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Biomedical subjects

L Lind

Publications and source records attributed to L Lind.

At least 181 records · Page 10Linked to original sources
PubMed1992

Serum urate and renal function in different forms of hypercalcemia.

In order to investigate the relationships between serum calcium, urate and kidney function, serum calcium, urate, creatinine and urea were measured at 100 occasions in hypercalcemic cancer patients together with 113 preoperative measurements in HPT subjects and 106 measurements in normocalcemic control persons. When compared to normocalcemic control subjects (serum urate 336 +/- 110 mumol/l) both HPT subjects (356 +/- 98 mmol/1, p less than 0.006) and the cancer patients (407 +/- 179 mmol/l, p less than 0.001) showed raised levels of serum urate. While serum urate was correlated to serum creatinine in all groups (r = 0.40-0.59, p less than 0.0001) a significant correlation to serum calcium was only seen in the HPT group (r = 0.28, p less than 0.004). This relation persisted also after correction for age, sex and serum creatinine in the multiple regression analysis. Serum creatinine was similar in all groups but significantly correlated to serum calcium only in the HPT subjects (r = 0.29, p less than 0.003). Serum urea was not significantly correlated to serum calcium in any of the groups but was elevated in the cancer group (8.3 +/- 4.4 vs 6.2 +/- 2.9 mumol/l in the control group, p less than 0.0001). This elevation in serum urea seen in the cancer patients might rather be explained by dehydration or catabolism than an impaired kidney function. In conclusion, while serum urate is related to the kidney function both in normo- and hypercalcemia, it also seems to be related to the hypercalcemia in HPT subjects but not in cancer patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Serum levels of 1,25-(OH)2-vitamin D are not altered by long-term supplementation with alphacalcidol (1-OH-vitamin D3). A double-blind, placebo-controlled study.

The endogenous production of 1,25-(OH)2-vitamin D has been estimated to be 1.5 micrograms daily. Despite the use of alphacalcidol (1,25-(OH)2-vitamin D) during more than a decade the long-term effects of the serum levels of 1,25-(OH)2-vitamin D have been poorly investigated. When 1 microgram of alphacalcidol was given daily to 39 non-vitamin D deficient subjects in a double-blind, placebo-controlled study during 4 months no significant effects on the serum levels of 1,25-(OH)2-vitamin D or 25-(OH)-vitamin D were found. The treatment however induced a 50% increase in urinary excretion of calcium (p less than 0.01). In conclusion, long-term supplementation with a physiological dose of alphacalcidol does not influence the serum levels of 1,25-(OH)2-vitamin D, despite a marked effect on urinary calcium excretion.

Adult↗
PubMed1992

Critical care hypercalcemia--a hyperparathyroid state.

Hypocalcemia is a well known finding in critically ill patients. Subsequent occurrence of mild hypercalcemia has also been reported. In order to investigate the incidence and nature of critical care hypercalcemia serum calcium was measured in 83 critically ill ICU patients (TISS score > or = 40) and related to the occurrence of acute renal failure (ARF) and severity of illness, evaluated by the APACHE-II and the multiple organ failure scoring systems. Thirty-two percent of the patients developed hypercalcemia (serum calcium > or = 2.60 mmol/l) during their ICU stay. These hypercalcemic episodes (mean maximal value 2.71 +/- 0.12 mmol/l) were more common and occurred earlier in patients with co-existing ARF. However, multiple regression analysis showed the number of failing organ systems in the first days to be the best predictors for later occurrence of hypercalcemia (p < 0.0001). When serum parathyroid hormone (PTH) was measured in 6 of the patients without ARF during their hypercalcemic episodes, PTH was not suppressed but slightly elevated, to a similar extent as in patients with mild primary hyperparathyroidism. In conclusion, a high incidence of hypercalcemia was found in critically ill ICU patients. The hypercalcemia was mild and was more frequently found in patients with co-existing renal failure. The most powerful predictor to later occurrence of hypercalcemia was however the severity of the illness in itself. The raised levels of PTH found during the hypercalcemic episodes suggest ICU hypercalcemia to be caused by parathyroid overactivity.

Acute Kidney Injury↗
PubMed1992

Metabolic cardiovascular risk factors and sodium sensitivity in hypertensive subjects.

