| 1. |
- Hvarfner, Andreas, et al.
(författare)
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Calcium metabolic indices, vascular retinopathy, and plasma renin activity in essential hypertension
- 1990
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Ingår i: American Journal of Hypertension. - 1941-7225. ; 3:12 Pt 1, s. 906-911
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Tidskriftsartikel (refereegranskat)abstract
- The interplays between calcium metabolic indices, retinal vascular status, plasma renin activity and blood pressure were examined in 67 patients with untreated essential hypertension. There was an inverse relationship between plasma ionized calcium and blood pressure (P = .002), whereas albumin-modified total serum calcium was directly related to blood pressure (P = .02). The plasma cyclic AMP level (P = .05) and the 24 h urinary excretion of cyclic AMP (P = .03) were also positively associated with blood pressure. Patients with vascular retinopathy had lower plasma ionized calcium concentrations (P = .01) and higher 24 h urinary cyclic AMP excretions (P = .05) than those without such changes, even when the differences in blood pressure, age, sex and body mass index were taken into account in analyses of covariance. Plasma renin activity did not interfere with the relationships between calcium metabolic indices and blood pressure, nor were there any associations between the renin status and the calcium metabolic indices. These findings suggest that a low concentration of plasma ionized calcium is an independent risk factor for vascular disease.
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| 2. |
- Lind, L, et al.
(författare)
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Fasting insulin, calcium metabolism and the electrocardiogram in hypertensive subjects
- 1992
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Ingår i: Journal of Internal Medicine. - 1365-2796. ; 232:4, s. 335-339
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Tidskriftsartikel (refereegranskat)abstract
- Changes in both calcium and insulin metabolism have been described in essential hypertension. Low levels of plasma ionized calcium (Ca2+) and high levels of insulin have previously been associated with vascular complications and coronary heart disease. In the present study, indices of calcium metabolism and fasting serum insulin were related to electrocardiographic (ECG) variables in 58 patients with untreated hypertension. Fasting insulin was found to be related to heart rate (r = 0.47, P < 0.001), diastolic interval (r = -0.39, P < 0.004) and electrical axis (r = -0.29, P < 0.03) while Ca2+ was found to be correlated with the QRS amplitude (r = -0.32, P < 0.03) and diastolic interval (r = 0.37, P < 0.02). Furthermore, non-ionized serum calcium was correlated with the QRS duration (r = 0.36, P < 0.02), ST-segment interval (r = -0.49, P < 0.002) and QT interval (QoT, r = -0.42, P < 0.008). These correlations were still significant when the influences of age, sex, obesity, blood pressure and heart rate were taken into account in the multiple regression analysis. In conclusion, the present study demonstrates that calcium and insulin metabolism are related to several basic characteristic functions of the heart, such as the systolic and diastolic function, as well as to signs of left ventricular hypertrophy.
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| 3. |
- Lind, L, et al.
(författare)
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Hypertension in primary hyperparathyroidism in relation to histopathology
- 1991
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Ingår i: European Journal of Surgery. - 1102-4151. ; 157:8, s. 457-459
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Tidskriftsartikel (refereegranskat)abstract
- Hypertension in primary hyperparathyroidism (HPT) was previously attributed to hypercalcemia per se or to impaired kidney function. Of 441 consecutive patients operated on for HPT over 24 years, 57% were hypertensive. Preoperative blood pressure remained fairly constant during the study period, despite otherwise markedly changing clinical picture with, latterly, more asymptomatic patients. The preoperative systolic blood pressure (SBP) was significantly correlated to both serum calcium (p less than 0.001) and serum creatinine (p less than 0.05), but not when the influence of age was taken into account in a multiple regression analysis. Other pathogenetic factors in hypertension were therefore probable. When the statistical analysis was adjusted for differences in age and serum calcium, blood pressure was lower in the HPT patients with parathyroid hyperplasia than in those with adenoma (153 +/- 31/90 +/- 14 vs. 163 +/- 29/91 +/- 14 mmHg, p less than 0.01 for SBP). The concept that parathyroid hyperplasia represents a mild (early) form of HPT that may precede adenoma formation is corroborated by our observations, which also indicate that there is no simple cause-and-effect relationship accounting for hypertension in primary HPT.
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| 4. |
- Lind, L, et al.
(författare)
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Indices of mineral metabolism in subjects with an impaired glucose tolerance
- 1990
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Ingår i: Experimental and Clinical Endocrinology. - 0232-7384. ; 96:1, s. 109-112
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Tidskriftsartikel (refereegranskat)abstract
- An altered mineral metabolism has been described both in insulin dependent and non-insulin dependent diabetes mellitus. In order to investigate if a disturbed mineral homeostasis was an early feature in the development of diabetes, 52 middle-aged men who all had recently developed an impaired glucose tolerance (IGT) were compared to healthy control persons. The IGT subjects showed higher levels of serum calcium (2.38 +/- 0.081 mmol/l (SD) vs 2.35 +/- 0.065 in controls) but similar levels of plasma ionized calcium indicating an increased protein binding of serum calcium in IGT. Serum magnesium was significantly lower in the IGT subjects (0.79 +/- 0.060 mmol/l vs 0.85 +/- 0.065, p less than 0.001) while serum phosphate was unaltered. This study demonstrates indices of an impaired mineral metabolism in IGT subjects similar in characteristics to what has previously been reported in manifest diabetes mellitus suggesting that an alteration of mineral homeostasis could be part of a primary event.
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| 5. |
- Lind, L, et al.
(författare)
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Influences of different antihypertensive treatments on indices of systemic mineral metabolism
- 1994
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Ingår i: American Journal of Hypertension. - 1941-7225. ; 7:4 Pt 1, s. 302-307
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Tidskriftsartikel (refereegranskat)abstract
- A negative calcium balance has previously been described in human hypertension with low levels of plasma ionized calcium (Ca2+) and an increased urinary excretion of calcium. The cause of this disturbance in mineral metabolism is not known, nor is it known if this derangement could be abolished if blood pressure is reduced by antihypertensive treatment. In the present investigation, the effects of antihypertensive monotherapy on serum and fasting urinary electrolytes were studied. For 3 to 6 months, 319 hypertensive patients entered 17 study groups, each group using one of the following antihypertensive drugs: dilevalol, metoprolol, antenolol, pindolol, propranolol, hydrochlorothiazide, bendrofluomethiazide, furosemide, spironolactone, doxazocine, prazocine, diltiazem, verapamil, nifedipine, isradipine, captopril, or lisinopril. Treatment with different beta-blockers, as well as diuretics, reduced the fasting urinary calcium excretion (P < .001). However, while the beta-blockers increased the proportion of the ionized form of calcium in blood (Ca2+) (P < .001), Ca2+ was further decreased by diuretic treatment (P < .05). Angiotensin converting enzyme inhibitors caused no major changes in mineral metabolism while of the calcium antagonists studied only verapamil raised the levels of Ca2+ (P < .01). No significant relationship between the changes in mineral metabolism and the reduction in blood pressure was observed in any of the treatment groups. Of the antihypertensive drugs used in the present study, beta-blockers appeared to reverse the basic abnormality with regard to calcium balance, suggesting that the activity of the sympathetic nerve system is involved in the disturbed calcium metabolism seen in hypertensive patients.
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