Arterial blood pressure, serum calcium and parathyroid hormone levels in pre- and postmenopausal women with primary hyperparathyroidism

Background: Arterial hypertension is common in patients with primary hyperparathyroidism (HPT), and a relationship between serum calcium, serum parathyroid hormone (PTH) and arterial blood pressure (BP) has long been hypothesized. The purpose of this study was to analyze whether a correlation exists between BP and the main clinical and biochemical parameters in pre- and postmenopausal women with primary HPT. Patients and Methods: A series of 241 consecutive patients (median age 56 years, range 18-82 years) with confirmed primary HPT was reviewed. There were 84 (34.8%) premenopausal (Group A, median age 45 years, range 18-52 years) and 157 (65.2%) postmenopausal (Group B, median age 62 years, range 47-82 years) women. All patients underwent successful parathyroidectomy and subsequent measurement of the removed parathyroid (PT) glands. BP was recorded preoperatively using an automatic device. Patients who were treated for hypertension as well those who used hormone replacement therapy were excluded. Results: Both systolic (133.6±16.4 vs. 150.1±17.8 mm Hg) and diastolic (82.5±12.0 vs. 91.2±10.7 mm Hg) BP differed significantly (p=0.00001) between Groups A and B, as well the mean serum calcium levels (3.10±0.41 vs. 2.95±0.30 mmol/L, respectively; p=0.001). Serum creatinine (79.5±23.7 vs. 83.6±31.9 micromol/L; p=0.30), alkaline phosphatase (162.4±139.7 vs. 156.8±111.7 U/L; p=0.74), and intact PTH levels (191.6±155.7 vs. 174.9±125.2 ng/L; p=0.37) did not differ between groups. There was no relationship between age and serum calcium (Group A: R=0.037, F=0.115, t=15.43, p=0.73; Group B: R=0.087, F=1.196, t=13.331, p=0.28), and between age and serum PTH (Group A: R=0.081, F=0.549, 25.717, p=0.46; Group B: R=0.073, F=0.832, t=59.281, p=0.36) in each group. Age significantly correlated with BP, both systolic (Group A: β=0.606, R2=0.37, p=0.000001; Group B: β=0.43, R2=0.18, p=0.000001), and diastolic (Group A: β=0.65, R2=0.42, p=0.00001; Group B: β=0.31, R2=0.10, p=0.00008), while serum creatinine correlated with BP only in premenopausal patients (systolic: β=0.33, R2=0.11, p=0.002; diastolic: β=0.23, R2=0.05, p=0.04). No correlation was found between systolic BP and both serum calcium (Group A: β=0.08, R2=0.01, p=0.45; Group B: β=0.11, R2=0.01, p=0.17) and PTH (Group A: β=0.06, R2=0.004, p=0.58; Group B: β=0.01, R2=0.0001, p=0.89). There was no correlation between diastolic BP and both serum calcium (Group A: β=0.02, R2=0.0005, p=0.84; Group B: β=0.10, R2=0.01, p=0.19) and PTH (Group A: β=0.07, R2=0.004, p=0.55; Group B: β=0.06, R2=0.003, p=0.49) in each Group. Conclusions: Both in pre- and in postmenopausal women with primary HPT, no relationship between BP, serum calcium, and serum PTH levels was found. Although the prevalence of hypertension among such patients could be higher than in the general population, BP should be considered related exclusively to age and serum creatinine levels.