Dose–response of sodium excretion and blood pressure change among overweight, nonhypertensive adults in a 3-year dietary intervention study

Abstract

A cross-sectional dose-response relationship between sodium intake and blood pressure (BP) has been demonstrated, but evidence for a graded longitudinal effect is limited. Evaluation of BP response to sodium reduction was assessed in a 3-year lifestyle dietary intervention trial. BP changes at 18 and 36 months after enrollment were analysed according to concurrent quantitative changes in sodium excretion and by categories of success in sodium reduction among 1157 men and women, ages 30-54 years, with a diastolic BP (DBP) 83-89 mmHg, systolic BP (SBP) o140 mmHg, body weight 110-165% of sex-specific standard weight, and valid baseline urinary sodium excretion. Participants were randomized to a Sodium Reduction intervention (n ¼ 581) or Usual Care (n ¼ 576). From a 187 mmol/24 h baseline mean sodium excretion, net decreases were 44 mmol/24 h at 18 months and 38 mmol/24 h at 36 months in Sodium Reduction vs Usual Care. Corresponding net decreases in SBP/DBP were 2.0/1.4 mmHg at 18 months, and 1.7/0.9 mmHg at 36 months. Significant dose-response trends in BP change over quintiles of achieved sodium excretion were seen at both 18 (SBP and DBP) and 36 (SBP only) months; effects appeared stronger among those maintaining sodium reduction. Estimated SBP decreases per 100 mmol/24 h reduction in sodium excretion at 18 and 36 months were 2.2 and 1.3 mmHg before and 7.0 and 3.6 mmHg after correction for measurement error, respectively. DBP changes were smaller and nonsignificant at 36 months. In conclusion, incremental decreases in BP with lower sodium excretion were observed in these overweight nonhypertensive individuals.

The effects of weight loss and salt reduction on visit-to-visit blood pressure variability

“…For secondary analyses, the effects of achieved weight loss and sodium reduction over time on VVV of BP were examined, separately, at the within-subject level, using criteria defined previously 16,17 . Participants were stratified into three groups according to patterns of achieved weight loss: (1) participants with successful maintenance of weight loss were defined as those who lost 4.5 kg or more at 6 months and maintained at least 4.5 kg of weight loss at 36 months; (2) participants who relapsed were those who lost at least 4.5 kg at 6 months but whose weight loss at 36 months was less than 2.5 kg; and (3) participants with no weight loss were defined as those who had weight loss of 2.5 kg or less at 6 and 36 months (referent group).…”

Sodium reduction for hypertension prevention in overweight adults: further results from the Trials of Hypertension Prevention Phase II

“…The dose response of blood pressure change per unit sodium intake change is addressed in a separate paper. 13 …”

Adiponectin and hypertension: a putative link between adipocyte function and atherosclerotic risk?

“…With increasing evidence implicating circulating adiponectin concentrations as a marker of 'vascular protection' (against the clustering of multiple cardiovascular risk factors), a firmer understanding of this ubiquitous protein is certainly needed. From a clinical perspective, given the links between hypertension (and its complications) and obesity, [47][48][49][50] as well as the so-called 'metabolic syndrome', urgent action is clearly required.…”