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Query: UMLS:C0221002 (primary hyperparathyroidism)
 4,921 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Some secondary forms of hypertension are characterized by an abnormal circadian blood-pressure rhythm. Therefore, the circadian blood-pressure variability was investigated in a prospective study using ambulatory blood-pressure monitoring in patients with hyperthyroidism and in patients with primary hyperparathyroidism. Both endocrine disorders are often associated with hypertension. Out of 17 patients with hyperthyroidism 73% were hypertensive, and out of 15 patients with hyperparathyroidism 80% were hypertensive. The blood-pressure profiles were compared to profiles from controls comprising normotensive subjects and patients with essential hypertension. The patients with hyperthyroidism and hypertension had a blunted circadian blood-pressure curve with only a small nocturnal reduction of systolic and diastolic blood pressure as compared to control patients. In patients with hyperthyroidism and normal blood pressure, the circadian blood-pressure rhythm was normal; however, in these patients the circadian heart-rate curve was blunted. All patients with hyperparathyroidism (with and without hypertension) had a normal circadian blood pressure and heart-rate rhythm. From these observations we conclude that in hyperthyroidism the circadian regulation of blood pressure or heart rate is significantly blunted. The circadian blood pressure and heart-rate curve is normal in primary hyperparathyroidism.
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PMID:[Circadian blood pressure rhythm in hyperthyroidism and primary hyperparathyroidism]. 151 9

Circadian blood pressure variability was recorded in patients with primary hypertension and with different forms of secondary hypertension using ambulatory 24-h blood pressure measurement. A group of 20 patients with different forms of secondary hypertension was compared with a matched group of patients with primary hypertension. Although the mean 24-h blood pressure was not different between the two groups, the patients with secondary hypertension had significantly higher systolic blood pressure during sleep and higher systolic and diastolic blood pressure in the early morning, compared with the primary hypertension group. This nocturnal blood pressure fall was then investigated in various groups of patients with different forms of secondary hypertension and compared with normotensives and patients with primary hypertension. Patients with mild primary hypertension (n = 152) and with severe primary hypertension (n = 30) had the same blood pressure fall (14-16 mm Hg systolic and diastolic) during the night (23:00-05:00 h) as normotensives (n = 20). However, in patients with renoparenchymal hypertension (n = 29), renovascular hypertensions (n = 20), hyperaldosteronism (n = 6), and hyperthyroidism (n = 14), the nocturnal blood pressure fall was significantly (p less than 0.01) reduced. One patient with coarctation of the aorta and nine patients with primary hyperparathyroidism and elevated blood pressure had a normal circadian blood pressure profile with a normal nocturnal blood pressure fall. The heart rate decrease during the night was equal in all patient groups. Ambulatory blood pressure measurement allows blood pressure recording under everyday conditions, including nighttime. In primary hypertension the blood pressure variability exhibits the same circadian variation as in normotension, showing a marked nocturnal fall.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Circadian blood pressure rhythm in primary and secondary hypertension. 179 27

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

A retrospective study of 89 patients with surgically proven primary hyperparathyroidism was done to gain insight into the pathogenesis of hypertension associated with this condition. The 43 patients (48%) who were hypertensive did not differ significantly from the normotensive patients with regard to age, sex, serum calcium and phosphate levels, and creatinine clearance. However, the mean serum magnesium level was significantly lower in hypertensive hyperparathyroid patients (1.52 +/- 0.24 mEq/L) than in normotensive hyperparathyroid patients (1.76 +/- 0.18 mEq/L; P less than .001), irrespective of use of diuretics in the former group. Although some studies implicate hypomagnesemia in the pathogenesis of essential hypertension, we are unaware of any previous human study reporting a link between hypomagnesemia and hypertension associated with primary hyperparathyroidism. This study suggests that a low level of serum magnesium may play a role in the pathogenesis of hypertension associated with primary hyperparathyroidism, a finding that needs further evaluation.
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PMID:Hypomagnesemia and hypertension in primary hyperparathyroidism. 277 81

