This is a single centre,study in diabetic patients already undergoing a planned procedure, that is, a percutaneous coronary intervention (PCI). They are patients who are deemed to have an enhanced risk of contrast induced nephropathy by virtue of their diabetic and renal status, the latter being defined by a reduced eGFR which is a marker of renal disease and is based on the creatinine and characteristics of the patient. No additional interventions that are not part of their routine clinical care will be undertaken in these patients. We will be identifying natural biomarkers by obtaining serum and urine samples from these patients.