Association between global biomarker of oxidative stress and quantitative ultrasound parameters in middle-aged and elderly adults: A cross-sectional study

Introduction

With the population aging, osteoporosis has become a major public health concern. Elevated oxidative stress is a vital detrimental factor for bone health. Compared to common oxidative stress-related biomarkers, Fluorescent Oxidation Products (FlOPs) reflect the global levels of oxidation from proteins, lipids, and DNA. Nevertheless, whether plasma FlOP levels are related to bone health measured by Quantitative ultrasound (QUS) is unclear. Thus, the present study examined the association between FlOPs and QUS parameters in middle-aged and elderly adults.

Methods

This community-based cross-sectional study was conducted in Changchun, northeast China. Plasma FlOPs were determined by a fluorescent microplate reader at a wavelength of 320/420 nm (excitation/emission). QUS parameters [speed of sound (SOS) and broadband ultrasound attenuation (BUA)] of the calcaneus were assessed by an ultrasound bone densitometer. We used multivariable linear regression to examine the association between FlOPs and QUS parameters.

Results

A total of 491 subjects were included in this study. Their average age was 65.2 years (standard deviation [SD]: 9.7 years). FlOPs were inversely associated with SOS (β for an increase of logarithmic interquartile range = -10.64; P = 0.018). Higher FlOP levels were marginally associated with lower SOS in females (β for an increase of logarithmic interquartile range = -9.68, P = 0.066), but not in males (β for an increase of logarithmic interquartile range = -11.84, P = 0.131). No significant relationship between FlOPs and BUA was observed.

Conclusions

Plasma FlOP levels were inversely associated with SOS, but not with BUA in middle-aged and elderly adults.

Knee Osteoarthritis Grade does not Correlate with Quadriceps Muscle Strength or Bone Properties of the Calcaneus in Men Aged 80 Years or More who Can Walk independently

Purpose: Muscle weakness and bone deterioration in the elderly are related to falls and fractures, resulting in decreased mobility. Knee osteoarthritis also may contribute to falls and fractures and thereby affect mortality rates. The Kellgren–Lawrence (KL) classification is widely used in the radiographic evaluation of knee osteoarthritis. Aims: This study aimed to evaluate the quadriceps strength and bone properties of the calcaneus for each KL grade, and to clarify the impact of knee osteoarthritis grade on quadriceps strength and bone properties. Methods: This prospective cross-sectional study included data on 108 male patients (213 knees), aged ≥80 years, who could walk independently. A handheld dynamometer was used to measure quadriceps strength. Bone properties were evaluated using broadband ultrasound attenuation with a portable bone densitometer. Weight-bearing standing knee radiographs were evaluated using KL classification. Quadriceps strength and bone properties were evaluated for each KL grade and the correlations between the grade and quadriceps strength and bone properties were assessed simultaneously. Results: The numbers of participants in KL grades I–IV were 46, 102, 45, and 20, respectively. There were no differences among grades for either quadriceps strength or bone properties. Conclusions: Participants exhibited good quadriceps strength and bone properties regardless of their KL grade. Relatively high mechanical loading of muscle and bone incurred while walking independently, likely explaining this result. Clinically, this study demonstrated the absence of correlations between KL grade and quadriceps strength and bone properties, as was previously reported in studies showing the absence of a correlation between KL grade and pain.

Calcaneal Broadband Ultrasound Attenuation and Speed of Sound Measurements in a Population of Nigerian Children: Reference Data and the Influence of Sociodemographic Variables

OBJECTIVES

The aim of our study was to establish a reference database of calcaneal broadband ultrasound attenuation (BUA) and the speed of sound (SOS) in a healthy Nigerian population of children aged 6 to 14 years and also to investigate the influence of sociodemographic and anthropometric variables on them.

METHODS

The BUA and SOS of 1016 healthy children were measured by quantitative ultrasound densitometry. Height and weight were measured with a stadiometer and weighing balance, respectively, whereas the sociodemographic parameters of the participants were collected on a semistructured questionnaire. A multiple regression model using stepwise selection and Pearson correlation coefficients were used to examine the relationship between the ultrasound parameters and sociodemographic and anthropometric parameters. Comparisons between various age groups were made by analysis of variance.

RESULTS

The mean BUA and SOS ± SD of the participants were 60.57 ± 16.21 dB/MHz and 1563.48 ± 21.74 m/s, respectively, for boys and 58.18 ± 15.16 dB/MHz and 1560.03 ± 22.32 m/s for girls. The BUA in both sexes was positively influenced by age and weight (P < .05), whereas only the father's educational status was its predictor (P < .05) in the boys. For the girls, the family size and mother's educational status were predictors of the BUA (P < .05). The SOS was marginally influenced by age and family size in the boys (P < .05), whereas the father's educational status was the predictor in the girls.

