Effect of clustering of metabolic syndrome factors on capillary and cerebrovascular impairment.

BACKGROUND: Hypertension and metabolic disorders, attended by impaired microcirculation, represent major risk factors for cerebrovascular impairment, as well as being individual components of the metabolic syndrome (MetS). Aim of the study was to establish whether mild hypertensives, aged ≤65years, may be affected by progressive microvascular damage impairing cerebrovascular perfusion, related to a progressive clustering of MetS components.
METHODS: Twenty-two normotensives with no MetS component (NTN-0), 29 hypertensives with no (HTN-0), 30 with one (HTN-1), 29 with two (HTN-2), 27 with three (HTN-3), 25 with all four (HTN-4) MetS components, were recruited. The study required office and twenty-four hour ambulatory blood pressure monitoring and video capillaroscopy. Functional (fCD), anatomical (aCD) and recruited (RECR) phalangeal skin capillarity were assessed. Cerebral vasodilatory reserve was measured by the breath-holding index (BHI), using transcranial Doppler, in HTN-1 and HTN-2 with MetS.
RESULTS: The fCD and aCD were reduced in hypertensives and progressively reduced in those with MetS, while RECR was also impaired. BHI was lower in HTN-2 than in HTN-1 (p<0.001). BHI was correlated with fCD in HTN-1 (.396, p: .046), HNT-2 (.497, p: .011), and with aCD in HTN-2 (.494, p: .012), by partial Pearson test. DISCUSSION: The findings show that hypertensives exhibit an increasing microvascular rarefaction with MetS progression and that an impaired cerebral perfusion occurs when the MetS is established. The data underline the importance of preventing MetS in mild hypertensives, as it causes microvascular damage and impairs cerebral arterial perfusion.