Serum Heart Type Fatty Acid Binding Protein Levels in Prediabetes-An Invaluable Cardiovascular Biomarker

Abstract

Background: The pathophysiological effects of diabetes on the heart and the rest of the cardiovascular system begins much earlier in its precedent stage of prediabetes and one major underlying defect is insulin resistance. Heart-type fatty acid binding protein (H-FABP) is a recently studied molecule inherent to the cardiac myocytes found to rise in both coronary and non-coronary heart diseases. The utility of the molecule in prediabetes and its relationship with insulin resistance is being studied.

Objective: The aim of the study is to compare serum levels of H-FABP in prediabetics and controls and correlate them with Homeostatic model assessment - insulin resistance (HOMA-IR).

Methods: 50 prediabetic patients and 50 age, sex and BMI matched controls were employed in the case control study. Serum fasting and postprandial blood sugars, glycosylated hemoglobin (HbA1c), fasting insulin levels were measured in cases and controls. HOMA-IR index was calculated from fasting glucose and insulin values. Serum H-FABP was measured in both cases and controls using Immunoturbidimetric method with anti- H-FABP coated latex reagent kits. The values were compared between both the groups.

Results: The mean serum fasting insulin level among cases was 12.22mIU/ml and that of the control group was 5.37mIU/ml (p value <0.0001). HOMA- IR mean values were 3.31 ± 1.56 and 1.16 ± 0.44 in cases and controls respectively (p- <0.001). The mean serum levels of H-FABP among cases and controls were 6.38± 2.76ng/ml and 3.24 ± 2.47 ng/ml respectively (p <0.0001). The correlation between the two variables, HOMA-IR and H-FABP was also found to be strongly positive (r=0.675). Linear regression analysis showed that for 1 unit increase in HOMA-IR, H-FABP increased by 1.095 and for 1 unit increase in Fasting insulin, H-FABP increased by 0.038.

Conclusion: Prediabetics have a higher risk of cardiovascular morbidity when compared to normoglycemics with insulin resistance being the single most important contributor. Serum H-FABP levels are elevated in prediabetes representing a marker of subclinical cardiovascular disease (CVD).