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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The factors responsible for the frequent occurrence of hypertension in patients with primary hyperparathyroidism have not been elucidated. Suggested mediators have included hypercalcemia, renal insufficiency, and increased plasma renin activity. However, experimental results have not been reported in any species that test the hypothesis that sustained hypertension in this clinical syndrome is due to consequences of parathyroid hormone (PTH) excess versus unrelated factors (e.g., primary hypersecretion of other hormones, NaCl sensitivity, genetic factors). Moreover, no systematic evaluation of the renin or adrenal cortical responses to chronic PTH excess has been reported in any species. Accordingly, the present studies assessed the effects of chronic (12 days) continuous intravenous b-(1-34) PTH infusion in normal human subjects (n = 4). PTH infusion resulted in persistent hypercalcemia and hypertension, reversible during a 4-8-day recovery period. Transient but significant increases in urinary tetrahydroaldosterone excretion and plasma cortisol concentration were observed as hypercalcemia and hypertension developed. No significant changes in plasma potassium concentration or plasma renin activity were observed, suggesting that hypercalcemia-induced transient hypersecretion of ACTH was responsible for both cortisol and aldosterone responses. The present results suggest that hypertension associated with clinical primary hyperparathyroidism results from either direct or indirect effects of PTH excess, per se, and requires neither the long-term consequences/complications of the clinical disorder (e.g., severe nephrocalcinosis, renal insufficiency) nor primary hypersecretion of additional hormones. These results are consistent with the hypothesis that hypercalcemia alone or in combination with at least permissive levels of PTH can generate short-term, but persistent (12 days) hypertension in human subjects and thus may be the initiating mechanism for hypertension in clinical primary hyperparathyroidism.
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PMID:Chronic continuous PTH infusion results in hypertension in normal subjects. 354 30

From 1965 to 1985, 412 patients were operated on for primary hyperparathyroidism (pHPT). Of these, 35 (8.7%) were without specific symptoms and findings. The follow-up investigations after six months to 14 years (median: 31 months) revealed a normalization of the preoperative pathological parameters of alkaline phosphatase, uric acid, creatinine and hypertension in the majority of patients apart from the improvement of their general condition. All patients were normocalcemic. According to these results, the indication for early surgical therapy of the asymptomatic pHPT is to be advocated in order to avoid long-term complications.
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PMID:[Asymptomatic hyperparathyroidism. An indication for surgery?]. 356 55

The metabolic manifestations and operative findings in 10 patients with a diagnosis of parathyroid carcinoma were analyzed to determine whether they differ from those in patients with parathyroid adenomas and similar degrees of hypercalcemia. Two groups of patients with parathyroid adenomas were used for comparison. Group A consisted of eight patients with "atypical" benign adenomas (mean preoperative level of serum calcium: 13.4 mg/dl); group B consisted of 13 patients with benign typical adenomas--all with preoperative serum calcium levels greater than or equal to 13.0 mg/dl (mean: 14.2 mg/dl). The patients with carcinoma (mean preoperative level of serum calcium: 15.3 mg/dl) had a frequency of osteoporosis and osteitis fibrosa cystica (50%) comparable with that of group A (33%) and group B (62%). Seventy percent of the patients with carcinoma had renal disease (nephrolithiasis, nephrocalcinosis, or impaired renal function), whereas only 38% of group A and 15% of group B had similar disorders. The patients with carcinomas had the highest frequency of combined bone and renal disease (50% versus 14% in group A and 15% in group B). Anemia, peptic ulcer disease, and hypertension occurred with similar frequencies in the three groups. Three patients with recurrent parathyroid carcinoma died of profound hypercalcemia, renal failure, or cardiac arrhythmia. In general, although patients with parathyroid carcinomas have more profound metabolic abnormalities than do patients with primary hyperparathyroidism, the metabolic manifestations in patients with parathyroid carcinoma are comparable with those in patients with parathyroid adenomas and profound hypercalcemia. Furthermore atypical adenomas share many anatomic and histopathologic features with parathyroid carcinomas, and distinguishing between the two is sometimes possible only in cases of tumor recurrence.
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PMID:Parathyroid carcinoma versus parathyroid adenoma in patients with profound hypercalcemia. 358 61

