Kidney stone formers with essential hypertension have increased acid excretion, Italian researchers reported.
Attilio Losito, MD, of Ospedale Santa Maria della Misericordia in Perugia, and colleagues retrospectively studied 234 consecutive subjects with a mean age of 47 years following episodes of kidney stones. Of these patients, 82 (35%) had essential hypertension.
The researchers investigated urinary excretion of different solutes, particularly citrate and acids, in kidney stone formers and examined the solutes’ association with high BP.
Hypertensive patients were older and had a higher BMI and serum uric acid levels. They also had a significantly lower urinary pH (5.6 vs. 6.0 for non-hypertensives) and citrate (2.55 vs. 2.83 mmol/24 hr) and higher titratable acid (38.8 vs. 26.8 mEq/24 hr) and ammonium (41.6 vs. 34.2 mmol/24 hr). Urinary acid excretion increased with the stage of hypertension.
The researchers observed no difference in the urinary excretion of other solutes.