CONCLUSIONS

The established BUA and SOS values in this study are baseline values, and further study, which would also involve data from a large number of Nigerian children, would be needed to support their effectiveness as reference values.

Posterior Cruciate Ligament Retention or Substitution During Total Knee Arthroplasty Does Not Affect Long-Term Bone Mineral Density or Quality

BACKGROUND

Physical activity is recognized as one of the factors that influence bone mineral density (BMD) and bone quality after total knee arthroplasty (TKA). According to biomechanical analyses after posterior cruciate ligament (PCL) retaining (PCLR) and substituting (PCLS) TKA, each implant design has different kinematics and kinetics. The purposes of this study were: (1) to perform within-patient comparisons of the midterm and long-term effects of PCL retention in mobile-bearing TKA on proximal femur and tibia BMD and calcaneus bone quality measured using ultrasound and (2) to identify correlations between them.

METHODS

A prospective, quasi-randomized design was used. Thirty-seven patients (74 knees) who underwent bilateral TKA (PCLR on one side and PCLS on the other) were evaluated. Mean follow-up periods were 118 months (standard deviation 40) and 117 months (standard deviation 36) in knees with PCLR and PCLS implants, respectively. The BMDs of the total hip and proximal tibia and broadband ultrasound attenuation (BUA; dB/MHz) through the calcaneus were measured.

RESULTS

The mean BMD of PCLR and PCLS were equivalent at the proximal hip and tibia. The BUA of the calcaneus was also the same between implants. There were significant correlations between the 3 anatomic sites.

CONCLUSION

When measured approximately 10 years after TKA, PCL retention had no substantial effect on the BMD of the proximal femur and tibia, or on the bone quality of the calcaneus. The measurement of noninvasive BUA may predict BMD, although further analysis is required.

Impact of Walking and Running on the Heel bone: the Adventist Health Study-2

Aims

Physical activity is well recognized for its bone health benefit. We examined the benefit of walk/run/jog on bone health using broadband ultrasound attenuation (BUA) of the calcaneus.

Methodology

Caucasian and African American males (n=593) and females (n=1,106) had their calcaneal BUA measured two years later after enrollment into the AHS-2. The association between calcaneal BUA (dB/Mhz) and the distance of walk/run/ jog level per week (miles) was assessed using multiple linear regression.

Results

In a multivariable model adjusted for important covariates, BUA was positively associated with BMI (P < .001), total calcium intake (P =0.31), total protein intake (P =0.38) and inversely associated with age (P < .001) and smoking (P < .05). Compared to women who did not walk/ run/ jog, women walking 10 or more miles per week had an increase in BUA by 4.08 (dB/Mhz) (P _trend=0.03). Similarly, compared to men who did not walk/ run/ jog, men walking 10 or more miles per week had an increase in BUA by 5.97 (dB/Mhz) (P _trend=0.01).

Conclusions

We concluded that BUA is positively associated with walk/ run/jog after accounting for age, BMI, smoking status, calcium intake, protein intake and estrogen usage.

Effects of phase cancellation and receiver aperture size on broadband ultrasonic attenuation for trabecular bone in vitro

Phase cancellation in ultrasound due to large receiver size has been proposed as a contributing factor to the inaccuracy of estimating broadband ultrasound attenuation (BUA), which is used to characterize bone quality. Transducers with aperture size ranging from 2 to 5 mm have been used in previous attempts to study the effect of phase cancellation. However, these receivers themselves are susceptible to phase cancellation because aperture size is close to one center wavelength (about 3 mm at 500 KHz in water). This study uses an ultra small receiver (aperture size: 0.2 mm) in conjunction with a newly developed two-dimensional (2-D) synthetic array system to investigate the effects of phase cancellation and receiver aperture size on BUA estimations of bone tissue. In vitro ultrasound measurements were conducted on 54 trabecular bone samples (harvested from sheep femurs) in a confocal configuration with a focused transmitter and synthesized focused receivers of different aperture sizes. Phase sensitive (PS) and phase insensitive (PI) detections were performed. The results show that phase cancellation does have a significant effect on BUA. The normalized BUA (nBUA) with PS is 8.1% higher than PI nBUA while PI BUA is well correlated with PS BUA. Receiver aperture size also influences the BUA reading for both PI and PS detection and smaller receiver aperture tends to result in higher BUA readings. The results also indicate that the receiver aperture size used in the confocal configuration with PI detection should at least equal the aperture of the transmitter to capture most of the energy redistributed by the interference and diffraction from the trabecular bone.