Hypertension has previously been suggested to be a part of a metabolic syndrome also involving hyperlipidemia, hyperinsulinemia, and decreased insulin sensitivity. In the present study, 10 untreated hypertensive subjects were challenged with a high-salt diet (20 g NaCl) for 1 week after 7 days on a low-salt diet (less than 3 g). The difference in mean blood pressure (MBP) at the end of the high-salt diet v the low-salt diet was denoted salt sensitivity. We related the salt sensitivity to indices of glucose and lipid metabolism and studied the effect of salt deprivation on these metabolic variables. Salt sensitivity was found to be significantly correlated to HDL cholesterol (r = 0.79, P less than .007), insulin sensitivity (M value at the euglycemic clamp, r = 0.68, P less than .003), and fasting serum insulin (r = 0.69, P less than .04). Salt deprivation induced an increase in fasting insulin (P less than .03), but did not significantly affect any other indices of glucose and lipid metabolism. In conclusion, our study shows that hyperinsulinemia, decreased sensitivity to insulin, and low levels of HDL cholesterol were most commonly seen in hypertensive subjects with a low sodium sensitivity. A putative mechanism might be an increased activity in pressor systems also affecting glucose and lipid metabolism.

Aged↗
PubMed1992

Fasting insulin, calcium metabolism and the electrocardiogram in hypertensive subjects.

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.

Adult↗
PubMed1992

Plasma ionized calcium and cardiovascular risk factors in mild primary hyperparathyroidism: effects of long-term treatment with active vitamin D (alphacalcidol).

Primary hyperparathyroidism (HPT) has been associated with hypertension, hyperinsulinaemia, hypertriglyceridaemia and hyperuricaemia. In the present study, plasma ionized calcium (Ca2+) was studied in relation to cardiovascular risk factors in 20 subjects with mild hypertension. Plasma Ca2+ was found to be negatively correlated with fasting serum insulin, triglycerides and urate, and with diastolic blood pressure (DBP). However, after the interaction of the different risk factors had been taken into account in the multiple regression analysis, only the relationship between Ca2+ and serum insulin was significant (r = 0.55, P less than 0.01). In a previous double-blind, placebo-controlled study 1 micrograms alphacalcidol, a synthetic analogue of 1,25 dihydroxy-vitamin D3, induced a decrease in blood pressure in mild HPT subjects. In the present study, the highest dose that did not further aggravate the hypercalcaemia was given in a long-term study over a 12-month period to 18 mild HPT subjects (average dose, 1.75 micrograms daily). The treatment induced a reduction in body weight of 0.9 kg (P less than 0.05) and an increase in serum urate from 330 +/- 92 to 380 +/- 104 mmol l-1 (P less than 0.01). A reduction in blood pressure was only observed at the end of the study, from 142 +/- 17/86.6 +/- 9.1 to 139 +/- 13/82.9 +/- 8.9 mmHg (P less than 0.05 for DBP). The reduction in systolic blood pressure was significantly correlated with the reduction in body weight induced by treatment (r = 0.63, P less than 0.02). No consistent changes in glucose or lipid metabolism were induced by treatment.

Blood Glucose↗
PubMed1992

Therapeutic intervention scoring system (TISS)--a method for measuring workload and calculating costs in the ICU.

The Therapeutic Intervention Scoring System (TISS) is an easily applicable method for measurement of workload in the intensive care unit (ICU). In the present study a modified TISS-scoring (mTISS) was performed daily during 1988-1989 on 2693 patients in a general ICU. Of these, 900 could be classified as 'true' ICU-patients (ICU-stay > or = 24 h or TISS > or = 20 points), whereas the rest were postoperative. In ICU-patients the average length of stay was 4.5 +/- 8.9 days and the average workload 114 +/- 218 mTISS-points. The workload was not significantly related to age or type of admission (scheduled vs unscheduled). Hospital non-survivors (13.6%) showed a significantly increased mean total mTISS-score (239 +/- 364, P < 0.001). Critically ill (TISS Class IV) patients (14% of the sample), with an average workload of 437 +/- 401 mTISS-points, consumed 53% of the total resources. Patients categorized (ICD-9) to respiratory and infectious diseases showed the greatest average workload (207 +/- 315 and 208 +/- 355 mTISS-points, respectively). A workload-index was also developed relating the actual workload to the ICU personnel. The cost of each mTISS-point was calculated. In conclusion, the present study showed that mTISS is a valuable tool when evaluating resource utilization in the ICU. Together with the proposed workload-index and calculation of costs, mTISS could be used for ICU management control.

