Factors associated with endometrial thickness and uterine size in a random sample of postmenopausal women

OBJECTIVE: The objective of this study was to investigate factors possibly associated with endometrial thickness and uterine size in a random sample of postmenopausal women. STUDY DESIGN: A random sample (n = 1000) of the total population of women 45 to 80 years of age, resident in the city of Goteborg, was invited to attend for a transvaginal sonography examination, Eight hundred twenty-seven women accepted the invitation and underwent a gynecologic and a transvaginal sonography examination with measurement of endometrial thickness and uterine size. The women's weight and height were measured and a blood sample for analysis of serum estradiol and follicle-stimulating hormone was taken. The women also provided information regarding previous medical and gynecologic history, possible medication, and smoking habits. RESULTS: Five hundred fifty-nine women were postmenopausal, and 183 (33%) of the postmenopausal women were taking some form of hormonal substitution. Factors associated with endometrial thickness and uterine size were analyzed by means of univariate and stepwise multiple regression analyses. The current use of hormone replacement therapy was the most important factor associated with both endometrial thickness and all the uterine size parameters studied. The presence of fibroids was also associated with endometrial thickness. Other factors shown to be associated with uterine size were age, parity, smoking, hypertension, and the presence of diabetes mellitus. CONCLUSIONS: Several of the known risk factors for endometrial cancer were shown to be associated with endometrial thickness and uterine size parameters.