| Part I The characteristics and risk factors of diabetic peripheral neuropathy of Type 1 diabetes mellitus patientsObjectives Diabetic peripheral neuropathy is one of the most common complications of diabetes mellitus, which is main cause of death and disability for diabetic patients. DPN may involve nerve fibers of different sizes, in which small nerve fibers are more commonly injured than large ones. The Neurometer CPT/C nerve detector detects the function of small nerve fibers. The study investigated the characteristics and related risk factors of DPN of T1 DM patients using nerve conduction velocity and CPT value, which provided evidences for early diagnosis and treatment of DPN of T1 DM patients.Methods 70 patients with T1 DM diagnosed in our hospital and 48 healthy volunteers were included in our study. All subjects accepted nerve conduction velocity and CPT examinations for four limbs. CPT examination consisted of CPT values of bilateral median and sural nerves under 2000 Hz, 250 Hz and 5Hz current stimulus. Neuropathy symptom scores and neuropathy disability scores were evaluated and detailed clinical indicators were recorded for every T1 DM patients. CPT values under current stimulus of three frequencies were compared between TIDM group and the control group. The risk factors affecting DPN were further explored.Results Compared with the control group, the CPT values under current stimulus of three frequencies were decreased in T1 DM group. Using CPT values as standards, 95.7% patients have peripheral nerve dysfunction. The abnormality rate of sural nerves was higherthan that of median nerves on the same side(P<0.001). Moreover, the CPT values of sural nerves were lower than that of median nerves on the same side, except the CPT values of the left side under 250 Hz current stimulus(P<0.05). Median nerve dysfunction mainly presented as hypoesthesia under 250 Hz and 5Hz current stimulus. And sural nervedysfunction mainly presented as hyperesthesia under current stimulus of three frequencies. The dysfunction incidence of left sural nerves was higher under 5Hz current stimulus(P=0.001). Compared with the left median nerve, the abnormal rate of right median nerve was higher under 2000 Hz current stimulus(P=0.035). However, the abnormal rate of left sural nerve was higher than that of right side under 250 Hz and 5Hz current stimulus(P=0.001, <0.001). The CPT values of left sural nerves were smaller than that of right side under 5Hz current stimulus(P=0.040). All results indicated Aβ thick myelinated nerves were more likely injured in the right upper limb and that Aδ thin myelinated and C amyelinated nerves were more likely injured in the left lower limb. Duration, NDS scores and CPT values of right median nerve under 2000 Hz current stimulus were independent risk factors of abnormal nerve conduction velocity.Conclusions The study proved that DPN of T1 DM are mainly lower limb-injured, and amyelinated and thin myelinated nerve fiber-involved. The characteristics of injured nerve fibers of different sides and limbs varied. Median nerve dysfunction were more likely to present as hypoesthesia and sural nerve dysfunction were more likely to present as hyperesthesia. Duration, NDS scores and CPT values of right median nerve under 2000 Hz current stimulus were independent risk factors of abnormal nerve conduction velocity. CPT provides a new tool for quantitative evaluation of small nerve fibers, which can be combined with traditional nerve conduction velocity examination. This will help the diagnosis of DPN of T1 DM earlier and more comprehensively, and make early diagnosis and monitoring of treatment outcomes of DPN possible.Part II The characteristics and risk factors of cognitive dysfunction of Type 1 diabetes mellitus patientsObjectives The effects of diabetes mellitus on cognitive function attract extensive attention nowadays. It has been widely accepted that T2 DM can affect cognitive function, even result in dementia. Recently, the change of cognition function of T1 DM patients has attracted more and more attention. However, the change of cognitive function and influencing factors were reported contradictorily. The study compared the cognitive function between T1 DM patients and healthy volunteers and explored the details and risk factors of cognitive dysfunction of T1 DM patients.Methods 70 T1 DM patients diagnosed in our hospital and 48 healthy volunteers were included. All subjects accepted evaluation of MMSE and Mo CA scales. The differences of cognitive function between the two groups were compared and cognitive dysfunction of T1 DM patients was analyzed in details. Detailed clinical indicators were recorded for every T1 DM patients. The risk factors affecting cognitive function were further explored.Results The abnormal rate of Mo CA scale was higher in T1 DM group than that in control group(40.0% vs. 11.1%, P=0.001). Scores of both MMSE and Mo CA scales in T1 DM group were lower than that in control group(29.1±1.2 vs.28.3±1.9, P=0.007; 27.1±2.3 vs.25.8±2.9, P=0.006). For MMSE scale, scores of orientation and language function in T1 DM groups were lower than that in control group(9.57±0.84 vs.9.87±0.39, P<0.001; 8.55±0.65 vs.8.81±0.39, P<0.001). For Mo CA scale, scores of visuospatial/executive function, memory, language function, abstraction and calculating ability were lower in T1 DM group than that in control group(4.27±0.92 vs.4.56±0.68, P=0.001;2.90±1.51 vs.3.75±1.27, P<0.001; 4.57±0.93 vs.5.31±0.80, P=0.002;1.50±0.71 vs.1.74±0.56, P=0.001; 2.81±0.63 vs.2.96±0.20, P=0.002). Using Mo CA scores for diagnosis of cognitive dysfunction, logistic regression showed age, C peptide, educational level and nerve conduction velocity abnormality were risk factors of cognitive dysfunction.Conclusions The study showed the cognitive dysfunction of adult patients of T1 DM, which mainly presented as dysfunction of visuospatial/executive, language, abstraction andcalculating ability. Mo CA scale can be applied as a main screening tool for evaluation of cognitive function of T1 DM patients. Age, C peptide levels, educational levels and nerve conduction velocity abnormality were risk factors of cognitive dysfunction. |
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