The aim of this study was to investigate the association between relative fat mass (RFM) and the risk of arthritis in middle-aged and elderly Chinese adults.
A cross-sectional analysis was performed using 2011 CHARLS data and included a total of 12 921 participants, including 6 144 males (47.55%) and 6 777 females (52.45%), with a mean age of (59.49 ± 9.60) years. Multivariable logistic regression and restricted cubic splines (RCS) were used to analyze the cross-sectional association between RFM and arthritis. A total of 8 350 middle-aged and elderly people who were not diagnosed with arthritis in the 2011 cross-sectional study were included in the longitudinal study and followed up until 2018. Kaplan-Meier curves, multivariable Cox proportional hazards regression models, and RCS were used to analyze the longitudinal association between different baseline RFM levels and the risk of incident arthritis in 2011. Meanwhile, the consistency of this association in different population subgroups was assessed by subgroup analysis, and sensitivity analysis was used to verify the stability of the model results.
In the cross-sectional study, multivariable logistic regression analysis showed that higher RFM was associated with an increased risk of arthritis after adjusting for confounders (OR=1.02, 95% CI: 1.02-1.03). Middle-aged and older adults in the Q3 (OR=1.30, 95% CI: 1.15-1.48) and Q4 (OR=1.60, 95% CI: 1.40-1.82) groups had a higher risk of arthritis compared with the first quartile (Q1). In the longitudinal study, a total of 916 individuals were first diagnosed with arthritis during the follow-up period. Multivariable Cox regression analysis showed that higher RFM was associated with an increased risk of incident arthritis after adjusting for confounders (HR=1.02, 95% CI: 1.02-1.04). The risk of incident arthritis was significantly higher in the Q4 group(HR=1.56, 95% CI:1.23-1.98) compared with Q1. Subgroup analysis showed no significant interactions between RFM and each subgroup variable. The results of the sensitivity analysis were generally consistent with the conclusions of the primary analysis. ROC curves showed that RFM had a better diagnostic efficacy for arthritis than obesity indicators such as BMI.
Higher levels of RFM are associated with an increased risk of arthritis in the middle-aged and elderly Chinese population, paying attention to RFM levels may help in the early identification of populations at risk for arthritis, providing new insights for disease prevention and intervention.
| 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 |