RBP4 and diabetic neuropathy: IV: Intravenous; N: Number of participants; CT: Clinical trial; TTR: Transthyretin; SC: Subcutaneously; RBP4: Retinol-binding protein 4; QoL: Quality of life; QoL-DN: Quality of life-diabetic neuropathy; MAE: Major adverse event; GN: Glomerulonephritis; TCP: Thrombocytopenia.