Lower serum levels of IL-13 is associated with increased carotid intima-media thickness in old age subjects.

Background: Cardiovascular diseases due to atherosclerosis represent the major cause of disability and mortality in old age subjects. The atherosclerotic process is linked to a low grade of systemic inflammation with the involvement of many cytokines and inflammatory proteins. Among them, evidence from animal studies suggests that IL-13 has a protective property. However, the role of IL-13 in the pathogenesis of atherosclerosis in humans is still unknown.

Aims: With this study, we aim to investigate a potential association between IL-13 and carotid intima-media thickness (IMT) in old age subjects.

Methods: This is a retrospective study conducted among 79 old age subjects (over 75 years old). All subjects underwent IMT assessment by high-resolution B-mode ultrasonography and IL-13 measurement in serum by ELISA.

Results: Subjects (41 M/38F) had a mean age of 81.0 ± 4.5 years and were mostly overweight. Stratifying the whole cohort by IMT thickness (IMT ≤ 0.9, n = 17; IMT ≥ 1 and ≤ 1.3, n = 50; IMT ≥ 1.4, n = 12) among the main variables explored, only BMI and triglycerides differed among groups, having subjects with higher IMT significantly higher BMI and lower triglycerides. Serum IL-13 levels significantly differed among groups having subjects with IMT ≥ 1.4 lower levels as compared to other groups (p < 0.0001). In all sample population, IMT values significantly correlate with IL-13 levels (r = - 0.454, p < 0.0001). Indeed, a linear regression analysis showed that independent of age, gender, body mass index, triglycerides, systolic blood pressure, statin use and smoking habit, lower IL-13 serum levels were associated with higher IMT values.

Conclusions: IL-13, an anti-inflammatory cytokine, may have a protective role in the human atherosclerotic process. It could be used as an effective and promising novel therapeutic target development.