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

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

1. Because disturbances of calcium metabolism have been described in hypertension, measurements of plasma and serum concentrations of ionized calcium, total calcium, magnesium and renin were made in 38 patients with essential hypertension and age- and sex-matched control subjects. Urinary excretion of calcium, magnesium and sodium was also determined. 2. The mean serum concentration of ionized calcium was 1.23 +/- 0.04 (SD) mmol/l in the hypertensive group and 1.21 +/- 0.03 mmol/l in controls, and results were similar after correction for pH. There was a weak positive correlation between serum ionized calcium (pH 7.4) and systolic pressure (r = 0.26, P less than 0.02), but no correlation with plasma renin concentration. 3. Although the difference between serum total calcium concentration in the hypertensive (2.29 +/- 0.09 mmol/l) and control (2.26 +/- 0.07 mmol/l) subjects was not significant, there was a significant correlation between total calcium and systolic pressure (r = 0.23, P less than 0.05) which was maintained after correction for other variables. 4. There were no differences in plasma concentrations of parathyroid hormone or 1,25-dihydroxycholecalciferol between hypertensive and control subjects. 5. The hypertensive group showed higher urinary excretion of calcium (5.9 +/- 3.0 mmol/24 h) than controls (4.6 +/- 1.7 mmol/24 h), but the difference was not maintained after correction for sodium excretion. 6. Serum concentrations of magnesium were similar in the two groups, but urinary excretion of magnesium was significantly lower in hypertensive (3.7 +/- 1.3 mmol/24 h) than control (4.5 +/- 1.6 mmol/24 h) subjects and there was an inverse correlation between magnesium excretion and blood pressure (r = 0.3-0.35, P less than 0.01).
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PMID:Calcium and magnesium in essential hypertension. 305 75

Calcium gluconate (22.4 g/day; 2 g/day as Ca) was administered orally for 8 weeks to eight hospitalized elderly patients with essential hypertension in order to confirm the hypotensive effect of oral calcium supplementation and to clarify its hypotensive mechanism by analyzing changes in hormonal factors. After 2 weeks of calcium supplementation, both systolic and diastolic pressures decreased significantly and remained decreased for the duration of the study. An elevation of plasma PGE2 correlated with blood pressure reduction was observed at 2 weeks. Plasma norepinephrine decreased significantly from 4 weeks. Plasma parathyroid hormone decreased significantly from 4 weeks, and 1,25-dihydroxyvitamin D (1,25-[OH]2D) decreased significantly at 8 weeks. The reduction of plasma 1,25-(OH)2D correlated with blood pressure decrease at 8 weeks. The present study indicates that the mechanism of its hypotensive effect is multifactorial and may be different during different phases of calcium supplementation. The suppression of plasma 1,25-(OH)2D following reduction of parathyroid hormone may be involved in the hypotensive effect in the chronic phase of calcium supplementation. Enhancement of PGE2 production in the early phase and suppression of sympathetic nervous activity in the chronic phase may also be factors in blood pressure reduction.
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PMID:Hypotensive effect of long-term oral calcium supplementation in elderly patients with essential hypertension. 309 67

To study the role of parathyroid gland activity in early primary hypertension plasma concentrations of intact parathyroid hormone were measured in 90 untreated young subjects, aged 16-29, with stable midly raised blood pressure and in 40 normotensive control subjects selected from the same population in Zoetermeer, The Netherlands. Intact parathyroid hormone concentration was significantly higher in the hypertensive than the normotensive group (2.34 (SE 0.11) pmol/l v 1.47 (0.13) pmol/l, respectively; difference 0.87 pmol/l; 95% confidence interval 0.55 to 1.21; p less than 0.0001). Serum total calcium concentration was 2.36 (0.01) mmol/l in the hypertensive group and 2.42 (0.01) mmol/l in the normotensive group (difference 0.06 mmol/l; 95% confidence interval 0.02 to 0.09; p = 0.02). Urinary calcium excretion over 24 hours did not differ significantly between the two groups (4.17 (0.28) mmol/24 h in the hypertensive group and 3.89 (0.39) mmol/24 h in the normotensive group; difference 0.28 mmol/24 h; 95% confidence interval -0.66 to 1.22). In the hypertensive group both systolic and diastolic blood pressures increased slightly though significantly with intact parathyroid hormone concentrations. No obvious associations between serum calcium concentration and blood pressure were observed. These findings support the view that enhanced activity of the parathyroid gland may play a part in the early stage of primary hypertension.
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PMID:Raised plasma intact parathyroid hormone concentrations in young people with mildly raised blood pressure. 313 Sep 26

Forty-year old men with untreated mild essential hypertension (n = 35) had decreased serum phosphate (P less than 0.001) concomitant with elevated resting plasma epinephrine (P less than 0.05) and heart rate (P less than 0.001) compared with age-matched, normotensive control men (n = 44). Blood pressure correlated negatively with serum phosphate (P less than 0.001) and positively with plasma epinephrine (P less than 0.01) and heart rate (P less than 0.01). Serum phosphate was significantly lowered during infusion of epinephrine, increasing arterial plasma epinephrine within the lower pathophysiological range corresponding to arousal reactions. Serum concentrations of immunoreactive parathyroid hormone were unchanged. Thus, hypophosphatemia in patients with mild essential hypertension appears to be inversely related to sympathetic adrenal tone and may be caused by increased plasma epinephrine within pathophysiologic arterial concentrations.
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PMID:Decreased serum phosphate in essential hypertension. Related to increased sympathetic tone. 321 62

