Relationship of insulin resistance with heart structure, function, and metabolism in young, nonobese adults

Abstract

Introduction: although insulin resistance is related to alterations in cardiac structure and function, and lipids and glucose metabolism in type 2 diabetics and obese individuals, it is unknown if these changes occur in young adults neither obese nor diabetic.

Objective: to evaluate the relationship between insulin resistance, cardiac structure and function, and metabolism in nonobese, young adults.

Materials and methods: this is a cross-sectional study, in young adults between 17 and 44 years of age, who were evaluated for cardiovascular risk.

Results: 249 individuals were included with a mean age of 24.7 ± 6.7 years and a Body Mass Index (BMI) of 22.2 ± 2.9 kg/m². The individuals with insulin resistance had greater mean BMI, Systolic Arterial Pressure (SAP) and unfavorable changes in lipids and glucose metabolism (p value < 0.05). In the 5th quintile of the Index of Insulin Resistance, HOMA (HOMA-IR) a greater mean posterior wall thickness during left ventricle systole, greater ejection fraction and endocardial fractional shortening (p value < 0.05) was found. Between 1st and 5th quintile of the HOMA-IR there were no differences in the cardiac mass or diastolic function. Correlation between the HOMA-IR and some echocardiographic measurements appeared during ventricular systole.

Conclusion: nonobese young adults with insulin resistance present with unfavorable changes in their lipid and glucose metabolism, an increase in myocardial shortening and left ventricle systolic function, which suggest a greater cardiac stimulation and contractility due to activation of the sympathetic tone.