Ambulatory blood pressure 16-26 years after the first urinary tract infection in childhood

Abstract

Objective: To evaluate blood pressure in a population-based cohort with urographic renal scarring after childhood urinary tract infection.

Design: Follow-up investigation 16-26 years after the first recognized urinary tract infection.

Setting: University out-patient clinic for children with urinary infections serving the local area.

Patients: From the original cohort of 1221 consecutive children with first urinary tract infection diagnosed during 1970-1979, 57 of 68 with non-obstructive renal scarring participated as well as 51 matched subjects without scarring.

Main outcome measure: 24 h ambulatory blood pressure.

Results: Acceptable blood pressure monitorings were obtained from 53 individuals with and 47 without scarring. There were no significant differences between the two groups even when only patients with the most extensive scarring (individual kidney clearance < 30 ml/min per 1.73 m2) or patients with bilateral scarring were compared with the non-scarring group. Mean systolic or diastolic blood pressure above +2 SD were found in 5/53 (9%) and 3/47 (6%) in the scarring and non-scarring group, respectively. Plasma renin activity, angiotensin II and aldosterone concentrations were not significantly different, but atrial natriuretic protein was significantly higher in the scarring group (P = 0.004).

Conclusion: This study demonstrates a low risk of hypertension two decades after childhood urinary tract infection. It should be stressed that the patients with renal scarring were under close supervision throughout childhood. Those with scarring had higher concentrations of atrial natriuretic protein which might indicate a counter-regulation mechanism.