Assessment of salt sensitivity in essential hypertension by 24-h ambulatory blood pressure monitoring.
We used ambulatory blood pressure monitoring (ABPM) in the assessment of salt sensitivity in 40 essential hypertensive patients, comparing 24-h mean blood pressure during 7 days of low salt (20 mmol NaCl/day) and high salt (260 mmol NaCl/day) intake. Salt sensitivity was diagnosed in 18 essential hypertensive patients (45%), each of them showing a significant increase in mean blood pressure (P < .05) from low to high salt diet. Salt-sensitive patients exhibited a high-salt-dependent increase in all blood pressure parameters including 24-h systolic, mean, diastolic blood pressure, blood pressure load, area under the curve, and awake and asleep blood pressure values. These patients exhibited a nondipper profile on both low-salt and high-salt diets. Salt-resistant patients (55%) showed a decrease in awake, and an increase in asleep blood pressure values after high salt intake, thus tending to flatten the circadian blood pressure profile. We conclude that ABPM is a useful method to assess salt sensitivity. In salt-resistant patients high salt intake induces a significant increase in asleep blood pressure with no significant changes in 24-h blood pressure, promoting a flattened blood pressure curve and tending to transform a dipper into a nondipper profile, which could have important implications in end-organ damage.
de la Sierra
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A
Department of Internal Medicine, Hospital Clinic, University of Barcelona, Spain.
Lluch
M M
MM
Coca
A
A
Aguilera
M T
MT
Sánchez
M
M
Sierra
C
C
Urbano-Márquez
A
A
D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects*; D018660:Blood Pressure Monitoring, Ambulatory; D002940:Circadian Rhythm; D004039:Diet, Sodium-Restricted; D004351:Drug Resistance; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012965:Sodium Chloride / Q000494:pharmacology*
D012965:Sodium Chloride