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Query: UMLS:C0085580 (essential hypertension)
 14,686 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several studies have demonstrated that patients with hypertension have greater plasma insulin levels than normotensive subjects. The aim of the present study was to clarify if hyperinsulinemia in hypertension is a consequence of either increased pancreatic secretion or decreased hepatic clearance, and to determine whether abnormalities of glucose metabolism are equally present in essential and secondary hypertension. In an observational cross-sectional study, fasting blood glucose, plasma insulin, and plasma C-peptide levels were measured in five patient groups: 34 lean normotensive, 19 overweight normotensive, 25 lean essential hypertensive, 27 overweight essential hypertensive, and 20 secondary hypertensive subjects. The blood glucose/plasma insulin and plasma insulin/plasma C-peptide ratios were calculated as indexes of insulin sensitivity and hepatic insulin clearance, respectively. Subjects with essential hypertension and, to a greater extent, those who were overweight, exhibited significantly higher fasting insulin and C-peptide levels and significantly lower glucose/insulin ratios as compared with lean normotensive subjects. In contrast, no differences were observed between secondary hypertensive and control subjects. Mean blood pressure was significantly and independently correlated to body mass index, plasma insulin and plasma C-peptide levels, and the glucose/insulin ratio. In lean essential hypertensive and secondary hypertensive subjects, the insulin/C-peptide ratios were comparable to controls, indicating normal hepatic insulin clearance. In both overweight groups, a trend to increased insulin/C-peptide ratios was observed. This study shows that in essential hypertensive subjects, hyperinsulinemia is caused by insulin hypersecretion, whereas in overweight subjects, both increased insulin secretion and decreased hepatic insulin clearance might be involved.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Insulin hypersecretion: a distinctive feature between essential and secondary hypertension. 143

The incidence of hypertension is increased in obesity, a state associated with an insulin resistance syndrome. By using an euglycemic clamp method, Ferrannini et al. demonstrated the existence of an insulin resistance state in patients with essential hypertension. However, the body mass index of the subjects studied appeared to be slightly excessive. This abnormality has not been observed in patients with secondary hypertension. Insulin resistance is probably localized to peripheral tissues such as muscles and may be associated with other cellular abnormalities. Can insulin resistance, characterized by a raised circulating insulin concentration in the presence of normal blood glucose, be responsible for certain "modifications" associated with essential hypertension? Insulin induces sodium retention and increases the aldosterone-secreting effect of angiotensin II. These effects are likely to promote a rise in blood pressure and an increase in the sensitivity of vessels to endogenous substances. Moreover, insulin is a known growth factor and is involved in lipoprotein metabolism. If insulin resistance plays an important role in the maintenance of complications of essential hypertension, it is important that the treatments used tend to correct this anomaly. Thiazide diuretics and beta-blockers aggravate insulin resistance while angiotensin converting-enzyme inhibitors correct this condition.
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PMID:[Arterial hypertension, hyperinsulinism and insulin resistance]. 143

1. The purpose of the present study was to examine changes in membrane fluidity in hypertension by means of an electron spin resonance (ESR) and a spin labelling methods. 2. Erythrocytes from spontaneously hypertensive rats (SHR) and from patients with essential hypertension were examined and compared with those from age-matched normotensive controls. ESR spectra were obtained for a fatty acid spin label agent (5-nitroxide stearate) in the membranes. The values of outer hyperfine splitting (2T' parallel) and of order parameter (S) of the ESR spectra were significantly higher in erythrocytes from SHR and patients with essential hypertension than in those from normotensive controls. Similar results were obtained in cultured vascular smooth muscle cells of SHR. This finding shows that the membrane fluidity might be lower in SHR and in essential hypertension. 3. When Ca was loaded to erythrocytes with a Ca-ionophore (A23187), the parameters of the ESR spectra showed a greater increase (membrane fluidity was decreased) in SHR and in patients with essential hypertension than that in the normotensive controls. The Ca-induced alterations in membrane fluidity were not definitely observed in secondary hypertension. 4. These results suggest that the lower membrane fluidity might be a genetically determined abnormality of hypertension. The marked reduction of the membrane fluidity by Ca-loading in SHR and in essential hypertension might support the hypothesis that an abnormality of the Ca-handling at cellular levels could affect physical properties of the biomembranes in genetic hypertension.
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PMID:Membrane fluidity as a genetic marker of hypertension. 144 3

