Systolic blood pressure (setting unspecified)

Method

Brachial systolic blood pressure by cuff sphygmomanometry or a validated automated device, pooled across trials whose acquisition protocol the source report does not record and whose devices were not standardised. The defining property of this node is that the acquisition conditions are unrecoverable from the published pooled estimate.

The method is part of the endpoint identity. Studies measuring the same quantity by a different method are held as separate endpoints.

Notes

Diastolic blood pressure appears alongside it in every one of these papers and dissociates systematically: PMID 40045266 found a diastolic effect with no systolic effect, PMID 37419751 the reverse, PMID 25682973 a systolic effect alone, and PMID 24610882 a dose threshold that applied to only one component. Averaging them into 'blood pressure' halves every real signal. Also distinct from systolic blood pressure (office/clinic): that node's edges carry a documented seated clinic acquisition, and matching an unrecoverable protocol to it asserts a fact the source does not supply. Distinct again from 24-hour ambulatory systolic blood pressure, which names its acquisition explicitly.

Findings

4 findings from 3 compounds, strongest first.

• magnesium(2+) — decreases

  BLikelyGrade B, Likely. Human evidence, limited replication or design limits.Finding

  “Magnesium intake resulted in a reduction in systolic BP of -2.81 mm Hg (95% CI, -4.32 to -1.29) and diastolic BP by -2.05 mm Hg (95% CI, -3.23 to -0.88) compared with placebo.”

  Study

  meta-analysis

  Dose

  median 365 mg/d elemental magnesium (range 82.3-637 mg), median intervention period 12 weeks

  Population

  hypertensive and normotensive adults in randomized controlled trials of at least 4 weeks

  Magnesium Supplementation and Blood Pressure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.2025PMID:41000008

• curcumin — no detected effect on

  BLikelyGrade B, Likely. Human evidence, limited replication or design limits.FindingNull result

  “Five studies assessed changes in blood pressure indicating no significant effect of curcumin supplementation on both SBP and DBP with pooled MD (95% CI) of −0.29 (−0.91, 0.34) and −0.02 (−0.55, 0.52) mmHg, respectively, see Supplementary Appendix V–W.”

  Study

  meta-analysis

  Dose

  80–3000 mg/day pooled across bioavailability-enhanced forms (80–1000 mg/day), curcumin extracts (1500 mg/day) and turmeric powder (2000–3000 mg/day)

  Population

  Adults with MAFLD (NAFLD/NASH); 5 RCTs; blood pressure was an additional (secondary) outcome and the acquisition protocol is not recoverable from the pooled estimate

  Effect -0.29 mean difference, 95% CI -0.91 to 0.34

  An updated meta-analysis of effects of curcumin on metabolic dysfunction-associated fatty liver disease based on available evidence from Iran and Thailand.2023PMID:37037891

• melatonin — no detected effect on

  CSuggestiveGrade C, Suggestive. Weak human evidence, or strong evidence in a mismatched population.FindingNull resultreplicated ×1

  “Mean Daytime Systolic Blood Pressure (SBP) (SECONDARY, mmHg) -- NCT01114360: Melatonin 135.13 +/-2.2 (n=36) vs Placebo 133.9 +/-2.2 (n=36); difference 1.23; p=0.64, no significant difference”

  Study

  crossover

  Participants

  72

  Population

  Hypertension; 18 Years+

  Effect 1.23 mean difference

  Melatonin and Nighttime Blood Pressure in African Americans-8 mg Study2015NCT01114360

• melatonin — no detected effect on

  CSuggestiveGrade C, Suggestive. Weak human evidence, or strong evidence in a mismatched population.FindingNull resultreplicated ×1

  “Mean Daytime Systolic Blood Pressure (SBP) (SECONDARY, mmHg) -- NCT01114373: Melatonin 134.2 +/-2.4 (n=36) vs Placebo 137.3 +/-2.4 (n=36); difference -3.1; p=0.16, no significant difference”

  Study

  crossover

  Participants

  72

  Population

  Hypertension; 18 Years+

  Effect -3.1 mean difference

  Melatonin and Nighttime Blood Pressure in African Americans--24 mg Study2015NCT01114373