Association Of Serum Chemerin Level With Cognitive Impairment And Rs-fMRI Abnormality In Patients With Type 2 Diabetes Mellitus

Objective:Type 2 diabetes mellitus is an independent risk factor for the mild cognitive impairment and dementia in elderly.About half of the T2DM patients have cognitive decline.But the symptoms of cognitive impairment are diverse and not obvious.Most patients have not been diagnosed until they have severe cognitive impairment or dementia.Early detection and intervention of T2DM with MCI is important to delay or prevent the occurrence of dementia.Chemerin,a new adipokine,plays a significant role in metabolic diseases through regulating immune response,glycolipid metabolism and inflammation.Studies have shown that chemerin has a certain correlation with diabetes and chronic complications,but the relationship between chemerin and cognitive impairment in diabetic patients has not been studied.Resting-state function magnetic resonance imaging is a new imaging technique which combines neural spontaneous activity with MRI.It can be used to assess early occult brain damage in patients with T2DM.This study measured the serum chemerin level,cognitive function scale and brain rs-fMRI in order to investigate the association of the serum chemerin level with cognitive impairment and rs-fMRI abnormality in patients with T2DM.Methodology:214 patients with T2DM cared in the endocrinology department of Jinling Hospital were recruited.General data:age,gender and duration of disease were collected,body weight,height,blood pressure and BMI were measured.Serological indicators:HbAlc,TC,TG,LDL-C,HDL-C,ALT,AST and UA were detected.The serum chemerin level was determined by ELISA assay and cognitive function was assessed by MoCA.On this basis,64 patients were selected for brain rs-fMRI,and the differences of ALFF were analyzed to evaluate the degree of brain damage in T2DM patients.Results:1)All patients were divided into two groups[cognitive impairment(MCI group)and non-cognitive impairment(non-MCI group)]based on the MoCA score.The serum chemerin level in the MCI group was significantly lower than that in the non-MCI group(81.07±23.33 vs 108.93±32.92 ng/ml,P<0.01);the systolic blood pressure,body weight index,educational level and serum uric acid in the MCI group were significantly lower than that in the non-MCI group(P<0.05).2)Spearman analysis between the score of MoCA and the serum chemerin level and other metabolic parameters of diabetic patients showed that the MoCA score was positively correlated with the serum chemerin level(r=0.35),educational level(r=0.318),body mass index(r=0.184),systolic blood pressure(r=0.15)and serum uric acid(r=0.078)(P<0.05);further study found that the serum chemerin level was positively correlated with the visual spatial ability score(r=0.261),language score(r=0.012),memory score(r=0.189)and orientation score(r=0.189)(P<0.05).Logistic analysis showed that the serum chemerin and educational level were protective factors for cognitive function in patients with T2DM.3)64 patients were selected for brain rs-fMRI and divided into low chemerin group(chemerin:<80ng/ml)? medium chemerin group(80ng/ml<chemerin<130ng/ml)and high chemerin group(chemerin? 130ng/ml).The study showed that the ALFF value of prefrontal lobe in low chemerin group was lower than that in high chemerin group(1.31±0.63 vs 1.060.37,P<0.001)and middle chemerin group(1.20±0.53vs 1.06±0.37,P<0.05),there was no significant difference between the high chemerin group and the middle chemerin group(P>0.05).Conclusion:In patients with T2DM,decreased serum chemerin may lead to cognitive dysfunction.The serum chemerin is positively correlated with MoCA score and the patients with low serum chemerin level have lower ALFF value of prefrontal lobe.The serum chemerin may be a protective factor of cognitive function in diabetic patients.