Age Factors↗
PubMed1992

Metabolic cardiovascular risk factors and the renin-aldosterone system in essential hypertension.

Impairment of glucose and lipid metabolism is common in hypertensive subjects. In the present study the relationships between indices of lipid and glucose metabolism and the renin-aldosterone system were studied in 37 untreated hypertensive subjects (DBP greater than 95 mmHg). Fasting insulin and the early insulin response at an intravenous glucose tolerance test were both correlated to plasma renin activity (r = 0.48, P less than 0.003 and r = 0.55, P less than 0.002, respectively) while HDL-cholesterol was found to be inversely related to the urinary excretion of aldosterone (r = 0.35, P less than 0.03). These relations were still significant when influences of age, sex, obesity (BMI) and serum creatinine were taken into account in the multiple regression analysis. In conclusion, hyperinsulinaemia and low levels of HDL-cholesterol were found in hypertensive subjects with a high activity of the renin-aldosterone system and might explain the high incidence of cardiovascular diseases found in this group.

Adult↗
PubMed1991

Beta-lactamase production and bacterial tolerance in recurrent acute otitis media.

Different reasons for treatment failure or relapse of acute otitis media (AOM) have been suggested. In this study 38 children (8 treatment failures, 13 relapses of AOM within one month and 17 with a new AOM) were compared to 25 matching healthy children, regarding beta-lactamase producing bacteria and tolerance to penicillin V and ampicillin. Branhamella catarrhalis was the most common bacteria found in the nasopharynx and was isolated in 60% of children with AOM and in 48% of the control group. Fifty-two percent of the children classified as treatment failure or relapse of AOM had aerobic beta-lactamase producing bacteria in NPH. No bacteria tolerant to penicillin or ampicillin were found. Thus, beta-lactamase-producing bacteria seem to play a decisive role in treatment failure and relapse of AOM. On the other hand, tolerance to penicillin V or ampicillin does not seem to have any impact on healing of AOM.

Acute Disease↗
PubMed1991

Serum chloride in the differential diagnosis of hypercalcemia.

In hospitalized patients primary hyperparathyroidism (HPT) and neoplasms account for more than 90% of all hypercalcemias. Measurements of parathyroid hormone, particularly when combined with dynamic tests using calcitonin and EDTA have a high specificity and sensitivity in the differential diagnosis of hypercalcemia but are time-consuming and costly for screening purposes. Most chemical autoanalyzers beside serum calcium also measure serum chloride, phosphate and albumin. In order to evaluate how these simple variables could differentiate between HPT and hypercalcemia due to malignant disorders, 110 measurements from HPT subjects and 111 measurements from cancer patients with hypercalcemia were used. Serum chloride was best among the simple variables to separate the two disorders and classified 84% of the hypercalcemic subjects correctly. When serum phosphatase and albumin were added giving the formula (serum chloride-84) x (albumin-15)/phosphate, only 3% of the cancer and 4% of the HPT subjects were misclassified when borderline values (400-500) were excluded (5% of the sample). In conclusion, while other more sensitive and expressive tests exist to establish the cause of hypercalcemia the above mentioned formula is a cheap and easy screening test for a preliminary diagnosis.

Chlorides↗
PubMed1991

Blood pressure response during long-term treatment with magnesium is dependent on magnesium status. A double-blind, placebo-controlled study in essential hypertension and in subjects with high-normal blood pressure.

