Development and reproducibility of the bone loading history questionnaire

Purpose: To develop an historical bone loading questionnaire that assesses loads applied to the skeleton using bone loading units and to determine its reproducibility. Additional purposes were to correlate bone loading units with areal bone mineral density (aBMD) and to determine whether low levels of bone loading increase the odds for low aBMD in healthy premenopausal women. Methods: Premenopausal women (N = 80; age: 31 ± 7.7 yr) completed the newly developed bone loading history questionnaire (BLHQ) twice within 4-6 wk to establish reproducibility. aBMD (g·cm^-2) of the whole body, lumbar spine (L_2-4), and right hip (proximal femur) were assessed with dual energy x-ray absorptiometry (DXA) in the women. Results: The questionnaire demonstrated good test-retest reliability in premenopausal women using intraclass correlation coefficients (spine r = 0.89, P < 0.001; hip r = 0.92, P < 0.001). Total spine bone loading exposure (r = 0.338; P = 0.002) and hip bone loading exposure (r = 0.317; P = 0.004) were significantly and independently correlated with femoral neck aBMD, after adjusting for BMI. Logistic regression analyses revealed increased odds for low femoral neck aBMD among those in the lowest fertile for recent hip bone loading exposure after adjusting for older ages, oral contraceptive use, low calcium intake, and an overweight BMI (OR = 3.62; CI = 1.09-11.94; P = 0.035). Conclusion: Historical bone loading activity can be reliably assessed and is moderately associated with femoral neck aBMD. This questionnaire could help to identify women with low femoral neck aBMD prior to menopause.