Association of serum lycopene and brachial-ankle pulse wave velocity with metabolic syndrome

Metabolic syndrome (MetS) is known to inversely correlate with antioxidant status. Recently, it has been reported that MetS is associated with arterial stiffness, a composite risk factor for early atherosclerosis. In addition, our recent study for healthy women showed an inverse relationship between arterial stiffness and circulating lycopene. Therefore, this study aimed to investigate the interrelationship between arterial stiffness, antioxidant status, and the risk of MetS. Korean men (N = 299) were subgrouped according to the number of MetS risk factors (RF 0, RF 1-2, RF ≥3). Anthropometric parameters, brachial-ankle pulse wave velocity (baPWV; a marker of arterial stiffness), antioxidants (lycopene, β-carotene, α-tocopherol), lipid profiles, glucose, insulin, and oxidative stress (low-density lipoprotein [LDL] particle size, oxidized LDL) were measured. Corresponding to the number of MetS RF, baPWV (1306 ± 17, 1364 ± 16, and 1420 ± 33 cm/s; P < .001) and insulin resistance (1.5 ± 0.1, 1.9 ± 0.1, and 2.7 ± 0.2; P < .001) gradually increased after adjustment for age, body mass index, smoking, and drinking, whereas serum lycopene among antioxidants and LDL particle size gradually decreased (0.036 ± 0.001, 0.031 ± 0.001, and 0.028 ± 0.001 mmol/L; P = .004 and 23.9 ± 0.1, 23.7 ± 0.1, and 23.3 ± 0.1 nm; P < .001, respectively). Brachial-ankle pulse wave velocity inversely correlated with serum lycopene after adjustment for the above confounders, blood pressure, insulin resistance, and oxidative stress (r = −0.136, P < .05). Oxidative stress markers also significantly correlated with baPWV as well as serum lycopene. Study subjects were divided into 2 groups by the median level of serum lycopene. When serum lycopene was lower than median level (≤0.0294 mmol/L), baPWV was significantly higher in MetS subjects than non-MetS subjects (1436 ± 41 vs 1367 ± 23 cm/s) after adjustment for age, body mass index, smoking, drinking, and oxidative stress (P = .041). However, when serum lycopene levels were high, no statistically significant difference was observed between the 2 subject groups (1386 ± 36 vs 1326 ± 13 cm/s). In conclusion, our result shows the interrelationship between circulating lycopene, baPWV, and MetS. In addition, much enhanced baPWV in MetS may be associated with lower lycopene concentration.