Greater phosphorus intake has been associated with lower levels of blood pressure in cross-sectional studies. This association, however, has not been assessed prospectively.

We studied 13 444 participants from the Atherosclerosis Risk in Communities cohort and the Multi-Ethnic Study of Atherosclerosis,

with diet assessed at baseline using validated food frequency questionnaires.

Blood pressure and use of antihypertensive medication were determined at baseline and during follow-up visits.

Compared with individuals in the lowest quintile of phosphorus intake at baseline, those in the highest quintile had lower baseline systolic and diastolic blood pressures after adjustment for dietary and nondietary confounders (–2.0 mm Hg [95% CI: –3.6 to –0.5], P for trend=0.01; and –0.6 [95% CI: –1.6 to +0.3], P for trend=0.20, respectively).

During an average 6.2 years of follow-up, 3345 cases of hypertension were identified.

Phosphorus intake was associated with the risk of hypertension (hazard ratio: 0.80 [95% CI: 0.80 to 1.00], comparing extreme quintiles; P for trend=0.02) after adjustment for nondietary factors but not after additional adjustment for dietary variables (hazard ratio: 1.01 [95% CI: 0.82 to 1.23], P for trend=0.88). Phosphorus from dairy products but not from other sources was associated with lower baseline blood pressure and reduced risk of incident hypertension. Hazard ratios (95% CIs) comparing extreme quintiles were 0.86 (0.76 to 0.97; P for trend=0.01) for phosphorus from dairy foods and 1.04 (0.93 to 1.17; P for trend=0.48) for phosphorus from other foods. These findings could indicate an effect of phosphorus in conjunction with other dairy constituents or of dairy itself without involvement of phosphorus.

Key Words: phosphorus • cohort • dairy product • epidemiology • blood pressure • hypertension

Hypertension. 2010;55:776

Alvaro Alonso; Jennifer A. Nettleton; Joachim H. Ix; Ian H. de Boer; Aaron R. Folsom; Aurelian Bidulescu; Bryan R. Kestenbaum; Lloyd E. Chambless; David R. Jacobs, Jr

From the Division of Epidemiology and Community Health (A.A., A.R.F., D.R.J.), School of Public Health, University of Minnesota, Minneapolis, Minn; Department of Preventive Medicine and Public Health (A.A.), School of Medicine, University of Navarra, Pamplona, Spain; Division of Epidemiology (J.A.N.), School of Public Health, University of Texas Health Sciences Center, Houston, Tex; Division of Nephrology (J.H.I.), Department of Medicine, and Division of Preventive Medicine (J.H.I.), Department of Family and Preventive Medicine, University of California, San Diego, San Diego, Calif; Nephrology Section (J.H.I.), Veterans’ Affairs San Diego Healthcare System, San Diego, Calif; Division of Nephrology (I.H.d.B., B.R.K.), Department of Medicine, University of Washington, Seattle, Wash; Cardiovascular Research Institute and Department of Community Health and Preventive Medicine (A.B.), Morehouse School of Medicine, Atlanta, Ga; Department of Biostatistics (L.E.C.), School of Public Health, University of North Carolina, Chapel Hill, N.C.

Correspondence to Alvaro Alonso, Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, 1300 S 2nd St, Suite 300, Minneapolis, MN 55454. E-mail aalogut@alumni.unav.es