EFFECT OF LOW-DOSAGE HYDROCHLOROTHIAZIDE ON BONE-MINERAL CONTENT IN LUMBAR VERTEBRAE AND RADIUS

An increase in bone mineral content (BMC) as well as a decrease in the incidence of fracture of the proximal femur have been described in pa tients on thiazide diuretic treatment. A study was undertaken to asses s, by means of dual X-ray absorptiometry, the effect of chronic low-do sage antihypertensive treatment with hydrochlorothiazide (HCT; less th an or equal to 25 mg daily) an lumbar vertebrae (representing the axia l skeleton) and the nondominant radius (peripheral skeleton). Measurem ents were made on 27 women (mean age 63.8 +/- 8.2 years) and 23 men (6 5.9 +/- 9.5 years) and compared with a control group of 19 women (62 /- 8.7 years) and 20 men (65.9 +/- 9.5 years) with minor surgical or d ermatological lesions who had never taken HCT or other drugs with pote ntial effects on mineral bone metabolism. In men who had been on HCT f or more than 5 years, BMC of the lumbar Vertebrae was higher by 10.3% and of the radius by 3.8% than among the controls (differences not sig nificant). In women who had been on HCT for more than 5 years, the cor responding increases were 19.6% (P < 0.05) and 5.4% (not significant). Among those patients who had been on HCT for less than 5 years there were no significant differences compared with the control group. There were no significant differences between the groups relating as regard s the proximal radius which, in contrast to the ultradistal radius, co nsists predominantly of cortical bone. - These data indicate that, whi le HCT has only a slight influence on BMC, it can be considered to hav e a desirable associated effect in the antihypertensive treatment of e lderly patients.