Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Women’s reproductive factors and the risk of rheumatoid arthritis

04.11.2004


Study suggests prolonged preventive effect of breastfeeding and links irregular menstrual cycles to increased risk of disease



Rheumatoid arthritis (RA), an inflammatory disease of the immune system, is between two and four times more likely to strike women than men. Among women, RA is more likely to develop when reproductive hormonal levels are changing, such as in the first few months following a pregnancy and around the time of menopause. Although previous researchers have studied this topic, the relationship between hormones and the risk of developing RA remains unclear.

Seeking more conclusive evidence, a team of researchers led by Elizabeth Karlson, M.D. at Brigham and Women’s Hospital in Boston drew on a large sample – 121,700 women – to explore the contribution of hormonal factors occurring prior to the onset of RA and the impact of postmenopausal hormone replacement therapy on the risk of disease. Their findings, published in the November 2004 issue of Arthritis & Rheumatism, strongly support the lasting benefits of breastfeeding in protecting against the disease. What’s more, the researchers identified a new risk factor for RA: irregular menstrual cycles.


The study’s subjects were all women enrolled in the Nurses’ Health Study, a sweeping investigation of disease, health, and lifestyle, ongoing since 1976. Through extensive questionnaires, the research team documented each woman’s reproductive history with attention to potential RA risk factors, including age at menarche, age at first birth, history of breastfeeding, use of oral contraceptives, and regularity of menstrual cycles and in older women studied the use of estrogen after menopause. Among these women, the researchers confirmed 674 RA patients, diagnosed anywhere between 1976 and 2002. Most of the women were middle-aged at disease onset; the mean age was 56 years.

Upon analyzing the data, adjusting for variables such age and cigarette smoking, the researchers noted several interesting trends. One of the strongest was a decreasing risk of RA with increasing duration for breastfeeding. Looking at total lifetime breastfeeding, regardless of number of children, women who had breast-fed for between 13 and 23 months had a 20 percent reduction in the risk of RA compared with women who did not breastfeed. Women who had breast-fed for at least 24 months – two full years out of their childbearing years – increased their risk reduction to 50 percent. "Our data suggest breast-feeding confers long lasting protection against developing RA," Dr. Karlson states, "because the mean time since the last pregnancy among women with RA was 25 years." In addition, women who experienced irregular menstrual cycles between the ages of 20 and 35 were shown to have an increased risk of subsequent RA. Women who had begun menstruating at an early age, 10 or younger, were more likely to develop seropositive RA. The study’s results did not show any association between a history of oral contraceptive use and disease risk, or any significant differences in disease risk related to a woman’s number of pregnancies.

Focusing on the sample of RA patients, compared to women who did not develop RA, the researchers confirmed that the risk of RA increases with age and demonstrated a peak risk at the typical time of menopause, age 50 to 54. Because the onset of RA often coincides with menopause, some studies have linked the disease to falling estrogen levels, indicating the potential benefits of estrogen therapy. In this study, however, estrogen therapy among postmenopausal women did not protect against RA. "These findings suggest avenues for further research into the hormonal mechanisms involved in RA, because the complex relationships between RA and reproductive hormones clearly warrant further study," Dr. Karlson concludes.

David Greenberg | EurekAlert!
Further information:
http://www.interscience.wiley.com/journal/arthritis
http://www.wiley.com

More articles from Health and Medicine:

nachricht One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center

nachricht The gut microbiota plays a key role in treatment with classic diabetes medication
01.06.2017 | University of Gothenburg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>