Determination of Cutoff Values for the Screening of Osteosarcopenia in Obese Postmenopausal Women

Nurdiana Z. Abidin,Yong-Fang Kuo,Soma R. Mitra

doi:10.1155/2021/6634474

Abstract

Osteosarcopenic obesity (OSO) describes the concurrent presence of obesity, low bone mass, and low muscle mass in an individual. Currently, no established criteria exist to diagnose OSO. We hypothesized that obese individuals require different cut-points from standard cut-points to define low bone mass and low muscle mass due to their higher weight load. In this study, we determined cutoff values for the screening of osteosarcopenia (OS) in obese postmenopausal Malaysian women based on the measurements of quantitative ultrasound (QUS), bioelectrical impedance analysis (BIA), and functional performance test. Then, we compared the cutoff values derived by 3 different statistical modeling methods, (1) receiver operating characteristic (ROC) curve, (2) lowest quintile of the study population, and (3) 2 standard deviations (SD) below the mean value of a young reference group, and discussed the most suitable method to screen for the presence of OS in obese population. One hundred and forty-one (n = 141) postmenopausal Malaysian women participated in the study. Bone density was assessed using calcaneal quantitative ultrasound. Body composition was assessed using bioelectrical impedance analyzer. Handgrip strength was assessed using a handgrip dynamometer, and physical performance was assessed using a modified Short Physical Performance Battery test. ROC curve was determined to be the most suitable statistical modeling method to derive the cutoffs for the presence of OS in obese population. From the ROC curve method, the final model to estimate the probability of OS in obese postmenopausal women is comprised of five variables: handgrip strength (HGS, with area under the curve (AUC) = 0.698 and threshold ≤ 16.5 kg), skeletal muscle mass index (SMMI, AUC = 0.966 and threshold ≤ 8.2 kg/m2), fat-free mass index (FFMI, AUC = 0.946 and threshold ≤ 15.2 kg/m2), broadband ultrasonic attenuation (BUA, AUC = 0.987 and threshold ≤ 52.85 dB/MHz), and speed of sound (SOS, AUC = 0.991 and threshold ≤ 1492.15 m/s). Portable equipment may be used to screen for OS in obese women. Early identification of OS can help lower the risk of advanced functional impairment that can lead to physical disability in obese postmenopausal women.

Highlights

Osteosarcopenic obesity (OSO) is a term used to describe the concurrent presence of obesity, low bone mass, and low muscle mass in an individual [1,2,3,4]
Participants were categorized into “OSO,” “osteopenic obesity (OO),” “SO,” “OB,” and “normal-weight participants (NR)” groups based on the criteria and standard cutoff proposed by previous studies, WHO (T-score ≤ 2.5) [17], Ilich et al (BFP ≥ 32%) [1], and the Asian Working Group for Sarcopenia (AWGS, Appendicular skeletal muscle mass index (appSMMI) ≤ 5.7 kg/m2) [11]
Obese participants had significantly higher body fat percent (BFP) and trunk fat percent and significantly weaker handgrip strength compared to the normal-weight participants (NR) (p < 0.001)

Summary

Introduction

Osteosarcopenic obesity (OSO) is a term used to describe the concurrent presence of obesity, low bone mass (osteoporosis), and low muscle mass (sarcopenia) in an individual [1,2,3,4]. Other possible manifestations of this syndrome include osteopenic obesity (OO) and sarcopenic obesity (SO), where “obesity” is not necessarily confined only to a clinical diagnosis of overweight or obesity and includes the aspect of fat infiltration in muscle tissue and its impact on the skeleton. With time, both conditions (OO and SO) are likely to result in OSO. When it comes to adiposity, the researchers found inflection points between 22 and 40 kg in fat mass and 33–38% of body fat, whereby negative relationships were noted with BMD

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