Associations of Fat Mass and Fat Distribution With Bone Mineral Density in Non-Obese Postmenopausal Chinese Women Over 60 Years Old

Abstract

BackgroundBone mineral density (BMD) loss is a major complication of menopause, and this loss is closely associated with Fat mass (FM). The relationship between FM, fat distribution (FD), and BMD in postmenopausal women, however, remains incompletely understood. The present study was thus developed to explore these associations between body fat accumulation, FD, and BMD among non-obese postmenopausal women over the age of 60.MethodsThis was a cross-sectional analysis of 357 healthy postmenopausal women between the ages of 60.2 and 86.7 years. Dual-energy X-ray absorptiometry (DXA) was utilized to measure total and regional BMD as well as fat-related parameters including total FM, android and gynoid fat, body fat percentage (BF%), and total lean mass (LM) for all subjects. The android-to-gynoid fat ratio (AOI) was used to assess FD. Pearson’s correlation testing and multiple regression analyses were used to explore relationships among AOI, LM, FM, and BMD.ResultsBoth LM and FM were positively correlated with total and regional BMD in univariate analysis (all P < 0.01), whereas BMD was not significantly associated with AOI in any analyzed site other than the head. Multivariate linear regression models corrected for age, height, and years post-menopause, revealed a sustained independent positive relationship between FM and BMD (standard β range: 0.141 – 0.343, P < 0.01). The relationship between FM and BMD was unaffected by adjustment for LM (standard β range: 0.132 – 0.258, P < 0.01), whereas AOI had an adverse impact on BMD at most analyzed skeletal sites (total body, hip, femoral neck, arm, leg, and head) (standard β range: −0.093 to −0.232, P < 0.05). These findings were unaffected by using BF% in place of FM (standard β range: −0.100 to −0.232, P < 0.05).ConclusionsIn this cohort of non-obese postmenopausal women over the age of 60 from China, total FM was positively associated with BMD, while AOI was negatively correlated with BMD. As such, a combination of proper weight gain and the control of central obesity may benefit the overall bone health of women after menopause.

The association between Body Fat Distribution and Bone Mineral Density: Evidence from the US population

“…The main nding of this study was that body fat mass (Android or Gynoid) was positively associated with BMD, regardless of gender (Males or Females) and sites (Femur or Lumbar spine). This was similar to the conclusions reached by numerous previous studies, for example, in Asian regions 11,16,20 and European regions 21,22 . Also, some studies have concluded that there was no association or negative association between fat distribution and BMD [23][24][25] .…”

“…Furthermore, the extant studies that had examined the association between body fat and BMD reached controversial conclusions. In studies of Chinese populations, some studies had concluded that body fat mass was positively associated with BMD in both men and women [11][12][13] , while other studies had concluded that increased fat had a negative effect on BMD 14 . Differential ndings across gender in studies of populations in Brazil 15 , Japan 16 , Australia 17 , and elsewhere were also found.…”

The association between body fat distribution and bone mineral density: evidence from the US population

“…The positive association was similar to the conclusions reached by numerous previous studies, for example, in Asian regions [ 11 , 16 , 30 ], and European regions [ 31 , 32 ]. Also, some studies have concluded that there was no association or negative association between fat distribution and BMD [ 33 – 35 ].…”

“…Furthermore, the extant studies that had examined the association between body fat and BMD reached controversial conclusions. In studies of Chinese populations, some studies had concluded that body fat mass was positively associated with BMD in both men and women [ 11 – 13 ], while other studies had concluded that increased fat had a negative effect on BMD [ 14 ]. Differential findings across gender in studies of populations in Brazil [ 15 ], Japan [ 16 ], Australia [ 17 ], and elsewhere were also found.…”

Influence of sex hormones status and type of training on regional bone mineral density in exercising females

“…These lower oestradiol levels may lead to an imbalance between bone resorption and bone formation (Khosla et al, 2012), as well as affect the mechanosensitivity of osteocytes by reducing the stress response of bone cells (Klein-Nulend et al, 2015). In fact, several studies have shown lower BMD in postmenopausal females compared to premenopausal ones (Fan et al, 2022;Fu et al, 2011). Although theoretically this reduction in oestradiol may promote a loss of BMD, in the literature there is controversy about the effect of OC use on BMD (Rocca et al, 2021).…”