1. Disturbances of calcium metabolism, mimicking mild, compensated secondary hyperparathyroidism, accompany essential hypertension, but it is not known whether these alterations are primary or only secondary to the elevated blood pressure. 2. Indices of systemic calcium metabolism were followed prospectively during 6 months' treatment with either propranolol, bendroflumethiazide or verapamil in 35 patients with essential hypertension. Multivariate statistical methods were employed to study the effects of blood pressure reduction upon the metabolic indices with adjustment for the effects of the different antihypertensive agents. 3. Propranolol treatment increased the plasma ionized calcium and serum phosphate concentrations, and reduced the serum levels of parathyroid hormone, free fatty acids and glycerol. Neither the total nor the total albumin-modified serum calcium concentration was significantly affected. Thus, presumably the decrease in free fatty acids reduced the calcium complex and the calcium binding to albumin, and consequently increased the plasma ionized calcium, thereby suppressing the secretion of parathyroid hormone. 4. Bendroflumethiazide caused a reduction of the fasting renal calcium excretion to half the pretreatment level, but produced no other significant changes in the various indices of calcium metabolism. 5. During verapamil treatment, the fasting renal excretion of calcium and magnesium increased, whereas the free fatty acids and glycerol concentrations in serum were reduced. These two changes presumably balanced each other, as the plasma ionized calcium and serum parathyroid hormone concentrations were not significantly altered. 6. There were no consistent relationships between the decrease in blood pressure and the changes in the metabolic indices, either in the total sample or within any subgroup.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Changes in calcium metabolic indices during long-term treatment of patients with essential hypertension. 325 68

Relationships between cytosolic free calcium ([Ca2+]i) in platelets, indices of systemic calcium metabolism and blood pressure were examined in 86 subjects; 29 patients with untreated and 29 patients with treated essential hypertension, six patients with borderline hypertension and 22 healthy reference subjects. In order to analyse interactions between the variables, multivariate statistical analyses were employed. The patients with untreated hypertension had higher [Ca2+]i values in non-activated platelets (P = 0.04) and lower levels of plasma ionized calcium (P = 0.02) than the reference subjects. In multivariate models analysing platelet [Ca2+]i mean blood pressure (MBP), plasma ionized calcium, serum parathyroid hormone (PTH) and body mass index (BMI), the relationship between platelet [Ca2+]i and blood pressure was attenuated (P = 0.13), whereas the inverse relationships between plasma ionized calcium and MBP (P = 0.01) and between platelet [Ca2+]i and serum PTH (P = 0.06) seen in univariate analyses persisted. According to the multivariate models the [Ca2+]i value explained only 5% of the MBP variability. Thus, the data from this investigation do not support a close relationship between basal platelet [Ca2+]i and blood pressure. The inverse relationship between plasma ionized calcium and blood pressure, independent of platelet [Ca2+]i and serum PTH, suggests a direct interaction between plasma ionized calcium and blood pressure regulation.
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PMID:Cytosolic free calcium in platelets: relationships to blood pressure and indices of systemic calcium metabolism. 335 Dec 96

Total and ionized calcium, parathyroid hormone, calcitonin, and renin activity were measured in 27 untreated patients with essential hypertension. There was no relationship between any of these parameters and diastolic blood pressure. However, a significant inverse relationship was found between diastolic blood pressure and the ratio of either total or ionized calcium to parathyroid hormone (r = -0.40, P less than 0.05; and r = -0.38, P less than 0.05, respectively). The ratios did not correlate with patient age or plasma renin level. This preliminary finding suggests that the role of plasma calcium in hypertension may need to be analyzed in the context of overall calcium metabolism, as influenced by the parathyroid hormone. The role of an altered relationship between plasma calcium level and parathyroid hormone in the pathophysiology of essential hypertension remains to be studied.
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PMID:Parathyroid hormone and calcium. A relationship in hypertension. 341 13

Forty-year old, normocalcaemic men with mild essential hypertension (n = 35) had decreased serum phosphate (p less than 0.001) concomitant with elevated plasma adrenaline (p less than 0.03) and heart rate (p less than 0.001). All had unchanged serum immunoreactive parathyroid hormone concentrations compared to age-matched normotensive control men (n = 44). Serum phosphate levels correlated negatively with plasma adrenaline (p less than 0.05), plasma noradrenaline (p less than 0.05), mean blood pressure (p less than 0.001) and heart rate (p less than 0.05). Serum phosphate was significantly lowered by infusion of small amounts of adrenaline at all four infusion rates in a hypertensive group (n = 12) while a similar effect was obtained only at the two highest infusion rates in a normotensive group (n = 10). No change in serum calcium was observed in either group. Thus, hypophosphataemia appears to be inversely related to sympathetic tone in essential hypertension.
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PMID:Serum phosphate and sympathetic tone in mild essential hypertension. 347 34

Circulating levels of the calcium-regulating hormones, calcitonin, calcitriol, and parathyroid hormone, were analyzed in relation to plasma renin activity in 10 persons with normal blood pressure and in 51 persons with essential hypertension. Calcitriol (p less than 0.008) and parathyroid hormone (p less than 0.01) levels were elevated in hypertensives with low renin activity, whereas calcitonin levels were higher in patients with high renin activity (p less than 0.008), compared with normotensive controls and other hypertensive patients. Continuous relationships were observed between calcitriol levels and plasma renin activity in all patients (r = -0.65, p less than 0.001) and between parathyroid hormone levels and urinary sodium excretion in hypertensive patients with low renin activity (r = -0.63, p less than 0.01). Together, these results support a linkage between calcium metabolism and renin-sodium factors in essential hypertension. Calcium-regulating hormones and the renin-aldosterone system may coordinately mediate the blood pressure effects of differing dietary calcium and sodium intakes at the cellular level by altering cellular handling of monovalent and divalent ions.
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PMID:Calcium-regulating hormones in essential hypertension. Relation to plasma renin activity and sodium metabolism. 353 93


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