Antidiabetic Effect of Brain-Derived Neurotrophic Factor and Its Association with Inflammation in Type 2 Diabetes Mellitus

Table 1

Publication	Ethnic and duration of T2DM	Material/criteria	Number of T2DM patients/control	Characteristics of the T2DM patients	Alteration of BDNF level with T2DM	Positive-correlated parameters with BDNF level	Negative-correlated parameters with BDNF level	Independent association with BNDF level
Suwa et al. [9] 2006	Japanese female, newly diagnosed	(i) Serum; (ii) No treatment	24/7	(i) BMI (kg/m^2): 26.1 ± 3.3; (ii) HbA1c (%): 6.52 ± 0.90; (iii) HOMA-IR: 2.32 ± 1.38	↑ Increased	(i) BMI; (ii) Body fat percent; (iii) Subcutaneous fat; (iv) HOMA-IR; (v) Triglycerides; (vi) Fasting glucose; (vii) HbA1c (weak correlation)	(i) Age
Krabbe et al. [53] 2007	Caucasian, long standing	(i) Plasma; (ii) No treatment with insulin; (iii) No antidiabetic drug for 1 week before the blood sampling; (iv) No drug 24 hours before the blood sampling	Diabetes obese/obese: 46/41; Diabetes nonobese/nonobese: 50/62	Diabetes obese patients: (i) BMI (kg/m^2): 35.5 ± 0.7; (ii) Fasting glucose (mmol/L): 9.6 ± 0.9; Diabetes nonobese patients: (iii) BMI (kg/m^2): 26.6 ± 0.3; (iv) Fasting glucose (mmol/L): 9.9 ± 0.6	↓ Decreased with patient with diabetes compared to nondiabetic; ↓ Decreased with obese patients compared to nonobese	(i) CRP	(i) Fasting glucose level (strong correlation)	(i) Obesity
Fujinami et al. [58] 2008	Japanese, long standing	(i) Serum; (ii) No treatment with insulin; (iii) No treatment with thiazolidinedione; (iv) No hormonal treatment	112/80	(i) BMI (kg/m^2): 23.1 ± 3.1; (ii) Fasting glucose (mmol/L): 8.51 ± 2.18; (iii) HbA1c (%): 7.4 ± 1.3; (iv) HOMA-R: 2.42 ± 2.16	↓ Decreased; ↑ Increased female patients with diabetes compared to male patients with diabetes	(i) Immunoreactive insulin; (ii) HOMA-R	(i) Adiponectin level (weak correlation)
Zhen et al. [56] 2013	Han Chinese, long standing	(i) Serum; (ii) No treatment with insulin; (iii) Some patients received metformin and/or repaglinide	208/212	(i) BMI (kg/m^2): 25.9 ± 3.8; (ii) Fasting glucose (mmol/L): 9.2 ± 3.1; (iii) HbA1c (%): 7.5 ± 2.0	↓ Decreased	(i) Delayed memory index; (ii) Cognitive deficit	(i) Fasting glucose level; (ii) Duration of illness
He et al. 2014 [55] (pilot study)	Chinese, long standing	(i) Serum; (ii) No data	37/37	(i) BMI (kg/m^2): 26.4 ± 2.3; (ii) Fasting glucose (mmol/L): 8.37 ± 3.39; (iii) HbA1c (%): 9.11 ± 2.92	↓ Decreased; ↑ Increased female patients with diabetes compared to male patients with diabetes
Passaro et al. [57] 2014	Caucasian, long standing	(i) Plasma; (ii) Some patients received antidiabetic drug; (iii) Antihypertension drug	37/154		↓ Decreased	(i) Total cholesterol; (ii) LDL	(i) Age; (ii) Systolic blood pressure	(i) T2DM
Boyuk et al. [52] 2014	Caucasian, long standing	(i) Serum; (ii) Some patients received oral antidiabetic drug; (iii) Oral antidiabetic drug plus insulin; (iv) Insulin; (v) Antihypertension drug; (vi) Antilipid drug	88/33	(i) BMI (kg/m^2): 31.52 ± 5.80; (ii) Fasting glucose (mg/dL): 170.36 ± 91.21; (iii) HbA1c (%): 8.30 ± 2.37; (iv) HOMA-IR: 3.73 ± 3.05	↑ Increased	(i) HOMA-IR; (ii) Triglyceride; (iii) WBC		(i) T2DM
Li et al. [54] 2015	Chinese, long standing	(i) Serum; (ii) Some patients received insulin; (iii) Lipid-lowering medication; (iv) Blood pressure treatment	292/200	(i) BMI (kg/m^2): 26.8 (24.7–29.4); (ii) Fasting glucose (mmol/L): 8.6 (6.7–9.9); (iii) HbA1c (%): 7.9 (6.4–9.2); (iv) HOMA-IR: 3.80 (2.35–5.47)	↓ Decreased		(i) Fasting glucose level; (ii) Duration of illness; (iii) BMI; (iv) CRP

BMI: body mass index; HbA1c: glycated hemoglobin; HOMA-IR: homeostatic model assessment insulin resistance; CRP: c-reactive protein; LDL: low-density lipoprotein.