
  ➡️Acromegaly
• Sleep apnoea syndrome
• Coarctation of the aorta
• DRUGS (oral contraception)

Question 2

When to suspect secondary hypertension

Answer 2

• Severe or refractory hypertension.
• An acute rise in blood pressure over a
  ➡️previously stable value / associated
  ➡️concerning new onset symptoms.
• Proven age of onset before puberty
• Age less than 30 years in non-obese patients with a confirmed negative
  ➡️family history of hypertension and no other clinical risk factors.
• Malignant or accelerated HT
• Electrolyte disturbance

Question 3

Endocrine diseases associated with hypertension

Answer 3

• Metabolic Syndrome (T2 DM..)
• Cushing syndrome (Increase cardiac output and vascular tone via effect on vasocostrictors, IR and”metabolic syndrome”)-> cortisol excess
• Acromegaly (IR and “metabolic syndrome”, mitogenic GH effects, fluid retention) -> growth hormone excess
• Hyperparathyroidism
• Thyroid dysfunction
  ➡️hypo: diastolic hypertension, ⬆️ECF, ⬆️PVR
  ➡️ hyper: Systolic hypertension, ⬆️CO, ⬇️PVR

Question 4

Endocrine disease primarily presenting with hypertension

Answer 4

• Primary hyperaldosteronism
• Pheochromocytoma

Question 5

Primary hyperaldosteronism
Aldosterone production
Net effect of excess aldosterone
Mechanisms involved
Causes
Classical triad

Answer 5

• Aldosterone production controlled via the:
  ➡️RA- system (main)
  ➡️K+ levels
  ➡️ACTH

Nett effect of excess aldosterone
- Na+ and fluid retention
- Increased peripheral vascular resistance
- Hypokalemia
- Suppression of RA system ( negative feedback, LOW renin)

Mechanisms involved
- renin suppression
- ⬆️ aldosterone
- potassium depletion
- ⬆️ total peripheral resistance
- sodium retention
- fluid retention

Causes
- Hyperplasia of the adrenal cortex (uni- or bilateral)
- Adenoma (= CONN’s tumor) – 30-60% of cases
- Dexamethazone remedial aldosteronism (rare)
- Aldosterone producing adrenocortical carcinoma

Classical triad
- Hypertension
- Unexplained hypokalemia
- Metabolic alkalosis (increased renal H+ excretion)
- Less than 50 percent of diagnosed cases are hypokalemic at presentation

Question 6

Pheochromocytoma
Def
Clinical triad

Answer 6

Def
- RARE tumour of the adrenal medulla (90% of cases)
- Secrete excessive amounts of catecholamines (adrenalin and noradrenalin)
- Excessive release of these catecholamines cause severe hypertensive episodes
- RARE cause of hypertension (<0.1% of the hypertensive population)
- IMPORTANT: potentially life-threatening and potentially curable
- mostly single and sporadic

Clinical triad
- Headache (severe)
- palpitations
- sweating
- Episodic: + anxiety, impending doom, chest discomfort, tremor, abdominal pain and vomiting……
- some asymptomatic