Purpose: Peroxisome proliferator-activated receptor gamma (PPAR-γ) has a key role in hepatic fibrogenesis by virtue of its effect on the hepatic stellate cells (HSCs). Although many studies have shown that PPAR-γ agonists inhibit liver fibrosis, the mechanism remains largely unclear, especially regarding the cross-talk between PPAR-γ and other potent fibrogenic factors. Methods: This experimental study involved 25 male Wistar rats. Twenty rats were subjected to bile duct ligation (BDL) to induce liver fibrosis, further divided into an untreated group (BDL; n=10) and a group treated with the PPAR-γ agonist thiazolidinedione (TZD), at 14 days post-operation (BDL+TZD; n=10). The remaining 5 rats had a sham operation (sham; n=5). The effect of PPAR-γ agonist on liver fibrosis was evaluated by histopathology, protein immunohistochemistry, and mRNA expression quantitative polymerase chain reaction. Results: Histology and immunostaining showed markedly reduced collagen deposition, bile duct proliferation, and HSCs in the BDL+TZD group compared to those in the BDL group (p<0.001). Similarly, significantly lower mRNA expression of collagen α-1(I), matrix metalloproteinase-2, platelet-derived growth factor (PDGF)-B chain, and connective tissue growth factor (CTGF) were evident in the BDL+TZD group compared to those in the BDL group (p=0.0002, p<0.035, p<0.0001, and p=0.0123 respectively). Moreover, expression of the transforming growth factor beta1 (TGF-β1) was also downregulated in the BDL+TZD group (p=0.0087). Conclusion The PPAR-γ agonist inhibits HSC activation in vivo and attenuates liver fibrosis through several fibrogenic pathways. Potent fibrogenic factors such as PDGF, CTGF, and TGF-β1 were downregulated by the PPAR-γ agonist. Targeting PPAR-γ activity may be a potential strategy to control liver fibrosis.

Background: Abrupt implementation of lockdowns during the coronavirus disease 2019 (COVID-19) pandemic affected the management of diabetes mellitus in patients worldwide. Limited access to health facilities and lifestyle changes potentially affected metabolic parameters in patients at risk. We conducted a meta-analysis to determine any differences in the control of metabolic parameters in patients with diabetes, before and during lockdown. Methods: We performed searches of five databases. Meta-analyses were carried out using random- or fixed-effect approaches to glycaemic control parameters as the primary outcome: glycosylated hemoglobin (HbA1c), random blood glucose (RBG), fasting blood glucose (FBG), time-in-range (TIR), time-above-range (TAR), time-below-range (TBR). Mean difference (MD), confidence interval (CI), and P value were calculated. Lipid profile was a secondary outcome and is presented as a descriptive analysis. Results: Twenty-one studies enrolling a total of 3,992 patients with type 1 or type 2 diabetes mellitus (T1DM or T2DM) were included in the study. Patients with T1DM showed a significant improvement of TIR and TAR (MD=3.52% [95% CI, 0.29 to 6.74], I2=76%, P=0.03; MD=–3.36% [95% CI, –6.48 to –0.25], I2=75%, P=0.03), while FBG among patients with T2DM significantly worsened (MD=3.47 mg/dL [95% CI, 1.22 to 5.73], I2=0%, P<0.01). No significant difference was found in HbA1c, RBG, and TBR. Use of continuous glucose monitoring in T1DM facilitated good glycaemic control. Significant deterioration of lipid parameters during lockdown, particularly triglyceride, was observed. Conclusion Implementation of lockdowns during the COVID-19 pandemic did not worsen glycaemic control in patients with diabetes. Other metabolic parameters improved during lockdown, though lipid parameters, particularly triglyceride, worsened.