Application of bone turnover markers and DXA and QCT in an elderly Chinese male population

Background: To investigate the clinical values and relationships of bone turnover markers (BTMs), dual-energy X-ray absorptiometry (DXA), and quantitative computed tomodensitometry (QCT) in the screening of osteoporosis (OP) in elderly Chinese males. Methods: General data, including age, height, and weight, the results of BTM measurements, and the findings of DXA and QCT in 357 male patients aged >= 50 years who visited the outpatient or inpatient Department of Geriatrics, Beijing Jishuitan Hospital from June 2017 to May 2019 were retrospectively analyzed. Results: The OP detection rates based on T-scores of DXA L1-4, DXA total hip, and spine QCT were 3.4% (12/357), 13.2% (47/357), and 40.3% (144/357), respectively. QCT had a significantly higher OP detection rate than did DXA (P<0.001). There were 24 cases of fragility fractures, which were significantly correlated with the DXA total hip BMD and its T-score, with risk cut-off values of 0.607 g/cm(2) and -2.950, respectively. The measured levels of the 5 BTMs were as follows: total procollagen type I amino-terminal propeptide (tPINP), 39.23 +/- 20.82 ng/mL; beta-isomerized C-terminal telopeptides (beta-CTX), 0.38 +/- 0.21 ng/mL; osteocalcin (OC), 13.50 +/- 8.80 ng/mL; 25-hydroxycholecalciferol (25(OH)D-3), 12.90 +/- 7.46 ng/mL; and parathormone (PTH), 54.50 +/- 25.35 pg/mL. The elevation of tPINP, beta-CTX, and OC were negatively correlated with aging and positively correlated with decreased BMD (all P<0.05). OC and 25(OH)D-3 values were significantly lower than their normal range. Among the 43 patients with normal bone mass on both DXA and QCT examinations, 34 presented with abnormal BTMs, including elevated tPINP in 2 cases, elevated beta-CTX in 2 cases, and OC decreased in 31 cases. Conclusions: In the Chinese elderly male population, spine QCT has a higher detection rate of OP than DXA, whereas hip DXA is more advantageous in predicting the risk of fragility fracture. tPINP, beta-CTX, and OC can be used as reliable indicators for the dynamic observation of bone content changes and may screen for early bone metabolism abnormalities when BMD examinations still show negative results.

Automated summary

In elderly Chinese males, spine QCT has a higher OP detection rate than DXA, while hip DXA is more advantageous in predicting the risk of fragility fracture. tPINP, beta-CTX, and OC can serve as reliable indicators for dynamically monitoring bone content changes and may identify early bone metabolism abnormalities even when BMD examinations are negative.