title: Relationship between olfactory dysfunction and cognitive impairment in elderly patients with type 2 diabetes mellitus.
abstract: OBJECTIVE
  Recent clinical studies identified the relation between olfactory dysfunction and cognitive impairment in the elderly without type 2 diabetes mellitus. The aim of the present study was to define the relation between olfactory function and cognition in elderly patients with type 2 diabetes mellitus.
  
  
  METHODS
  The study participants comprised 250 elderly (age, 68-77, median 72) Japanese outpatient with type 2 diabetes mellitus free of clinically-evident cognitive impairment. Olfactory and cognitive functions were evaluated by the Open Essence (OE) test and Mini-mental State Examination (MMSE), respectively.
  
  
  RESULTS
  Based on the MMSE score, 62.0%, 24.4%, and 13.6% of the participants were considered to have no impairment, possible cognitive impairment and probable dementia, respectively. The OE test score of the probable dementia group was significantly lower than other groups. Furthermore, age and serum uric acid were significantly higher in the probable dementia group than other groups. Simple correlation analysis showed positive correlation between the MMSE score and diastolic blood pressure, education, OE test score, total cholesterol, LDL cholesterol, folic acid, and negative correlation with age, HbA1c, aspartate aminotransferase, serum adiponectin and urinary albumin excretion. Multivariate regression analysis showed that OE test score correlated significantly and independently with MMSE score (standardized coefficients β=0.542, R(2)=0.478, P<0.01), in addition to education level, HbA1c and serum adiponectin.
  
  
  CONCLUSIONS
  The results suggested the association of olfactory dysfunction with cognitive impairment in elderly patients with type 2 diabetes mellitus.
authors.affiliation: Department of Metabolism & Endocrinology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyoku, Tokyo 113-8421, Japan.
authors.forename: Haruna
authors.initials: H
authors.lastname: Sanke
authors.affiliation: Department of Metabolism & Endocrinology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyoku, Tokyo 113-8421, Japan; Center for Molecular Diabetology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyoku, Tokyo 113-8421, Japan. Electronic address: tom-m@juntendo.ac.jp.
authors.forename: Tomoya
authors.initials: T
authors.lastname: Mita
authors.affiliation: Department of Medicine, Diabetology & Endocrinology Juntendo Tokyo Koto Geriatric Medical Center, Shinsuna 3-3-20, Koto-ku, Tokyo 136-0075, Japan.
authors.forename: Hidenori
authors.initials: H
authors.lastname: Yoshii
authors.affiliation: Department of Medicine, Diabetology & Endocrinology Juntendo Tokyo Koto Geriatric Medical Center, Shinsuna 3-3-20, Koto-ku, Tokyo 136-0075, Japan.
authors.forename: Ayako
authors.initials: A
authors.lastname: Yokota
authors.affiliation: Department of Medicine, Diabetology & Endocrinology Juntendo Tokyo Koto Geriatric Medical Center, Shinsuna 3-3-20, Koto-ku, Tokyo 136-0075, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Yamashiro
authors.affiliation: Department of Medicine, Diabetology & Endocrinology Juntendo Tokyo Koto Geriatric Medical Center, Shinsuna 3-3-20, Koto-ku, Tokyo 136-0075, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Ingaki
authors.affiliation: Department of Medicine, Diabetology & Endocrinology Juntendo Tokyo Koto Geriatric Medical Center, Shinsuna 3-3-20, Koto-ku, Tokyo 136-0075, Japan.
authors.forename: Tomio
authors.initials: T
authors.lastname: Onuma
authors.affiliation: Department of Metabolism & Endocrinology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyoku, Tokyo 113-8421, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Someya
authors.affiliation: Department of Metabolism & Endocrinology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyoku, Tokyo 113-8421, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Komiya
authors.affiliation: Department of Metabolism & Endocrinology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyoku, Tokyo 113-8421, Japan; Sportology Center, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyoku, Tokyo 113-8421, Japan.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Tamura
authors.affiliation: Department of Metabolism & Endocrinology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyoku, Tokyo 113-8421, Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Shimizu
authors.affiliation: Department of Metabolism & Endocrinology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyoku, Tokyo 113-8421, Japan.
authors.forename: Chie
authors.initials: C
authors.lastname: Ohmura
authors.affiliation: Department of Metabolism & Endocrinology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyoku, Tokyo 113-8421, Japan; Center for Therapeutic Innovations in Diabetes, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyoku, Tokyo 113-8421, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Kanazawa
authors.affiliation: Department of Metabolism & Endocrinology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyoku, Tokyo 113-8421, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Fujitani
authors.affiliation: Department of Metabolism & Endocrinology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyoku, Tokyo 113-8421, Japan; Center for Therapeutic Innovations in Diabetes, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyoku, Tokyo 113-8421, Japan; Center for Molecular Diabetology, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyoku, Tokyo 113-8421, Japan; Sportology Center, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyoku, Tokyo 113-8421, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Watada
mesh_terms: D000368:Aged; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D000857:Olfaction Disorders / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D012189:Retrospective Studies; D012903:Smell / Q000502:physiology*
keywords: Cognitive impairment; Elderly patients; Olfactory function; Type 2 diabetes mellitus