Serum pro-brain natriuretic peptide correlates with optical coherence tomography indices in diabetic retinopathy

Serum pro-brain natriuretic peptide (BNP) is a 108-amino-acid prohormone that inhibits vascular endothelial growth factor (VEGF) secretion, protecting pericytes from cell death and decreasing retinal vascularization. The purpose of this study was to investigate the correlation of serum pro-BNP with optical coherence tomography (OCT) indices in diabetic retinopathy.

This cross-sectional study investigated 96 consecutive subjects aged between 40 and 65 years: controls n = 24, no diabetic retinopathy (NoDR) n = 24, non-proliferative diabetic retinopathy (NPDR) n = 24, and proliferative diabetic retinopathy (PDR) n = 24. Same-day analysis of blood samples for serum pro-BNP levels was performed and spectral-domain OCT (SD-OCT) was used to measure the following OCT indices: OCT angiography (OCTA) superficial vessel density (SVD), deep vessel density (DVD), and foveal avascular zone (FAZ); OCT retinal nerve fiber layer (RNFL); and OCT ganglion cell analysis (GCA).

The mean serum pro-BNP levels for the control, NoDR, NPDR, and PDR groups were 14.07 ± 11.51, 27.35 ± 11.81, 280.44 ± 106.13, and 122.33 ± 43.66 pg/ml, respectively. The mean values of the various OCT parameters correlated with serum pro-BNP were OCTA SVD (r = $-$ 0.360), OCTA DVD (r = 0.408), OCTA FAZ (r = 0.475), OCT RNFL (r = $-$ 0.215) and OCT GCA (r = $-$ 0.285; p<0.001).

The serum pro-BNP levels were higher in the NPDR group than in the NoDR group and much lower in the PDR group than in the NPDR group, reflecting a lowering of the protective barrier. These results correlated with the changes in various OCT indices.