A 1-year retrospective study of all serum profiles of patients with hypercalcaemia analysed at the Johannesburg Hospital was carried out to ascertain the causes of hypercalcaemia and physician awareness of primary hyperparathyroidism. Hypercalcaemia was found in 560 subjects (2.9% of 19,200), but in 147 of these (26%) this was not confirmed by repeat estimations. Malignant tumours were the commonest cause (38.4%) and accounted for the most severe hypercalcaemia (mean serum calcium 2.93 mmol/l). Renal disease resulted in significant hypercalcaemia, at times requiring parathyroidectomy. Drug-associated hypercalcaemia was usually mild and reversible on drug withdrawal. Although primary hyperparathyroidism occurred in 21.3% of cases, overall physician awareness of the disease was poor (39%). 'Incidental' profile hypercalcaemia (P less than 0.005) and hypertension (P less than 0.005) were frequent presenting features in this study. Renal disease (P less than 0.001) occurred infrequently.
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PMID:Hypercalcaemia in the Johannesburg Hospital. Differential diagnosis and physician awareness of primary hyperparathyroidism. 361 82

The long-term clinical courses of 212 "cured" (normocalcemic) patients were analyzed for 1 to 25 years (mean, 6.8 +/- 5.4 years). Preoperatively, 181 patients (85%) were classified as having typical symptoms, 22 patients (11%) as having minimal symptoms, and nine patients (4%) as having no symptoms of primary hyperparathyroidism (PHP). Although the formation of urinary calculi was stopped in 91% of patients, deteriorated renal function and hypertension were seen in patients with symptoms (14% and 8%, respectively) and patients with minimal symptoms of PHP (6% and 15%, respectively). Renal function changes and hypertension were unpredictable despite normalization of the hyperactive parathyroid metabolism and had decisive results: 7% of the patients died of uremia or of the consequences of hypertension (stroke). Large, multiple bone lesions healed functionally and were of no prognostic significance. In the majority of patients with symptoms of PHP, gastrointestinal manifestations healed postoperatively, but two patients who had no preoperative gastrointestinal complaints died of acute pancreatitis. Almost all symptoms of the hypercalcemia syndrome disappeared immediately and permanently in patients with symptoms and patients with minimal symptoms of PHP. Neither deterioration of renal function nor elevation of blood pressure were observed postoperatively in "cured" patients who showed no symptoms of PHP preoperatively. Even in these patients, immediate surgical treatment may have avoided the complications of chronic renal failure or hypertension. As soon as organic manifestations, even in mild form, have been established, it seems impossible to predict the course and to prevent an unfavorable clinical outcome.
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PMID:Successful parathyroidectomy in primary hyperparathyroidism: a clinical follow-up study of 212 consecutive patients. 368 53

Hypertension is common in primary hyperparathyroidism, but the mechanisms are not clear. Significant hypercalcemia induces elevation in blood pressure (BP), whereas excessive parathyroid hormone (PTH) lowers BP. However, in chronic renal failure (CRF) and secondary hyperparathyroidism, the hypercalcemia-induced hypertension is more severe. We examined the interaction between PTH and calcium on BP in normal rats and in those with CRF. Calcium caused a dose-related rise in serum calcium and a rise in mean arterial pressure (MAP). For a comparable rise in serum calcium, the increment in MAP in parathyroidectomized (PTX) rats (7 +/- 3 mmHg) was significantly lower (P less than 0.05) than in sham PTX rats (19 +/- 7.3 mmHg). In PTX rats receiving PTH, the MAP response to calcium infusion (17 +/- 2.4 mmHg) was similar to that in the sham PTX rats. The infusion of similar amounts of calcium in CRF rats caused a greater rise in serum calcium. In CRF-PTX rats, the changes in MAP during calcium infusion were significantly lower (P less than 0.05) than in CRF-sham PTX animals, despite similar rise in serum calcium. For a comparable rise in serum calcium, the rise in MAP in CRF rats was greater than in normal rats. These data suggest that the presence of PTH plays an important permissive role for the hypertensive action of the hypercalcemia.
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PMID:Effects of hypercalcemia and parathyroid hormone on blood pressure in normal and renal-failure rats. 370 44

A retrospective study of 75 patients who were surgically cured of primary hyperparathyroidism from 1976 to 1984 was performed to evaluate the blood pressure and metabolic responses to parathyroid surgery. Published data on the population prevalence of hypertension (HT) in South Africa were used for comparison. The overall prevalence of HT before surgery was 47%, compared with 23% in the general population. Hypertension was most frequent in patients older than 60 years (62% vs 39% expected). Renal insufficiency was found in 13 of 35 hypertensive patients and in two of 40 normotensive patients. However, the prevalence of HT in patients with normal creatinine levels (37%) exceeded that expected. The frequency of urolithiasis and mean levels of serum and urine calcium and phosphate were similar in normotensive and hypertensive patients. Parathyroidectomy resulted in a substantial fall in both mean systolic and mean diastolic blood pressures in 54% of the hypertensive subjects, unrelated to improvement in renal function.
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PMID:Parathyroid hypertension. A reversible disorder. 375 10

