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

Essential hypertension has been associated with disturbed calcium metabolism, but the available data are controversial. We measured parameters of calcium metabolism in groups of untreated male subjects (n = 78) with elevated diastolic blood pressure (101 +/- 6 mmHg, mean +/- SD) and age-matched male subjects (n = 79) with low diastolic blood pressure (62 +/- 4 mmHg). The participants of the study were drawn from a random population sample. Subjects with high diastolic blood pressure had significantly higher carboxy-terminal parathyroid hormone (PTH) plasma concentrations than controls with low diastolic blood pressure (median 114 vs. 43 pmol/l, P less than 0.01). The 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D concentrations were comparable in both groups. Individuals with high diastolic blood pressure had significantly lower total serum calcium (2.41 +/- 0.10 vs. 2.47 +/- 0.10 mmol/l, mean +/- SD; P less than 0.01). PTH concentrations were correlated with diastolic pressure (r = -0.39, P less than 0.001). The data are compatible with increased parathyroid activity despite unchanged concentrations of vitamin D metabolites in human hypertension.
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PMID:Disturbed calcium metabolism in subjects with elevated diastolic blood pressure. 848 30

A hypotensive effect of active vitamin D treatment (alphacalcidol 1 mg daily) has previously been reported in three double-blind, placebo-controlled studies over 4-6 months in subjects with mild primary hyperparathyroidism (HPT), intermittent hypercalcemia and essential hypertension. The commonly used antihypertensive drugs, thiazides and betablockers, both induce impairments in both glucose and lipid metabolism and the thiazides are known to cause an elevation of serum urate. The effects of vitamin D treatment on these metabolic variables were recorded in these studies. Alphacalcidol did not induce any changes in fasting glucose HbA1c or insulin, serum triglycerides, cholesterol or serum urate in any of the treated groups. Neither was HDL cholesterol affected, except for a rise seen in the HPT subjects. It is therefore concluded that no major metabolic alterations in glucose or lipid metabolism or serum urate accompany the hypotensive effect of vitamin D.
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PMID:No major metabolic alterations accompany the hypotensive effect of active vitamin D. 181 79

Several abnormalities of calcium metabolism have been described in patients with essential hypertension, and they have been linked to the pathogenesis of hypertension. Intestinal calcium absorption has been shown to be decreased in rats with spontaneous hypertension, but it has not been studied in patients with essential hypertension. In these studies we have for the first time measured intestinal absorption of calcium (using oral and intravenous administration of 47Ca), along with other parameters of calcium metabolism, in 14 patients with essential hypertension and normal renal function and in 16 normal subjects. There was no difference in serum total or ionized calcium, serum phosphorus, parathyroid hormone (PTH), 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D (1,25(OH)2D), and 24,25-dihydroxy-vitamin D(24,25(OH)2D) among hypertensives and normotensives. The urinary excretion of calcium, on the other hand, was greater in hypertensive than in normotensive subjects (195 +/- 33 v 107 +/- 13 mg/24 h, P less than .05). There was also no difference in intestinal absorption of calcium after 2 and 24 h among hypertensives and normotensives. When hypertensive patients were stratified according to plasma renin activity (PRA) we found that patients with low PRA had higher intestinal absorption of calcium at 2 h (23 +/- 2.9 v 18 +/- 0.6%, P less than .05) but not at 24 h. Serum total and ionized calcium, PTH, and 1,25(OH)2D were not different between patients with low and those with normal-high PRA. The major derangement of calcium metabolism in patients with essential hypertension is hypercalciuria. This abnormality is more pronounced in patients with low PRA, and it may lead to increased vitamin D-dependent intestinal absorption of calcium.
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PMID:Intestinal absorption of calcium and calcium metabolism in patients with essential hypertension and normal renal function. 206 73

