such as insulin-resistance, endothelial dysfunction, arterial stiffening, cardiac hypertrophy, and

sympathetic activation. The present article will review the evidence collected throughout by years

that an increase in the different markers of adrenergic drive, such as plasma norepinephrine and

muscle sympathetic nerve traffic, characterizes this condition. Frequently, the increase also

involves heart rate, as documented by the results of different epidemiological studies, such as the

Pressioni Arteriose Monitorate E Loro Associazioni, in which an increase in heart rate has been

shown in patients with metabolic syndrome, in which this hemodynamic parameter has been

assessed in the doctor's office, at home, or during the 24-hour period. Finally, current findings

suggest that in metabolic syndrome heart rate displays a significant correlation with other indirect

and direct adrenergic markers. Taken together, these findings reinforce the concept that drugs used

in the metabolic syndrome should exert sympathoinhibitory effects. (Prog Cardiovasc Dis

2009;52:31-37)