Effect of Hormone Replacemcet Therapy on Lipoprotein(a) and Lipids in Postmenopausal Women: Influence of Duration of Medication

Kim, Chee Jeong; Kwak, Mi Hyang; Kim, Kyung Man; Lee, Kwang Je; Chung, Yoo Suk; Min, Young Ki; Ryu, Wang Seong; Ryoo, Un Ho

Abstract

OBJECTIVES
Hormone replacement therapy(HRT) in postmenopausal women decreases lipoprotein(a) [Lp(a)]. The influences of progesterone on Lp(a) and lipids, administered with estrogen, are controversial. However, previous studies had variable duration of therapy, and there was no report evaluating the effect of the duration of medication.
METHODS
A total 246 postmenopausal women were divided into 4 groups: group A; 0.625mg conjugated equine estrogen(CEE)(n=90), group B; 0.625mg CEE plus 5mg medroxyprogesterone acetate(MPA)(n=35), group C; 0.625mg CEE plus 10mg MPA(n=43), and group D; 2mg estradiol valerate(E2) plus 0.5mg norgestrel(N)(n=76). Lp(a) and lipids levels were measured before, 2, 6 and 12 months after HRT.
RESULTS
In total subjects, Lp(a) was decreased with medication for 2 months by 20.7%(p<0,0001). Compared with levels at 2 months after medication, levels at 6 and 12 months revealed further reduction(p<0.001) by 5.3% and 9.0% respectively. Medication for 2 months increased HDL-C in group A, not changed in group B and C, and decreased in group D. After 12 months, HDL-C levels were increased in Group A, B, and C, and not changed in group D, In total subjects, low density lipoprotein-cholesterol(LDL-C) was decreased by 12.2% after 2 months(p<0.001). Compared with levels at 2 months after medication, LDL-C level was decreased by 3.4% after 6 months(p<0.001) and there was no further reduction after 12 months.
CONCLUSION
The effect of hormone replacement therapy on Lp(a) and lipids were dependent upon the duration of medication. Inconsistent results in previous studies can be partially explained by the difference in this parameter.