HR-pQCT in vivo imaging of periarticular bone changes in chronic inflammatory diseases: Data from acquisition to impact on treatment indications

Bone erosions associated with systemic bone loss on HR-pQCT in women with longstanding polyarticular juvenile idiopathic arthritis

OBJECTIVES

To analyze longstanding polyarticular juvenile idiopathic arthritis (pJIA) for possible associations between localized bone damage (erosions), and systemic bone loss. Besides, to compare the systemic bone mass of pJIA with healthy controls.

METHODS

Thirty-four pJIA women and 99 healthy controls (HC) were included. Radius and tibia of all subjects were scanned by HR-pQCT. Volumetric bone mineral density (vBMD), bone microarchitecture, and -finite element parameters were analyzed. Patients underwent HR-pQCT of 2nd and 3rd metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints of the dominant hand, for bone erosions quantification.

RESULTS

The mean age of patients was 31.5 ± 7.4yrs with a mean disease duration of 21.7 ± 9.2yrs. Bone erosions were detectable in 79% of patients. The number of bone erosions was positively correlated with cortical porosity (Ct.Po) at tibia (r = 0.575, p = 0.001), and radius (r = 0.423, p = 0.018); and negatively correlated with cortical vBMD at tibia (r=-0.420, p = 0.015). In a logistic regression analysis, adjusted for anti-CCP, the presence of bone erosions was independently associated with Ct.Po at radius (p = 0.018) and cortical vBMD at tibia (p = 0.020). Moreover, cortical and trabecular vBMD, trabecular number, and μ-finite element parameters were decreased in patients compared to HC (p < 0.05).

CONCLUSION

Bone erosions in longstanding pJIA women were associated with decreased cortical bone parameters, and these patients showed systemic bone impairment at peripheral sites compared with healthy controls.

Chronic hypoparathyroidism is associated with increased cortical bone density evaluated using high-resolution peripheral quantitative computed tomography

PURPOSE

This cross-sectional study aimed to assess bone mineral density (BMD), bone microarchitecture and fracture prevalence in women with chronic postsurgical hypoparathyroidism (hypoPT).

METHODS

Twenty-seven women with postsurgical hypoPT and 44 age-matched healthy women were included. Dual-energy X-ray absorptiometry was used to evaluate areal BMD and vertebral fracture assessment. High-resolution peripheral quantitative computed tomography assessed microarchitecture and volumetric BMD at the distal radius and tibia. Biochemical parameters, including fibroblast growth factor 23, C-terminal cross-linking telopeptide of type I collagen (ICTP), and procollagen type I N-terminal propeptide (P1NP), were also measured. Previous low-impact fractures were assessed and the 10-year fracture risk was estimated using the FRAX tool for the Brazilian population.

RESULTS

No participant had prevalent clinical fractures, and both groups showed low risk for major and hip based on FRAX tool, but two hypoPT patients had moderate to severe morphometric vertebral fractures. Women with hypoPT had increased aBMD in the lumbar spine, femoral neck and total hip (p < 0.05) and higher cortical vBMD in the radius (p = 0.020) and tibia (p < 0.001). Trabecular bone was not affected. Both P1NP and ICTP suggested low bone turnover rates, but no significant correlation was observed between bone density or microstructure and any of the biochemical parameters.

CONCLUSIONS

The prevalence of fragility fractures was low in HypoPT women and compatible with low fracture risk estimated by the FRAX tool. Patients had a higher aBMD and cortical vBMD than those of healthy control women, but the association with decreased bone turnover remains unclear.

Normal bone mineral density and bone microarchitecture in adult males with high and low risk of exercise addiction

Exercise addiction describes a pattern of excessive and obsessive exercise and is associated with hypoleptinemia and low testosterone that may have adverse skeletal effects. We used a validated questionnaire to identify males with high and low risk of exercise addiction. In a cross-sectional design, males (aged 21–49 years) with high (n = 20, exercise addictive) and low risk (n = 20, exercise controls) of exercise addiction had examinations of bone mass, bone microarchitecture, and estimated bone strength performed using dual-energy x-ray absorptiometry of the hip and spine and high-resolution peripheral quantitative computed tomography of the distal radius and tibia. Findings were compared between the groups and to a population-based sample of healthy men aged 20–80 years (n = 236). We found similar hip and spine bone mineral density in exercise addictive and controls. Cortical and trabecular bone microarchitecture and estimated bone strength in radius and tibia did not differ significantly between the groups. Multiple regression analyses adjusting for age, body weight, free testosterone, and hours of weekly training did not alter findings. Also, bone indices from both groups were within 95% prediction bands derived from the population-based sample for the vast majority of indices. Neither group had no associations between circulating leptin or free testosterone and bone outcomes. In conclusion, in a study on younger males, we found no associations between high risk of exercise addiction and various indices of bone mass and bone quality indicative of altered skeletal health.

The Role of Imaging in Predicting the Development of Rheumatoid Arthritis

Rheumatoid arthritis (RA) remains a chronic debilitating disease with a significant negative societal impact, despite the expanding landscape of treatment options. This condition is often preceded by a phase of systemic autoimmunity with circulating autoantibodies, elevated pro-inflammatory cytokines, or subtle structural changes. The capability of identifying individuals in the preclinical phase of RA disease makes a "preventive window of opportunity" possible. Much recent work has focused on the role of imaging modalities including ultrasound (US), magnetic resonance imaging (MRI), and high-resolution peripheral quantitative computer tomography (HR-pQCT) in identifying at-risk individuals with or without early joint symptoms for the development of inflammatory arthritis. This article will review the evidence and discuss the challenges as well as opportunities of proactive risk assessment by imaging in RA.