In humans with essential hypertension, salt-induced increases in blood pressure have been reported to correlate directly with salt-induced increases in intracellular free calcium [( Ca2+]i) in circulating mononuclear cells. These findings are consistent with the hypothesis that salt-induced increases in [Ca2+]i mediate the phenomenon of salt sensitivity. Circumstantial evidence suggests that salt-induced increases in intracellular sodium or in plasma levels of 1,25-dihydroxy vitamin D might mediate salt-induced increases in [Ca2+]i and blood pressure. However, in humans with salt-sensitive hypertension, it remains to be determined: (1) whether salt-induced increases in white blood cell [Ca2+]i reflect corresponding increases in vascular smooth muscle [Ca2+]i; (2) whether salt-induced increases in [Ca2+]i are a cause or consequence of salt-induced increases in blood pressure; and (3) whether salt-induced increases in 1,25-dihydroxy vitamin D or intracellular sodium precede salt-induced increases in [Ca2+]i.
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PMID:Sodium-calcium interactions and salt-sensitive hypertension. 222 61

Alterations of calcium metabolism have been described in human essential hypertension and experimental hypertension. We investigated the interrelationship of parathyroid hormone (PTH) and 1,25(OH)2-vitamin D (1,25(OH)2D) in patients with untreated essential hypertension as compared to normotensive controls. The hypertensive subjects (n = 75; 43 men, 32 women) had a mean blood pressure of 138 +/- 8/95 +/- 5 mm Hg as compared with 120 +/- 11/80 +/- 8 in the normotensive group (n = 40; 22 men, 18 women). Serum PTH was measured with an intact molecule immunochemiluminometric assay and 1,25(OH)2D was measured with radioimmunoassay after HPLC separation. Hypertensive men had PTH levels that were 36% higher than normotensive men (5.3 +/- 2.9 v 3.9 +/- 0.8 pmol/L, P = .005). When blood pressure was analyzed as a continuous variable, there was a direct correlation between it and serum PTH in men (r = .31, P = .004). In women, by contrast, there was no difference in serum PTH between hypertensive and normotensive subjects and no relationship between blood pressure and the serum PTH concentration. Blood pressure was inversely correlated with serum phosphorus levels in both sexes (r = -0.20, P = .04). In men, the elevated serum PTH levels and depressed serum phosphorus levels would have predicted that serum 1,25(OH)2D would be higher in the hypertensive subjects. However, that was not observed, as serum 1,25(OH)2D was slightly lower in hypertensive (38.3 +/- 15.2 pg/mL) than normotensive men (42.7 +/- 11.3, P = .21).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Calcium regulating hormones in essential hypertension. Importance of gender. 222 63

In recent years abnormalities of calcium metabolism have been described in human hypertension. In this study, the relationships between indices of calcium metabolism and the renin-aldosterone system were studied in 39 subjects with untreated essential hypertension. No significant associations were found between the major determinants of calcium metabolism (plasma ionised calcium, parathyroid hormone and 1,25(OH)2-vitamin D) and the renin-aldosterone system. Serum magnesium was, however, positively correlated to plasma renin activity (PRA) (r = 0.38, P less than 0.05) while both 24 h urinary excretion of calcium and cAMP were found to be correlated to both PRA and urinary aldosterone in a positive way (r = 0.39-0.42, P less than 0.01 and r = 0.33-0.57, P less than 0.01, respectively). In this study there was no other evidence of any major influence of the renin-aldosterone status on the calcium balance in human hypertension. The urinary leak of calcium might be determined by the action of the renin-aldosterone system.
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PMID:An association between mineral metabolism and the renin-aldosterone system in human hypertension. 254 51

In 13 patients with essential hypertension (EH) and in 10 normotensive controls, the influence of ultraviolet irradiation on plasma calcium, phosphorus, 25-OH-D, 1,25(OH)2D and calcitonin (CT) was studied. The basal levels of total calcium (2.47 +/- 0.02 mmol/liter) and phosphorus (1.10 +/- 0.04 mmol/liter) in patients with essential hypertension were not different from the control subjects (2.49 +/- 0.05 mmol/liter and 1.22 +/- 0.06 mmol/liter, respectively). However, patients with essential hypertension had elevated levels of 25-OH-D (68.09 +/- 7.48 vs. 26.51 +/- 3.3 mg/ml), 1,25(OH)2D (175.15 +/- 32.5 pmol/liter vs. 118.0 +/- 13.23 pmol/liter) and CT (131.7 +/- 32.36 pg/ml vs. 49.0 +/- 18.62 pg/ml) than in control subjects. In contrast to normotensive subjects, the majority of hypertensive patients showed no rise of plasma 25-OH-D and 1,25(OH)2D in response to ultraviolet irradiation. The results of this study suggest involvement of abnormal vitamin D metabolism in the pathogenesis of hypertension, at least in some patients.
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PMID:Influence of ultraviolet irradiation on plasma vitamin D and calcitonin levels in humans. 263 50

