Obesity and lipid indices in relation to physical performance and sarcopenia among older Chinese adults: a cross-sectional study

Objectives Besides body mass index (BMI), various obesity and lipid-related indices may effectively be associated with diminished physical performance (PP) and sarcopenia. However, comparative studies on their association strength power are scarce and yield inconsistent results. The aim of this study was to identify the obesity and lipid-related indices most strongly associated with diminished PP and (pre-) sarcopenia. Design Cross-sectional observational studies. Setting Tertiary care hospitals. Participants Our study population comprised 1323 Chinese community older adults (mean±SD age: 68.0±6.1 years; 58.2% women). Primary and secondary outcome measures 12 obesity and lipid-related indices, including BMI, waist hip ratio(WHR), waist-to-height ratio (WHtR), Body Roundness Index (BRI), Body-Shape Index (ABSI), Conicity Index (C-index), Hepatic Steatosis Index (HSI), lipid accumulation product, Triglyceride-Glucose (TyG) Index and TyG index-related parameters (TyG-BMI, TyG-WC, TyG-WHtR), were measured and calculated. Sarcopenia is defined by the definition of Asian Working Group for Sarcopenia (2019 Consensus Update); diminished PP was defined by grip strength <28 kg for men and <18 kg for women or walking speed <1.0 m/s or repeated chair stand ≥12 s or Simple PP battery ≤9 with relatively maintained muscle mass. Results After multivariate adjustments for all the concomitants (age, gender, weight and other health indicators), we found that higher WHtR, BRI, HSI, TyG-BMI, TyG-WC and TyG-WHtR (p value for trend =0.010, 0.003, 0.014, 0.004, 0.013 and 0.001, respectively) were significantly associated with an increased incidence of diminished PP, while higher ABSI (p value for trend=0.016) was significantly associated with a higher prevalence of sarcopenia. Moreover, higher values of obesity indices (BMI, WHtR, BRI, ABSI, C-index) and TyG-related indices (TyG-BMI, TyG-WC, TyG-WHtR) were associated with a greater number of diminished PP measures in both diminished PP and sarcopenia (OR ranging from 1.722 to 2.772 for two and more; OR ranging from 1.741 to 7.913 for three and more). Conclusions The present study indicates that abdominal obesity, along with lipid-related indices, may play a role in the development and advancement of sarcopenia and sarcopenic obesity. Notably, central body shape indices, particularly ABSI and C-index, demonstrated stronger associations with these conditions than traditional measures such as BMI. Consequently, in diagnosing and assessing sarcopenia and sarcopenic obesity, we should take into account not only the loss of muscle mass but also the effects of lipid accumulation and alterations in glycolipid metabolism.