Nerve conduction velocity (NCV) is one of the simplest ways to evaluate diabetic polyneuropathy (DPN). We measured NCV annually for eight years in 442 type 2 diabetic patients divided into 3 groups based on the degree of diabetic retinopathy and studied the correlation between the progression of diabetic retinopathy and NCV. We also studied the eight-year time course of NCV for each retinopathy grade. In the study of the correlation between the progression of diabetic retinopathy and NCV, NCV was lower the higher the grade of retinopathy. In the 8-year time course of NCV, NCV significantly decreased for all retinopathy grades, but the averaged NCV in one retinopathy grade did not decrease below the averaged NCV of the upper grade of retinopathy. From these results, we concluded that DPN is more progressive at higher retinopathy grade, and DPN steadily progresses from the period of no retinopathy to proliferative retinopathy in parallel with retinopathy progression.

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To determine the clinical utility of sensory symptoms, neurological examination (NE), and nerve conduction studies (NCS) of the feet in the early detection of diabetic polyneuropathy (DPN), we examined 100 adult patients with type 2 diabetes. After an interview regarding sensory symptoms of the feet, vibration thresholds of the great toe (V-1) and medial malleolus (V-M), light touch sensation of the great toe with a tissue (TT), and the Achilles tendon reflex (ATR) were examined. In the NCS, we evaluated the dorsal sural (DSN), the medial and lateral plantar (MPN, LPN), the tibial (TN) and sural nerves (SN). We found that only 34% of patients had sensory symptoms of the feet, while 55-59% of patients were judged as abnormal in V-1, TT, and ATR. Each of these examinations correlated significantly with indices in the NCS of the LPN, DSN, MPN, and TN. The NCS showed that 67-57% of patients had at least 2 or more abnormal values in the LPN, DSN, MPN, and TN. These findings suggest that neurological examination and NCS of the feet are useful in detecting early changes in DPN, while sensory symptoms contribute less.

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Low-density lipoprotein cholesterol (LDL-C) is an established risk factor for atherosclerosis, although recent studies have reported that serum levels of apolipoprotein B (Apo B) were better predictors of atherosclerotic vascular disease than LDL-C. We measured common carotid intima-media thickness (CCA-IMT) in 181 patients with type 2 diabetes and determined the best marker of the two lipid parameters, LDL-C and Apo B, for CCA-IMT risk assessment. Patients who had carotid atherosclerosis had significantly higher age, body mass index, blood pressure, glucose, insulin, insulin resistance, total cholesterol, triglyceride, LDL-C, and Apo B. In the multiple regression model, age, body mass index, Apo B, and systolic blood pressure were independently and significantly related to CCA-IMT. Contrary to Apo B, LDL-C was not determined as an independent risk factor for CCA-IMT. CCA-IMT increased associated with the tertile of Apo B levels independent of LDL-C or triglyceride or HDL-C levels.
In conclusion, Apo B may be a greater risk factor for carotid atherosclerosis than LDL-C in Japanese patients with type 2 diabetes.

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We investigated the clinical characteristics of patients with early-onset type 1 or type 2 diabetes with diabetic foot. The subjects were 39 patients of diabetes diagnosed at the age of 30 years or earlier, composed of 11 patients with type 1 diabetes (Group T1) and 28 patients with type 2 diabetes (Group T2).
The mean interval from the diagnosis of diabetes to the development of diabetic foot was 22.2 years in Group T1 and 20.0 years in Group T2. However, 25.9% of the patients in Group T2 showed onset of diabetic foot within 10 years of the diagnosis. All of the Group T1 patients also had diabetic neuropathy and diabetic retinopathy, and 72.7% had diabetic nephropathy, Stage 5. All of the patients in Group T2 had diabetic neuropathy, 96.4% had diabetic retinopathy and 32.1% had diabetic nephropathy, Stage 5. Over half of the patients in Group T2 (67.9%) had intermittently discontinued diabetes treatment.
Patients with early-onset type 1 diabetes mainly had other advanced diabetic complications. In the early-onset type 2 diabetes patients, the interval from the diagnosis of diabetes mellitus to the onset of diabetic foot varied widely, and many had intermittently discontinued diabetes treatment. We demonstrated differences in clinical characteristics between early-onset type 1 and type 2 diabetes patients with diabetic foot.

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[in Japanese]

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[in Japanese]

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A 54-year-old man was admitted to the hospital because of poor glycemic control, liver dysfunction and elevation of the serum level of creatine kinase. Although the patient was under treatment with glimepiride for diabetes, his blood glucose level was 323 mg/dl and HbA₁c was 10.7%. The BMI was 29.9 kg/m² and waist circumference, 91 cm. The patient was also diagnosed to have hypertension and fatty liver. At admission, thyroid function test results revealed marked hypothyroidism (TSH 135.7 μU/ml, FT₄ 0.1 ng/dl, FT₃ 1.49 pg/ml) and the serum was positive for anti-thyroid peroxidase antibody and anti-thyroglobulin antibody. Thus, the patient was diagnosed to have Hashimoto's thyroiditis. Administration of levothyroxine sodium resulted in improvement of the patient's thyroid function test results. To clarify the reason for the liver dysfunction, a percutaneous liver biopsy was performed. The histological findings were compatible with a diagnosis of nonalcoholic steatohepatitis (NASH) (the patient did not have a history of alcohol abuse). Administration of ursodesoxycholic acid and insulin therapy resulted in improvement of the glycemic control and liver function. Type 2 diabetes mellitus is an important risk factor for the development of NASH. In addition, hypothyroidism due to Hashimoto's thyroiditis was also thought to be involved in the pathogenesis of NASH in this case.

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