Background and aim Cholestasis-associated renal injury or cholemic nephropathy (CN) is a serious clinical problem. Previous studies mentioned that oxidative stress and mitochondrial impairment play a role in CN. There is no specific pharmacological intervention for CN. Metformin is an anti-diabetic drug administered for decades. On the other hand, novel pharmacological properties have emerged for this drug. The effect of metformin on oxidative stress parameters has been well-recognized in different experimental models. It has also been found that metformin positively affected mitochondrial function. The current study aimed to evaluate the effects of metformin in an animal model of CN. Methods Rats underwent bile duct ligation (BDL) and were treated with metformin (250 and 500 mg/kg) for 14 consecutive days. Two weeks after the BDL operations, urine, serum, and kidney samples were collected and analyzed. Results Markers of oxidative stress, including reactive oxygen species (ROS) formation, lipid peroxidation, protein carbonylation, depleted antioxidant capacity, and decreased glutathione (GSH) levels were detected in BDL animals. Moreover, mitochondrial indices, including adenosine triphosphate (ATP) level, dehydrogenase activity, mitochondrial membrane potential, and mitochondrial permeability, were impaired in the kidney of cholestatic rats. Renal histopathological alterations in cholestatic animals included tubular degeneration and interstitial inflammation, cast formation, and fibrosis. It was found that metformin significantly alleviated oxidative stress and improved mitochondrial indices in the kidney of cholestatic rats. Tissue histopathological alterations were also mitigated in metformin-treated groups. Conclusions Metformin could be a candidate for managing CN. The nephroprotective role of metformin is primarily associated with its effects on oxidative stress parameters and mitochondrial function.

BACKGROUND AND PURPOSE: Interventions to reduce the risk for cerebrovascular events (CVE; stroke and transient ischemic attack [TIA]) after radiotherapy (RT) for head and neck cancer (HNCA) are needed. Among broad populations, statins reduce CVEs; however, whether statins reduce CVEs after RT for HNCA is unclear. Therefore, we aimed to test whether incidental statin use at the time of RT is associated with a lower rate of CVEs after RT for HNCA. METHODS: From an institutional database we identified all consecutive subjects treated with neck RT from 2002 to 2012 for HNCA. Data collection and event adjudication was performed by blinded teams. The primary outcome was a composite of ischemic stroke and TIA. The secondary outcome was ischemic stroke. The association between statin use and events was determined using Cox proportional hazard models after adjustment for traditional and RT-specific risk factors. RESULTS: The final cohort consisted of 1,011 patients (59±13 years, 30% female, 44% hypertension) with 288 (28%) on statins. Over a median follow-up of 3.4 years (interquartile range, 0.1 to 14) there were 102 CVEs (89 ischemic strokes and 13 TIAs) with 17 in statin users versus 85 in nonstatins users. In a multivariable model containing known predictors of CVE, statins were associated with a reduction in the combination of stroke and TIA (hazard ratio [HR], 0.4; 95% confidence interval [CI], 0.2 to 0.8; P=0.01) and ischemic stroke alone (HR, 0.4; 95% CI, 0.2 to 0.8; P=0.01). CONCLUSIONS: Incidental statin use at the time of RT for HNCA is associated with a lower risk of stroke or TIA.
Cohort Studies ; Data Collection ; Female ; Follow-Up Studies ; Head and Neck Neoplasms ; Head ; Humans ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; Ischemic Attack, Transient ; Neck ; Proportional Hazards Models ; Radiotherapy ; Risk Factors ; Stroke