Patients with essential hypertension, in particular those with low plasma renin activity (PRA), are reported to have lowered plasma-ionized calcium and elevated parathyroid hormone levels. In this study 1 microgram alphacalcidol (1 alpha-hydroxy-vitamin D3) was given in a double-blind, placebo-controlled fashion over four months to 39 subjects with mild to moderate hypertension. There was a significant rise in PRA in the treatment group when compared to placebo (P less than .05), but the mean blood pressure response was similar in the two groups. When the treatment group was divided according to pretreatment PRA it was, however, seen that subjects with low PRA displayed a reduction in diastolic blood pressure, whereas those with high PRA raised their blood pressure compared to placebo. Also subjects with low pretreatment values for plasma-ionized calcium and high levels of parathyroid hormone showed a reduction in diastolic blood pressure. This study supports the idea of a relationship between calcium metabolism and the renin-aldosterone system in essential hypertension and describes a beneficial effect of vitamin D supplementation on blood pressure in low-renin hypertension.
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PMID:Reduction of blood pressure during long-term treatment with active vitamin D (alphacalcidol) is dependent on plasma renin activity and calcium status. A double-blind, placebo-controlled study. 264 69

The effects of dietary sodium upon serum and urinary calcium and selected vitamin D metabolites were studied in two groups (n = 10 each) of age and gender matched, white normotensive subjects and patients with normal-renin hypertension. Isocaloric diets were consumed on a metabolic ward with sequential daily sodium intake of 109 meq for 5 days and 9 meq and 259 meq for 6 days each. Values for serum and urinary calcium, phosphorus, magnesium and electrolytes, creatinine clearance, plasma immunoreactive parathyroid hormone, and serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D were similar in both study groups on each diet. Measurements of plasma renin activity and serum aldosterone levels were higher in the hypertensive than in the normotensive group on each diet (p less than .05-.01). Serum 1,25-dihydroxyvitamin D and urinary calcium increased on the high sodium diet in the normotensive (p less than .05) and the hypertensive groups (p less than .01). When the data for normotensive subjects and hypertensive patients were pooled by gender, males had a 1 1/2 to 3 times the urinary calcium excretion than females, regardless of diet. The present study indicates that there are no differences in the selected components of calcium and vitamin D metabolism in response to sodium intake in patients with essential hypertension and normal plasma renin activity as compared to normal controls.
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PMID:Normal vitamin D and mineral metabolism in essential hypertension. 305 8

Alterations of calcium metabolism in hypertensive disease have been increasingly observed, although the specific manner in which these alterations contribute to the increased blood pressure remains unclear. We have studied calcium metabolism in essential hypertension and have adopted an approach based on analysis of renin system activity, which emphasizes the heterogeneity of human hypertensive disease. With this approach we have defined parallel deviations of plasma renin activity, circulating ionized calcium, and calcium-regulating hormones, which suggest a calcium deficiency in some hypertensives and, an excess of calcium in others. These deviations can be used to predict and may mediate the blood pressure sensitivity of hypertensives to dietary salt, and may also target those individuals most likely to benefit from oral calcium supplementation. Calcium itself has enhanced antihypertensive effects in low renin subjects, having lower ionized calcium and higher endogenous 1,25-dihydroxyvitamin D values, and in subjects on higher dietary salt intakes. Calcium may alter pressure, at least in part, by suppressing endogenous vitamin D metabolites and by stimulating calcitonin secretion. We hypothesize that calcium-regulating hormones participate in the physiology of the renin-angiotensin system and in the pathophysiology of human hypertension.
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PMID:Alterations of dietary calcium intake as a therapeutic modality in essential hypertension. 353 Apr 9


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