Estrogen deprivation and joint pain

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Estrogen deprivation and joint pain

Women treated with aromatase inhibitors often experience joint pain

and musculoskeletal aching --severe enough, in some cases, to make

them stop the treatment.

Two researchers, T. Felson, of Boston University Clinical

Epidemiology Unit, and R. Cummings, of California Pacific

Medical Center Research Institute and University of California, San

Francisco, have thoroughly examined the evidence linking aromatase

inhibitors and, more broadly, estrogen deprivation joint pain.

" Estrogen's effects on inflammation within the joint are not well

known, " Felson and Cummings observe. Yet, as they note, estrogen has

well-established tissue-specific effects on inflammatory cytokines.

Estrogen's role in joint inflammation could account for the increased

sensitivity to pain that some women suffer with estrogen depletion.

Aromatase inhibitors have been linked to higher rates of joint and

muscle pain than Tamoxifen and placebo in various clinical trials for

breast cancer treatment and prevention.

In a National Cancer Institute of Canada study, 5,187 postmenopausal

women who completed a 5-year course of Tamoxifen therapy for breast

cancer were randomized to a further 5 years receiving the aromatase

inhibitor Letrozole ( Femara ) or a placebo. 21 percent of women

taking Letrozole reported joint pain compared with 16 percent of the

women receiving placebo.

In a study of Leuprolide ( Lupron ), a hormonal agent used to treat

infertility and a variety of gynecological disorders, 102

premenopausal women experienced symptoms of estrogen deprivation,

such as vaginal dryness, after 2 weeks of treatment, and suffered

joint pain between weeks 3 and 7 of treatment. Overall, 25 percent of

the women developed persistent joint pain, affecting the knees,

elbows, ankles, and other areas, during the study.

The pain was resolved in all women between 2 and 12 weeks after

stopping the leuprolide therapy.

In a postmenopausal estrogen/progestin intervention trial, women who

received estrogen had a significantly decrease chance of

musculoskeletal symptoms--between 32 and 38 percent--compared with

women randomly assigned placebo.

Symptoms reported in the placebo group included joint pain, muscle

stiffness, and skull and neck aching. In other studies, however,

estrogen replacement therapy had no beneficial effect on

musculoskeletal pain.

Felson and Cummings also highlight recent data showing that Asian

women undergoing menopause have lower estradiol levels than Caucasian

women and seem to be more vulnerable to a syndrome commonly known as

" menopausal arthritis. "

They also note the high rate of both osteoarthritis and rheumatoid

arthritis in postmenopausal women.

Authors have concluded by stressing the need for further research

into the contribution of estrogen deficiency to arthritis, as well as

for recognizing the risks of musculoskeletal syndrome when

prescribing aromatase inhibitors and other estrogen-depleting

treatments.

Source: Arthritis & Rheumatism, 2005