Under normal physiological conditions, the volume and composition of body fluids vary within narrow limits due to proper function of kidneys. They also sub-serve a host of metabolic and endocrine functions. Failure of renal function results ultimately in alterations of milieu interior that affects every system in the body. Acute kidney injury (AKI) or acute renal failure (ARF) is defined as an abrupt or rapid decline in renal filtration function. Nearly all of the contrast media (CM) used during diagnostic and therapeutic percutaneous procedures is eliminated by the kidneys. The concentration achieved in the renal tubular system is less than or equal to the concentration achieved in plasma and approaches less than or equal to injected solution [1] so it is not surprising that CM could be a cause of AKI. Contrast induced nephropathy (CIN) is now a well recognized form of iatrogenic AKI causing acute detoriation of kidney function with risk of chronic kidney disease are at increased risk of death [2-6]. Once the other causes of AKI have been excluded this detoriation in renal function is usually attributed to exposure of contrast material and is termed as contrast induced nephropathy (CIN). Fortunately, most of the cases of CIN are self-limited and kidney function returns to normal in 2 weeks after exposure to contrast media. CM is increasingly used in both diagnostic and therapeutic procedures in the modern era of interventional cardiology. This results in increasing incidence of iatrogenic renal function impairment.

CM makes the arteries radio opaque and help in viewing with fluoroscopy. The ideal contrast medium would achieve a very high concentration in tissues without producing any adverse effects. Unfortunately, this has not been possible and so far, all CM have adverse effects. Kidneys being the primary portal of excreting waste products of metabolism and foreign chemicals. With this, a study on incidence and adverse effects of contrast agents on renal function based on serum creatinine and creatinine clearance in patients without a pre-existing renal disease.

Study design: Hospital based cross sectional study

Sample size: Random sampling was considered during the study period; 80 subjects who underwent elective angiography/angiogram were included in the study.

Total 80 study subjects were included in this study; in this 48 (60%) were male and 32 (40%) were female participants. The male female ratio in this study was 1.5, Gender wise CIN developed ratio was 1.9.

Age wise, highest number (33) of participants were included in 51-60 years age group followed by 41-50 years group (2.5%), 61-70 years group (18.8%), 31-40 years group (10%) and less number (7.5%) in 71-80 years age group. When CIN was considered, highest (31%) in 41-50, 51-60 years age group, respectively. Age wise, CIN was increased with age (Table 1). When the comorbid conditions were considered, 37.9% diabetics, 48.3% smokers, 41.4% alcoholics developed CIN; statistically there was no significant difference.

Table-1: Incidence of CIN according to the age; n (%).

In the normal category 10 (34.5%), mild category 12 (41.4%), moderate renal dysfunction category 67 (24.1%) developed CIN. There were no study subjects in the fourth category i.e severe renal dysfunction. When the CM effect was correlated with renal function tests, the mean serum creatinine levels were 1.00±0.19, 1.21±0.34 respectively in pre and post angio groups; statistically there was significant difference. Whereas the mean creatinine clearance value was 81.98±21.5, 68.36±22.01 respectively in pre and post angio groups; statistically there was significant difference (Table 2).

Table-2: Effect of CM on renal function tests; Mean + standard deviation

CIN is an iatrogenic disorder with high morbidity and mortality with a high incidence in elderly, diabetics, and patients with pre-existing renal dysfunction.

Whereas the mean creatinine clearance value was 81.98±21.5, 68.36±22.01 respectively in pre and post angio groups; statistically there was significant difference (Table 2). The mean serum creatinine was reported to be 1.53±0.4 mg/dl and the eGFR was 46.47±8.9 ml/mt. Previous studies show that patient demographics like older patients, anemia, the presence of diabetes mellitus, a low ejection fraction, usage of loop diuretics and procedural characteristics like intra procedure hypotension, increased contrast volume confer a significant risk of CIN [16-18]. In this study, 48.3% smokers and 41.4% alcoholics developed CIN. But the exact role of smoking and alcohol is not established. Probably smoking may add to incidence by increasing the oxidative stress. Higher (63%) rate of CIN was reported among smokers by M Akhataruzzaman et al., [19] report, but the exact predictor for CIN could not be established. The final end point of the present study was to evaluate rise in serum creatinine or decrease in creatinine clearance. Minimum and maximum serum creatinine values were 0.5mg/dl and 1.2 mg/dl in pre angio and the levels were 0.6 and 2.6 mg/dl in post angio. Similarly, the pre angio minimum and maximum values of creatinine clearance were 44.08 and 143 ml/min and the levels were 28 and 143 ml/min in post angio; statistically the difference were significant. When these values were correlated with CIN, the rate of incidence was 36.2% (29) for serum creatinine and statistically the difference was significant (p = 0.0001). But Priya SV et al reported 0.6% CIN only [20].

Single centric research and small sample size are the limitations of this research.

With these findings we conclude that overall increase in the incidence of CIN with age and no influence of gender as well as conditions like diabetes and hypertension. But studies on large sample size with additional comorbid conditions is recommended for better conclusion.

Overall increase in the incidence of CIN with age and no influence of gender as well as conditions like diabetes and hypertension