Diabetology International

, Volume 7, Issue 4, pp 361–367 | Cite as

Smoking status is associated with mild cognitive impairment assessed with the mini-mental state examination in Japanese diabetic patients

  • Nao SonodaEmail author
  • Akiko Morimoto
  • Satoshi Ugi
  • Katsutaro Morino
  • Osamu Sekine
  • Ken-ichi Nemoto
  • Hiroshi Maegawa
  • Naomi Miyamatsu
Original Article



We assessed the association between smoking status and mild cognitive impairment (MCI) in Japanese diabetic patients.


This cross-sectional study included 323 diabetic patients, aged 40–79 years, who were referred to an outpatient diabetic clinic between January and July 2013 at Shiga University of Medical Science Hospital (Otsu, Japan). Cognitive function was assessed using the mini-mental state examination (MMSE), and patients were classified into two categories: normal cognitive function (MMSE score ≥27) and MCI (MMSE score 22–26). Logistic regression analysis was used to estimate the multivariable-adjusted odds ratios (ORs) and 95 % confidence intervals (CIs) for MCI in current smokers and ex-smokers compared with never-smokers.


Of the 323 patients, 55 (17.0 %), 134 (41.5 %), and 134 (41.5 %) were current smokers, ex-smokers, and never-smokers, respectively. Of these, 68 (21.0 %) patients had MCI. After adjusting for age, sex, systolic blood pressure, body mass index, high-density lipoprotein cholesterol, estimated glomerular filtration rate, hemoglobin A1c, insulin therapy, sulfonylurea, history of coronary heart disease, exercise habit, drinking status, and education, the OR for MCI was 3.62 (95 % CI 1.26–10.40) in current smokers compared with never-smokers. In addition, the multivariable-adjusted ORs for MCI were 3.02 (95 % CI 0.64–14.32) in current smokers <30.0 pack-years and 4.90 (95 % CI 1.32–18.16) in current smokers ≥30.0 pack-years, compared with never-smokers (p for trend = 0.017).


Current smoking, especially current smoking for which cumulative lifetime exposure was high, was associated with MCI, as assessed using the MMSE in Japanese diabetic patients.


Smoking Mild cognitive impairment Mini-mental state examination Diabetes 



This work was supported by the Fund for Care Prevention from NPO Biwako Health and Welfare Consortium and Shiga Prefecture. This work was supported by a Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for Young Scientists (B) (Grant Number: 25862144, 15K20762).

Compliance with ethical standards

Conflicts of interest

Nao Sonoda, Akiko Morimoto, and Naomi Miyamatsu declare that they have no conflict of interest. Satoshi Ugi, Katsutaro Morino, Osamu Sekine, Ken-ichi Nemoto, and Hiroshi Maegawa received scholarship grants from Takeda Pharmaceutical Co., Ltd., Astellas Pharma Inc., Merck Sharp & Dohme Corp., Kowa Pharmaceutical Co., Ltd., AstraZeneca K.K., Teijin Pharma Ltd., Nippon Boehringer Ingelheim Co., Ltd., Kyowa Hakko Kirin Co., Ltd., Taisho Toyama Pharmaceutical Co., Ltd., and Ono Pharmaceutical Co., Ltd..

Human rights statement and informed consent

All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (Ethics Committee of Shiga University of Medical Science) and with the Helsinki Declaration of 1964 and later revisions. Informed consent was obtained from all patients included in the study.

Supplementary material

13340_2016_256_MOESM1_ESM.docx (38 kb)
Supplementary material 1 (DOCX 37 kb)


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Copyright information

© The Japan Diabetes Society 2016

Authors and Affiliations

  • Nao Sonoda
    • 1
    Email author
  • Akiko Morimoto
    • 1
  • Satoshi Ugi
    • 2
  • Katsutaro Morino
    • 2
  • Osamu Sekine
    • 2
  • Ken-ichi Nemoto
    • 2
  • Hiroshi Maegawa
    • 2
  • Naomi Miyamatsu
    • 1
  1. 1.Department of Clinical NursingShiga University of Medical ScienceOtsuJapan
  2. 2.Department of MedicineShiga University of Medical ScienceOtsuJapan

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