Key findings:

• Postmenopausal women with a reproductive period of 35 years or longer had a lower risk of multimorbidity.
• Each additional reproductive year was associated with a 4.2 percent reduction in the risk of chronic disease.

In postmenopausal women in China, a longer reproductive lifespan was associated with a lower prevalence of multimorbidity, according to menopause.

“To our knowledge, only one study in an industrialized country has examined the association between age at natural menopause and multimorbidity in older postmenopausal women,” Dr. from the Department of Reproductive Medicine at the Second Affiliated Hospital of Shandong University of Traditional Chinese Medicine in China and colleagues wrote: “It is unclear whether reproductive lifespan is associated with multimorbidity, especially in developing countries.”

Jiao and colleagues conducted a cross-sectional study of 1,310 postmenopausal women (mean age, 56.9 years) to examine the association between female reproductive lifespan and multimorbidity. All participants were categorized according to reproductive lifespan of 32 years or less (n = 377), 33 to 34 years (n = 275), 35 to 37 years (n = 371), and 38 years or more (n = 287). The researchers defined reproductive lifespan as the interval between menarche and menopause and multimorbidity as the presence of two or more self-reported chronic diseases.

Overall, the reproductive lifespan of postmenopausal women was 34.3 years with a multimorbidity prevalence of 22.2%.

Postmenopausal women with a reproductive period of 35 to 37 years (OR = 0.53; 95% CI 0.35–0.81) or 38 years or longer (OR = 0.51; 95% CI 0.31–0.84) were less likely to have multimorbidity than postmenopausal women with a reproductive period of 33 to 34 years or 32 years or less.

In addition, the researchers observed a linear trend in the association between reproductive lifespan and multimorbidity, with longer reproductive lifespan being associated with a lower risk of multimorbidity. In a sensitivity analysis, each additional reproductive year was associated with a 4.2% reduction in the risk of multimorbidity (OR = 0.96; 95% CI, 0.92-0.99).

The researchers found that several mechanisms could explain the association between reproductive lifespan and multimorbidity, including higher estrogen exposure with delayed onset of menopause.

“Considering the protective effects of estrogen, a short reproductive lifespan suggests that postmenopausal women may experience a prolonged period of estrogen deficiency, leading to a much higher risk of multimorbidity,” the researchers write.

They added that healthcare professionals should screen and assess reproductive factors to identify women at high risk.