Essential hypertension is a multifactorial disease. Many experimental studies have elucidated
the role of oxidative stress and atherosclerosis in the pathogenesis of essential hypertension. Apolipoprotein
E is a plasma protein that is found to have antioxidant properties, and it also protects against atherosclerosis.
Interestingly, the biological function of apolipoprotein E is strongly affected by polymorphisms in its gene.
Based on this evidence, our aim was to investigate the association of apolipoprotein E gene polymorphisms with
essential hypertension.
Normotensive subjects with family history of hypertension (FHT) have been reported to have increased left ventricular mass index and reduced ventricular compliance. Of interest is whether blood pressure variability (BPV), which has been associated with target organ damage, is then part of this complex inherited syndrome? The objectives of this study are to determine whether there are any significant differences in BPV, arterial compliance and humoral factors in subjects with FHT as compared to controls. Thirty-five subjects with self reported FHT and 35 matched controls underwent 24 hour BP monitoring (BR-102, Schiller Inc. Germany). Arterial compliance was measured using systolic pulse wave tonometry (HDI/Pulsewave Cardiovascular Profiling Instrument, Hypertension Diagnostic Inc. USA). None of the subjects were hypertensive or diabetic. Out of these numbers, 25 subjects with FHT and 26 controls had measurements of plasma catecholamines, plasma renin and serum aldosterone. Catecholamines were assayed with high performance liquid chromatography, while both renin and aldosterone measurements were by radioimmunoassay. Subjects with FHT have higher night time BPV. There was no significant difference in arterial compliances between both groups. There were increased level of norepinephrine (NE) in subjects with FHT but epinephrine (E), renin and aldosterone levels were similar in both groups. There were no correlations between NE and BPV but E was negatively associated with daytime and mean arterial systolic BPV. In conclusion subjects with FHT demonstrated a higher night time BPV and NE level as compared to controls.
Apart from the mean 24 hour ambulatory blood pressure (ABP), the blood pressure variability (BPV) also bears an independent relationship with target-organ damage in hypertension. A reduction in arterial compliance has been demonstrated in hypertension but its relation to BPV is still unknown. The aim of the study is to compare BPV and arterial compliance between hypertensive and normotensive subjects. Eighteen hypertensives and 18 controls were enrolled. Noninvasive 24-hour ABP monitoring was performed with BR-102 monitor (Schiller Inc. Germany). Arterial compliance was determined by the HDI/Pulsewave Research Cardiovascular Profiling Instrument (Hypertension Diagnostic Inc. USA). There were significantly higher systolic, diastolic and mean arterial BPV in hypertensives as compared to normotensive group. Only systolic BPV remained significantly high in hypertensives during night time. There were lower arterial compliances in hypertensive as compared to normotensive group. No significant relationship however was found between BPV and arterial compliance in hypertensive subjects. In conclusion, there were higher BPV and lower arterial compliances in hypertensive subjects as compared to normotensive subjects.
It is debatable whether the assessment of low density lipoprotein or total cholesterol (TC) alone is sufficient to identify an individual's risk of having myocardial infarction. In the Framingham study, the risk of coronary artery disease was better indicated by an increase in the TC to high density lipoprotein cholesterol (TC: HDL) ratio. The aim of this study is to determine the relationship between blood pressure variability (BPV) and arterial compliances in hyperlipidaemics, which was defined as TC:HDL of more than 5.0 as compared to normolipidaemics.