Visceral fat metabolic activity evaluated by F-18-FDG PET/CT is associated with osteoporosis in healthy postmenopausal Korean women

Abstract

Background: Traditionally, obesity has been regarded as protective against osteoporosis. However, recent accumulating evidences suggest that visceral obesity can increase the risk of osteoporosis and obesity-driven dysfunctional metabolic activity in visceral adipose tissue (VAT) is considered as a key underlying mechanism. Visceral obesity is known to increase during menopausal transition. F-18-fluorodeoxyglucose positron emission tomography/computed tomography (F-18-FDG PET/CT) is an established method to assess the degree of VAT metabolic activity. We aimed to investigate the association between VAT metabolic activity evaluated by F-18-FDG PET/CT and osteoporosis in healthy postmenopausal Korean women. Methods: A total of 115 postmenopausal women who underwent routine health check-up were enrolled in this study, retrospectively. They all underwent dual-energy X-ray absorptiometry and F-18-FDG PET/CT. Osteoporosis was defined as bone mineral density (BMD) T-score = -2.5 at either lumbar spine or femoral neck. VAT metabolic activity was defined as the maximum standardized uptake value (SUVmax) of VAT divided by the SUVmax of subcutaneous adipose tissue (V/S ratio). Results: The participants with osteoporosis showed significantly higher V/S ratio, age, body mass index, waist circumference, and postmenopausal period than the participants without osteoporosis. V/S ratio of 1.33 was proposed as an optimal cut-off value for identifying osteoporosis. Furthermore, V/S ratio was the most significant predictive factor for osteoporosis in postmenopausal woman by uni-and multivariate analyses. Interestingly, V/S ratio showed significant positive correlation with high sensitivity C-reactive protein, a surrogate marker for systemic inflammation. Conclusion: VAT metabolic activity assessed by F-18-FDG PET/CT is associated with osteoporosis in healthy postmenopausal Korean women. (C) 2020 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.