Salt and the metabolic syndrome

Nutr Metab Cardiovasc Dis. 2009 Feb;19(2):123-8. doi: 10.1016/j.numecd.2008.02.011. Epub 2008 Jun 16.

Abstract

Background and aims: 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.

Methods and 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Blood Pressure
  • Body Mass Index
  • Female
  • Humans
  • Hypertension / etiology*
  • Hypertension / physiopathology
  • Hypertension / urine
  • Male
  • Metabolic Syndrome / etiology*
  • Metabolic Syndrome / physiopathology
  • Metabolic Syndrome / urine
  • Middle Aged
  • Obesity / etiology*
  • Obesity / physiopathology
  • Obesity / urine
  • Potassium / urine
  • Severity of Illness Index
  • Sodium / urine*
  • Sodium Chloride, Dietary / adverse effects*
  • Venezuela
  • Waist Circumference

Substances

  • Sodium Chloride, Dietary
  • Sodium
  • Potassium