1. Twenty-four patients with primary hyperparathyroidism were studied before and 18 restudied 6.5 months (mean) after parathyroidectomy, to investigate the pathogenesis of the hypertension which may accompany this condition. Comparison was made with age-matched patients with essential hypertension and with normotensive control subjects. 2. There was a significant inverse relationship between mean arterial pressure and 51Cr-labelled ethylene-diaminetetra-acetate (51Cr-EDTA) clearance in patients with hyperparathyroidism both before and after parathyroidectomy, but not in patients with essential hypertension. 3. Creatinine clearance appeared to overestimate glomerular filtration rate in some patients with hyperparathyroidism, falling significantly after surgery while 51Cr-EDTA clearance was unchanged. This observation may explain the failure of some previous studies to relate hypertension to impairment of renal function. 4. Plasma renin activity, plasma aldosterone and whole-body exchangeable sodium did not differ between normotensive and hypertensive patients with primary hyperparathyroidism and were unchanged after surgery. 5. Parathyroidectomy did not result in any change in blood pressure or in glomerular filtration rate measured by 51Cr-EDTA clearance.
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PMID:Hypertension and renal dysfunction in primary hyperparathyroidism: effect of parathyroidectomy. 292 21

The cause of hypertension in primary hyperparathyroidism and its response to corrective surgery remains a matter of controversy. We therefore studied blood pressure, vasoactive hormones and plasma calcium responses to parathyroidectomy in six hypertensive and two normotensive patients with primary hyperparathyroidism. Twenty-four-hour intra-arterial pressure recordings, together with hourly blood sampling for plasma renin activity (PRA), aldosterone, cortisol, catecholamines and calcium levels, were undertaken in each patient before surgery and were repeated under identical conditions 3-6 months after parathyroidectomy. Mean plasma calcium was 3.03 +/- 0.1 before, and 2.35 +/- 0.02 mmol/l after, parathyroidectomy. Changes in arterial pressure were small and variable in individual patients. Group mean arterial pressures before and after surgery were identical. Plasma cortisol and PRA were significantly higher in the hypercalcaemic state (P less than 0.01 and P less than 0.05, respectively) but there was no significant difference in plasma aldosterone or catecholamine levels. No correlations between changes in plasma calcium or parathyroid hormone levels and concomitant changes in plasma concentration of other hormones were observed. Our findings show that correction of primary hyperparathyroidism has no systematic effect on arterial pressure in a heterogeneous group, including some patients with probable background essential hypertension, when evaluated 3-6 months after surgery. Compared with values after corrective surgery, mean levels of PRA and cortisol-but not aldosterone or catecholamines--are elevated in patients with primary hyperparathyroidism. These findings are consistent with an inhibitory effect of raised ionic calcium concentration on the response of the adrenal glomerulosa to angiotensin and adrenocorticotrophic hormone.
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PMID:Hormone, calcium and blood pressure relationships in primary hyperparathyroidism. 305 96

To elucidate the pathophysiology of elevated blood pressure in hypercalcemic patients, we studied the plasma concentration of catecholamines and their major metabolites (as an index of sympathetic function) and the blood pressure response to norepinephrine infusion (vascular reactivity) in patients with primary hyperparathyroidism, in patients with primary hypertension, and in normal controls. In addition, we evaluated the hemodynamic response to calcium infusion in normotensive and hypertensive subjects. Plasma levels of both norepinephrine and epinephrine and the metabolites normetanephrine and dihydroxyphenyl-glycol were significantly higher in the hypercalcemic group than in the other two groups. Norepinephrine infusion increased blood pressure by 8.5 +/- 1.4 mm Hg in the control group, by 19 +/- 2 mm Hg in the hypercalcemic group and by 29 +/- 3 mm Hg in the primary hypertensive group. Infusion of calcium produced a significant rise in both systolic and diastolic blood pressures and in peripheral resistance in the hypertensives, whereas in the normotensive group only systolic blood pressure increased, associated with a rise in cardiac output. We conclude that the observed increased activity of the sympathetic nervous system in hypercalcemia could account for the elevation in blood pressure and the enhanced vascular reactivity could explain the hypertension in some patients with primary hyperparathyroidism.
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PMID:Sympathetic system function and vascular reactivity in hypercalcemic patients. 706 99

