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

Abstract

Objectives As evidence suggests visit-to-visit variability (VVV) of blood pressure (BP) is associated with cardiovascular events and mortality, there is increasing interest in identifying interventions that reduce VVV of BP. We investigated the effects of weight loss and sodium reduction, alone or in combination, on VVV of BP in participants enrolled in phase II of the Trials of Hypertension Prevention. Methods BP readings were taken at 6-month intervals for 36 months in 1,820 participants with high-normal diastolic BP (DBP) who were randomized to weight loss, sodium reduction, combination (weight loss and sodium reduction), or usual care groups. VVV of BP was defined as the standard deviation of BP across 6 follow-up visits. Results VVV of systolic BP (SBP) was not significantly different between participants randomized to the weight loss (7.2 ± 3.1 mmHg), sodium reduction (7.1 ± 3.0 mmHg), or combined (6.9 ± 2.9 mmHg) intervention groups vs. the usual care group (6.9 ± 2.9 mmHg). In a fully adjusted model, no difference (0.0 ± 0.2 mmHg) in VVV of SBP was present between individuals who successfully maintained their weight loss versus individuals who did not lose weight during follow-up (p=0.93). Also, those who maintained a reduced sodium intake throughout follow-up did not have lower VVV of SBP compared to those who did not reduce their sodium intake (0.1 ± 0.3 mmHg; p=0.77). Results were similar for VVV of DBP. Conclusions These findings suggest that weight loss and sodium reduction may not be effective interventions for lowering VVV of BP in individuals with high-normal DBP.

Effect of One-Week Salt Restriction on Blood Pressure Variability in Hypertensive Patients with Type 2 Diabetes

“…Fourth, the study was not designed as a long-term study and patients were followed up for one week only. Although it is generally accepted that long-term salt restriction leads to reductions in BP levels and variability, one study reported that salt restriction over 36 months did not decrease visit-to-visit BP variability [ 29 ]. Fifth, short-term glycemic control status may have affected BP parameters in some way, given the STOP-NIDDM study finding that long-term glycemic control leads to reductions in the incidence of hypertension [ 30 ].…”

The Science of Salt: A Systematic Review of Clinical Salt Studies 2013 to 2014

“…Four studies assessed the relationship between salt intake and BP. Diaz and colleagues conducted an RCT investigating the effects of weight loss and salt reduction on visit‐to‐visit (VVV) BP variability. VVV of BP was defined as the standard deviation of BP across six follow‐up visits.…”

Factors associated with intra-individual visit-to-visit variability of blood pressure in four countries: the INTERMAP study

“…Therefore, the inverse association between urinary sodium excretion and visit-to-visit BP variability may be due to reverse causality. An intervention study reported that weight reduction and salt reduction did not reduce visit-to-visit BP variability of persons with high normal DBP [25].…”