Use of loop diuretics appears to increase the rate of bone loss in the hips of older men compared with bone loss in peers who do not take the medication, according to a report in the April 14 issue of Archives of Internal Medicine.

Medications in this class increase the amount of calcium excreted in urine, potentially damaging bones over the long term. In observational studies, use of loop diuretics has been associated with an increased risk of hip and other fractures. However, prior to the current study it was unclear whether fractures related to bone loss, factors increasing the risk of falls, or comorbid conditions.

In the current study, Lionel S. Lim, MD, MPH, of Griffin Hospital, Derby, Conn., and colleagues studied 3,269 men age 65 years and older (average, 72.7 years). At an initial examination between 2000 and 2002 and at a follow-up evaluation an average of 4.6 years later, men answered questions about medication use and brought in containers for all medication taken during the past 30 days. Bone mineral density of the total hip and two subregions was measured.

A total of 84 men continuously used loop diuretics between the two time periods, 181 used them intermittently and 3,004 did not use them. After adjusting for related factors, the average annual rate of decline in total hip bone mineral density was 0.33 percent in non-users, 0.58 percent in intermittent users and 0.78 percent among continuous users.

"Compared with rates of hip bone loss among non-users of diuretics, adjusted rates of loss were about two-fold greater among intermittent loop diuretic users and about 2.5-fold greater among continuous loop diuretic users," the authors wrote.

Findings were similar at the subregions of the hip.

"We conclude that loop diuretic use in older men in associated with increased rates of hip bone loss," the authors wrote. "Our findings suggest that health care providers should take into account loop diuretic use when evaluating older men for risk factors for bone loss and fracture risk."