Can parathyroid adenoma (parathyroid gland tumor) cause hypertension (high blood pressure)?

Parathyroid Adenoma and Hypertension

Yes, parathyroid adenomas can cause hypertension through several mechanisms, though the relationship is complex and not present in all cases. 1

Pathophysiological Mechanisms

• Primary hyperparathyroidism (PHPT), most commonly caused by parathyroid adenomas (80% of cases), is recognized as a secondary cause of hypertension in clinical practice guidelines 1
• The mechanisms linking parathyroid adenomas to hypertension include:
  • Direct effects of parathyroid hormone (PTH) on renin secretion, contributing to activation of the renin-angiotensin-aldosterone system 2
  • Elevated angiotensin II and vasopressin levels in patients with primary hyperparathyroidism 3
  • Increased vascular reactivity to pressor agents like norepinephrine in hypertensive PHPT patients 2
  • Renal impairment secondary to hypercalcemia, which may contribute to hypertension 4

Clinical Evidence

• In studies of patients with primary hyperparathyroidism:
  • Hypertension prevalence ranges from approximately 50-55% 2, 4
  • Plasma renin activity and aldosterone levels are higher in hypertensive PHPT patients compared to normotensive PHPT patients 2
  • Pressor response to norepinephrine is significantly greater in hypertensive PHPT patients 2

Effect of Parathyroidectomy on Hypertension

• The impact of surgical treatment (parathyroidectomy) on hypertension in PHPT patients shows mixed results:
  • Some studies show normalization of blood pressure, PRA, and plasma aldosterone levels in a majority of hypertensive patients after parathyroidectomy 2
  • Other research suggests parathyroidectomy has limited effect on hypertension prevalence long-term 4
  • Even after successful parathyroidectomy with normalized calcium and PTH levels, many patients continue to show abnormal circadian blood pressure patterns (non-dipper status) 4

Clinical Considerations

• Hyperparathyroidism is listed as a secondary cause of hypertension in major hypertension guidelines, though it is considered rare compared to more common causes like obstructive sleep apnea or renal disease 1
• When evaluating patients with resistant hypertension, primary hyperparathyroidism should be considered in the differential diagnosis 1
• Screening for primary hyperparathyroidism in hypertensive patients involves measuring serum calcium levels, with follow-up parathyroid hormone testing if calcium is elevated 1

Associations with Other Endocrine Disorders

• Primary hyperparathyroidism can occasionally coexist with primary hyperaldosteronism, which can further contribute to hypertension 1, 5
• In rare cases, parathyroid adenomas may be part of multiple endocrine neoplasia syndromes, which can include other causes of secondary hypertension 1

Treatment Implications

• The definitive treatment for primary hyperparathyroidism is surgical excision of the abnormally functioning parathyroid tissue 1
• Surgery is typically indicated even when asymptomatic, given potential negative effects of long-term hypercalcemia, which may include persistent hypertension 1
• Blood pressure monitoring should continue after parathyroidectomy, as hypertension may persist in some patients despite normalization of calcium and PTH levels 4