Sodium and potassium intake present a J-shaped relationship with arterial stiffness and carotid intima-media thickness.
OBJECTIVE
The purpose of this study was to analyse the relationship between sodium and potassium intake and vascular structure and function and to ascertain whether said relationship follows the pattern of a J-shaped curve.


METHODS
A cross-sectional study was carried out in a primary care setting. Three hundred fifty-one subjects from the Vasorisk study were included and ranged in age from 30 to 80 years (mean 54.8, SD 11.7); 219 (62.4%) were females. Sodium and potassium intake were evaluated by means of a food frequency questionnaire. Arterial stiffness was assessed according to pulse wave velocity (PWV), ambulatory arterial stiffness index (AASI, AASI_BPVR), and central and peripheral augmentation index (AIx). Carotid intima-media thickness (C-IMT) was evaluated by ultrasonography.


RESULTS
Age was lower in the quartiles with the highest sodium intake (p < 0.05), and no difference was observed between the sexes. Mean C-IMT, CAIx, AASI and AASI_BPVR were higher in the quartiles with higher sodium intake (p < 0.05 for both AASI and AASI_BPVR). Sodium intake was negatively correlated with C-IMT (r = -0.121, p < 0.05), PWV (r = -0.114, p < 0.05), AASI and AASI_BPVR (r = -0.155, p < 0.01). Potassium intake was positively correlated with Cornell VDP (r = 0.119, p < 0.05), CAIx (r = 0.178, p < 0.01) and PAIx (r = 0.202, p < 0.01). After adjustment, the morphology of the relationship between arterial stiffness parameters and C-IMT with quartiles of sodium intake resembles a J-shaped curve. The relationship between central and peripheral AIx and C-IMT and potassium intake resembles a J-shaped curve.


CONCLUSIONS
The relationship of sodium and potassium intake with vascular structure and function, as evaluated with C-IMT, PWV, AASI and peripheral and central AIx, resembles a J-shaped curve, which is similar to what has been proposed in the case of cardiovascular morbimortality.
Primary care Research unit, La Alamedilla, Sacyl. IBSAL, REDIAPP, Salamanca, Spain. Lgarciao@usal.es
Luis
L
García-Ortiz
José I
JI
Recio-Rodríguez
Emiliano
E
Rodríguez-Sánchez
María C
MC
Patino-Alonso
Cristina
C
Agudo-Conde
Carmela
C
Rodríguez-Martín
Carmen
C
Castaño-Sánchez
Isabelle
I
Runkle
Manuel A
MA
Gómez-Marcos
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002339:Carotid Arteries / Q000000981:diagnostic imaging*; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000503:physiopathology; D059168:Carotid Intima-Media Thickness; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D017419:Potassium, Dietary / Q000009:adverse effects*; D011237:Predictive Value of Tests; D011320:Primary Health Care; D063177:Pulse Wave Analysis; D018570:Risk Assessment; D012307:Risk Factors; D012982:Sodium, Dietary / Q000009:adverse effects*; D013030:Spain / Q000453:epidemiology; D011795:Surveys and Questionnaires; D059289:Vascular Stiffness
D017419:Potassium, Dietary; D012982:Sodium, Dietary