Prevalence of mild cognitive impairment in type 2 diabetes mellitus is associated with serum Galectin-3 level.

INTRODUCTION: Galectin-3 (Gal3) contributes to insulin resistance, inflammation, and obesity, the three risk factors for mild cognitive impairment (MCI) in type 2 diabetes mellitus (T2DM) patients. PATIENTS AND METHODS: 134 hospitalized T2DM patients were assessed by the Montreal Cognitive Assessment (MoCA) method and divided into 65 MCI and 69 controls. Levels of variables Gal3 and Abeta42 were investigated in relationship with cognitive function in both T2DM patients with MCI and high-fat diet (HFD)/streptozotocin (STZ) induced T2DM rats. RESULTS: A significant higher level of serum Gal3 and lower level of plasma Abeta42 (all P < 0.05) were found in MCI T2DM group as compared to non-MCI T2DM control. Partial correlation analysis showed that Gal3 is negatively correlated with both MMSE score (r=-0.51, P < 0.01) and MoCA score (r=-0.47, P < 0.001) after adjustment for HbA1c, HOMA-IR and Abeta42 in total T2DM patients, with stronger effect seen in MCI T2DM group after further analysis with MCI strata. Simple logistic regression model demonstrated that Gal3 and Abeta42 are significantly associated with MCI T2DM patients after adjustment with the covariates sex, age, BMI, HbA1c, HOMA-IR, and anti-diabetics drugs. Serum and brain Gal3 levels were significantly increased in HFD/STZ diabetic rats, which correlate to the impairment of learning and memory ability. Gal3 inhibitor modified citrus pectin (MCP) decreased serum and brain Gal3 levels in diabetic rats, accompanied by the amelioration of learning and memory impairment. CONCLUSIONS: Gal3 may be associated with cognitive impairment in T2DM and serum Gal3 level may be a new risk factor of MCI in T2DM patients.