Transdermal estradiol reduces plasma myeloperoxidase levels without affecting the LDL resistance to oxidation or the LDL particle size.
OBJECTIVE
This study was designed to investigate the effects of different therapeutic range doses of transdermal estradiol (E(2)), alone or in combination with progesterone (P) or medroxyprogesterone acetate (MPA), on plasma lipoprotein levels and on three parameters related with LDL oxidizability, the resistance of LDL to oxidation by copper, the LDL particle size, and the myeloperoxidase levels.


METHODS
Thirty-five healthy postmenopausal women who had been amenorrheic for at least 1 year received two consecutive, 2-month doses of transdermal estrogen (25-microg and 50-microg E(2) patch). Thereafter, they were randomly assigned to receive a 2-month treatment of either a 100-microg E(2) patch or a 50-microg E(2) patch combined with P (300 mg/day) or MPA (5 mg/day) during the last 14 days.


RESULTS
Neither transdermal E(2) alone nor transdermal E(2) plus progestogen modified the lipoprotein profile, the LDL resistance to oxidation, or the LDL particle size. However, all treatments similarly reduced the myeloperoxidase protein levels.


CONCLUSIONS
Different dosages of transdermal E(2) within the therapeutic range were equally effective in reducing myeloperoxidase protein levels. The effect remained after addition of P or MPA in a sequential regime.
Hermenegildo
Carlos
C
Research Unit, Hospital Clinic Universitari de Valencia, Spain.
García-Martínez
María Cinta
MC
Valldecabres
Carmen
C
Tarín
Juan J
JJ
Cano
Antonio
A
D000279:Administration, Cutaneous; D008078:Cholesterol, LDL / Q000097:blood / Q000737:chemistry / Q000187:drug effects*; D003300:Copper / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004958:Estradiol / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D017258:Medroxyprogesterone Acetate / Q000008:administration & dosage / Q000494:pharmacology*; D008875:Middle Aged; D010084:Oxidation-Reduction; D010316:Particle Size; D009195:Peroxidase / Q000097:blood / Q000187:drug effects*; D011374:Progesterone / Q000008:administration & dosage / Q000494:pharmacology*; D011446:Prospective Studies
D008078:Cholesterol, LDL; D011374:Progesterone; D004958:Estradiol; D003300:Copper; D017258:Medroxyprogesterone Acetate; D009195:Peroxidase