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Biomedical subjects

R Jorde

Publications and source records attributed to R Jorde.

At least 37 records · Page 2Linked to original sources

Intra-individual variability and longitudinal changes in glycaemic control in patients with Type 1 diabetes mellitus.

AIMS: Patients with Type 1 diabetes mellitus (DM) appear to have remarkably stable HbA1c levels, regardless of the need for improvement. The purpose of the present study was therefore to study predictors of intra-individual variability of the HbA1c level together with changes in HbA1c over time. METHODS: Hospital records of patients with Type 1 DM seen at our diabetes clinic from February 1992 to May 1997 were reviewed for HbA1c measurements and clinical data. In the main study, 214 patients who had been on insulin for more than 1 year, and in a sub-study, 14 patients newly started on insulin, were included. RESULTS: The coefficient of variation (CV) of the intra-individual HbA1c measurements, after at least 1 year of insulin, was 8.8 +/- 3.7% (mean +/- SD). There was a positive association between the CV and the HbA1c measurement at inclusion in the study (P < 0.05), and also a negative association between the CV and age (P < 0.05). Fifty per cent of the patients had a difference between first and last HbA1c below 1%, and 83.6% had a difference below 2%. In the sub-study, there was a positive association between the mean HbA1c value the first year on insulin (excluding the first 3 months) and the last HbA1c measurement (P < 0.01). CONCLUSIONS: The HbA1c levels in individual patients remain remarkably stable over time. Furthermore, the HbA1c level shortly after starting insulin is a predictor of future glycaemic control.

Adult↗

Plasma beta-endorphin concentrations are increased in chronic obstructive pulmonary disease patients.

The present study is concerned with plasma beta-endorphin and glucose tolerance in patients with chronic obstructive pulmonary disease (COPD). Plasma beta-endorphin, glucagon and insulin concentrations were measured during an oral glucose tolerance test in 20 COPD patients and in 18 age-matched healthy controls (mean age 62 years). Seven patients had a moderate COPD (group I) and seven a severe COPD (group II). The remaining six severe COPD patients received long-term oxygen therapy (group III). We found that fasting levels of beta-endorphin were significantly increased in all patient groups compared to healthy controls (p < 0.01, 0.05 and 0.005, respectively). Six of the 13 severely diseased COPD patients had impaired glucose tolerance. Plasma beta-endorphin levels decreased significantly during OGTT in the COPD patients (p < 0.05). Fasting beta-endorphin levels were higher in patients with impaired glucose tolerance than in those patients with normal OGTT (42.0 pmol/L +/- 11.4 SD versus 34.8 +/- 10.2). However, this difference was not statistically significant. In conclusion, this study showed that beta-endorphin concentrations are increased in COPD patients whether or not they receive oxygen therapy.

Blood Glucose↗

Calcium from dairy products, vitamin D intake, and blood pressure: the Tromso Study.

BACKGROUND: The present epidemiologic study was conducted in Tromso, Northern Norway, in 1994-1995. OBJECTIVE: The objective was to evaluate the relation between calcium intake from dairy products and the intake of vitamin D on systolic and diastolic blood pressure. DESIGN: Subjects who were taking drugs for hypertension or heart disease, those taking calcium tablets, subjects reporting cardiovascular disease, and pregnant women were excluded, leaving 7543 men and 8053 women aged 25-69 y for analysis. Calcium and vitamin D intakes were calculated from a food-frequency questionnaire. RESULTS: After correction for age, body mass index, alcohol and coffee consumption, physical activity, cigarette smoking, and vitamin D intake, there was a significant linear decrease in systolic and diastolic blood pressure with increasing dairy calcium intake in both sexes (P < 0.05). However, the difference in blood pressure between subjects with the highest and those with the lowest calcium intake was </=1-3 mm Hg. Similarly, with increasing blood pressure there was a significant (P < 0.001) linear decrease in age-adjusted calcium intake from dairy sources; the difference between the highest and the lowest blood pressure groups was 3-10%. Vitamin D intake had no significant effect on blood pressure. CONCLUSIONS: There is a negative association between calcium intake from dairy products and blood pressure. However, although the effect of calcium on blood pressure appears to be small, calcium could have a significant effect on primary prevention of cardiovascular diseases.