Both experimental and epidemiological studies support the idea of magnesium supplementation in essential hypertension. We added 15 mmol Mg to a free diet in 71 subjects with mild essential hypertension or a high-normal blood pressure in a double-blind, placebo-controlled study over 6 months. The treatment, which raised urinary magnesium excretion 30%, induced no general effects on the blood pressure. However, when the changes in blood pressure in the actively treated group were related to the pretreatment magnesium status, a correlation was found between pretreatment urinary magnesium excretion and the induced change in supine blood pressure (P less than .05) with a blood pressure reduction in subjects with a low pretreatment urinary excretion of magnesium, and a pressor effect in the subjects with the highest pretreatment levels of urinary magnesium. The induced change in blood pressure was furthermore found to be inversely correlated to the changes in serum magnesium and urinary excretion of sodium (P less than .03) induced by treatment indicating that both a direct calcium antagonist action of magnesium at the cellular level as well as a diuretic effect of the increased magnesium load might be involved in the blood pressure effects of magnesium. Pretreatment serum potassium concentration also appeared to be a predictor of the induced change in standing blood pressure (P less than .03). In conclusion, magnesium supplementation does not seem to be effective in unselected mild hypertensive subjects or in subjects with a high-normal blood pressure and can therefore not be generally recommended.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1991

Cardiovascular risk factors in primary hyperparathyroidism: a 15-year follow-up of operated and unoperated cases.

The need for treatment of mild and apparently asymptomatic primary hyperparathyroidism (HPT) is questioned, but a raised incidence of cardiovascular disease has been regarded as evidence in favour of surgery. While it is well known that several risk factors for cardiovascular disease (hypertension, hyperlipidaemia and diabetes mellitus/impaired glucose tolerance) are overrepresented in HPT, it is not known whether surgery provides long-term normalization in these respects and reduces the risk of premature death. In a 15-year follow-up of a cohort of 172 subjects in whom mild hypercalcaemia was initially detected during a health screening, it was found that 56 subjects had died. 17 individuals had been operated on for HPT, 47 individuals were persistently hypercalcaemic, while 45 subjects had serum calcium within the normal range (seven individuals were lost to follow-up). There had been no significant differences in blood pressure between these groups of mildly hypercalcaemic patients and age- and sex-matched controls at the initial screening, but at follow-up blood pressure was significantly higher not only in subjects with persistent hypercalcaemia, but also in those who had been successfully operated on for HPT. Neither of the hypercalcaemic groups showed any significant deviations from the controls with regard to indices of lipid or glucose metabolism. These findings suggest that there is no simple cause-and-effect relationship to account for the propensity toward high blood pressure in primary HPT. Consequently it cannot be assumed that surgery for HPT will eliminate the increased risk of cardiovascular disease in patients with mild HPT.

Cardiovascular Diseases↗
PubMed1991

Reduction in serum alkaline phosphatase levels by treatment with active vitamin D (alphacalcidol) in primary and secondary hyperparathyroidism and in euparathyroid individuals.

Raised levels of alkaline phosphatases (ALP) are seen in conditions with a high bone turn-over, such as in primary and secondary hyperparathyroidism (HPT). To study the effects of active vitamin D treatment on ALP, alphacalcidol (1-alpha-hydroxyvitamin D3), was given to patients with primary HPT as well as HPT secondary to chronic renal failure and also to healthy, euparathyroid subjects. Oral alphacalcidol (1 microgram daily) significantly reduced serum ALP (3.2 +/- 1.1 to 2.8 +/- 1.2 mu kat/l, p less than 0.05) in a 6-month double-blind, placebo-controlled study in patients with mild primary HPT, and alphacalcidol given intravenously to uremic subjects induced a reduction in serum ALP levels (3.5 +/- 3.1 to 2.6 +/- 1.7 mu kat/l, p less than 0.05) during a 4 months' study. A reduction in serum ALP was also seen in the euparathyroid subjects (2.4 +/- 0.77 to 2.2 +/- 0.64 mu kat/l, p = 0.03). This study indicates that treatment with active vitamin D is effective in reducing the increased bone turnover seen in subjects with both primary and secondary HPT.

Aged↗
PubMed1991

Potassium and blood pressure.

The relationships between serum potassium and urinary excretion of potassium and blood pressure were determined in an unmedicated adult population with a wide range of blood pressure (mean arterial blood pressure 100-130 mm Hg, n = 71). Inverse correlations between both serum potassium concentration and urinary excretion of potassium and standing (but not supine) mean blood pressure were seen (r = -0.41, p less than 0.005 and r = -0.33, p less than 0.01 respectively). These relationships persisted also when the influences of age, sex, obesity and kidney function were taken into account in a multiple regression analysis. The present observation is in accordance with previous reports of an association between potassium metabolism and blood pressure.

Aged↗