Unlike in men, kidney or bladder stones do not appear to be an independent risk factor for osteoporosis in postmenopausal women, according to data published in the Journal of Bone and Mineral Research.
"We know in men that if you have a kidney stone, you are more likely to have osteoporosis," study researcher Laura D. Carbone, MD, chief of the section of rheumatology at the Medical College of Georgia at Georgia Regents University, said in a press release.
"We were trying to find out if that is also the case for women. We found that, unlike what has been reported in men, a woman having a kidney stone is not a risk factor for osteoporosis. However, having one urinary tract stone does put women at increased risk for a second one."
For their study, Carbone and colleagues evaluated data from slightly more than 150,000 postmenopausal women who participated in the Women's Health Initiative. About 10,000 women reported urinary tract stones at the start of or during the course of the study. Follow-up lasted for an average of 8 years.
Although unadjusted results demonstrated a link between urinary tract stones and incident total fractures, the researchers found no significant associations between urinary tract stones and changes in bone mineral density at any skeletal site or incident fractures after adjustment for covariates.
"We wanted women and their physicians to have this information," study researcher Monique Bethel, MD, of the Medical College of Georgia, said in the release. "If the two relate, and a patient who has not been screened for osteoporosis comes to the office with a kidney stone, her physician might have been concerned she also has a higher risk for osteoporosis. Our studies indicate she likely does not."
Even so, the researchers noted that women with kidney or bladder stones do have an increased risk for subsequent stones and therefore should work with their physicians to reduce this risk, such as addressing water or fluid intake and evaluating diet.
Kidney and bladder stones (urinary tract stones) and osteoporosis are prevalent, serious conditions for postmenopausal women. Men with kidney stones are at increased risk of osteoporosis; however, the relationship of urinary tract stones to osteoporosis in postmenopausal women has not been established. The purpose of this study was to determine whether urinary tract stones are an independent risk factor for changes in bone mineral density (BMD) and incident fractures in women in the Women’s Health Initiative (WHI).