Heterogeneous patterns of sodium excretion during sodium restriction in essential hypertensive patients.
OBJECTIVE
To study the sodium excretory pattern by which sodium balance is reached.


METHODS
Ninety untreated essential hypertensives with a median age of 47 (range: 18-70 years) were admitted to a metabolic ward for 7 days and put on a sodium diet of 55 mmol/day. During these 7 days urinary excretions of sodium, potassium and creatinine were determined daily along with mean arterial pressure (MAP) and weight.


RESULTS
Changes in urinary sodium excretion were not uniform, but according to the pattern of attaining sodium balance, subjects could be divided into four groups. Group 1 (n = 31) gradually reached sodium balance, whereas group 2 (n = 10) showed an abrupt fall in sodium excretion on the third day and an extremely fluctuating sodium excretion thereafter. Group 3 (n = 32) reached sodium balance on day four, but displayed a rise in sodium excretion during the following days and group 4 (n = 17) attained sodium balance only very slowly or not at all. Compared to the other groups, group 4 lost more sodium and at the same time displayed a greater fall in blood pressure.


CONCLUSIONS
Our data suggest that there may be at least four different patterns by which sodium balance can be reached following a reduction in sodium intake. The determinants of these responses remain, however, elusive.
Krekels
M M
MM
Department of Medicine, University Hospital Maastricht, The Netherlands.
Houben
A J
AJ
Lavrijssen
A T
AT
van Es
P N
PN
De Leeuw
P W
PW
D000293:Adolescent; D000328:Adult; D000368:Aged; D001794:Blood Pressure; D004039:Diet, Sodium-Restricted; D006801:Humans; D006973:Hypertension / Q000178:diet therapy* / Q000503:physiopathology / Q000652:urine*; D008875:Middle Aged; D009318:Natriuresis; D011188:Potassium / Q000652:urine; D013997:Time Factors
D011188:Potassium