Oral contraceptives and rheumatoid arthritis: new data from the Royal College of General Practitioners' oral contraception study

Article Abstract:

The relationship between oral contraceptive use and the risk of rheumatoid arthritis (RA) is unclear. Numerous studies have reported decreased risk of RA in contraceptive users, while other studies have been unable to find this protective effect. In the Royal College of General Practitioners's oral contraception study, the new diagnosis of rheumatoid arthritis in 23,000 women has been evaluated in relation to contraceptive usage since the study began in 1968. Three main user groups have developed, namely current, former, and never users of oral contraceptives. Data from the earlier part of the study suggested that there was a 50 percent reduction in incidence of RA in contraceptive users. In this most recent analysis of the data, the relative risk of RA occurrence in current users was 0.82 (i.e. current users were only about four-fifths as likely to develop RA), while that in former users was 0.94, compared with never users. There was a significant trend toward increasing risk with age in former and never users but not in current users. There was a significant decrease in the incidence of RA among former and never but not current users, and this contributed to the differences between previous reports and this current report. Interestingly, other studies have also found a similar trend. No relationship between incidence of RA and smoking, number of live births, social class, duration of contraceptive use, or hormonal content of contraceptives was found. In addition, nearly 65 percent of the original study subjects were lost to follow-up, but these subjects and the remaining ones have similar characteristics. The study suggests that oral contraceptive use does lead to a decreased risk of RA, but the current secular trend of total decreasing incidence of RA in former and never users of oral contraceptives has somewhat obscured this relationship. This secular trend may explain some of the discrepancies among different studies on this topic. (Consumer Summary produced by Reliance Medical Information, Inc.)

Oral contraceptives

---

Clinical implications of IgA rheumatoid factor subclasses

Article Abstract:

Measuring levels of immunoglobulin A2 rheumatoid factor (IgA2 RF) may be more helpful in diagnosing patients with rheumatoid arthritis (RA) than levels of IgA1 RF. IgA1 RF and IgA2 RF are subclasses of the antibody IgA RF, which is usually elevated in patients with rheumatoid arthritis and some healthy people as well. Researchers measured blood levels of IgA1 RF and IgA2 RF in 58 patients with RA and 30 healthy individuals with elevated total IgA RF. Thirty-two RA patients had elevated total IgA RF. All of these RA patients had elevated IgA1 RF and 97% also had elevated IgA2 RF. Ninety-seven percent of the healthy individuals had elevated IgA1 RF, but only 67% had elevated IgA2 RF.

Measurement

---

A prospective study on the incidence of rheumatoid arthritis among people with persistent increase of rheumatoid factor

Article Abstract:

People with persistently increased blood levels of rheumatoid factor are very likely to develop rheumatoid arthritis. Those with increased levels of more than one form of rheumatoid factor are more likely to develop rheumatoid arthritis than those with increased levels of only one form.

Health aspects

Similar abstracts:

• Abstracts: The high-risk sexual practices of crack-smoking sex workers recruited from the streets of three American cities
• Abstracts: Ovral as a "morning-after" contraceptive. An emergency contraceptive kit. Plan B: A progestin-only emergency contraceptive
• Abstracts: Tumor necrosis factor blockers in rheumatoid arthritis. Abatacept for rheumatoid arthritis refractory to tumor necrosis factor alpha inhibition
• Abstracts: Alkaline phosphatase isoenzyme activities in rheumatoid arthritis: hepatobiliary enzyme dissociation and relation to disease activity
• Abstracts: Involvement of simultaneous multiple transcription factor expression, including cAMP responsive element binding protein and OCT-1, for synovial cell outgrowth in patients with rheumatoid arthritis

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.