[Hypertension and salt intake in an urban population].
OBJECTIVE
To evaluate the salt intake and urinary Na+/K+ ratio in a randomized sample from an ethnically mixed urban population.


METHODS
A randomized residential sample of 2,268 individuals aged 25-64 in Vit ria, ES, was selected, of whom 1,663 (73.3%) reported to the hospital for standardized tests. Salt, Na+ and K+ intake was estimated from 12-hour urine excretion (7 p.m. to 7 a.m.) and from the monthly salt consumption at home reported in the interview. Clinic arterial pressure was measured twice under standard conditions by two trained investigators, using mercury sphygmomanometry. The Student t and Tukey tests were utilized for statistical analysis.


RESULTS
Urinary Na+ excretion was higher in men and individuals of lower socioeconomic level (P<0.000). No difference between ethnic groups was observed. K+ excretion was unrelated to socioeconomic level and ethnicity, but was significantly higher among men (25 18 vs. 22 18 mEq/12h; P=0.002). Positive linear correlation was observed between urinary Na+ excretion and systolic (r=0.15) and diastolic (r=0.19) arterial pressure. Hypertensive individuals showed higher urinary Na+ excretion and Na+/K+ ratio than normotensive individuals. Reported salt intake was around 50% of the intake estimated from 12-hour urine collection (around 45% of 24-hour urinary excretion).


CONCLUSIONS
Salt intake is strongly influenced by socioeconomic level and may partially explain the higher prevalence of hypertension in lower socioeconomic classes.
Bisi Molina
Maria del Carmen
Mdel C
Departamento de Enfermagem, Centro Biomédico, Universidade Federal do Espírito Santo, Vitória, ES, Brasil. mdcarmen@escelsa.com.br
Cunha
Roberto de Sá
Rde S
Herkenhoff
Luis Fernando
LF
Mill
José Geraldo
JG
D000328:Adult; D001938:Brazil / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology* / Q000209:etiology / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000652:urine; D015995:Prevalence; D011897:Random Allocation; D012959:Socioeconomic Factors; D012964:Sodium / Q000652:urine; D017673:Sodium Chloride, Dietary / Q000009:adverse effects*; D014505:Urban Population
D017673:Sodium Chloride, Dietary; D012964:Sodium; D011188:Potassium