The role of hypertension in metabolic syndrome [Ruolo dell'ipertensione nella sindrome metabolica]

The metabolic syndrome term is generally used to define the co-presence of risk factors responsible for an important increase of cardiovascular diseases incidence in patients with overweight, obesity, hypertension and type II diabetes mellitus. Long the history of such syndrome, if it is considered that already in the 50's the Framingham study's first observations concluded that the presence of more factors was increasing the relative risk of cardiovascular events (Ictus, myocardial infarct, death, etc.) in an exponential way. In 1988 Reaven coined the X syndrome term, recognizing this entity like a multiple and independent risk factor for cardiovascular disease. A recent report of the National Cholesterol Education Programme Adult Treatment Panel (NCEPT-ATP III) has identified the metabolic syndrome as an independent risk factor for cardiovascular disease and considers it like tightening indication for an intense modification of the life style. Currently there are three definitions more commonly recognized, as the one suggested by the World Health Organisation (WHO), by the European Group For The Study Of insulin Resistance (EGIR) and the National Cholesterol Education Programme Adult Treatment Panel (ATP III). In all cases a central role has the hypertension. In fact, beyond the differences in the definition and the emergency of the so-called new risk factors, all of metabolic, proinflammatory and prothrombotic nature, it has to point out that the hypertension is a constant in all the definition, reaching the prevalence of 100% in the metabolic syndrome of the elderly. The prevalence of the syndrome increases with the age and is present in almost half of the over 60 population. In particular, it increases from 6.7% in patients with 20-29 years to 43% in the over 70. In both sexes the prevalence quickly increases after the third decade of life, reaching a peak between the 50 and 70 years in the men and the 60-80 years in the women. Regarding to the pathogenesis of the hypertension in subjects with metabolic syndrome: the hyperinsulinemia secondary to insulin-resistance seems to play an important role determining both the stimulation of the sympathetic nervous system, with consequent vasoconstriction, and the retention of sodium, responsible of increase in arterial blood pressure values, such to antagonize the vasodilator effects of the insulin. In particular, the chronic hyperinsulinemia associated to the metabolic syndrome could modulate the renal sodium excretion, since it has been shown that such hormone is able to regulate the reabsorption of the sodium at tubular level or to increase the Sodium/Hydrogen pump by renal tubuli. As regards the management of this disease, the necessity of a treatment to 360° of the metabolic syndrome in its entirely and of its single aspects, included the hypertension, seems not questionable. However, we have to point out the necessity of a particular attention both of the doctor and the patient in the management of the polipharmacotherapy that, in the elderly, is a clear risk factor for the iatrogenic damage. Probably, the engagement of the doctors to choose drugs with pharmacocinetic and pharmacodinamic profiles more appropriates to the total treatment of the syndrome and their ability to induce a stable modification of the life style will make surer and more effective the management of such syndrome also in the elderly subject