Meta-analysis: effect of hormone-replacement therapy on components of the metabolic syndrome in postmenopausal women.
Level 1 - systematic review of randomized trials
Meta-analysis of randomized controlled trials.
PubMed 16918589 · doi:10.1111/j.1463-1326.2005.00545.x
What was done
A meta-analysis of randomized controlled trials (searches from April 1966 to October 2004) evaluating hormone-replacement therapy (HRT) of at least 8 weeks duration in postmenopausal women. The study evaluated effects on metabolic, inflammatory, and thrombotic markers, with insulin resistance assessed by HOMA-IR. Subgroup analyses examined route of administration (oral vs. transdermal) and diabetes status.
What was found
Pooled results from 107 trials showed: - Non-diabetic women: HRT reduced abdominal fat by -6.8% (CI, -11.8 to -1.9%), HOMA-IR by -12.9% (CI, -17.1 to -8.6%), and new-onset diabetes risk (relative risk 0.7; CI, 0.6-0.9). - Diabetic women: HRT reduced fasting glucose by -11.5% (CI, -18.0 to -5.1%) and HOMA-IR by -35.8% (CI, -51.7 to -19.8%). - Overall markers: HRT reduced LDL/HDL ratio by -15.7% (CI, -18.0 to -13.5%), lipoprotein(a) by -25.0% (CI, -32.9 to -17.1%), mean blood pressure by -1.7% (CI, -2.9 to -0.5%), E-selectin by -17.3% (CI, -22.4 to -12.1%), fibrinogen by -5.5% (CI, -7.8 to -3.2%), and plasminogen activator inhibitor-1 by -25.1% (CI, -33.6 to -15.5%). - Route differences: Oral HRT led to larger beneficial metabolic changes but increased C-reactive protein by 37.6% (CI, 17.4-61.3%) and reduced protein S by -8.6% (CI, -13.1 to -4.1%), while transdermal HRT had no effect on CRP or protein S.
Why it matters
This paper demonstrates that HRT improves multiple components of the metabolic syndrome and reduces new-onset diabetes risk in postmenopausal women, while highlighting that transdermal regimens avoid the adverse hepatic/inflammatory and prothrombotic effects seen with oral therapy.
Limits
The abstract does not report the total number of participants across the 107 included trials. Specific drug formulations, dosages, progestin regimens, and trial durations beyond the 8-week minimum are not detailed. Hard clinical outcomes (cardiovascular events, mortality) were not evaluated.
Cited by
- supports Loss of estrogen leads to increasing insulin resistance.