A review of the use of dual-energy X-ray absorptiometry (DXA) in rheumatology

The Impact of Bariatric Surgery on Bone Health: State of the Art and New Recognized Links

Bariatric surgery (BS) is the most effective therapy for severe obesity, which improves several comorbidities (such as diabetes, hypertension, dyslipidemia, among others) and results in marked weight loss. Despite these consensual beneficial effects, sleeve gastrectomy and Roux-en-Y gastric bypass (the two main bariatric techniques) have also been associated with changes in bone metabolism and progressive bone loss. The objective of this literature review is to examine the impact of bariatric surgery on bone and its main metabolic links, and to analyze the latest findings regarding the risk of fracture among patients submitted to bariatric surgery.

Bone fragility via degradation of bone quality featured by collagen/apatite micro-arrangement in human rheumatic arthritis

Although increased bone fragility is a well-recognized consequence in patients with rheumatoid arthritis (RA), the essential cause of degenerate bone strength remains unknown. This study aimed to determine factors contributing to bone dysfunction in RA by focusing on the bone matrix micro-arrangement, based on the preferential orientation of collagen and the related apatite c-axis as a bone quality index. The classical understanding of RA is limited to its severe pathological conditions associated with inflammation-induced bone loss. This study examined periarticular proximal tibiae from RA patients as compared with osteoarthritis (OA) patients as controls. Bone tissue material strength was disrupted in the RA group compared with the control. Collagen/apatite micro-arrangement and vBMD were significantly lower in the RA group, and the rate of decrease in apatite c-axis orientation (-45%) was larger than that in vBMD (-22%). Multiple regression analysis showed that the degree of apatite c-axis orientation (β = 0.52, p = 1.9 × 10^-2) significantly contributed to RA-induced bone material impairment as well as vBMD (β = 0.46, p = 3.8 × 10^-2). To the best of our knowledge, this is the first report to demonstrate that RA reduces bone material strength by deteriorating the micro-arrangement of collagen/apatite bone matrix, leading to decreased fracture resistance. Our findings represent the significance of bone quality-based analysis for precise evaluation and subsequent therapy of the integrity and soundness of the bone in patients with RA.

Association Between FGF-23 Levels and Risk of Fracture in Women With Systemic Sclerosis

INTRODUCTION/BACKGROUND

The purpose of this study was to evaluate the association between Fracture Risk Assessment Tool (FRAX) and serum fibroblast grow factor-23 (FGF-23) levels in SSc women patients compared with healthy controls.

METHODOLOGY

This cross-sectional study was performed in San Cecilio Hospital, Granada (Spain) from November 2017 to May 2019. Sixty-two women with SSc and 62 age and sex matched healthy controls were included in this study. FGF-23 serum concentration was evaluated by indirect enzyme-linked immunosorbent assay. The FRAX scoring tool was applied using the on-line calculator (www.shef.ac.uk/FRAX).

RESULTS

Even though there was no significant difference in FGF-23 levels between SSc women patients and healthy controls (78.2 ± 60.5 vs 80.3 ± 56.3 pg/mL, p = 0.662). FGF-23 levels were positively associated with FRAX index within the study group.

CONCLUSIONS

This study shows that FGF-23 status is associated with FRAX index in women with SSc. FGF-23 could be a promising biomarker for detecting risk fracture in SSc women patients.

Influence of weight status on bone mineral content measured by DXA in children

INTRODUCTION

Childhood obesity is a public health problem with repercussions in later life. As tissue formation peaks in childhood we determined how weight status influences bone mineral content.

MATERIAL AND METHODS

We studied 553 children aged 4-18 years over 10 years (46.8% girls). We measured age, weight, height and through bone densitometry (DXA), bone mineral content (BMC), bone mineral density (BMD), and waist, arm and hip circumferences. The patients were divided into groups using the body mass index z-score: underweight, normal weight, overweight, obese and very obese.

