Figure 4

Age-dependent changes of circulating monocyte-related chemokine levels. Box plots display serum concentrations of the chemokines MCP-1 (A), MIP1α (D), MIP1β (E) and fractalkine (F) for the different groups of young (<30 years, n = 51), middle-aged (30-50 years, n = 70) and old (>50 years, n = 60) healthy volunteers. The bold black line indicates the median per group, the box represents 50% of the values, and horizontal lines show minimum and maximum values of the calculated non-outlier values; open circles indicate outlier values. Significant differences (Kruskal-Wallis and U-test) are marked by ***p < 0.0015. (B+C) MCP1 serum concentrations correlate with the age (r = 0.266, p = 0.001) and the body-mass index (BMI, r = 0.430, p = 0.013) in healthy volunteers (Spearman rank correlation test).