Premium
The influence of lifetime physical activity and calcium intake on current measures of bone strength in postmenopausal women
Author(s) -
Shedd Kristine M,
Hanson Kathy B,
Alekel D Lee,
Hanson Laura N,
Van Loan Marta D
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a355-a
Subject(s) - tibia , femur , postmenopausal women , medicine , cortical bone , calcium , osteoporosis , physical activity , strain (injury) , dentistry , chemistry , anatomy , surgery , physical therapy
We examined lifetime contributions of physical activity (PA) and calcium intake (Ca) to bone strength in postmenopausal women. We assessed bone strength at the distal tibia (N=182) and midshaft femur (N=239) using peripheral quantitative computed tomography. With questionnaires we assessed lifetime dairy Ca from five periods and PA from six periods, collapsing into three: 5–18 y (youth), 19–34 y (young adult: YA), and 35 y‐current (midlife: ML). We scored PA using published methods (peak strain, hip bone loading exposure [BLE]). Hip BLE based on ML PA was negatively related to trabecular area (β = −0.181), periosteal circumference (β = −0.203), cross‐sectional moment of inertia (β = −0.179), polar moment of inertia (PMI: β = −0.132), and strength‐strain index (SSI; β = −0.147) at the tibia. Peak strain score based on ML PA was negatively related to PMI (β = −0.232) and SSI (β = −0.208) at the tibia. Peak strain and BLE scores, respectively, based on YA PA were positively related to cortical area (β = 0.190 and 0.135) and thickness (β = 0.166 and 0.125) at the femur (p < 0.05 for all). Ca at any age was not significant. Lifetime PA was positively related to femur—but negatively to tibia—strength properties. PA performed in ML may not be sufficient to counter the negative skeletal effects of aging, particularly at trabecular sites. Supported by NIAMS/NIH ( AR046922 , NIH– RR019975 ); CCRC at UCD (1M01RR19975‐01); USDA, ARS, WHNRC.