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 Minimising risks of transplants
22.02.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

nachricht FAU researchers demonstrate that an oxygen sensor in the body reduces inflammation
22.02.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

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: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Stiffness matters

22.02.2018 | Life Sciences

Magnetic field traces gas and dust swirling around supermassive black hole

22.02.2018 | Physics and Astronomy

First evidence of surprising ocean warming around Galápagos corals

22.02.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>