HBA1C AND INSULIN RESISTANCE AS PREDICTORS FOR THE SEVERITY OF CORONARY ARTERY DISEASE AND SYSTOLIC HEART FAILURE IN NON DIABETIC PATIENTS.

Abstract

Coronary heart disease (CAD) is the main cause of morbidity and mortality in developed countries, its prevalence is increasing in developing countries. (1) Insulin resistance (IR) has known to be associated with coronary artery disease (CAD), assessment of severity of the CAD based on IR has not been established in details. (2) Multiple angiographic scoring systems were used systematically to evaluate number of affected epicardial vessels, detailed assessment of lesion severity and quantification of the functional significance of myocardium affected by stenotic lesions. (3) HbA1c is a useful index of glucose intolerance and hyperglycemia, even when fasting glucose concentrations are normal. (4)
Aim of the work: to study the relationship between HbA1c, IR as predictors for the severity of CAD in chronic stable angina and Systolic Heart Failure in Non-Diabetic Patients.
Patient and methods: This study was done in Cardiology department, Zagazig University on 100 patients; 64 males (64%) & 36 females (36%), our patients with CAD were grouped according to Ejection Fraction (EF) into G1 with EF>50%, G2 with EF<50%. They were fatherly divided according to positive family history (FH) of DM; G1a with -ve FH, G1b with +ve FH, G2a with –ve FH, G2b with +ve FH. We searched for IR by measuring HOMA-IR and measured fasting Blood sugar (FBS) and HbA1c as markers of glycaemia. Coronary angiography was done and severity of coronary artery disease was calculated by Gensini score.
Results: In our study we discovered a cutoff point = 5.5% for HbA1c to predict the systolic heart failure. It showed a good specificity and fair sensitivity (73.5%, 43.9%) respectively. There was a highly statistical significant difference between HbA1c and number of coronary arteries affected (X = 9.7, p =0.004). As regard HbA1c and Gensini score, there was a highly statistical significant difference (X = 10.5, p =0.001). We also discovered a cutoff point = 1.9 for HOMA-IR to predict the systolic heart failure in our study. There was a significant relation between Gensini Score and dyslipidemia(r =0.337, p= 0.001), hypertension (r = 0.255, p = 0.011) and fasting blood sugar (r = 0.229, p = 0.022). There was also a significant correlation between systolic heart failure and dyslipidemia (r =0.315, p= 0.001) and hypertension (r = 0.251, p = 0.012) in non-diabetic patients.
Conclusions: We conclude that in non-diabetic patients with CAD, HbA1c above the cutoff point 5.5% can predict an increasing severity of the coronary artery disease and the number of the affected coronary arteries.
Key words: Coronary artery disease, Insulin resistance, Hba1c, Heart Failure, HOMA-IR.