Increased plasma resistin concentrations are associated with atherogenic small, dense low-density lipoproteins in patients with type-2 diabetes
Manfredi Rizzo1, Beatrice Amann-Vesti2, Cornelia Zwimpfer3, Giatgen Spinas3 & Kaspar Berneis3
Background: Resistin was originally proposed in animal models as a link between obesity and insulin resistance, but later studies in humans have shown a divergent role. Yet, resistin seems to be involved in the development of atherosclerosis in humans by promoting the formation of foam cells; further, its expression is induced by oxidized low-density lipoproteins (LDL) in human macrophages.
Methods: We assessed the relationships between resistin and markers of insulin resistance and atherogenic dyslipidemia, including small, dense LDL, in subjects with type-2 diabetes (n=31, age: 67±10 years, BMI: 28±3 kg/m2). Serum resistin was assessed by ELISA and LDL size and subclasses by non-denaturing gradient gel electrophoresis of whole plasma. Correlation analysis was performed using the Spearman rank correlation method.
Results: No associations were found between resistin and age, BMI, waist and hip circumferences as well as markers of insulin resistance, including fasting or postprandial glucose, insulin, HOMA and HbA1c, with the exception of a significant association with C-peptid levels (r=+0.435, P<0.05). Further, no associations were found between resistin and plasma lipids or LDL size. Regarding LDL subclasses, resistin was inversely associated with larger LDL-I (r=0.414, P<0.05) and positively with smaller, denser LDL-III and -IV (r=+0.345, P=0.05).
Conclusion: These findings suggest that increased plasma resistin concentrations may be associated with atherogenic small, dense LDL in subjects with type-2 diabetes. Yet, whether these findings affect the atherogenic process and clinical end-points in this category of patients remains to be determined by future prospective studies.