Normative Standards for HRpQCT Parameters in Chinese Men and Women

Abstract

Assessing bone architecture using high-resolution peripheral quantitative computed tomography (HRpQCT) has the potential to improve fracture risk assessment. The Normal Reference Study aimed to establish sex-specific reference centile curves for HRpQCT parameters. This was an age-stratified cross-sectional study and 1072 ambulatory Chinese men (n = 544) and women (n = 528) aged 20 to 79 years, who were free from conditions and medications that could affect bone metabolism and had no history of fragility fracture. They were recruited from local communities of Hong Kong. Reference centile curves for each HRpQCT parameter were constructed using generalized additive models for location, scale, and shape with age as the only explanatory variable. Patterns of reference centile curves reflected age-related changes of bone density, microarchitecture, and estimated bone strength. In both sexes, loss of cortical bone was only evident in mid-adulthood, particularly in women with a more rapid fashion probably concurrent with the onset of menopause. In contrast, loss of trabecular bone was subtle or gradual or occurred at an earlier age. Expected values of HRpQCT parameters for a defined sex and age and a defined percentile or Z-score were obtained from these curves. T-scores were calculated using the population with the peak values as the reference and reflected age- or menopause-related bone loss in an older individual or the room to reach the peak potential in a younger individual. These reference centile curves produced a standard describing a norm or desirable target that enables value clinical judgements. Percentiles, Z-scores, and T-scores would be helpful in detecting abnormalities in bone density and microarchitecture arising from various conditions and establishing entry criteria for clinical trials. They also hold the potential to refine the diagnosis of osteoporosis and assessment of fracture risk. © 2018 American Society for Bone and Mineral Research.

Age-, Site-, and Sex-Specific Normative Centile Curves for HR-pQCT-Derived Microarchitectural and Bone Strength Parameters in a Chinese Mainland Population

“…A study from HK using the first-generation HR-pQCT found results similar to ours, suggesting that race may actually play a more prominent role compared with technical aspects of the machine itself. (17) In general, we found that HR-pQCT parameters differed by sex, age period (before versus after 50 years of age), site (tibia versus radius), and bone compartment (trabecular versus cortical bone). After the age of 50 years, greater age-related differences were observed in radial parameters compared with tibial parameters among both men and women.…”

“…In these parameters, a higher value indicates poorer structural trait and, therefore, decline. (9,10,16,17) Across progressively older age groups, we observed increases in Ct.Po, Ct.Pm, Tt.Ar, Tb.Ar, Tb.Sp, Tb.Inhomogeneity and decreases in volumetric BMD, Ct.Ar, Ct.Th, Tb.…”

“…This pattern of early loss of trabeculae starting in young adulthood followed by increasing cortical loss after 50 years has also been confirmed in other populations. ( 15,17,35–40 ) This may be explained by the accessibility of the trabecular bone compartment to remodeling during young adulthood due to its larger surface area; however, this process becomes self‐limited with age as more and more trabeculae are disrupted. Conversely, intracortical porosity increases with age (due to chronic slight negative imbalances at each remodeling unit), gradually providing more bone surface for intracortical bone remodeling to occur.…”

“…Indeed, HR-pQCT-based studies in recent years have shown that agerelated skeletal deterioration is driven not only by BMD decline but also by alteration of the bone microarchitecture. (5,(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17) Before HR-pQCT can be applied in clinical practice to screen for osteoporosis or detect bone damage, a population-based normative reference database and reference intervals must be established. However, because HR-pQCT parameters are highly dependent on age, the reference intervals should be replaced by reference centile curves.…”

“…(18) Such curves have been published for HR-pQCT in the UK, US, Canada, Denmark, Brazil, and Hong Kong. (5,(7)(8)(9)(10)(12)(13)(14)(15)(16)(17) Given the variability in BMD, bone microarchitecture, and fracture incidence among different races and even potentially those of the same race from different geographic regions, data from these prior studies are not necessarily directly applicable to the Chinese mainland population.…”