Adipocyte fatty acid binding protein and C-reactive protein levels as indicators of insulin resistance development.

Background: Adipocyte fatty acid-binding protein (aFABP) has recently been identified as a potential circulating marker for metabolic syndrome. C-reactive protein (CRP), a sensitive marker of inflammation, is increased in individuals with diabetes and metabolic syndrome due to the development of subclinical inflammation. The study uses logistic regression models to analyze the relations between aFABP and CRP along with other parameters of insulin resistance. The objective was to investigate the potential use of aFABP and CRP levels as tools in the diagnosis of the metabolic syndrome.

Methods And Results: The following groups were studied: healthy individuals (A, n=122), obese individuals (B, n=213) and patients diagnosed with metabolic syndrome (C, n=79). Obese persons in Group B had parameters suggestive of early insulin resistance: hypertension, hyperglycaemia, QUICKI (0.305) and higher aFABP levels as compared with the healthy subjects. Group C individuals were diagnosed with metabolic syndrome, as evidenced by the QUICKI markers for insulin resistance (0.293), high aFABP levels (35.3 mg/l). CRP concentrations were lowest in Group A healthy individuals (0.67 mg/l), higher in Group B obese subjects (2.65 mg/l) and highest in Group C patients with metabolic syndrome (3.62 mg/l). Logistic regression models showed an association of aFABP and CRP with BMI (OR 1.12 and 1.39, compared Group A vs C). An association of aFABP and CRP with the QUICKI index showed OR 1.48 and 1.37 (Group A vs C); with triglyceride levels showed OR 1.68 and 1.52 (Group A vs C). An association of aFABP and CRP with glycaemia showed OR 1.48 and 1.51 (Group A vs C), with insulinaemia showed OR 1.44 and 1.38 (Group A vs C) respectively.

Conclusions: AFABP levels were higher in obese individuals and highest in those with metabolic syndrome. CRP concentrations were increased in obese persons whereas individuals with metabolic syndrome were found to have high-risk CRP levels. Logistic regression models showed an association of aFABP and CRP with BMI as well as an association of aFABP and CRP with parameters of insulin resistance, namely the QUICKI index, triglyceride levels, glycaemia and insulinaemia. Both methods are of diagnostic benefit for predicting metabolic syndrome, especially in previously untreated patients.