In many different clinical situations, including some cases of secondary hypertension, nighttime blood pressure (BP) is abnormally increased in the majority of patients, with consequent flattening of the 24-hour BP profile, but the clinical importance of this finding in such conditions is unknown. In patients with essential hypertension, ambulatory BP has been shown to decrease by 10-20% from day to night, but in severe or malignant hypertension this diurnal BP rhythm may be blunted or even abolished. One of the reasons why the noninvasive monitoring of BP may be a reliable tool in assessing the day-night BP changes is the demonstration that frequent cuff inflations do not interfere to a significant extent with the haemodynamic effects of sleep. Part of the differences between the studies in the reported day-night BP drop may be artifactual, owing to the very different time intervals defining the daytime and nighttime subperiods in the single studies. In unselected patients with essential hypertension, a sizable proportion of subjects (17 to 40%) shows abnormally high nighttime BP, with consequent flattening of the 24-hour BP profile (the so called "non dippers", as opposed to the "dippers" who show a maintained diurnal BP rhythm). Several clinical studies carried out in independent laboratories show that the target organ damage induced by hypertension (left ventricular hypertrophy, cerebrovascular lesions) is more severe in hypertensive "non dippers" than in "dippers", possibly because of the different duration of exposure to high BP levels over the 24 hours.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[The day-night changes in ambulatory blood pressure: another risk indicator in hypertension?]. 147 64

Patients (pts) with essential hypertension normally exhibit a typical diurnal variation with a nocturnal blood-pressure (BP) decreased. A lack of this periodicity is often reported in pts with secondary hypertension. 24-h BP measurement was therefore performed in 308 pts with essential hypertension, and in 172 pts with secondary hypertension, in order to evaluate the diagnostic value of nocturnal BP decrease. Diagnoses of the secondary hypertensives were: renoparenchymatous hypertension (n = 29), diabetic nephropathy (n = 24), morbus Conn (n = 6), renal artery stenosis (n = 32), pheochromocytoma (n = 5), hemodialysis pts (n = 30), and kidney transplantation (n = 44). Pts with essential hypertension showed a mean systolic and diastolic BP decrease during the nighttime period of 22 +/- 7 mmHg and 17 +/- 5 mmHg, respectively. In contrast, the corresponding values in secondary hypertension were 5.7 +/- 9.2 mmHg (systolic decrease) and 5.2 +/- 5.9 (diastolic decrease). Pts with pheochromocytoma who had a nighttime increase in BP demonstrated the greatest difference from the essential hypertensives, followed by pts with either diabetic nephropathy or after kidney transplantation. A lack of nocturnal BP decline (less than 10% of the daytime values) was detected in 69.8% of pts with secondary hypertension, but only in 5.2% of pts with essential hypertension. In summary, these results suggest that the absence of a nighttime decline in BP during 24-h ambulatory monitoring is an indication of secondary hypertension and should lead to further investigations. Furthermore, a nightly hypertension is associated with a higher risk of complications.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Diagnostic significance of absent nocturnal blood pressure decrease in 24-hour long-term blood pressure measurement]. 151 20

To assess the cardiac characteristics and postoperative courses in patients with Cushing's syndrome, electrocardiography and echocardiography were performed to study 12 consecutive, unselected patients, and results were compared with those of essential hypertension and primary aldosteronism. Eleven patients had hypertension and 7 had diabetes mellitus. Before adrenalectomy, common electrocardiographic abnormalities consisted of high-voltage QRS complexes (10 patients) and negative T waves (7 patients). Echocardiograms showed left ventricular hypertrophy in 9 patients, and all the patients had evidence of asymmetric septal hypertrophy. In patients with left ventricular hypertrophy, the thickness of the interventricular septum ranged from 16 to 32 mm, whereas the ratio of the thickness of interventricular septum to that of the posterior wall ranged from 1.33 to 2.67. The interventricular septum in Cushing's syndrome was extremely thicker and asymmetric septal hypertrophy occurred more often than essential hypertension and primary aldosteronism. Nine patients could be followed up after operation. In these patients abnormal electrocardiographic findings had normalized, the thickness of interventricular septum had decreased and asymmetric septal hypertrophy had disappeared except in 1 patient. The reason why left ventricular hypertrophy in Cushing's syndrome is severe is still unknown. Because left ventricular hypertrophy is more severe and the frequency of asymmetric septal hypertrophy much greater in Cushing's syndrome than in essential and other secondary hypertension, it is thought that not only increased aortic pressure but excessive plasma cortisol may be etiologic factors in the progression of left ventricular hypertrophy in Cushing's syndrome.
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PMID:Cardiac characteristics and postoperative courses in Cushing's syndrome. 153 96

