| 1. |
- Lind, Lars, et al.
(författare)
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Hypertension in primary hyperparathyroidism--reduction of blood pressure by long-term treatment with vitamin D (alphacalcidol) : A double-blind, placebo-controlled study
- 1988
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Ingår i: American Journal of Hypertension. - 0895-7061 .- 1941-7225. ; 1:4 Pt 1, s. 397-402
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Tidskriftsartikel (refereegranskat)abstract
- Patients with primary hyperparathyroidism (HPT) often have raised blood pressure but a simple cause-and-effect relationship has not been established. In 33 persons with probable primary HPT and mild hypercalcemia detected in a health survey, diastolic blood pressure (DBP) was significantly higher than among age- and sex-matched, normocalcemic, controls (89.4 +/- 9.8 (SD) v 85.2 +/- 8.9 mm Hg; P less than 0.05). Among the hypercalcemic individuals, DBP was, in a multivariate analysis, inversely related to the serum calcium and plasma-ionized calcium concentrations and to the serum levels of parathyroid hormone. A prospective, placebo-controlled, double-blind, study evaluating the effects of active vitamin D, alphacalcidol, (1 microgram daily) was carried out in the hypercalcemic patients over a six-month period. This treatment caused a slight further increase (0.05 mmol/L) of both serum calcium and plasma-ionized calcium concentrations. At the same time there was a significant reduction of DBP with a mean of 6.7 mm Hg compared with placebo (P less than 0.05). The hypotensive action of the vitamin D compound was inversely related to the pretreatment serum levels of 1,25(OH)2D3 and additive to concomitant, unchanged, antihypertensive medications. The negative correlation between serum calcium and blood pressure is similar to that obtained in normocalcemic individuals and suggests that raised blood pressure, at least in the milder forms of primary HPT, is only independently associated with the disease. Active vitamin D, although it raises serum calcium, can lower blood pressure also in hypercalcemic patients as previously demonstrated in normocalcemic individuals.
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| 2. |
- Lind, L, et al.
(författare)
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Long-term treatment with active vitamin D (alphacalcidol) in middle-aged men with impaired glucose tolerance. Effects on insulin secretion and sensitivity, glucose tolerance and blood pressure
- 1989
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Ingår i: Diabetes Research (Edinburgh, Scotland). - 0265-5985. ; 11:3, s. 141-147
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Tidskriftsartikel (refereegranskat)abstract
- There are specific receptors for the active metabolite of vitamin D on the pancreatic beta cells and severe vitamin D deficiency can inhibit insulin secretion. In the present study 14 middle aged men with impaired glucose tolerance and low glucose-stimulated insulin values received 2 micrograms alphacalcidol daily for 18 months. On treatment there was a transient increase of both the peak and the late insulin response to intravenous glucose while neither intravenous nor oral glucose tolerance were consistently altered. Nor was the peripheral insulin sensitivity, measured by the euglycemic clamp technique, significantly affected. In the untreated state there was a positive relationship (r = 0.77) between the tissue insulin sensitivity and the serum concentrations of 25-hydroxyvitamin D. There was also an inverse relationship (r = 0.61) between systolic blood pressure and the serum levels of 1,25-dihydroxy vitamin D. Although the subjects were normotensive and not overweight, treatment with alphacalcidol tended to lower both systolic (6 +/- 12 mmHg) and diastolic blood pressures (5.8 +/- 9.1 mmHg) and there was a small reduction (0.9 kg) in body weight. In conclusion, subjects with impaired glucose tolerance without vitamin D deficiency do not benefit from vitamin D supplementation, which however has some hypotensive action also in normotensive individuals.
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| 3. |
- Ljunghall, S, et al.
(författare)
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Clinical studies of calcium metabolism in essential hypertension
- 1987
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Ingår i: European Heart Journal. - 1522-9645. ; 8:Suppl. B, s. 37-44
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Tidskriftsartikel (refereegranskat)abstract
- Many factors can ultimately lead to an increased blood pressure and it is a generally accepted view that an increase in the active tension of arterioles reflects an increase of the free calcium concentration in the cytosol of the vascular smooth muscle cells. Only recently, however, has the possibility been considered that blood pressure regulation could be influenced by calcium homeostasis. A background for these studies has been provided by the epidemiological observations which link hypertension to a low dietary intake of calcium as well as experimental studies in animals, mostly rats, which have demonstrated that various disturbances of calcium metabolism are related to a raised blood pressure. This review is focused on clinical studies of a possible association between systemic calcium metabolism and the regulation of blood pressure.
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