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.
Hoffmann
Irene S
IS
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.
Cubeddu
Luigi X
LX
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