Young Goo Shin

Effect of Chronic Alcohol Ingestion on Bone Mineral Density in Males without Liver Cirrhosis

Background: Osteoporosis in men is an important public health problem. Because of the tendency of the numbers of the elderly population to increase, and age-specific incidence of fractures, it is inevitable that the health burden due to fractures will increase. Chronic alcoholism is associated with other risk factors, such as poor nutrition, leanness, liver disease, malabsorption, vitamin D deficiency, hypogonadism, hemosiderosis, parathyroid dysfunction and tobacco use, and these may contribute to the pathogenesis of bone disease related to alcoholism. Chronic alcohol intake may reduce bone density, but can also increase bone density. It is well established that liver disease also induces bone density changes, thus it is difficult to distinguish the role of liver disease from that of alcohol itself in the bone alterations occurring in patients with chronic alcohol consumption. Chronic male alcoholics, not having liver cirrhosis were studied to assess the effect of chronic alcohol consumption on their bone mineral density. Methods: The study subjects comprised of 18 chronic heavy drinkers of more than 40 g of alcohol per day for at least 3 years and 18 age-matched controls who drank less than 20 g of alcohol per day. The serum and urinary parameters of bone and mineral metabolism were determined. The bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry at four axial sites (lumbar spine, femoral neck, Ward’s triangle and trochanter). Results: The alcoholic and control patients drank an average of 97.6 g and 7.2 g of alcohol per day. Osteocalcin, a marker of bone formation, was slightly decreased in alcoholic patients, and deoxypyridinoline, a marker of bone resorption, was slightly increased, but the difference was not statistically significant (p>0.05). There were no differences between the two groups in the levels of free testosterone, estradiol, 25(OH) vitamin D and parathyroid hormone. The Ward’s triangle and trochanter BMDs of the femur were significantly lower in the alcoholics than the controls, and lumbar spine BMD was decreased in proportion to the total alcohol intake in the alcoholics (r=−0.625, p=0.01). Conclusion: We suggest that chronic alcohol consumption induces low bone density in the femur Ward’s triangle and trochanter. There was also a significant inverse correlation between the lumbar spine BMD and the total amount of alcohol consumed. Large scaled randomized and prospective studies are needed to clarify the pathogenesis of alcohol-induced osteoporosis.

Angiotensin II receptor blocker attenuates overexpression of vascular endothelial growth factor in diabetic podocytes

VEGF expressed in glomerular podocytes, is known to increase vascular permeability to macromolecules. Angiotensin II can stimulate the release of VEGF, and the protective effects of angiotensin II antagonist against diabetic glomerular injury suggest that the angiotensin II-induced VEGF is an important pathogenetic mechanism in the development of proteinuria during diabetic nephropathy although this mechanism is not fully understood. In this study, the changes of VEGF expression was examined in the experimental diabetic nephropathy to determine whether these changes were modified by renoprotective intervention by blockers of angiotensin II receptors. The streptozotocin- induced diabetic rats were treated with L-158,809, a blocker of angiotensin II receptors, for 12 weeks. Age-matched rats with L-158,809 served as controls. RT-PCR and immunohistochemistry were used to assess and quantify gene and protein expression of VEGF. A progressive increase in urinary protein excretion was observed in diabetic rats. Glomerular VEGF expression was significantly higher in diabetic rats than in the control groups, with a significant reduction in glomerular VEGF expression and proteinuria in L-158,809- treated diabetic rats. VEGF mRNA was also significantly higher in diabetic kidneys than in the control groups, with a significant reduction in VEGF mRNA in L-158,809-treated diabetic kidneys. These results demonstrates that VEGF expression is significantly increased in diabetic podocytes, and angiotensin II receptor antagonist attenuated these changes in VEGF expression and prevented the development of proteinuria in vivo. Attenuation of increased VEGF expression in podocytes could contribute to the renoprotective effects of angiotensin II receptor antagonists in diabetic nephropathy.

Serum adipocyte fatty acid-binding protein levels are associated with nonalcoholic fatty liver disease in type 2 diabetic patients.

