Nocturnal blood pressure but not insulin resistance influences endothelial function in treated hypertensive patients

Abstract

The impact of insulin sensitivity, casual blood pressure and 24-h ambulatory blood pressure on endothelial function was studied in treated hypertensive subjects. Flow-mediated dilatation of the brachial artery after reperfusion was used to determine endothelial function. Insulin sensitivity indices were obtained by using the homeostasis model assessment, after 75 g Dextrose oral glucose tolerance tests (Matsuda index) and the euglycemic hyperinsulinemic clamp (M-value) in 49 patients with arterial hypertension. The insulin sensitivity indices were compared with healthy controls matched for body weight, age and sex (n ¼ 23). Hypertensive patients under therapy were insulin resistant, had higher LDL-cholesterol levels, higher blood pressure and lower endothelial function than healthy controls. Flow-mediated dilatation showed, in the study population being treated for arterial hypertension, no relationships of all insulin sensitivity indices with flow-mediated dilatation, casual blood pressure in the morning before the tests and 24-h ambulatory blood pressure. Flow-mediated dilatation was strongly influenced by nocturnal systolic and diastolic 24-h ambulatory blood pressure (systolic: R 2 ¼ 0.0943, Po0.05; diastolic: R 2 ¼ 0.0947, Po0.05). Therefore, endothelial function in these patients is predominantly influenced by nocturnal systolic and diastolic blood pressure and not by insulin sensitivity.

Endothelial function in postmenopausal women with nighttime systolic hypertension

“…There is some evidence of an inverse association between FMD and nighttime SBP in patients with hypertension or coronary heart disease. 27,28 However, these previous studies included few women and no studies evaluated the relationship between nighttime SBP and FMD in postmenopausal women. Given that postmenopausal women are at higher risk of cardiovascular disease and the relationship between nighttime SBP and cardiovascular risk increases more drastically for woman than men the objectives of this study were: (1) to evaluate whether nighttime SBP was associated with endothelial function (FMD) and; (2) to evaluate the hypothesis that endothelial function in postmenopausal women with nighttime hypertension (nighttime SBP≥120mm Hg) is impaired relative to postmenopausal women with normal nighttime SBP (<120mm Hg).…”

Endothelial dysfunction and diurnal variation of blood pressure: night secrets of arterial hypertension?

“…17,18 Endothelium-dependent vasodilatation is more severely blunted in non-dippers when compared with patients who have dipper hypertension. 19 The presence of more prominent endothelial perturbation in individuals with non-dipping nocturnal BP is also reflected by increased levels of von Willebrand factor, a marker of endothelial damage. 20 Quinaglia et al…”

“…Indeed, it has been previously demonstrated that nocturnal systolic and diastolic BP were the strongest predictors of endothelial dysfunction in hypertensive subjects. 29 Good control of night BP protects against organ damage by improving endothelial function. 30 …”

The Correlation Between Arterial Hypertension and Endothelial Function

“…Moreover brachial artery FMD correlates with the severity of hypertension: patients with uncontrolled resistant hypertension have, in fact, a greater impairment in endothelial function compared to controlled resistant hypertension ones, and this result is related to non-dipping BP pattern [8]. Furthermore, a study performed in treated hypertensive subjects showed that nocturnal systolic and diastolic BP mainly affected FMD of the brachial artery rather than insulin sensitivity [9].Lower brachial artery FMD was also related to increased risk of CV events during a 95 months-follow-up in 172 uncomplicated hypertensive patients [10].Endothelial dysfunction associated to arterial hypertension shows, however, of being a reversible alteration: six months of antihypertensive therapy improve brachial artery FMD in postmenopausal women and reduce CV events during a mean followup of 67 months compared to women in which FMD did not change during treatment [11]. Among the antihypertensive drugs nebivolol ameliorates vasodilatory response to acetylcholine [12], while reninangiotensin system blockers [13] and combination of perindopril/ indapamide [14] FMD values in hypertensive subjects.…”

“…Endothelial dysfunction associated to arterial hypertension shows, however, of being a reversible alteration: six months of antihypertensive therapy improve brachial artery FMD in postmenopausal women and reduce CV events during a mean followup of 67 months compared to women in which FMD did not change during treatment [11]. Among the antihypertensive drugs nebivolol ameliorates vasodilatory response to acetylcholine [12], while reninangiotensin system blockers [13] and combination of perindopril/ indapamide [14] FMD values in hypertensive subjects.…”