Key result
Absolute sodium intake was associated with a steeper rise in blood pressure at lower energy intakes, resulting in a 3.0 mm Hg higher systolic BP on a 2300 mg Na diet (95% CI 0.2-5.8; P<0.001).
Why the study?
Does the relationship between sodium intake and blood pressure vary with energy intake in patients with pre- or stage 1 hypertension?
RCT (n=379)
Randomized
Does the relationship between sodium intake and blood pressure vary with energy intake in patients with pre- or stage 1 hypertension?
Effect estimate: Difference 3.0 mm Hg (95% CI 0.2-5.8)
p-value: p=<0.001
The blood pressure response to dietary sodium is stronger at lower energy intakes, suggesting sodium density (mg/kcal) may be a more appropriate metric for dietary recommendations than absolute sodium amount.
May favor sodium density over absolute intake for BP control in hypertension; extends RCT evidence on energy-sodium interactions.
Dietary Na recommendations are expressed as absolute amounts (mg/d) rather than as Na density (mg/kcal). Our objective was to determine whether the strength of the relationship of Na intake with blood pressure (BP) varied with energy intake. The DASH (Dietary Approaches to Stop Hypertension)–Sodium trial was a randomized feeding trial comparing 2 diets (DASH and control) and 3 levels of Na density. Participants with pre- or stage 1 hypertension consumed diets for 30 days in random order; energy intake was controlled to maintain body weight. This secondary analysis of 379 non-Hispanic black and white participants used mixed-effects models to assess the association of Na and energy intakes with BP. The relationships between absolute Na and both systolic and diastolic BP varied with energy intake. BP rose more steeply with increasing Na at lower energy intake than at higher energy intake ( P interaction<0.001). On the control diet with 2300 mg Na, both systolic and diastolic BP were higher (3.0 mm Hg; 95% confidence interval, 0.2–5.8; and 2.7 mm Hg; 95% confidence interval, 1.0–4.5, respectively) among those with lower energy intake (higher Na density) than among those with higher energy intake (lower Na density). The association of Na with systolic BP was stronger at lower levels of energy intake in both blacks and whites ( P <0.001). The association of Na and diastolic BP varied with energy intake only among blacks ( P =0.001). Sodium density should be considered as a metric for expressing dietary Na recommendations.
No takes yet. Share an insight, caveat, or question.
Murtaugh et al. (2018) conducted an RCT in Pre- or stage 1 hypertension (n=379). Sodium intake at varying energy intake levels vs. Higher energy intake (lower Na density) was evaluated on Systolic and diastolic blood pressure (Difference 3.0 mm Hg, 95% CI 0.2-5.8, p=<0.001). Absolute sodium intake was associated with a steeper rise in blood pressure at lower energy intakes, resulting in a 3.0 mm Hg higher systolic BP on a 2300 mg Na diet (95% CI 0.2-5.8; P<0.001).
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: