Hyperparathyroidism, hypertension and loop diuretic medication in renal transplant recipients.

The associations between serum parathyroid hormone (PTH), blood pressure and hypotensive medication were analysed in 282 renal transplant recipients. Among patients with a normal concentration of serum creatinine there was no correlation between serum PTH and blood pressure but in those receiving hypotensive medication serum PTH was appropriately twofold greater than in those not taking hypotensive medication. Analysis revealed that the dominant contribution to this association was a specific association with loop diuretic therapy. When all patients were stratified according to creatinine clearance, serum PTH was always greater in patients receiving loop diuretics but this difference was particularly striking in the patients with the poorest graft function. It is postulated that loop diuretics exacerbate the hyperparathyroidism which complicates renal disease.