Plasma semicarbazide-sensitive amine oxidase activity in type 1 diabetes is related to vascular and renal function but not to glycaemia.

Purpose: Associations of semicarbazide-sensitive amine oxidase (SSAO) activity with renal and vascular function, oxidative stress, glycaemia and diabetes complications were determined. Methods: Plasma SSAO activity in 94 type 1 diabetes (T1DM) patients, including 34 with microvascular complications T1DM CX[+], and in 96 healthy subjects (CON) was measured by production of benzaldehyde using high-performance liquid chromatography (HPLC). Results: SSAO activity (mean +/- SD) was greater in T1DM than in CON (1049 +/- 294 vs 749 +/- 204 mU/L; p < 0.00001) and was higher in T1DM CX[+] vs complication-free DM subjects (1148 +/- 313 mU/L vs 982 +/- 269 mU/L; p = 0.01). In T1DM, SSAO activity correlated with renal dysfunction [ estimated glomerular filtration rate (eGFR): r = -0.44; p = 0.0001; cystatin C: r = 0.47; p = 0.0001] and markers of inflammation [ soluble vascular cell adhesion molecule-1 (sVCAM-1): r = 0.41, p = 0.0001; soluble intercellular adhesion molecule-1 (sICAM-1): r = 0.33, p = 0.002] and was inversely related to small artery elasticity (SAE) (r = -0.23, p = 0.03). In CON, SSAO activity correlated with HbA1c (r = 0.26; p = 0.02). Conclusion: In T1DM, SSAO activity correlates with renal dysfunction, but not with glycaemia, and may promote vascular inflammation and be a therapeutic target.