Postmenopausal hormone use and the risk of nephrolithiasis

January 01, 0001

Postmenopausal hormone use and the risk of nephrolithiasis

These US authors reviewed the incidence of nephrolithiasis in the Women's Health Initiative estrogen-alone and estrogen plus progestin trials conducted at 40 US clinical centers. A total of 10,739 postmenopausal women with hysterectomy were randomized to receive 0.625 mg/d of conjugated equine estrogens (CEE) or placebo, and 16,608 postmenopausal women without hysterectomy were randomized to receive placebo or estrogen plus progestin given as CEE plus medroxyprogesterone acetate (2.5 mg/d). The incidence of nephrolithiasis was determined for an average follow-up of 7.1 years for the CEE trial and 5.6 years for the estrogen plus progestin trial.

They found: "Baseline demographic characteristics and risk factors for nephrolithiasis were similar in the placebo and treatment arms. Estrogen therapy was associated with a significant increase in nephrolithiasis risk from 34 to 39 cases per 10,000 person-years (hazard ratio, 1.21). Censoring data from women when they ceased to adhere to study medication increased the hazard ratio to 1.39. The increased nephrolithiasis risk was independent of progestin coadministration, and effects did not vary significantly according to prerandomization history of nephrolithiasis."

The authors concluded: "These data suggest that estrogen therapy increases the risk of nephrolithiasis in healthy postmenopausal women. These findings should be considered in decision making regarding postmenopausal estrogen use. The mechanisms underlying this higher susceptibility remain to be determined."

It is not clear to what extent these findings can be generalized to other forms of oral or transdermal estrogen.

For the full abstract, click here.

Arch Intern Med 170(18):1678-1685, 11 October 2010
© 2010 to the American Medical Association
Postmenopausal Hormone Use and the Risk of Nephrolithiasis-Results From the Women's Health Initiative Hormone Therapy Trials. Naim M. Maalouf, Alicia H. Sato, Brian J. Welch, et al. Correspondence to Dr. Maalouf: [email protected]

Category: U. Urinary System. Keywords: conjugated equine estrogen, nephrolithiasis, progestin, Women’s Health Initiative, secondary analysis of randomized controlled trial, journal watch.
Synopsis edited by Dr Linda French, Toledo, Ohio. Posted on Global Family Doctor 2 November 2010 2010

Pearls are an independent product of the Cochrane primary care group and are meant for educational use and not to guide clinical care.