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論文

論文
Sakurai, Masaru ; Takamura, Toshinari ; Ota, Tsuguhito ; Ando, Hitoshi ; Akahori, Hiroshi ; Kaji, Kyosuke ; Sasaki, Motoko ; Nakanuma, Yasuni ; Miura, Katsuyuki ; Kaneko, Shuichi
出版情報: Journal of Gastroenterology.  42  pp.312-317,  2007-04-01.  Springer Verlag
URL: http://hdl.handle.net/2297/5487
概要: 金子, 周一<br />金沢大学大学院医学系研究科環境社会医学<br />Background: To address the hypothesis that liver steatosis causes systemic insulin resistance, we sought to determine the liver histological feature that most strongly contributes to insulin resistance in patients with nonalcoholic fatty liver disease (NAFLD). Methods: Liver biopsy specimens were obtained from 131 patients with clinically suspected NAFLD. The stage, grade of nonalcoholic steatohepatitis (NASH), and level of steatosis were scored and analyzed in relation to the homeostasis model assessment of insulin resistance (HOMA-IR) and the metabolic clearance rate (MCR), measured using the glucose clamp method. Results: In the univariate analysis, the degree of hepatic steatosis (r = 0.458, P < 0.001), stage (r = 0.360, P < 0.001), and grade (r = 0.349, P < 0.01) of NASH were significantly correlated with the HOMA-IR. Multiple regression analysis adjusting for age, sex, body mass index, and each histological score showed that steatosis was significantly and independently associated with HOMA-IR (coefficient = 1.42, P < 0.001), but not with the stage (coefficient = 0.33, P = 0.307) or grade (coefficient = 0.67, P = 0.134) of NASH. Similar independent relationships were observed between steatosis and MCR, but the relationship was weaker (coefficient = -0.98, P = 0.076). Conclusions: Steatosis of the liver, but not the stage or the grade of NASH, is associated with insulin resistance in patients with NAFLD. © Springer-Verlag Tokyo 2007. 続きを見る
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論文

論文
Kurita, Seiichiro ; Takamura, Toshinari ; Ota, Tsuguhito ; Matsuzawa-Nagata, Naoto ; Kita, Yuki ; Uno, Masafumi ; Nabemoto, Satoko ; Ishikura, Kazuhide ; Misu, Hirofumi ; Ando, Hitoshi ; Zen, Yoh ; Nakanuma, Yasuni ; Kaneko, Shuichi
出版情報: European Journal of Pharmacology.  588  2008-07-07.  Elsevier
URL: http://hdl.handle.net/2297/10979
概要: 金沢大学大学院医学系研究科<br />金沢大学医薬保健研究域医学系<br />Insulin resistance is a major pathological condition associated with obesity and metabolic syndrome. Insulin resistance and the renin-angiotensin system are intimately linked. We evaluated the role of the renin-angiotensin system in the pathogenesis of insulin resistance-associated, non-alcoholic steatohepatitis by using the angiotensin II type 1 receptor blocker olmesartan medoxomil in a diabetic rat model. The effects of olmesartan on methionine- and choline-deficient (MCD) diet-induced steatohepatitis were investigated in obese, diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats and control Long-Evans Tokushima Otsuka (LETO) rats. Components of the renin-angiotensin system were up-regulated in the livers of OLETF rats, compared with LETO rats. In OLETF, but not LETO, rats, oral administration of olmesartan for 8 weeks ameliorated insulin resistance. Moreover, olmesartan suppressed MCD diet-induced hepatic steatosis and the hepatic expression of lipogenic genes (sterol regulatory element-binding protein-1c and fatty acid synthase) in OLETF, but not LETO, rats. In both OLETF and LETO rats, olmesartan inhibited hepatic oxidative stress (4-hydroxy-2-nonenal-modified protein) and expression of NADPH oxidase. Olmesartan also inhibited hepatic fibrosis, stellate cell activation, and expression of fibrogenic genes (transforming growth factor-β, α1 [I] procollagen, plasminogen activator inhibitor-1) in both OLETF and LETO rats. In conclusion, pharmacological blockade of the angiotensin II type 1 receptor slows the development of steatohepatitis in the OLETF rat model. This angiotensin II type 1 receptor blocker may exert insulin resistance-associated effects against hepatic steatosis and inflammation as well as direct effects against the generation of reactive oxygen species and fibrogenesis. © 2008 Elsevier B.V. All rights reserved. 続きを見る
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論文

論文
Sakurai, Sho ; Miura, K. ; Takamura, Toshinari ; Ishizaki, Masao ; Morikawa, Y. ; Nakamura, K. ; Yoshita, Katsushi ; Kido, Teruhiko ; Naruse, Yuchi ; Kaneko, Shuichi ; Nakagawa, H.
出版情報: Diabetic Medicine.  26  pp.753-759,  2009-08-01.  Blackwell Publishing
URL: http://hdl.handle.net/2297/19144
概要: 金沢大学医薬保健研究域医学系<br />金沢医科大学健康増進予防医学(公衆衛生学)<br />Aims This study investigated the relationship between waist circumference and the subsequent incidence of Type 2 diabetes and the association with insulin resistance and pancreatic B-cell function in relatively lean Japanese individuals. Methods The study participants were 3992 employees (2533 men and 1459 women, aged 35-55 years) of a metal-products factory in Japan. The incidence of diabetes was determined in annual medical examinations during an 8-year follow-up. We calculated age- and sex-adjusted hazard ratios (HRs) according to the sex-specific quintile of waist circumference at baseline. Differences in baseline insulin resistance [homeostatis model assessment (HOMA)-IR] and pancreatic B-cell function (HOMA-B) were compared between participants who developed diabetes and those who did not. Results During the follow-up, 218 participants developed diabetes. Age- and sex-adjusted HRs across the quintiles of waist circumference were 1.78, 1.00 (reference), 1.59, 3.11 and 3.30, respectively (P for trend, < 0.0001). The HR for the lowest quintile was significantly higher than that for the second quintile. Among participants with waist circumference of the lowest quintile, HOMA-B was lower in those who developed diabetes than in those who did not [33.1 (24.1-45.0) vs. 54.3 (37.9-74.6) median (interquartile range), P < 0.0001], but HOMA-IR did not differ between these groups. Conclusions There was a J-shaped relationship between waist circumference and subsequent risk for Type 2 diabetes in relatively lean Japanese individuals; lower pancreatic B-cell function may also increase the risk of diabetes in very lean Japanese people. © 2009 Diabetes UK. 続きを見る