The effects of thiazide diuretics on calcium metabolism in the aged.
OBJECTIVE
To determine the effects of long-term use of the thiazide diuretic chlorthalidone on serum bone-related biochemical variables in older persons.


METHODS
Cross-sectional comparison.


METHODS
Community-dwelling subjects who had participated in the Systolic Hypertension in the Elderly (SHEP) program.


METHODS
Sixty-six Caucasians (36 male and 30 female), age range 70 to 89 years, of whom 23 were taking a thiazide diuretic.


METHODS
25-hydroxyvitamin D (25OHD), parathyroid hormone, osteocalcin, calcitonin, and serum bioavailable testosterone.


RESULTS
In both groups, there was a high prevalence of low 25 (OHD) levels (30%). Log 25OHD showed a significant inverse relationship to parathyroid hormone (r = .33, P < 0.05). Thiazide users had lower levels of osteocalcin (P < 0.05) and parathyroid hormone levels (P < 0.05) compared with non-thiazide users. Male thiazide users had decreased bioavailable testosterone levels compared with non-thiazide users (P < 0.05). Serum osteocalcin was significantly related to bioavailable testosterone in men not on thiazide (r = .43, P < 0.05).


CONCLUSIONS
Hypovitaminosis D is a common finding in older individuals with associated elevations in parathyroid hormone. Parathyroid hormone and testosterone concentration (in men) are correlated with serum osteocalcin, a measure of osteoblastic activity. Long-term thiazide use alters these relationships and produces a biochemical profile suggestive of decreased bone formation. Reduced bioavailable testosterone may also play a role in these biochemical changes.
Perry
H M
HM
Department of Medicine, St. Louis University School of Medicine, Missouri.
Jensen
J
J
Kaiser
F E
FE
Horowitz
M
M
Perry
H M
HM
Morley
J E
JE
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001682:Biological Availability; D001847:Bone Diseases / Q000097:blood* / Q000139:chemically induced / Q000453:epidemiology / Q000378:metabolism; D002116:Calcitonin / Q000097:blood; D002752:Chlorthalidone / Q000009:adverse effects*; D003430:Cross-Sectional Studies; D004341:Drug Evaluation; D005260:Female; D006801:Humans; D006887:Hydroxycholecalciferols / Q000097:blood; D008297:Male; D015675:Osteocalcin / Q000097:blood; D010281:Parathyroid Hormone / Q000145:classification; D015995:Prevalence; D012737:Sex Factors; D013739:Testosterone / Q000097:blood / Q000493:pharmacokinetics
D006887:Hydroxycholecalciferols; D010281:Parathyroid Hormone; D015675:Osteocalcin; D013739:Testosterone; D002116:Calcitonin; D002752:Chlorthalidone