Time since menopause, but not age, is associated with increased risk of osteoporosis

Abstract

Objectives: This study aimed to determine whether estrogen deficiency is a sole risk factor for osteoporosis or is also associated with age, through indicators such as gender, age, and time since menopause.

Methods: A cross-sectional study was conducted evaluating 938 postmenopausal women who underwent bone mineral densitometry. We collected the following data: age, ethnic group, body mass index, smoking, and time since menopause. These data were correlated to the presence of osteoporosis, according to the T-score of the femur and lumbar spine.

Results: The prevalence of osteoporosis was 37.8%. Ethnic group (p = 0.47) and smoking habits (p = 0.19) were not associated with osteoporosis. In the group of women with osteoporosis, mean age was significantly higher (p < 0.001), mean body mass index was significantly lower (p < 0.001), and time since menopause was significantly higher (p < 0.001) than in the group of women with no osteoporosis. After multivariate analysis was performed, the only variables that remained independently associated with osteoporosis were body mass index and time since menopause. Higher body mass index was a protective factor (odds ratio = 0.80 [95% confidence interval 0.76; 0.84], p < 0.001). Time since menopause represented a risk factor for osteoporosis (odds ratio = 1.04 [1.02; 1.06], p < 0.001). When divided into categories, the risk increased after 20 years of menopause and gradually every 5 years.

Conclusion: Time since menopause and body mass index were the most important factors associated with osteoporosis, confirming that estrogen deficiency, and not age, is the major cause of the disease.

Chinese abstract

目的：本研究旨在通过性别、年龄和绝经后时间等指标确定雌激素缺乏是否是骨质疏松症的唯一危险因素, 还是否与年龄相关。

方法：一项横断面研究对938名接受骨矿物密度测定的绝经后妇女进行了评估, 我们收集了以下数据：年龄, 种族, 体重指数, 吸烟和绝经后时间, 根据股骨和腰椎的T评分, 这些数据与骨质疏松症相关。

结果：骨质疏松症的患病率为37.8％, 种族（p = 0.47）和吸烟习惯（p = 0.19）与骨质疏松症无关。在患有骨质疏松症的女性组中, 平均年龄显着较高（p <0.001）, 平均体重指数显着降低（p <0.001）, 绝经后时间显着高于（p <0.001） 没有骨质疏松症的女性组。在进行多变量分析后, 与骨质疏松症独立相关的唯一变量是体重指数和绝经后时间。较高的体重指数是一个保护因素（优势比= 0.80 [95％置信区间0.76; 0.84], p <0.001）, 绝经后的时间是骨质疏松症的危险因素（优势比= 1.04 [1.02; 1.06], p <0.001）。当分为几组时, 绝经20年后骨质疏松症风险增加, 并且每5年逐渐增加。

结论：更年期和体重指数是与骨质疏松症相关的最重要因素, 证实雌激素缺乏而不是年龄是导致该病的主要原因。

Keywords:

• Osteoporosis
• risk factors
• time since menopause
• bone mineral density