Arch Dis Child 1997;77:11-16 ( July )
Nitric oxide activity in childhood hypertension
C D A Goonasekera,a
V Shah,a
D D Rees,b
M J Dillona
a Institute of Child Health and Great Ormond Street
Hospital for Children NHS Trust, London, b Centre for Clinical
Pharmacology, Cruciform Project, University College, London
Correspondence to: Dr M J Dillon,
Nephro-Urology Unit, Institute of Child Health, 30 Guilford
Street, London WC1N 1EH.
Accepted 26 February 1997
OBJECTIVES
To investigate nitric oxide (NO)
activity in childhood hypertension using nitrite and nitrate (NOx)
concentrations in plasma as an index of nitric oxide generation.
DESIGN
Cross sectional study.
SETTING
Tertiary care paediatric centre and
district general hospitals in the UK.
PATIENTS
Children attending the above centre for
treatment of hypertension. The control subjects were normotensive
healthy children attending district general hospitals for minor medical
and surgical disorders.
INTERVENTIONS
None.
MAIN OUTCOME MEASURES
Plasma (P) and urinary (U)
NOx concentrations, blood pressure, and glomerular filtration rate.
RESULTS
Sixteen normal children (mean age 6.9 years), 13 children with reno-vascular hypertension (mean age 7.8 years), and 25 children with hypertension associated with renal
parenchymal disease (mean age 10.7 years) were studied. Mean (SD)
PNOx values of children with hypertension with renovascular
disease (15.3 (11.4) µmol/l) and renal parenchymal disease (18.3 (11.4) µmol/l) were significantly above that of normal children (11.9 (5.9) µmol/l) after accounting for age and glomerular filtration rate
influences. Higher concentrations of PNOx in normal
children were associated with younger age, but not in the children with
hypertension. Higher PNOx concentrations were also
associated with a lower glomerular filtration rate in normal children
and children with hypertension with renal parenchymal disease, but not
in the children with hypertension with renovascular disease.
UNOx excretion expressed as a ratio against urine
creatinine (Ucreat) excretion was not statistically
different among the study groups.
CONCLUSIONS
PNOx is increased in
children with hypertension even after statistical elimination of the
glomerular filtration rate and age influences. This suggests a normal
or increased NO synthase activity in childhood hypertension in contrast
with adults with hypertension in whom it is described as reduced.
Keywords:
childhood hypertension;
nitric oxide;
plasma
nitrate;
renal function
© 1997 by Archives of Disease in Childhood