1585-P: Reduced Insulin Sensitivity and Muscle Strength Are Independent Risk Factors for Silent Lacunar Infarcts and Synergistically Increase the Risk among Japanese Elderly People: The Bunkyo Health Study
Authors: SOMEYA YUKI , TAMURA YOSHIFUMI , KAGA HIDEYOSHI , SUGIMOTO DAISUKE , KADOWAKI SATOSHI , SUZUKI RURIKO , KAWAMORI RYUZO , WATADA HIROTAKA 
Published: June 2020

Silent lacunar infarcts (SLI) are often incidentally found on brain MRI scans in asymptomatic elderly people, and are associated with the future onset of stroke and dementia. However, the risk factors for SLI have not been fully elucidated yet. We recently found that reduced muscle strength is a risk factor for SLI. Systemic insulin sensitivity (IS) that reflects the metabolic function of muscles could also be a risk factor for SLI; however, interactive effect of IS and muscle strength on SLI is totally unknown. Here, we evaluated SLI, recently established index of IS (PREDIM) and knee extensor muscle strength by MRI, oral glucose tolerance test, and dynamometer, respectively on 1,531 elderly people aged 65-84 years living in an urban area of Tokyo. The subjects were categorized into 3 groups based on the standard deviation of PREDIM and the tertiles of muscle strength, respectively, then categorized into 9 groups by their combination, then we estimated odd ratios for SLI by logistic regression analysis. Among the study subjects, we found 251 (16.4%) subjects had silent lacunar infarcts. IS was weakly correlated to muscle strength (r=0.185, p=0.001). Impaired IS [High; 1.00 (reference), Medium; 1.53 (95%CI: 0.94-2.48), Low; 1.85 (95%CI: 1.02-3.38), p for trend 0.047] and reduced muscle strength [High; 1.00 (reference), Medium; 1.42 (95%CI: 0.99-2.04), Low; 1.51 (95%CI: 1.05-2.16), p for trend 0.034] were independently associated with increased risk for SLI in the fully adjusted model. In terms of interactive association, subjects categorized in the lowest IS and muscle strength had 4.4 fold (95%CI: 1.67-11.64) higher risk for SLI compared with those categorized in both are the highest.
In summary, reduced muscle strength and IS were independently associated with higher risk for SLI in elderly subjects, and combination of both was synergistically elevated the risk for SLI.

Disclosure
Y. Someya: None. Y. Tamura: Advisory Panel; Self; Astellas Pharma Inc. Research Support; Self; Kowa Company, Ltd. Speaker’s Bureau; Self; Novo Nordisk Inc., Ono Pharmaceutical Co., Ltd. H. Kaga: None. D. Sugimoto: None. S. Kadowaki: None. R. Suzuki: None. R. Kawamori: None. H. Watada: Advisory Panel; Self; Abbott, Ajinomoto, Astellas Pharma Inc., Boehringer Ingelheim Pharmaceuticals, Inc., Fuji Film, Janssen Pharmaceuticals, Inc., Kowa Company, Ltd., Kyowa Hakko Kirin Co., Ltd., Mitsubishi Tanabe Pharma Corporation, Novo Nordisk Inc., Ono Pharmaceutical Co., Ltd., Sanofi-Aventis, Takeda Pharmaceutical Company Limited, Terumo Medical Corporation. Research Support; Self; Astellas Pharma Inc., Bayer Yakuhin, Ltd., Boehringer Ingelheim Pharmaceuticals, Inc., Daiichi Sankyo, Eli Lilly Japan K.K., Kissei Pharmaceutical Co., Ltd., Kowa Company, Ltd., Kyowa Hakko Kirin Co., Ltd., Merck Sharp & Dohme Corp., Mitsubishi Tanabe Pharma Corporation, Novartis Pharma K.K., Novo Nordisk Inc., Ono Pharmaceutical Co., Ltd., Otsuka Pharmaceutical Co., Ltd., Pfizer Japan Inc., Sanofi-Aventis, Sanwa Kagaku Kenkyusho, Shionogi & Co., Ltd., Sumitomo Dainippon Pharma Co., Ltd., Sumitomo Dainippon Pharma Co., Ltd., Taisho Pharmaceutical Co., Ltd., Takeda Pharmaceutical Company Limited, Teijin Pharma Limited, Yakult. Speaker’s Bureau; Self; Astellas Pharma Inc., AstraZeneca, Bayer Yakuhin, Ltd., Boehringer Ingelheim Pharmaceuticals, Inc., Daiichi Sankyo, Eli Lilly Japan K.K., Kissei Pharmaceutical Co., Ltd., Kowa Company, Ltd., Kyowa Hakko Kirin Co., Ltd., Merck Sharp & Dohme Corp., Mitsubishi Tanabe Pharma Corporation, Novartis Pharmaceuticals Corporation, Novo Nordisk Inc., Ono Pharmaceutical Co., Ltd., Sanofi-Aventis, Sanwa Kagaku Kenkyusho, Sumitomo Dainippon Pharma Co., Ltd., Takeda Pharmaceutical Company Limited.

Funding
Strategic Research Foundation at Private Universities (S1411006); Japan Society for the Promotion of Science (18H03184); Mizuno Sports Promotion Foundation; Mitsui Life Social Welfare Foundation