Automatic 24-hour blood pressure measurements were undertaken in 60 patients with primary systemic hypertension (24 women, 36 men; mean age 51 +/- 23 years) and 105 with secondary hypertension (36 women, 69 men; mean age 51 +/- 24 years). The aim of the study was to ascertain whether the absence of a day-night blood pressure rhythm is a reliable sign that the hypertension is secondary or whether it can also occur in primary hypertension. None of the patients was receiving any treatment. Day-night rhythm was abolished in 10 patients with primary hypertension (16%) and in 65 of those with secondary hypertension (62%). But an analysis of 11 case reports indicated that in an individual case there is no absolute rule. While absence of the day-night rhythm points to secondary hypertension, there are numerous exceptions.
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PMID:[The day-night rhythm in the 24-hour blood pressure profile. A possibility of distinguishing between primary and secondary hypertension?]. 156 28

To investigate the role of cytosolic free calcium, [Ca2+]i, in secondary hypertension, the levels in platelets from 14 secondary hypertensives (7 renovascular hypertension, 7 primary aldosteronism) were compared with those from 21 essential hypertensives and 15 normotensives by means of the fluorescent indicator, quin-2. The mean BP was significantly higher in both the secondary hypertensives and essential hypertensives (122 +/- 8 and 124 +/- 12 mmHg) than in the normotensives (89 +/- 10 mmHg). Cytosolic free calcium in platelets was significantly higher in the essential hypertensives, but not in the secondary hypertensives, compared with the normotensives (182 +/- 34, 141 +/- 17, 138 +/- 15 nM respectively). There was no significant difference in platelet [Ca2+]i between renovascular hypertension and aldosteronism (142 +/- 19 versus 139 +/- 16 nM). There was no correlation between platelet [Ca2+]i and plasma renin activity, plasma aldosterone concentration or plasma noradrenaline concentration in the three groups. Thus, the increase in platelet [Ca2+]i seen in essential hypertension was not found in patients with secondary hypertension. Our results suggest that the cytosolic calcium handling of secondary hypertensive patients with renal artery stenosis or primary aldosteronism differs from that of essential hypertensives.
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PMID:Cytosolic free calcium concentration in platelets in patients with renovascular hypertension and primary aldosteronism. 158 34

A crucial role of humoral factors in the pathogenesis of primary hypertension is discussed. In 1982 Hamlyn et al demonstrated the presence of a Na+, K(+)-ATPase inhibitor in the plasma of essential hypertensives and showed a significant correlation of the Na+, K(+)-ATPase inhibition with the blood pressure. In this study we examined whether an Na+, K(+)-ATPase inhibitor could be found in the blood of essential hypertensives as compared to patients with secondary hypertension (renal hypertension, renal artery stenosis, pheochromocytoma). Second, the possible correlation between an inhibition of Na+, K(+)-ATPase and the intracellular electrolyte composition was examined. The results demonstrate a similar reduction of Na+, K(+)-ATPase inhibition in both essential hypertensives and secondary hypertensives as compared to normotensive controls. Further, the intracellular electrolyte composition (Na+, Na; K+, Ca) does not show a significant correlation to the degree of Na+, K(+)-ATPase inhibition, whereas a significant correlation between the degree of Na+, K(+)-ATPase inhibition and intracellular Cl- concentration could be demonstrated. The present study shows that an endogenous Na+, K(+)-ATPase inhibitor is also present in secondary forms of hypertension, thus implying that a specific role in the pathogenesis of primary hypertension for an Na+, K(+)-inhibitor is unlikely.
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PMID:Na+, K(+)-ATPase inhibition and intracellular electrolyte content in essential and secondary hypertension. 164 95

The insulin sensitivity of five essential hypertensive patients was compared to five patients with renovascular hypertension, five patients with primary hyperaldosteronism, and five normotensive subjects, using the euglycemic hyperinsulinemic clamp technique. Essential hypertensive patients had significantly lower insulin sensitivity than patients with hyperaldosteronism and renovascular hypertensive patients (P = .0066, P = .004, respectively). Hyperaldosteronism patients also had less insulin sensitivity than renovascular hypertensive patients (P = .016). A significant negative correlation was found between body mass index and insulin sensitivity index for essential hypertension patients only (r = -0.87, P less than .003). No such correlation was found in the secondary hypertension patients. The findings suggest a causal relationship between insulin resistance and the development of essential hypertension. Secondary hypertension, on the other hand, is not such an insulin resistant state.
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PMID:Insulin resistance in secondary hypertension. 173 30


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