Visceral fat area is the measure of obesity best associated with mobility disability in community dwelling oldest-old Chinese adults

Kevin Yiqiang Chua,Wee-Shiong Lim,Xinyi Lin,Woon-Puay Koh,Yap-Seng Chong,Yeli Wang

doi:10.1186/s12877-021-02226-6

Abstract

BackgroundAlthough obesity can be clinically defined by body mass index (BMI), waist circumference, percent body fat, or visceral fat area, it is unclear which specific measure is best associated with mobility disability in oldest-old adults.MethodsAmong 589 Chinese participants aged 85 years and older in a population-based cohort in Singapore, we measured waist circumference, computed BMI, estimated appendicular skeletal muscle mass, percent body fat, and visceral fat area using bioelectrical impedance analysis, and evaluated mobility disability using the Loco-Check questionnaire. We computed areas under the receiver operating characteristic curves (AUCROC) to compare how well these measures discriminated between those with and without mobility disability. Logistic regression models were used to estimate the odds ratios (OR) and 95% confidence intervals (CI) for the associations between obesity defined by these measures and mobility disability.ResultsCompared to BMI, which had an AUCROC (95% CI) of 0.68 (0.64–0.72) for the discrimination of mobility disability, only visceral fat area had a significantly higher discriminative performance [AUCROC (95% CI) of 0.71 (0.67–0.75) (Padjusted = 0.002)]. The optimal cut-offs of visceral fat area for the discrimination of mobility disability were ≥ 104 cm2 in men and ≥ 137 cm2 in women. In fully adjusted models, only obesity defined by visceral fat area was significantly associated with mobility disability [OR (95% CI) of 2.04 (1.10–3.77)]; obesity defined by the other measures were not associated with mobility disability after adjusting for visceral fat.ConclusionIn oldest-old adults, visceral fat area was the best discriminator for obesity associated with mobility disability.

Highlights

Obesity can be clinically defined by body mass index (BMI), waist circumference, percent body fat, or visceral fat area, it is unclear which specific measure is best associated with mobility disability in oldestold adults
All the four measures of obesity had moderate to high correlations with one another; the Pearson’s correlation coefficients (r) for pairwise correlations ranged from 0.59 to 0.94 (Table 1). 284 (48.2%) participants were defined as having mobility disability using the Loco-Check questionnaire
Waist circumference and percent body fat initially appeared to have nominally higher in-sample discriminative performances when compared to BMI; these differences were no longer statistically significant after correction for multiple comparisons (Padjusted ≥ 0.075) (Table 2)

Summary

Introduction

Obesity can be clinically defined by body mass index (BMI), waist circumference, percent body fat, or visceral fat area, it is unclear which specific measure is best associated with mobility disability in oldestold adults. Body fat tissue has traditionally been thought to be distributed across two main compartments – subcutaneous fat, and visceral fat [11]. These two different fat depots have been shown to have disparate functions, biochemical features, and metabolic characteristics [11, 12]

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Discussion

Conclusion