Effects of oral combined hormone replacement therapy on plasma lipids and lipoproteins

Vadlamudi, Satyaprasad; MacLean, Paul; Israel, R.Gay; Marks, Richard H.; Hickey, Matthew; Otvos, James; Barakat, Hisham

« Previous Next »Metabolism - Clinical and Experimental
Volume 47, Issue 10 , Pages 1222-1226, October 1998

Effects of oral combined hormone replacement therapy on plasma lipids and lipoproteins☆

Satyaprasad Vadlamudi
- Department of Biochemistry, School of Medicine, East Carolina University, Greenville, NC, USA
- Department of Exercise and Sport Science, Colorado State University, Fort Collins, CO, USA
- Department of Biochemistry, North Carolina State University, Raleigh, NC, USA
Paul MacLean
- Department of Biochemistry, School of Medicine, East Carolina University, Greenville, NC, USA
- Department of Exercise and Sport Science, Colorado State University, Fort Collins, CO, USA
- Department of Biochemistry, North Carolina State University, Raleigh, NC, USA
R.Gay Israel
- Department of Biochemistry, School of Medicine, East Carolina University, Greenville, NC, USA
- Department of Exercise and Sport Science, Colorado State University, Fort Collins, CO, USA
- Department of Biochemistry, North Carolina State University, Raleigh, NC, USA
Richard H. Marks
- Department of Biochemistry, School of Medicine, East Carolina University, Greenville, NC, USA
- Department of Exercise and Sport Science, Colorado State University, Fort Collins, CO, USA
- Department of Biochemistry, North Carolina State University, Raleigh, NC, USA
Matthew Hickey
- Department of Biochemistry, School of Medicine, East Carolina University, Greenville, NC, USA
- Department of Exercise and Sport Science, Colorado State University, Fort Collins, CO, USA
- Department of Biochemistry, North Carolina State University, Raleigh, NC, USA
James Otvos
- Department of Biochemistry, School of Medicine, East Carolina University, Greenville, NC, USA
- Department of Exercise and Sport Science, Colorado State University, Fort Collins, CO, USA
- Department of Biochemistry, North Carolina State University, Raleigh, NC, USA
Hisham Barakat
- Address reprint requests to Hisham Barakat, PhD, Biochemistry Department, School of Medicine, East Carolina University, Greenville, NC 27858.
- Department of Biochemistry, School of Medicine, East Carolina University, Greenville, NC, USA
- Department of Exercise and Sport Science, Colorado State University, Fort Collins, CO, USA
- Department of Biochemistry, North Carolina State University, Raleigh, NC, USA

Received 10 November 1997; accepted 19 March 1998.

Abstract

Hormone replacement therapy has been shown to decrease the risk of coronary heart disease (CHD) in menopausal women. In this cross-sectional study, we addressed the following question: What effects would combined oral hormone replacement therapy have on plasma lipid and lipoprotein profiles independent of the other known CHD risk factors? We analyzed the plasma lipoproteins of two groups of menopausal women who were randomly selected from a large database of individuals. One group (n = 10) was not taking any hormone replacement therapy (NO HRT), while the second group (n = 8) was taking a daily dose of 0.625 mg conjugated estrogen and 2.5 mg medroxyprogesterone orally (PremPro, Wyeth-Ayerst, Philadelphia, PA) for at least 6 months (HRT). The two groups were not different in age, body weight, percent body fat, body mass index (BMI), waist to hip ratio, blood pressure, or insulin and glucose levels. High-density lipoprotein (HDL)-cholesterol was significantly higher (P < .05) in the HRT group. The total cholesterol (TC) to HDL-cholesterol ratio was significantly lower for HRT versus NO HRT (P < .05). Apolipoprotein (apo) A-1, the apo ratio, and lecithin:cholesterol acyltransferase (LCAT) activity were significantly higher in HRT (P < .05). Lipoprotein subclass profiles measured by nuclear magnetic resonance (NMR) spectroscopy showed an increase in larger HDL subpopulations (H3 and H4) in HRT (P < .05), which are considered antiatherogenic. No differences were seen in the cholesterol concentration or size of low-density lipoprotein (LDL) subpopulations in HRT compared with NO HRT. These results indicate that the combined estrogen and progesterone treatment leads to beneficial effects on plasma lipoproteins. The beneficial effects include (1) increases in HDL-cholesterol and predominance of HDL₂, (2) no adverse effects on LDL subpopulation distribution, and (3) increases in apo A-1 levels and LCAT activity, which indicate an improvement in reverse cholesterol transport.