Thiazolidinedione addition reduces the serum retinol-binding protein 4 in type 2 diabetic patients treated with metformin and sulfonylurea.
Retinol-binding protein 4 (RBP4) has been found to induce insulin resistance and to be increased in type 2 diabetes. Thiazolidinediones (TZDs) can improve insulin sensitivity through the activation of peroxisome proliferators-activated receptor-gamma (PPAR-gamma) and have been suggested as an adjunct to metformin (MF) and sulfonylurea (SU) in type 2 diabetes in a consensus statement from the ADA and EASD. Therefore, we investigated whether TZD could affect serum RBP4 level in type 2 diabetes already treated with MF and/or SU. Eighty-one type 2 diabetic patients were divided into 2 groups: (1) TZD group (n = 55): Pioglitazone 30 mg/day was given as an add-on medication; (2) SU group (n = 26): Gliclazide MR 30-120 mg or glimepiride 2-8 mg/day was prescribed. The average period of study was 97.1 days. Serum RBP4 and adiponectin were measured by enzyme-linked immunosorbent assay and radioimmunoassay, respectively. The addition of pioglitazone (TZD group) markedly decreased homeostasis model assessment of insulin resistance (HOMA-IR) (P = 0.021) compared with the SU group (P = 0.688). The change of RBP4 in the TZD group (-3.87 +/- 11.27 microg/mL) significantly differed from that in the SU group (2.52 +/- 8.24 microg/mL, P < 0.012). The increase of adiponectin in the TZD group (11.49 +/- 7.85 microg/mL) was apparently higher than that in the SU group (1.54 +/- 5.62 microg/mL, P < 0.001). Despite the change of glycosylated hemoglobin (HbA1c) did not differ (-0.77 +/- 1.3 vs -0.50 +/- 1.7, P = 0.446), the addition of pioglitazone could significantly lower serum RBP4 and HOMA-IR values, whereas an increased dosage of sulfonylurea agents did not alter HOMA-IR, RBP4, or adiponectin in type 2 diabetic patients who had been treated with metformin and/or sulfonylurea.
Lin
Kun-Der
KD
Graduate Institute of Medicine, Kaohsiung Medical University Hospital, Taiwan.
Chang
Yu-Hung
YH
Wang
Chiao-Ling
CL
Yang
Yi-Hsin
YH
Hsiao
Pi-Jung
PJ
Li
Tzu-Hui
TH
Shin
Shyi-Jang
SJ
D000284:Administration, Oral; D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000378:metabolism*; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D054839:Retinol-Binding Proteins, Plasma / Q000378:metabolism*; D013453:Sulfonylurea Compounds / Q000008:administration & dosage / Q000627:therapeutic use*; D045162:Thiazolidinediones / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use
D007004:Hypoglycemic Agents; C101326:RBP4 protein, human; D054839:Retinol-Binding Proteins, Plasma; D013453:Sulfonylurea Compounds; D045162:Thiazolidinediones; D008687:Metformin; C089946:2,4-thiazolidinedione