To examine the effects of primary hyperparathyroidism separately from those of hypertension per se on blood pressure regulation in patients with primary hyperparathyroidism, we studied the pressor response to infused angiotensin II (AII) and to norepinephrine (NE) in 7 normotensive patients with primary hyperparathyroidism before and after surgical cure, and compared it to that observed in 10 subjects with idiopathic hypertension and 10 normal controls. While the subjects were on an ad libitum diet, we measured urinary and plasma electrolytes, creatinine, and plasma renin activity. Except for calcium, these values were not significantly different among the three groups. The blood pressure was measured basally and in response to graded doses of AII or of NE until a 20-mmHg increase in the diastolic blood pressure was reached ("pressor dose"). The pressor doses of AII and of NE were lower in the normotensive patients with primary hyperparathyroidism than in normal controls [4.6 +/- 2.0 vs. 7.3 +/- 3.5 ng/kg/min (p < 0.05) and 164 +/- 114 vs. 302 +/- 176 ng/kg/min (p < 0.05) respectively] and not significantly different from those found in idiopathic hypertension (3.1 +/- 1.2 and 137 +/- 95 ng/kg/min). When the patients with primary hyperparathyroidism were studied again between 2-6 months after surgical cure, their pressor doses of AII and of NE remained unchanged from their preoperative values (5.4 +/- 2.9 and 137 +/- 80 mg/kg/min). We conclude that the hyperparathyroid condition can disrupt the normal responsiveness to pressor agents even if the blood pressure remains within normal limits, and that this abnormality may persist after surgical cure.
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PMID:Primary hyperparathyroidism and hypertension: persistently abnormal pressor sensitivity in normotensive patients after surgical cure. 807 14

It is generally known that patients with primary hyperparathyroidism (pHPT) feature disturbances in carbohydrate metabolism and hypertension. The incidence and prevalence of frank diabetes mellitus is significantly increased in these patients. The etiology and pathogenesis of the vascular and metabolic aberrations in this condition are still unclear. Glucose intolerance in pHPT is characterized by severe insulin resistance associated with pancreatic beta cell hypersecretion of insulin. Hypercalcemia is thought to be mainly responsible for the impaired glucose metabolism. However, several studies demonstrated that hypophosphatemia can also induce insulin hypersecretion and impair peripheral glucose uptake. Hypertension in primary hyperparathyroidism is mainly attributed to hypercalcemia. However, high peripheral insulin levels are also proposed to contribute to the development of essential hypertension and hyperinsulinemia per se is regarded as an important independent cardiovascular risk factor. After parathyroidectomy and decrease of the calcium levels to within the normal range, the blood pressure levels of the patients with pHPT normalised very quickly, whereas normalization of the high peripheral insulin levels was only found in a subgroup of patients. Thus, hypercalcemia seems to be mainly responsible for hypertension in primary hyperparathyroidism. Another important, yet unresolved issue is the question as to whether or to which extent the disturbances in glucose homeostasis are reversible after surgical correction of pHPT. At an early stage of the disease, insulin resistance and insulin hypersecretion are fully reversible after parathyroidectomy, whereas in patients with long-standing primary hyperparathyroidism and severely impaired glucose tolerance the metabolic disturbances will only partially improve. These results argue for improved screening to identify asymptomatic patients with primary hyperparathyroidism and for early surgical intervention in this disease.
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PMID:[Diabetes mellitus and carbohydrate metabolism in primary hyperparathyroidism]. 847 26

Free intracellular calcium is increased in primary hyperparathyroidism (HPT) and may be related to the higher incidence of hypertension in this disease. This elevation returns to normal when primary HPT is corrected. In essential hypertension, an alteration in calcium channels allows a intracellular accumulation of calcium. Aiming to asses if a similar mechanism operates in primary HPT, we measured intracellular calcium concentrations using QUIN-2-AM, before and after a 10 mg sublingual dose of nifedipine, in 9 subjects with primary HPT, 12 subjects with essential hypertension and 17 normal controls. Intracellular calcium was higher in subjects with primary HPT and with essential hypertension than in normal controls (276 +/- 56, 343 +/- 50 and 113 +/- 12 nM respectively). Among patient with primary HPT, intracellular calcium correlated with plasma PTH (r = 0.82). Nifedipine reduced intracellular calcium to 173 +/- 36 nM in subjects with primary HPT and to 188 +/- 35 nM in those with essential hypertension. In the latter, the decreased in intracellular calcium and blood pressure correlated significantly (r = 0.65 p < 0.03). We conclude that increased intracellular calcium in primary HPT and essential hypertension seems to depend on an increased inflow through specific channels. However in primary HPT, this alteration is related to PTH levels.
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PMID:[Nifedipine reduces the increase of free intracellular calcium in primary hyperparathyroidism: role of calcium channels and PTH]. 852 65


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