OBJECTIVE Adipocyte fatty acid-binding protein (A-FABP) is a major cytoplasmic protein in adipocytes and macrophages and is closely associated with metabolic syndrome, type 2 diabetes, and atherosclerosis. Here, we investigated whether A-FABP was associated with nonalcoholic fatty liver disease (NAFLD) in type 2 diabetes. RESEARCH DESIGN AND METHODS We enrolled 181 type 2 diabetic patients. Clinical and biochemical metabolic parameters were measured. The severity of NAFLD was measured by ultrasound. A-FABP, adiponectin, and retinol-binding protein-4 (RBP-4) were determined by enzyme-linked immunosorbent assay. RESULTS A-FABP levels, defined as more than a moderate degree of fatty liver compared with men, those without metabolic syndrome, and those without NAFLD, were higher in women, patients with metabolic syndrome, and patients with overt NAFLD, respectively. Adiponectin was decreased according to the severity of NAFLD, but RBP-4 showed no difference. Age- and sex-adjusted A-FABP showed positive correlations with BMI, waist-to-hip ratio, waist circumference, triglycerides, gamma-glutamyltransferase, fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), A1C, and C-reactive protein (CRP) but showed negative correlation with HDL cholesterol. The odds ratio (OR) for the risk of overt NAFLD with increasing levels of sex-specific A-FABP was significantly increased (OR 2.90 [95% CI 1.15-7.29] vs. 7.87 [3.20-19.38]). The OR in the highest tertile of A-FABP remained significant after adjustments for BMI, waist circumference, A1C, HDL cholesterol, triglycerides, HOMA-IR, CRP, and hepatic enzymes. CONCLUSIONS Our study demonstrates that serum A-FABP is significantly associated with NAFLD in type 2 diabetes, independent of BMI, waist circumference, HOMA-IR, A1C, triglycerides, HDL cholesterol, and CRP.

Peroxisome proliferator-activated receptor δ agonist attenuates hepatic steatosis by anti-inflammatory mechanism

Although peroxisome proliferator receptor (PPAR)-α and PPAR-γ agonist have been developed as chemical tools to uncover biological roles for the PPARs such as lipid and carbohydrate metabolism, PPAR-δ has not been fully investigated. In this study, we examined the effects of the PPAR-δ agonist GW0742 on fatty liver changes and inflammatory markers. We investigated the effects of PPAR-δ agonist GW0742 on fatty liver changes in OLETF rats. Intrahepatic triglyceride contents and expression of inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and monocyte chemo-attractant protein-1 (MCP-1) and also, PPAR-γ coactivator (PGC)-1α gene were evaluated in liver tissues of OLETF rats and HepG2 cells after GW0742 treatment. The level of TNF-α and MCP-1 was also examined in supernatant of Raw264. 7 cell culture. To address the effects of GW0742 on insulin signaling, we performed in vitro study with AML12 mouse hepatocytes. Rats treated with GW0742 (10 mg/kg/day) from 26 to 36 weeks showed improvement in fatty infiltration of the liver. In liver tissues, mRNA expressions of TNF-α, MCP-1, and PGC-1α were significantly decreased in diabetic rats treated with GW0742 compared to diabetic control rats. We also observed that GW0742 had inhibitory effects on palmitic acid-induced fatty accumulation and inflammatory markers in HepG2 and Raw264.7 cells. The expression level of Akt and IRS-1 was significantly increased by treatment with GW0742. The PPAR-δ agonist may attenuate hepatic fat accumulation through anti-inflammatory mechanism, reducing hepatic PGC-1α gene expression, and improvement of insulin signaling.

Prevalence and related factors assessment of osteoporotic fracture in rural population: the Korean Genomic Rural Cohort study

Department of Internal Medicine, Catholic Kwandong University College of Medicine: Department of Internal Medicine, Yonsei University Wonju College of Medicine1 : Department of Preventive Medicine, Yonsei University Wonju College of Medicine2 : Department of Preventive Medicine, College of Medicine, Chosun University3 : Department of Preventive Medicine, Chungnam University College of Medicine4 : Department of Preventive Medicine, Catholic Kwandong University College of Medicine5