Effects of hyperglycaemia and elevated glycosylated haemoglobin on contrast-induced nephropathy after coronary angiography

In patients undergoing percutaneous coronary intervention after acute myocardial infarction, hyperglycaemia on admission is associated with an increased risk of contrast-induced nephropathy (CIN). However, the effects of hyperglycaemia and elevated glycosylated haemoglobin (HbA1c) on CIN have remained to be fully elucidated. Therefore, a prospective cohort study was performed, comprising 258 patients who underwent coronary angiography between May 2017 and November 2017 at Zhongda Hospital affiliated with Southeast University (Nanjing, China). According to the diagnostic criteria for CIN (increase of serum creatinine by >44.2 mu mol/l or by 25% within 48-72 h of using contrast agent), the patients were divided into two groups: CIN (45 cases) and non-CIN (213 cases). For all patients, the baseline data, medical history, laboratory parameters, medication history and intraoperative situation were recorded and assessed using single-factor analysis and multiple logistic regression analysis to analyse the risk factors of CIN. The incidence of CIN in the hyperglycaemia group (blood glucose on admission, >11.1 mmol/l) was 25%, compared with 13.8% in the non-hyperglycaemia group (P=0.026). Furthermore, the incidence of CIN in the elevated HbA 1c group (HbA1c on admission, upper limit of normal) was 26.1%, compared with 14.3% in the group without elevated HbA1c (P=0.027). Hyperglycaemia was present on hospital admission in 84 of 258 patients (32.6%). The percentage of patients with elevated HbA1c was 26.7%. Age, estimated glomerular filtration rate, pre-operative blood cholesterol, hyperglycaemia on admission and elevated HbA1c were all identified to be associated with CIN. According to the multivariate logistic regression analysis, hyperglycaemia was an independent predictor of CIN (odds ratio, 2.815; 95% confidence interval, 1.042-4.581; P=0.029). In the acute coronary syndrome (ACS) and diabetes subgroups, hyperglycaemia was significantly associated with CIN. In the ACS subgroup, the incidence of CIN was 38.1%. It was indicated that hyperglycaemia is an independent risk factor for CIN, particularly in patients with ACS or diabetes.