Homocysteine levels are associated with hippocampus volume in type 2 diabetic patients


Tsuyoshi Shimomura, MD, PhD, Department of Neurosurgery, Faculty of Medicine, Oita University, Oita 879-5593 Japan. Tel.: +81 97 586 5862; fax: +81 97 586 5869; e-mail: simomura@oita-u.ac.jp


Eur J Clin Invest 2011; 41 (7): 751–758


Background  Elevated total plasma homocysteine (tHcy) levels are associated with cognitive dysfunction, in which changes in the hippocampus plausibly play a pivotal role. We tested the hypothesis that elevated tHcy levels are correlated with hippocampus volume and insulin resistance in nondementia patients with type 2 diabetes.

Materials and methods  The study included 43 nondementia patients with type 2 diabetes, who were divided into two groups: a high tHcy group (age: 65 ± 8 years, mean ± standard deviation, n = 16) and a normal tHcy group (64 ± 9 years, n = 27). Hippocampus volume was quantified with a computer-assisted analysis using a magnetic resonance imaging (MRI) voxel-based specific regional analysis system developed for the study of Alzheimer’s disease (VSRAD), which yields a Z-score as the end point for the assessment of hippocampal volume.

Results  The Z-score was higher in the high tHcy group compared to the normal tHcy group (P < 0·0001). The fasting plasma glucose (P < 0·01) and insulin (P < 0·0001) concentrations and the homoeostasis model assessment (HOMA) index (P < 0·0001) were higher in the high tHcy group than in the normal tHcy group. Multiple regression analysis showed that the main factors that influenced tHcy levels may be the Z-score and the HOMA index.

Conclusions  Our results indicate that the elevated levels of tHcy in Japanese nondementia patients with type 2 diabetes are characterised by hippocampal atrophy and insulin resistance and that the Z-score and HOMA index may be the primary factors that influence tHcy levels.