Is trabecular bone score associated with appendicular lean mass?

UNLABELLED: Among individuals aged ≥ 40 years old, we found that after controlling for age, sex, FMI, and tissue thickness, an increase of 1kg/m2 of ALMI is associated with an increase in TBS of 0.058, which is approximately half of one population standard deviation, or 4.7% of the average value for TBS.

BACKGROUND

Trabecular bone score (TBS) has been shown to be an independent risk factor for fracture. Muscle pulling on bone is hypothesized to be a mechanical stimulus for osteogenesis. Our aim was to explore whether TBS is associated with appendicular lean mass index (ALMI, appendicular lean mass divided by height squared, units kg/m2).

METHODS

We used visit data from individuals aged 40 years and older in the Manitoba DXA Registry (February 1999-March 2016). ALMI, total body lean mass index (LMI) and total body fat mass index (FMI) were estimated from weight, sex, and percent fat from spine and hip DXA (all R2 > 0.85 vs total body DXA). We used linear and logistic regression analyses to examine cross-sectional associations between ALMI or LMI and TBS in analyses adjusted for age and sex, and age, sex, FMI, and abdominal tissue thickness.

RESULTS

Among 60,196 individuals (90% female), descriptive statistics as mean (SD) were: TBS 1.245 (0.122), BMI 26.4 kg/m2 (4.4), ALMI 6.7 kg/m2 (0.9), LMI 15.3 kg/m2 (1.7) and FMI kg/m2 10.0 (3.3). ALMI was associated with TBS after adjustment for age and sex (Unstandardized β = 0.007, 95%CI 0.006 to 0.008, Adjusted R2 = 0.130, p < 0.001). The association and explained variation were stronger in a model including age, sex, FMI, and abdominal tissue thickness (Unstandardized β = 0.058, 95%CI 0.056 to 0.059, Adjusted R2 = 0.557, p < 0.001); an increase of 1kg/m2 of ALMI was associated with an increase in TBS of 0.058, approximately half of one population standard deviation, or 4.7% of the average value for TBS. Meeting the EWGSOP2 criterion for sarcopenia was associated with being in the lowest TBS tertile after adjustment for age, sex and FMI with odds ratio 1.46 (95% CI 1.38 to 1.55).

CONCLUSIONS

ALMI was associated with TBS after controlling for age, sex, FMI, and abdominal tissue thickness.