Change in bone mineral density as a function of age in women and men and association with the use of antiresorptive agents.
BACKGROUND
Measurement of bone mineral density is the most common method of diagnosing and assessing osteoporosis. We sought to estimate the average rate of change in bone mineral density as a function of age among Canadians aged 25-85, stratified by sex and use of antiresorptive agents.


METHODS
We examined a longitudinal cohort of 9423 participants. We measured the bone mineral density in the lumbar spine, total hip and femoral neck at baseline in 1995-1997, and at 3-year (participants aged 40-60 years only) and 5-year follow-up visits. We used the measurements to compute individual rates of change.


RESULTS
Bone loss in all 3 skeletal sites began among women at age 40-44. Bone loss was particularly rapid in the total hip and was greatest among women aged 50-54 who were transitioning from premenopause to postmenopause, with a change from baseline of -6.8% (95% confidence interval [CI] -7.5% to -4.9%) over 5 years. The rate of decline, particularly in the total hip, increased again among women older than 70 years. Bone loss in all 3 skeletal sites began at an earlier age (25-39) among men than among women. The rate of decline of bone density in the total hip was nearly constant among men 35 and older and then increased among men older than 65. Use of antiresorptive agents was associated with attenuated bone loss in both sexes among participants aged 50-79.


CONCLUSIONS
The period of accelerated loss of bone mineral density in the hip bones occurring among women and men older than 65 may be an important contributor to the increased incidence of hip fracture among patients in that age group. The extent of bone loss that we observed in both sexes indicates that, in the absence of additional risk factors or therapy, repeat testing of bone mineral density to diagnose osteoporosis could be delayed to every 5 years.
CaMos Methods Centre, McGill University, Montréal, Que.
Claudie
C
Berger
Lisa
L
Langsetmo
Lawrence
L
Joseph
David A
DA
Hanley
K Shawn
KS
Davison
Robert
R
Josse
Nancy
N
Kreiger
Alan
A
Tenenhouse
David
D
Goltzman
D015502:Absorptiometry, Photon; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density / Q000187:drug effects / Q000502:physiology*; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D002170:Canada / Q000453:epidemiology; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000453:epidemiology / Q000378:metabolism*; D011379:Prognosis; D012189:Retrospective Studies; D012424:Rural Population; D011795:Surveys and Questionnaires; D013997:Time Factors
D050071:Bone Density Conservation Agents