Salt and the metabolic syndrome.
OBJECTIVE
High blood pressure in subjects with the metabolic syndrome (MS) is largely related to dietary salt. We investigated in free-living men and women whether increase in dietary salt intake is associated with the presence and severity of the MS.


RESULTS
A total of 766 subjects (251M, 515F) of 44.9+/-0.5 years/age and SBP/DBP of 120+/-0.6/77+/-0.4 mmHg were studied. Twenty-four hour urinary sodium (UNa(+)) and potassium (UK(+)) excretions were 143+/-2.5 mmol (median: 131.5) and 48+/-0.9 mmol (median: 44). UNa(+) was higher in men than in women (median: 155.5 vs. 119.8 mmol/day; P<0.0001). UK(+) (r=0.34; P<0.0001), measures of obesity (r=0.26; P<0.0001) and BP (r=0.15; P<0.0001) were significantly associated with UNa(+). The association with BP was lost after adjusting for weight. Of the 766 subjects, 256 (33.4%) met the NCEP-ATPIII criteria for the MS. Median UNa(+) in men and women with no traits of the MS was 140 and 116.7 mmol/day, respectively (P<0.001), increasing to 176 in men and 135 mmol/day in women with 4-5 components of the syndrome (P<0.001). Weight, BMI and waist increased significantly across the quartiles of UNa(+) both in men and women; whereas, age, lipids and fasting glucose did not. SBP and DBP were associated with UNa(+) in men but not in women. UK(+) correlated with age in men and women (r=023; P<0.0001) and with obesity in women (r=0.14; P=0.001).


CONCLUSIONS
UNa(+) a measure of dietary sodium intake in free-living subjects was markedly increased in subjects with the MS. Higher UNa(+) was associated with obesity and higher BP, but not with age, dyslipidemia or fasting glucose.
Center for the Detection and Treatment of Silent Risk Factors for Cardiovascular and Metabolic Diseases, Clinical Pharmacology Unit, School of Pharmacy, Central University of Venezuela, Caracas, Venezuela.
Irene S
IS
Hoffmann
Luigi X
LX
Cubeddu
D000328:Adult; D001794:Blood Pressure; D015992:Body Mass Index; D005260:Female; D006801:Humans; D006973:Hypertension / Q000209:etiology* / Q000503:physiopathology / Q000652:urine; D008297:Male; D024821:Metabolic Syndrome / Q000209:etiology* / Q000503:physiopathology / Q000652:urine; D008875:Middle Aged; D009765:Obesity / Q000209:etiology* / Q000503:physiopathology / Q000652:urine; D011188:Potassium / Q000652:urine; D012720:Severity of Illness Index; D012964:Sodium / Q000652:urine*; D017673:Sodium Chloride, Dietary / Q000009:adverse effects*; D014687:Venezuela; D055105:Waist Circumference
D017673:Sodium Chloride, Dietary; D012964:Sodium; D011188:Potassium