RESULTS

BMC and BMD values were highest in the normal-weight and overweight groups. Logistic regression showed bone mineralization was inversely associated with waist circumference, the association being positive for weight and age. No differences were found according to sex.

DISCUSSION

Studies of the relationship between weight and bone mineralization report contradictory results, often because of different study designs. Moreover, studies in children are either few or with small samples. Our findings in a large sample show the importance of weight status in bone mineralization given the risk of bone fractures or osteoporosis.

CONCLUSIONS

Weight status influenced bone mineralization. BMC and BMD decreased in children with a higher degree of obesity. Waist circumference correlated negatively with bone mineralization.

Beyond Bone Mineral Density: A New Dual X-Ray Absorptiometry Index of Bone Strength to Predict Fragility Fractures, the Bone Strain Index

For a proper assessment of osteoporotic fragility fracture prediction, all aspects regarding bone mineral density, bone texture, geometry and information about strength are necessary, particularly in endocrinological and rheumatological diseases, where bone quality impairment is relevant. Data regarding bone quantity (density) and, partially, bone quality (structure and geometry) are obtained by the gold standard method of dual X-ray absorptiometry (DXA). Data about bone strength are not yet readily available. To evaluate bone resistance to strain, a new DXA-derived index based on the Finite Element Analysis (FEA) of a greyscale of density distribution measured on spine and femoral scan, namely Bone Strain Index (BSI), has recently been developed. Bone Strain Index includes local information on density distribution, bone geometry and loadings and it differs from bone mineral density (BMD) and other variables of bone quality like trabecular bone score (TBS), which are all based on the quantification of bone mass and distribution averaged over the scanned region. This state of the art review illustrates the methodology of BSI calculation, the findings of its in reproducibility and the preliminary data about its capability to predict fragility fracture and to monitor the follow up of the pharmacological treatment for osteoporosis.

Does the oral steroid treatment of patients with nasal polyposis cause osteopenia or osteoporosis?

OBJECTIVES

We aimed to investigate the bone mineral density (BMD) in a group of Swedish patients with chronic rhinosinusitis with nasal polyposis (CRSwNP) with or without asthma, as well as to evaluate whether the treatment of this patient group is in accordance with the EPOS recommendations.

DESIGN, SETTINGS AND PARTICIPANTS

Adult patients with a diagnosis of CRSwNP, and a history of at least two courses of oral corticosteroids (OCS) during the last year, were consecutively included in this study at five centres.

MAIN OUTCOME MEASURES

The BMD of the patients was measured by Dual-energy X-ray absorptiometry (DXA), which is the only technology for classifying BMD according to the criteria established by WHO.

RESULTS

A total of 51 patients, with an average number of 7 years with OCS treatment, were enrolled. During the last 12 months, the mean number of OCS courses was 2.76, and the total mean intake was 891 mg of Prednisone equivalents. According to the T-scores, 17 patients were measured to have ≤-1 SD T-score lumbar spine, which is considered to be osteopenia, and five patients had <-2.5 SD T-score, considered as osteoporosis. However, when taking age and gender into account and analysing the Z-scores, only 2 patients had a reduced density of the spine and none in the hip, which is no difference compared to a matched Swedish population.

CONCLUSIONS

This prospective study shows that 2-3 moderate courses of OCS annually may be used without high risk of causing osteopenia/osteoporosis in patients with CRSwNP.

A novel quantitative method for estimating bone mineral density using B-mode ultrasound and radiofrequency signals-a pilot study on patients with rheumatoid arthritis

