To investigate the correlation and potential causal association between abdominal obesity and bone mineral density(BMD) in people of different age groups.
This study combined a cross-sectional study with Mendelian randomization (MR) analysis.Cross-sectional study data were derived from the U.S. National Health and Nutrition Examination Survey (NHANES) 2011—2018. A total of 7 452 participants aged 20-60 years were included. Weighted linear regression analysis was employed to investigate the association between a body shape index (ABSI) and total body less head bone mineral density (TB-BMD). The MR study utilized a two-sample MR analysis to explore the causal relationship between genetically predicted waist circumference-adjusted for body mass index(WCadjBMI), an index of abdominal obesity, and TB-BMD.
Cross-sectional analysis revealed a significant negative correlation between ABSI and TB-BMD(β=-3.53, 95% CI: -4.146~-2.915, P<0.001), which was more pronounced in males and individuals aged 45-60 years. In the 45-60 age group, an “inverted U-shaped” non-linear relationship was observed between ABSI and pelvic BMD (inflection point=0.076). MR analysis indicated a negative causal relationship between WCadjBMI and TB-BMD (β=-0.16, 95% CI: -0.26~-0.07,P<0.01), which was significant across age groups of <15 years, 30-45 years, and >60 years.
Abdominal obesity is clearly associated with bone loss, and this negative effect varies among different age and sex groups. Maintaining abdominal fat at a low level before significant bone loss occurs is crucial for preserving skeletal health.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |