LPA and type 2 diabetes mellitus: Additionally, for each increase of 1 logarithmic unit in Lp(a), the risk of CIN increased by 1.27 times (OR = 1.27, 95% CI: 1.01-1.64, <i>P</i> <i>=</i> 0.045).<h4>Conclusions</h4>A higher serum Lp(a) level indicates an increased risk of CIN in T2DM patients undergoing CAG or PCI and can serve as an independent predictor of CIN in this population.