title: Effects of low-dose versus placebo or conventional-dose postmenopausal hormone therapy on variables related to cardiovascular risk: a systematic review and meta-analyses of randomized clinical trials.
abstract: BACKGROUND
  Hormone therapy (HT), the most efficient treatment for menopausal symptoms, might have deleterious cardiovascular (CV) effects.
  
  
  OBJECTIVE
  This study aimed to evaluate the effects of low-dose estrogen HT on CV risk factors vs conventional-dose HT and placebo in postmenopausal women with no established CV disease.
  
  
  METHODS
  MEDLINE, Cochrane Central, and EMBASE were searched for trials published in 1990-2013; a hand search of reference lists of selected articles was performed; and ClinicalTrials.gov was searched for unpublished trials.
  
  
  METHODS
  Within randomized controlled trials of healthy postmenopausal women comparing low-dose HT to placebo or conventional-dose HT, 11 418 studies were initially identified.
  
  
  METHODS
  Data were independently extracted by two investigators. Disagreements were resolved by a third author.
  
  
  RESULTS
  Twenty-eight trials (3360 patients) were included. Low-dose HT vs placebo or conventional-dose HT did not effect weight, body mass index (BMI), blood pressure, C-reactive protein, or high-density lipoprotein cholesterol (HDL-C). Low-dose HT was associated with lower levels of total cholesterol (-12.16 mg/dL, 95% confidence interval [CI], -17.41 - -6.92) and low-density lipoprotein cholesterol (LDL-C) (-12.16 mg/dL; 95% CI, -16.55 - -7.77) vs placebo. Compared with conventional-dose HT, low-dose HT was associated with higher total cholesterol (5.05 mg/dL; 95% CI, 0.88-9.21) and LDL-C (4.49 mg/dL; 95% CI, 0.59-8.39). Low-dose HT was not associated with differences in triglycerides vs placebo. Oral, low-dose HT was associated with lower triglycerides vs conventional-dose HT (-14.09 mg/dL; 95% CI, -24.2 - -3.93).
  
  
  CONCLUSIONS
  In this population of apparently healthy postmenopausal women, the effect of low-dose HT did not differ from that of placebo or conventional-dose HT regarding weight, BMI, blood pressure, CRP, or HDL-C. In contrast, low-dose HT was associated with better lipid profile vs placebo, and induced higher total and LDL-C and lower triglycerides vs conventional-dose HT.
authors.affiliation: Gynecological Endocrinology Unit, Division of Endocrinology (G.C., R.B.R., P.M.S.), Hospital de Clínicas de Porto Alegre, 90035-003 Porto Alegre, Brazil; Department of Statistics (P.Z.), Universidade Federal do Rio Grande do Sul (UFRGS), 90035-003 Porto Alegre, Brazil; and Laboratory of Molecular Endocrinology, Department of Physiology (P.M.S.), UFRGS, 90035-003, Porto Alegre, Brazil.
authors.forename: Gislaine
authors.initials: G
authors.lastname: Casanova
authors.forename: Ramon
authors.initials: R
authors.lastname: Bossardi Ramos
authors.forename: Patrícia
authors.initials: P
authors.lastname: Ziegelmann
authors.forename: Poli Mara
authors.initials: PM
authors.lastname: Spritzer
mesh_terms: D001794:Blood Pressure / Q000187:drug effects; D002097:C-Reactive Protein / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000209:etiology*; D002319:Cardiovascular System / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D015914:Estrogen Replacement Therapy / Q000009:adverse effects / Q000379:methods; D005260:Female; D006801:Humans; D008055:Lipids / Q000097:blood; D010919:Placebos; D017698:Postmenopause / Q000187:drug effects*; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data; D012307:Risk Factors
chemical_list: D008055:Lipids; D010919:Placebos; D002097:C-Reactive Protein