Abstract P319: Randomized Trial of a Multivitamin Supplement on Risk of Hypertension and Blood Pressure Change Among Middle-Aged and Older Men
Background: Adequate intake of selected vitamins and minerals has been hypothesized to lower blood pressure (BP). However, no randomized, controlled trial has specifically examined the effect of a multivitamin supplement, commonly used in the US, on BP and risk of developing hypertension.
Design: In the Physicians’ Health Study II - a randomized, double-blind, placebo-controlled trial of a daily multivitamin supplement among 14,641 men initially aged ≥50 years, systolic BP (SBP), diastolic BP (DBP), and use of antihypertensive medications was reported on baseline and annual follow-up questionnaires. Changes in BP from baseline were assessed at 36, 72, and 96 months, and at the end of the intervention. Incident hypertension was defined as self-reported SBP ≥140 mmHg, DBP ≥90 mmHg, or initiation of anti-hypertensive medication during follow-up that continued through June 1, 2011.
Results: Among 8,458 men free of hypertension at baseline (mean age: 62.1±8.5 years), 1,808 of 4,263 in the active multivitamin supplement group and 1,716 of 4,195 in the placebo group developed incident hypertension during a median treatment and follow-up of 11.2 years. In intention-to-treat analyses that adjusted for baseline age, other randomized treatments (beta-carotene, vitamin C, vitamin E), and PHS cohort (I, II), the hazard ratio (HR) of hypertension for daily multivitamin supplement versus placebo was 1.05 (95% CI: 0.98-1.12). Additional adjustment for hypertension risk factors marginally changed the risk estimate to a HR of 1.06 (95% CI: 0.98-1.13). The lack of effect was not different by subgroups of baseline age (<60, 60-<70, ≥70 years), body mass index (<25 kg/m2, ≥25 kg/m2), smoking status (never, ever-smoker), or physical activity (<1, ≥1 /month). On average, SBP increased by 0.70 mmHg and DBP decreased by 0.22 mmHg annually during follow-up. An annual increase in SBP was non-significantly lower in men taking a multivitamin versus placebo (+0.55 vs. +0.86 mmHg/year, P=0.088). When stratified by age group, the difference in annual SBP increase was significant only in men aged <60 years (+0.5 vs. +1.26 mmHg/year in multivitamin and placebo group, respectively, P=0.039) but not in others (p, interaction: >0.05). These associations did not materially change with multivariable adjustment. Annual changes in DBP did not differ by multivitamin treatment group.
Conclusion: Multivitamin supplementation has no overall effect on incident hypertension in middle-aged and older adult men. In men aged <60 years, however, a daily multivitamin supplement may be associated with a smaller aged-related increase in SBP.
Author Disclosures: L. Wang: None. S. Rautiainen: None. J.E. Manson: None. J.E. Buring: None. R.J. Glynn: None. J. Gaziano: None. H. Sesso: None.
- © 2015 by American Heart Association, Inc.