The objective of the present study was to evaluate whether an innovative quantitative ultrasound (QUS) technique, Radiofrequency Echographic Multi Spectromety, which combines B-mode ultrasound and radiofrequency signals, is reliable in typical Romanian patients compared to previous results obtained using dual-energy X-ray absorptiometry (DXA). The study prospectively included previously unscreened post-menopausal females with rheumatoid arthritis (RA) and age-matched healthy controls. Bone mineral density (BMD) measurements were performed with an EchoS machine (Echolight^®), which combines B-mode ultrasound and radiofrequency signals. The study included 106 RA patients, with a median disease duration of 3.2 (0.5–22) years and 119 controls. RA patients had a significantly lower body weight, body mass index (BMI) and basal metabolic rate (BMR) than the controls, while the prevalence of obesity and body fat differed insignificantly. RA patients had a significantly lower spine and hip BMD, higher fracture risk and higher prevalence of osteoporosis. Compared to RA patients without osteoporosis, those with osteoporosis were significantly older and had a longer menopause duration, but they had a significantly lower BMI, body fat, BMR and prevalence of obesity. Among the controls and RA patients, the median spine and hip BMD became significantly higher as the BMI increased from underweight to obesity. In conclusion, osteoporosis is prevalent among RA patients, as a part of a complex transformation of body mass composition, involving BMI and fat mass. The novel QUS scanning technique was able to replicate the results of the established DXA measurement of BMD and is potentially suitable for screening wide populations for osteoporosis.

The extra-articular impacts of rheumatoid arthritis: moving towards holistic care

Although treat-to-target has revolutionised the outcomes of patients with rheumatoid arthritis (RA) there is emerging evidence that attaining the target of remission is insufficient to normalise patients’ quality of life, and ameliorate the extra-articular impacts of RA. RA has a broad range of effects on patient’s lives, with four key “extra-articular” impacts being pain, depression and anxiety, fatigue and rheumatoid cachexia. All of these are seen frequently; for example, studies have reported that 1 in 4 patients with RA have high-levels of fatigue. Commonly used drug treatments (including simple analgesics, non-steroidal anti-inflammatory drugs and anti-depressants) have, at most, only modest benefits and often cause adverse events. Psychological strategies and dynamic and aerobic exercise all reduce issues like pain and fatigue, although their effects are also only modest. The aetiologies of these extra-articular impacts are multifactorial, but share overlapping components. Consequently, patients are likely to benefit from management strategies that extend beyond the assessment and treatment of synovitis, and incorporate more broad-based, or “holistic”, assessments of the extra-articular impacts of RA and their management, including non-pharmacological approaches. Innovative digital technologies (including tablet and smartphone “apps” that directly interface with hospital systems) are increasingly available that can directly capture patient-reported outcomes during and between clinic visits, and include them within electronic patient records. These are likely to play an important future role in delivering such approaches.

Body composition evaluated by body mass index and bioelectrical impedance vector analysis in women with rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is a complex inflammatory disease that modifies body composition. Although body mass index (BMI) is one of the clinical nutrition tools widely used to assess indirectly nutritional status, it is not able to identify these body alterations. Bioelectrical Vector Analysis (BIVA) is an alternative method to assess hydration and body cell mass of patients with wasting conditions.

OBJECTIVE

To investigate the differences in nutrition status according to BMI groups (normal, overweight and obesity) and BIVA classification (cachectic and non-cachectic) in women with RA.

METHODS

Women with confirmed diagnosis of RA were included from January 2015 to June 2016. Whole-body bioelectrical impedance was measured using a tetrapolar and mono-frequency equipment. Patients were classified according to BMI as: low body weight (n = 6, 2.7%), normal (n = 59, 26.3%), overweight (n = 88, 39.3%) and obese (n = 71, 31.7%), and each group was divided into BIVA groups (cachectic 51.8% and non-cachectic 48.2%).

RESULTS

A total of 224 RA patients were included, with mean age 52.7 years and median disease duration of 12 years. Significant differences were found in weight, arm circumference, waist, hip, resistance/height, reactance/height and erythrocyte sedimentation rate among all BMI groups. However, serum albumin levels were significantly different between cachectic and non-cachectic patients independently of BMI. In all BMI categories, cachectic groups had lower reactance and phase angle than non-cachectic subjects.

CONCLUSION

RA patients with normal or even high BMI have a significantly lower muscle component. Evaluation of body composition with BIVA in RA patients could be an option for cachexia detection.