Impact of hormone replacement on myocardial fatty acid metabolism: potential role of estrogen.
BACKGROUND
Estrogen increases fatty acid utilization and oxidation and may decrease glucose use in human skeletal muscle, whereas these effects are attenuated by progesterone. Whether these ovarian hormones exhibit similar effects on myocardial metabolism is unknown.


RESULTS
Myocardial blood flow and oxygen consumption, as well as glucose and fatty acid metabolism, were examined retrospectively by use of positron emission tomography in 24 postmenopausal women receiving estrogen (n = 7), estrogen plus progesterone (n = 8), or no hormone replacement (n = 9) and in 22 age-matched men. Myocardial blood flow was higher in women regardless of hormone replacement status. Myocardial oxygen consumption was higher in women taking estrogen only when compared with men (7.3 +/- 1.6 micromol.g(-1).min(-1) vs 4.6 +/- 1.2 micromol.g(-1).min(-1), P < .001). Glucose utilization was not affected by gender or hormone replacement. Whereas fatty acid levels and the degree of myocardial fatty acid uptake were not distinguished by gender or hormone use, myocardial fatty acid utilization was higher in women taking estrogen when compared with men (259 +/- 68 nmol.g(-1).min(-1) vs 176 +/- 50 nmol.g(-1).min(-1), P = .01) and trended higher when compared with women not receiving hormonal therapy (185 +/- 46 nmol.g(-1).min(-1), P = .07) but was not different from that of women taking estrogen plus progesterone (205 +/- 58 nmol.g(-1).min(-1), P = not significant).


CONCLUSIONS
In postmenopausal women, estrogen use is associated with increased myocardial fatty acid utilization. Thus, when the cardiac effects of hormone replacement therapy are being assessed, alterations in myocardial substrate metabolism should be considered.
Herrero
Pilar
P
Division of Radiological Sciences, Edward Mallinckrodt Institute of Radiology, 510 S. Kingshighway Boulevard, St Louis, MO 63110, USA.
Soto
Pablo F
PF
Dence
Carmen S
CS
Kisrieva-Ware
Zulfia
Z
Delano
Deborah A
DA
Peterson
Linda R
LR
Gropler
Robert J
RJ
D000368:Aged; D001783:Blood Flow Velocity / Q000187:drug effects / Q000502:physiology; D004338:Drug Combinations; D004967:Estrogens / Q000008:administration & dosage*; D005227:Fatty Acids / Q000378:metabolism*; D005260:Female; D005947:Glucose / Q000378:metabolism; D006321:Heart / Q000000981:diagnostic imaging / Q000187:drug effects*; D020249:Hormone Replacement Therapy / Q000379:methods*; D006801:Humans; D008657:Metabolic Clearance Rate / Q000187:drug effects; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects / Q000502:physiology*; D049268:Positron-Emission Tomography; D011374:Progesterone / Q000008:administration & dosage*; D012189:Retrospective Studies
D004338:Drug Combinations; D004967:Estrogens; D005227:Fatty Acids; D011374:Progesterone; D005947:Glucose