Macroalbuminuria as a marker of cardiac damage in patients with type 2 diabetes: insights from multimodality cardiac imaging and biomarkers.

BACKGROUND AND AIMS: Albuminuria reflects renal and cardiovascular damage in type 2 diabetes (T2D), but its association is not fully understood. We evaluated the association of macroalbuminuria with cardiac structure and function. METHODS: Cross-sectional study of 49 adults with T2D and stage 3 chronic kidney disease (CKD), stratified by macroalbuminuria, and 20 controls. Cardiac assessment included cardiac magnetic resonance (MRI), transthoracic echocardiography (TTE) and nine serum biomarkers, including soluble suppression of tumorigenicity 2 (sST2), a biomarker of myocardial stress and fibrosis. RESULTS: Patients with T2D exhibited higher circulating levels of TIMP-1, MMP-10, neutrophil gelatinase-associated lipocalin (NGAL), NT-proBNP and hs-TnT than controls (p < 0.05). Among patients with T2D, macroalbuminuria was associated with an additional increase in TIMP-1 (p < 0.05). Patients with T2D had higher T1 values in MRI scans, particularly those with macroalbuminuria (1051 ms [IQR: 1035-1074] vs. 1009 ms [IQR: 989-1020] in controls, p < 0.001). Although sST2 levels were higher in patients with T2D than in controls and tended to be higher in those with macroalbuminuria, these differences did not reach statistical significance. Nevertheless, higher T1 values were associated with higher sST2 levels, particularly in patients with macroalbuminuria (p for interaction < 0.01). Among patients with macroalbuminuria, high sST2 levels were associated with higher T1 values (1071 ms [IQR: 1052-1087] vs. 1029 ms [IQR: 1013-1043], p < 0.05). CONCLUSIONS: In T2D and stage 3 CKD, macroalbuminuria identifies a subgroup with more cardiac structural and functional abnormalities, particularly with elevated sST2. Prospective validation is needed.