AIM: Serum parathyroid hormone (PTH) and 25-hydroxyvitamin D (25OHD) concentrations might contribute to blood pressure (BP) levels. Mixed results in previous literature could be due to the failure to consider both these hormones concurrently, despite their long-known relationship. Our objective was to examine the association of serum intact PTH and 25OHD concentrations with BP levels amongst older inpatients, while accounting for each other.

METHODS: The participants were 284 Caucasian older inpatients with no suspicion of primary hyperparathyroidism (mean age 85.87 ± 5.90 years; 65.8% female) admitted to the geriatric acute care unit of Angers University Hospital, France. They were divided into two groups according to the existence of hypertension (i.e. systolic blood pressure [SBP] >140 mmHg, or diastolic blood pressure [DBP] >90 mmHg). Age, sex, numbers of chronic diseases and of drugs taken daily, use of antihypertensive or corticosteroid drugs and of calcium supplements/vitamin D, thyroid-stimulating hormone and albumin concentrations, creatinine clearance, and season tested were used as covariables.

RESULTS: Hypertensive participants (n=106) had higher intact PTH concentrations than normotensive patients (P=0.044). There was a positive linear association of BP with intact PTH concentrations (adjusted β=0.08, P=0.015 for SBP; adjusted β=0.05, P=0.044 for DBP), but not with vitamin D. Serum intact PTH concentration, unlike 25OHD, was associated with hypertension (adjusted OR 1.01, P=0.038).

CONCLUSIONS: Irrespective of 25OHD, PTH was associated with hypertension by increasing both SBP and DBP.