This article is more than 5 years old. Information may no longer be current.
Younger age at HT initiation decreases CHD mortality risk
Click Here to Manage Email Alerts
Women who are younger than 60 years when they begin estradiol-based hormone therapy have a reduced risk for coronary heart disease mortality, according to study results.
“Our data further demonstrate that being age 60 years at the initiation of HT is not a threshold age, but the earlier the HT has been started, the smaller was the cardiac mortality risk,” the researchers wrote. “This is in line with the fact that atherosclerotic changes start to develop already in premenopausal age. Thus, our findings support the ‘timing hypothesis’ but not the ‘window hypothesis’ because we did not detect a cardiac mortality increased when HT was initiated after 60 years of age.”
Tomi S. Mikkola, MD, PhD, of the department of obstetrics and gynecology at Helsinki University Hospital in Finland, and colleagues evaluated data from the nationwide prescription registry on 498,105 women who used estradiol alone or estradiol combined with various progestins during 3.7 million person-years from 1994 to 2009 to determine the links between death from CHD and age at HT initiation and if the progestin component affects risk.
Participants were followed from time of HT initiation to death or the end of 2009. Standardized mortality ratios (SMRs) with 95% CIs were used to compared with risk for CHD death in HT users and an age-matched background population.
There were significantly greater decreases in the risk for cardiac death with an age younger than 60 years at initiation compared with an age older than 60 years for estradiol alone (SMR = 0.53; 95% CI, 0.47-0.59 vs. SMR = 0.76; 95% CI, 0.71-0.82), estradiol with norethisterone acetate (SMR = 0.45; 95% CI, 0.41-0.49 vs. SMR = 0.74; 95% CI, 0.67-0.81) or tibolone (SMR = 0.35; 95% CI, 0.26-0.47 vs. SMR = 1.01; 95% CI, 0.67-1.46) with exposure of 5 years or less.
No significant differences existed for risk for cardiac mortality between estradiol with norethisterone acetate or estradiol with medroxyprogesterone acetate with exposure for 3 to 5 years.
The younger participants were at initiation of HT, the larger the decreases in risk for cardiac death in a subanalysis on 310,305 participants (P < .05 for trend).
There were significantly greater decreases in the risk for total mortality with an age younger than 60 years at initiation compared with an age older than 60 years for estradiol alone (SMR = 0.64; 95% CI, 0.63-0.65 vs. SMR = 0.75; 95% CI, 0.72-0.77) and estradiol with norethisterone acetate (SMR = 0.67; 95% CI, 0.66-0.69 vs. SMR = 0.76; 95% CI, 0.73-0.79).
“The younger women are at initiation of estradiol-based therapy or tibolone, the smaller their cardiac mortality risk,” the researchers wrote. “Thus, in our study population, 60 years of age at the initiation of HT was not a threshold age. Various progestins, such as [medroxyprogesterone acetate], [norethisterone acetate], dydrogesterone or some other progestins as complements to estradiol, show no differences in cardiac death risk or the ‘timing’ phenomenon.” – by Amber Cox
Disclosure: Mikkola reports speaking and/or consulting fees from Mylan and Novo Nordisk. Please see the full study for a list of all other authors’ relevant financial disclosures.
Click Here to Manage Email Alerts