Full normalization of severe hypertension after parathryoidectomy - A case report and systematic review

Abstract

Background: Although the relationship between hyperparathyroidism and hypertension has been described for decades, the role of hyperparathyroidism in hypertension in dialysis is still unclear. Following the case of a severely hypertensive dialysis patient, in which parathyroidectomy (PTX) corrected the metabolic imbalance and normalized blood pressure (BP), we tried to contextualize our observation with a systematic review of the recent literature on the effect of PTX on BP. Case presentation: A dialysis patient, aged 19 years at the time of this report, with chronic kidney disease (CKD) from childhood; he was an early-preterm baby with very low birth weight (910 g), and is affected by a so-far unidentified familial nephropathy. He started dialysis in emergency at the age of 17. Except for low-dose Bisoprolol, he refused all chronic medication; hypertension (165-200/90-130 mmHg) did not respond to attainment of dry weight (Kt/V > 1.7; BNP 70-200 pg/ml pre-dialysis). He underwent subtotal PTX 1 year after dialysis start; after PTX, his blood pressure stabilized in the 100-140/50-80 range, and is normal without treatment 5 months later. Conclusion: Our patient has some peculiar features: he is young, has a non-immunologic disease, poor compliance to drug therapy, excellent dialysis efficiency. His lack of compliance allows observing the effect of PTX on BP without pharmacologic interference. The prompt, complete and long-lasting BP normalization led us to systematic review the current literature (Pubmed, Embase, Cochrane Collaboration 2000-2016) retrieving 8 case series (194 cases), and one case report (3 patients). The meta-analysis showed a significant, albeit moderate, improvement in BP after PTX (difference: systolic BP -8.49 (CI 2.21-14.58) mmHg; diastolic BP -4.14 (CI 1.45-6.84) mmHg); analysis is not fully conclusive due to lack of information on anti-hypertensive agents. The 3 cases reported displayed a sharp reduction in BP after PTX. In summary, PTX may have a positive influence on BP control, and may result in complete correction or even hypotension in some patients. The potential clinical relevance of this relationship warrants prospective large-scale studies.