Haruhito Taneichi

Positive association of free triiodothyronine with pancreatic β-cell function in people with prediabetes

To analyse the effects of thyroid hormones on β‐cell function and glucose metabolism in people with prediabetes who are euthyroid.

Association of the TNF-α-C-857T Polymorphism With Resistance to the Cholesterol-Lowering Effect of HMG-CoA Reductase Inhibitors in Type 2 Diabetic Subjects

OBJECTIVE An association of the C-857T polymorphism of the tumor necrosis factor-α (TNF-α) gene promoter region with LDL cholesterol levels has been reported. This study was designed to evaluate the relationship between the TNF-α-C-857T polymorphism and LDL cholesterol levels according to statin treatment in subjects with type 2 diabetes. RESEARCH DESIGN AND METHODS DNA was obtained from 322 Japanese subjects (160 male and 162 female) with type 2 diabetes, and TNF-α-C-857T polymorphisms were determined by direct sequencing. Serum LDL cholesterol was measured by a direct method. RESULTS Although serum LDL cholesterol levels were significantly higher in the T carriers (C/T + T/T) than in the non–T carriers (C/C) (3.14 ± 0.86 vs. 2.89 ± 0.75 mmol/l, P < 0.05), there was no difference in LDL cholesterol levels between the non–T carriers and the T carriers in statin-untreated subjects (2.87 ± 0.73 vs. 2.89 ± 0.76 mmol/l, NS), whereas in statin-treated subjects, LDL cholesterol levels were significantly higher in the T carriers than in the non–T carriers (3.43 ± 0.89 vs. 2.90 ± 0.78 mmol/l, P = 0.0007). There were no differences in HDL cholesterol and triglyceride levels between the non–T carriers and the T carriers in both statin-treated and -untreated subjects. The percent decrease in LDL cholesterol levels after administration of statins was significantly smaller in the T carriers compared with the non–T carriers (27.6 vs. 36.4%, P = 0.031). CONCLUSIONS The mutant allele of the C-857T promoter polymorphism of the TNF-α gene may predispose to resistance to the LDL cholesterol–lowering effect of statins and could be one of the markers used to predict the efficacy of statins.

Response to the dipeptidyl peptidase‐4 inhibitors in Japanese patients with type 2 diabetes might be associated with a diplotype of two single nucleotide polymorphisms on the interleukin‐6 promoter region under a certain level of physical activity

Muscle‐derived interleukin‐6 (IL‐6) has been reported to promote glucagon‐like peptide‐1 (GLP‐1) secretion, and we explored the association of single nucleotide polymorphisms (SNPs) in the human IL‐6 promoter region with the responsiveness to dipeptidyl peptidase‐4 inhibitors (DPP‐4Is), drugs that increase circulating GLP‐1.