[Association of waist-to-height ratio with sarcopenic obesity in hemodialysis patients with normal body mass index].

Objective: To explore the association between waist-to-height ratio (WHtR) and sarcopenic obesity (SO) in maintenance hemodialysis (MHD) patients with normal body mass index (BMI). Methods: A multicenter and cross-sectional study that included adult patients undergoing MHD was conducted in 20 hemodialysis centers from June 1st to August 30th, 2021. Body composition was evaluated by body composition monitor based on bioimpedance spectroscopy. According to the quartiles of WHtR, patients were divided into four groups: Q1, Q2, Q3 and Q4 group. The association of WHtR with SO was determined by multiple logistic regression models, stratified analyses, interactive analyses, and receiver operating characteristic (ROC) analyses, respectively. Results: A total of 2 207 MHD patients (1 341 males and 866 females) were included, and aged [M (Q1, Q3)] 57 (44, 68) years. The prevalence of SO was increased with increasing quartiles of WHtR [8.6% (46/533), 22.5% (141/628), 35.4% (215/608), and 44.3% (194/438) for Q1, Q2, Q3, and Q4 group, respectively]. Multivariate logistic regression analysis showed that WHtR was associated with SO. The association remained statistically significant even after adjusting for age, gender, dialysis vintage, BMI, biochemical indicators, and various medical histories. Compared with Q1 group, the odds ratios (OR) were 2.54 (95%CI: 1.69-3.83), 4.30 (95%CI: 2.88-6.42) and 5.18 (95%CI: 3.37-7.96) for Q2, Q3 and Q4 group, respectively. The interaction analysis showed that age, sex and history of diabetes had interactive roles in the association between WHtR and SO (all P<0.05). The association stably existed across subgroups, and it was more obvious in male patients, those with older age and without a history of diabetes（all P<0.05）. Furthermore, the cut-off value of WHtR identifying SO in male patients was 0.49, and the corresponding area under the curve (AUC) was 0.73 (95%CI: 0.70-0.75), with the sensitivity of 72.7% and specificity of 60.3%. In female patients, the cut-off value was 0.51, and the AUC was 0.68 (95%CI: 0.65-0.71), with the sensitivity of 70.1% and specificity of 57.8%. Conclusion: WHtR could be used as a simple index to evaluate the risk of SO in MHD patients with normal BMI.

[Study of antioxidant effect of cannabinoid receptor type 2 agonist on rat hepatic stellate cell line].

Objective: To investigate the action and antioxidant effects of CB2 agonist AM-1241 on rat hepatic stellate cell line (HSC-T6). Methods: HSC-T6 was randomly divided into four groups: control group, oxidative stress group, AM-1241 intervention group and AM-1241+AM-630 antagonist group. Survival rate of HSC-T6 was detected by thiazolyl blue assay under 24 h interventions with 0, 20, 50, 80 µmol/L AM-1241 and 0, 10, 20, 30, 40 µmol/L AM-630, respectively. Besides control group, the remaining groups were well cultured in low-glucose DMEM containing 100 mU/L glucose oxidase (GO) for 12 h to prepare the oxidative stress model. Then, AM-1241 intervention group was treated with 50 µmol/L low-glucose DMEM medium. After incubation for 12 h, the AM-1241+AM-630 antagonist group was treated with CB2 antagonist AM-630 (20 µmol/L) for 2 h, and cultured with 50 µmol/L AM-1241 in complete low-glucose medium for 12 h. The optimal drug concentration was selected according to the cell viability considered by the experiment results. Type III collagen (C III) content in the HSC-T6 supernatant was detected by enzyme-linked immunosorbent assay. Glutathione (GSH) content in HSC-T6 was detected by spectrophotometry. CB2 and heme oxygenase-1(HO-1) in each group of HSC-T6 were detected by western blotting. Results: HSC-T6 proliferation was inhibited in each group of AM-1241 in a concentration-dependent manner (P < 0.05). The inhibition was highest at 80µmol/L, and the cell survival rate was (41.61% ± 3.13%) (P < 0.05). AM-630 concentration group had no significant inhibitory effect on the proliferation of HSC-T6 (P > 0.05). HSC-T6 expressed CB2 receptor in each group. The expression level of CB2 in the AM-1241 intervention group was higher compare with control group (P < 0.05).The expression of Col III were significantly higher in oxidative stress group (P < 0.05) than in control group, and the expression of Col III of AM-1241 intervention group was significantly lower than that in oxidative stress group (P < 0.05). Col III level in AM-1241+AM-630 antagonistic group was significantly higher than that in AM-1241 intervention group (P < 0.05). There was no significant difference between AM-1241+AM-630 antagonistic group and oxidative stress group (P > 0.05). The content of GSH and HO-1 in oxidative stress group was higher (P < 0.05) than control group. The content of GSH and HO-1 in the AM-1241 intervention group was higher compared with oxidative stress group, while content of AM-1241 + AM-630 antagonist group was lower compared to AM-1241 intervention group (P < 0.05), and the differences were not statistically significant for oxidative stress group. Conclusion: CB2 agonist AM-1241 can inhibit the proliferation and activation of HSC-T6 and its mechanism may activate the nuclear translocation of Nrf2 binding to HSC-T6, initiating the up-regulation of antioxidant enzymes HO-1 and GSH protein expression, and thus increase the antioxidant effect of HSC-T6.