Duk-Chul Lee, et al. Table 3. Relative Telomere Length Ratios* of Postmenopausal Women with and without HT Wilcoxon scores HT Group (N=65) non-HT Group (N=65) p-value Sum 4853.5 3661.5 <0.01 Expected 4257.5 4257.5 Mean 74.7 56.3 p-values are calculated by the Wilcoxon rank sum test because of the skewed distribution. * Telomere length ratio (T/S ratio) of study subjects relative to the ratio of a reference gene (from a healthy young female). Hormone therapy with estrogen (conjugated equine estrogen 0.625 mg or estradiol 2 mg) plus progesterone for more than five years. Postmenopausal women without hormone therapy after menopause. Table 4. Results from a Multiple Linear Regression Model* for the Relative Telomere Length Ratio Variables in Study Subjects and Dependent Variables HT§ SE 0.27 0.03 0.01 0.21 0.21 0.01 0.01 1.10 0.24 Coefficient 0.57 -0.04 0.01 0.15 0.37 0.01 0.02 0.92 -0.16 T value p-value -2.17 <0.05 Age -1.48 0.15 Pulse pressure 0.68 0.45 Exercise¶ 0.70 0.49 Vitamin use** 1.72 0.09 HDL cholesterol 1.58 0.12 Fasting glucose 1.64 0.10 TAS 0.83 0.41 Hs-CRP -0.60 0.50 * F value, 2.21; p<0.05, R2, 0.14. Telomere length ratio (T/S ratio) of study subjects relative to the ratio of a reference gene (from a healthy young female), the log2 values of relative telomere length ratios (ΔΔCT) were used as the relative telomere length ratios in this procedure because of skewed distribution. Standard error. §Hormone therapy with estrogen (conjugated equine estrogen 0.625 mg or estradiol 2 mg) plus progesterone for more than five years. Calculated by {Systolic blood pressure diastolic blood pressure}. ¶Doing regular exercise 3 times per week. **Use of one or more vitamin among vitamin C, vitamin E, or multivitamin. Total plasma antioxidant status. High-sensitivity C-reactive protein. S ratios are described in Table 4. HT showed significant correlation with relative T/S ratios (β= 0.56 SE=0.27 p<0.05), and no significant interac- tion was found between relative T/S ratios and the other variables. DISCUSSION In the present study, we demonstrated that telomere lengths were significantly higher in post- menopausal women who had undergone long- term hormone therapy than in women who had never taken estrogen after menopause. This result Yonsei Med J Vol. 46, No. 4, 2005 suggests that conventional doses of long-term hormone therapy after menopause might have the effect of attenuating telomere attrition. From a broader perspective, long-term hormone therapy may affect human health by influencing telomere biology in a manner that had not been previously explored. Recent reports have demonstrated the association between telomere length and age related diseases,3,8-10 as well as mortality in the elderly.11 There are several factors that regulate telomere attrition. Cellular replication is the principal regu- lator of telomere attrition due to the so-called end replication problem. Telomerase counteracts telo-