title: A Randomized Trial of a Low-Fat Diet Intervention on Blood Pressure and Hypertension: Tertiary Analysis of the WHI Dietary Modification Trial.
abstract: This post hoc analysis determined if the Women's Health Initiative (WHI) Diet Modification intervention (DM-I) resulted in a significantly different rate of incident hypertension (HTN), as well as longitudinal changes in blood pressure.
  
  
  
  Participants were 48,835 postmenopausal women aged 50-79 years who were randomly assigned to either the intervention or comparison group. HTN was defined as self-report of treated HTN collected semiannually or blood pressure ≥140/90mm Hg at one of the annual follow-up clinic visits.
  
  
  
  After a mean follow-up of 8.3 years, and among those who did not have HTN at baseline (n = 31,146), there were 16,174 (51.9%) HTN cases and those assigned to the intervention group had a 4% lower overall risk of developing incident HTN (hazard ratio (HR): 0.96, 95% confidence interval (CI): 0.93-0.99). Although the risk of HTN was lower in the DM-I group in the first few years, the HR became greater than 1 after year 5 (P-trend < 0.01). Similarly, randomization to the DM-I arm resulted in a small but significantly lower average systolic blood pressure (SBP) at 1 year of follow-up (-0.66mm Hg, 0.44-0.89) that increased over the following 8 years (0.16mm Hg/year, 0.11-0.21), such that any early benefit was eliminated by year 5 and a minimal deleterious effect emerged by year 7.
  
  
  
  Randomization to an intensive behavioral dietary modification program aimed at a lower total fat intake is not associated with sustained reductions in blood pressure or risk of HTN in postmenopausal women.
  
  
  
  url http://www.clinicaltrials.gov, unique identifier nct00000611.
authors.affiliation: Department of Family Medicine and Public Health, University of California San Diego, La Jolla, California, USA; mallison@ucsd.edu.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Allison
authors.affiliation: Department of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA;
authors.forename: Aaron K
authors.initials: AK
authors.lastname: Aragaki
authors.affiliation: Department of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington, USA;
authors.forename: Roberta M
authors.initials: RM
authors.lastname: Ray
authors.affiliation: HealthPartners Institute for Education and Research, Minneapolis, Minnesota, USA;
authors.forename: Karen L
authors.initials: KL
authors.lastname: Margolis
authors.affiliation: School of Public Health, University of Washington, Seattle, Washington, USA;
authors.forename: Shirley A A
authors.initials: SA
authors.lastname: Beresford
authors.affiliation: Department of Epidemiology, Pittsburgh University, Pittsburgh, Pennsylvania, USA;
authors.forename: Lewis
authors.initials: L
authors.lastname: Kuller
authors.affiliation: Department of Obstetrics and Gynecology, University of Miami, Miami, Florida, USA;
authors.forename: Mary
authors.initials: M
authors.lastname: Jo O'Sullivan
authors.affiliation: Department of Epidemiology and Population Health, Albert Einstein University, Bronx, New York, USA;
authors.forename: Sylvia
authors.initials: S
authors.lastname: Wassertheil-Smoller
authors.affiliation: Department of Preventive Medicine, Northwestern University, Chicago, Illinois, USA.
authors.forename: Linda
authors.initials: L
authors.lastname: Van Horn
mesh_terms: D000368:Aged; D001794:Blood Pressure; D018752:Diet, Fat-Restricted; D005260:Female; D006801:Humans; D006973:Hypertension / Q000178:diet therapy*; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D016387:Women's Health
keywords: blood pressure; diet; hypertension; trial; women.