Depending on their symptomatology 152 cured (i.e., normocalcemic) patients with surgically proven primary hyperparathyroidism (pHPT) showed typical symptoms preoperatively. Besides hypercalcemia and elevated parathyroid hormone levels, 15 patients suffered only from hypertension and/or diffuse osteoporosis and/or complaints caused by the hypercalcemic syndrome (oligosymptomatic patients). Nine patients had no complaints (asymptomatic patients). The long-term clinical course of all patients was analyzed up to 22 years. Although the formation of urinary calculi was stopped in 94% of cases, a deterioration of renal function and hypertension was seen in symptomatic (12.5% and 9.2%, respectively) and oligosymptomatic patients (6.7% and 13.3%, respectively). Renal function and hypertension were unpredictable despite normalization of the hyperactive parathyroid metabolism and were of decisive prognostic significance; 6% died of acute or chronic renal failure, or of the consequences of hypertension. Multiple bone lesions, even large, healed functionally and were of no prognostic significance. In the majority of symptomatic patients gastrointestinal manifestations held postoperatively, but two patients died of acute pancreatitis without gastrointestinal complaints preoperatively. Almost all symptoms of the hypercalcemic syndrome disappeared immediately and permanently in symptomatic and oligosymptomatic patients. No deterioration of renal function and no elevation of blood pressure was observed in cured asymptomatic patients postoperatively. Immediate surgical treatment even in asymptomatic patients may have avoided complications of chronic renal failure or of hypertension. As soon as organic manifestations, even in a mild form, have been established, it seems impossible to predict the course and to prevent an unfavorable clinical outcome.
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PMID:[Clinical experiences following the surgical therapy of asymptomatic, oligosymptomatic and symptomatic parathyroid gland hyperfunction]. 378 42

This study comprised 100 white patients with primary hyperparathyroidism treated between 1975 and 1984. Of these, 75 attended Johannesburg Hospital and 25 were managed by private practitioners. The mean age was 56.4 +/- 1.4 years at the time of diagnosis. There were almost twice as many women as men. In patients attending Johannesburg Hospital there was a progressive increase in the detection rate after 1979, which corresponded with the introduction of automated multichannel serum analysis. The commonest major complications were renal stones (54%), renal insufficiency (27%), a history of skeletal fractures (12%), radiographic evidence of osteopenia (38%) and peptic ulcers (20%). Bone disease was particularly common in postmenopausal women (64%). Other notable features were the frequency of weakness and fatigue (40%) and hypertension (45%). Coincidental thyroid abnormalities were frequent (18%). Ninety-three patients were treated surgically; 76 (81.7%) had a single adenoma. Our findings are compared with those of other large series. This study indicates the need for a greater awareness of this condition and earlier diagnosis to forestall the development of its harmful complications, and for the collection of additional information from a prospective study.
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PMID:Primary hyperparathyroidism. A study of 100 patients in Johannesburg. 394 58

A retrospective survey was performed on 265 patients with primary hyperparathyroidism who had received three forms of treatment on a non-randomised basis. 'Successful' surgery (normalisation of serum calcium) was carried out in 142 patients, 'unsuccessful' surgery (persistence of hypercalcaemia after neck exploration) in 33 and no surgery in 90. Patients subjected to surgery were significantly younger than patients in the unoperated group and their serum calcium values at the time of decision were approximately 10 per cent higher. The mean follow-up period was significantly longer in the operated groups. The percentages of patients who had died were similar in each group. Clinical events relating to renal stones depended on the presence or absence of calculi at the time of decision rather than on the method of treatment. At the time of follow-up the prevalence of hypertension, renal impairment and vertebral crush fractures were similar in all three groups. Forearm osteo-densitometry showed a higher bone mineral content in the 'successful' group than in the other two groups. In spite of the selection bias inherent in a study of this kind, it is clear that untreated hyperparathyroidism is compatible with long survival and a lack of demonstrable deleterious effects on kidney and bone.
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PMID:Is parathyroidectomy of benefit in primary hyperparathyroidism? 399 79


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