Background Previous studies presumed that the disturbed neurovascular coupling to be a critical risk factor of cognitive impairments in type 2 diabetes mellitus (T2DM), but distinct clinical manifestations were lacked. Consequently, we decided to investigate the neurovascular coupling in T2DM patients by exploring the MRI relationship between neuronal activity and the corresponding cerebral blood perfusion. Methods Degree centrality (DC) map and amplitude of low-frequency fluctuation (ALFF) map were used to represent neuronal activity. Cerebral blood flow (CBF) map was used to represent cerebral blood perfusion. Correlation coefficients were calculated to reflect the relationship between neuronal activity and cerebral blood perfusion. Results At the whole gray matter level, the manifestation of neurovascular coupling was investigated by using 4 neurovascular biomarkers. We compared these biomarkers and found no significant changes. However, at the brain region level, neurovascular biomarkers in T2DM patients were significantly decreased in 10 brain regions. ALFF-CBF in left hippocampus and fractional ALFF-CBF in left amygdala were positively associated with the executive function, while ALFF-CBF in right fusiform gyrus was negatively related to the executive function. The disease severity was negatively related to the memory and executive function. The longer duration of T2DM was related to the milder depression, which suggests T2DM-related depression may not be a physiological condition but be a psychological condition. Conclusion Correlations between neuronal activity and cerebral perfusion maps may be a method for detecting neurovascular coupling abnormalities, which could be used for diagnosis in the future. Trial registry number: This study has been registered in ClinicalTrials.gov ( NCT02420470 ) on April 2, 2015 and published on July 29, 2015.

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Previous studies have shown that glucose fluctuation is closely related to oxidative stress and diabetic complications. However, only few studies have evaluated the influencing factors of glycemic variability (GV) in type 2 diabetes (T2D) patients so far.This was a cross-sectional study design. A total of 366 cases of hospitalized patients with T2D using insulin therapy, whom received continuous glucose monitoring from January 2014 to December 2016, were enrolled for this study. The evaluation variables of GV included standard deviation of blood glucose, coefficient of variation (CV%), mean amplitude of glycemic excursion, and absolute means of daily differences.In 366 T2D patients with insulin therapy, 148 were used multiple daily injections (MDI) insulin regimen; 144 were on premixed insulin injection; and 74 were treated with continuous subcutaneous insulin injection. Compared with MDI insulin regimen, patients on premixed insulin injection have less insulin dose per day, lower mean blood glucose, and better glycated hemoglobin (HbA1c) (all P <.05). Generalized linear model showed that family history of diabetes, duration of diabetes, higher HbA1c, and higher level of aspartate aminotransferase and high-density lipoprotein cholesterol were positively associated with GV parameters. Otherwise, serum levels of C-peptide, premixed insulin injection, history of cardiovascular disease, and serum concentration of uric acid were inversely associated with GV parameters.Dysfunction of pancreatic β-cell and better insulin sensitivity were independent contributors to the fluctuation of blood glucose. Moreover, premixed insulin therapy may obtain better glucose control and lower within-day and day-to-day glucose variability for Chinese T2D patients with insulin therapy.