Endocrine Abstracts

Introduction: Primary aldosteronism (PA) is the most common cause of endocrine hypertension. In recent studies, increased prevalence of hyperparathyroidism (HP) has been observed in PA patients. However, the prevalence of HP in overt or milder forms of PA has not been evaluated yet.

Objectives: To estimate the prevalence of HP in patients with PA (overt and milder forms) and investigate the effect of treatment (eplerenone or surgery) on PTH secretion.

Patients and Methods: We included prospectively 60 (39 men) PA patients (mean age 58.4 ± 11 years) with normal renal function. The diagnosis of PA was based on the combination of valsartan, captopril and dexamethasone suppression test (DCVT)¹. The patients were divided in two groups: overt (based on basal aldosterone/renin ratio (ARR) > 84 pmol/mU² and positive DCVT) and mild PA (based only on positive DCVT). Mean systolic (SBP) and diastolic (DBP) blood pressure, iPTH, 25OHD, serum and 24 h-urinary calcium, potassium and phosphate levels at time of PA diagnosis and after surgical or medical treatment with eplerenone were evaluated.

Results: Primary HP was found in 5% (3/60) and secondary HP in 51.6% (31/60). Overt and mild PA was found in 40% (24/60) and 60% (36/60) respectively. Fifty one out of 60 PA patients were followed-up for 11 ± 6months, without receiving supplementary vitamin D treatment. After treatment, there was a significant decrease of mean SBP and DBP (P < 0.001), iPTH (P < 0.001) and 24 h-urinary calcium (P < 0.001) and a significant increase of serum potassium (P < 0.001), corrected Calcium (P = 0.01) and 25OHD (P < 0.001) levels in both primary and secondary HP patients. Furthermore, there was no significant difference between patients with overt and mild PA, concerning the iPTH, serum calcium and 25OHD levels, neither prior or after treatment. Aldosterone levels before treatment were positively correlated with serum PTH levels (P = 0.04).

Conclusions: The prevalence of HP was found to be particularly high in PA patients, both in overt and mild cases. Treatment has a significant impact equal in overt and mild PA on serum calcium, 25OHD and iPTH levels, suggesting an association between mild or overt PA and primary or secondary PH.

References

1. Tsiavos V et al., Eur J Endocrinol. 2016 175 21–8.

2. Gouli A et al., Eur J Clin Invest. 2011 41 1227–36.