Menopause may worsen functional decline in rheumatoid arthritis
Menopause was associated with worsening of physical function in women with rheumatoid arthritis (RA), suggests a study.
The longitudinal observational study involved 8,189 women who had been diagnosed with RA before menopause, based on a US-wide national registry for rheumatic diseases. Participants were administered questionnaires every 6 months, which included the Health Assessment Questionnaire (HAQ) to assess for functional decline, demographic characteristics, and reproductive components such as last menstruation cycle. Those who responded to at least two waves of questionnaires were included in the study. [Rheumatology 2018;doi:10.1093/rheumatology/kex526]
Among the participants, 24.5 percent (mean age 39.7 years) were premenopausal, 7.5 percent (mean age 50.7 years) were in menopause during the study, and 68.1 percent (mean age 62.3 years) were post-menopausal.
Compared with post-menopausal women with RA, premenopausal women had better functional status, as reflected by the negative HAQ scores indicating less functional decline (-0.50, 95 percent confidence interval [CI], -0.55 to -0.19). The results remained even after controlling for age and other potential confounding factors including length of reproductive life*, RA comorbidity, disease duration, smoking status, and use of hormone replacement therapy (HRT).
“This translates to a mean difference in HAQ scores between pre- and post-menopausal women of -0.18 for a 40-year-old woman, -0.11 for a 45-year-old woman and -0.04 for a 50-year-old woman,” observed the researchers.
Use of HRT, having been pregnant, and more reproductive years were associated with less functional decline in women with RA (p<0.001 for all).
Also, the progression of functional decline became more severe after menopause compared with premenopause, with an annual change of HAQ scores of -1.49 per year (95 percent CI, -2.08 to -0.91) between the two groups of women, after adjusting for income, comorbidities, baseline HAQ, and use of tumour necrosis factor inhibitor.
“By age, for example, a premenopausal 40-year-old woman would have an annual HAQ change of -0.61, whereas a post-menopausal woman of the same age would have a change of 0.88. Similar estimates for women of 50 years old would be -0.88 and -0.61 for premenopausal and post-menopausal, respectively,” explained the researchers.
As the data were self-reported, the researchers cautioned that biases could not be discounted. Also, no causal relationship could be established based on the findings.
“Women experience shifts in their disease surrounding reproductive and hormonal life events. RA hormonal involvement in women is most pronounced surrounding childbirth,” said the researchers, noting that RA incidence decreased during pregnancy but incidence of disease development and flare increased during the postpartum period in a previous study.
“Not only is this decline causing suffering for women, it is costly to both individuals and the healthcare system as a whole. Research is specifically needed on the mechanism connecting these variables with the eventual goal of identifying interventions that can maintain or improve function in post-menopausal women with RA,” said lead author Dr Elizabeth Mollard of the University of Nebraska Medical Center in Omaha, Nebraska, US.