Adult↗

Relation between low calcium intake, parathyroid hormone, and blood pressure.

In a population health survey in 1995, serum parathyroid hormone (PTH) was measured in 1113 subjects, aged 30 to 79 years, and was found to be elevated (>6.9 pmol/L) in 118 subjects. In 1998, this group and 131 subjects with normal PTH levels were invited for reexamination, and 82 and 90 subjects from each respective group attended the follow-up. At the follow-up, 72 subjects had elevated and 100 had normal serum PTH levels. Those with elevated serum PTH levels (8 subjects with hyperparathyroidism were excluded) had significantly lower serum calcium levels and intake of calcium than those with normal PTH (2.24+/-0.09 and 2.29+/-0.10 mmol/L [mean+/-SD] and 400.3+/-227.3 and 592.1+/-459.6 mg/d, respectively; P<0.01). Serum levels or intake of vitamin D did not differ between the 2 groups. Subjects with elevated PTH in both 1995 and 1998 had significantly lower bone mineral content and bone mineral density in the lumbar spine than did those with persistently normal PTH levels (P<0.05). In the females, but not in the males, the systolic and diastolic blood pressures were significantly higher in those with elevated serum PTH (158.0+/-27.5 versus 141.5+/-19.2 mm Hg and 90. 5+/-13.6 versus 82.6+/-8.6 mm Hg, respectively; P<0.01). This difference was even more pronounced when those with persistently elevated PTH were considered separately. In conclusion, reduced intake of calcium is frequently associated with high levels of serum PTH. This is associated with moderately reduced bone mineral content and bone mineral density in the lumbar spine. In women, high levels of serum PTH are also associated with markedly increased blood pressure.

Adult↗

Effect of long-term oxygen therapy on cognitive and neurological dysfunction in chronic obstructive pulmonary disease.

The aim of this study was to assess effect of long-term oxygen therapy (LTOT) on the function of central and autonomic nervous system in patients with hypoxaemic chronic obstructive pulmonary disease (COPD). A battery of neuropsychological tests was used together with the Short Test of Mental Status in addition to transcranial Doppler ultrasonography, and five cardiovascular tests as well as a questionnaire on autonomic function. Ten COPD patients, 4 males and 6 females, with a mean age of 65.9 +/- 7.3 (SD) years, were studied at the beginning and after 3 months of LTOT. At start PaO2 was 6.7 +/- 1.1 kPa without oxygen and 9.9 +/- 1.5 kPa after 3 months with oxygen. Our results demonstrate that neuropsychological function, cerebral blood flow velocity and autonomic function were positively influenced after 3 months of LTOT although the changes did not reach statistical significance. The COPD patients were cognitively impaired as compared to age-matched healthy controls. Our findings were consistent with the previous notion of improvement of hypoxic cognitive dysfunction by LTOT.

Aged↗

Serum calcium and cardiovascular risk factors and diseases: the Tromsø study.

Total serum calcium levels were measured in 12 865 men and 14 293 women, between the ages of 25 and 97 years, in the Tromsø Study during 1994 and 1995. With the use of a sex-specific multiple linear regression model with age, calcium, body mass index, cholesterol, HDL cholesterol, triglycerides, systolic and diastolic blood pressure, and pulse as possible covariates, serum calcium was significantly (P<0.001) and positively associated with systolic and diastolic blood pressure, serum cholesterol, and HDL cholesterol in both sexes. A similar but weaker association was observed between serum calcium and triglycerides in men (P<0.01). In all age groups, serum calcium levels were higher in men with a history of myocardial infarction than in those without, and the difference was significant (P<0.0001) in a linear regression analysis adjusted for age. When all the other variables were also included in a logistic regression model, serum calcium was a highly significant (P<0.0001) predictor of myocardial infarction in men, with an odds ratio of 1.2 per 0.1 mmol/L increase in serum calcium. In women, a nonsignificant trend was again seen. Because the free or ionized form of calcium is the physiologically important form and serum calcium was not corrected for serum albumin in our study, the results must be interpreted with caution. However, it appears likely that serum calcium is a predictor of cardiovascular disease in men.

Adult↗

Population based study on serum ionised calcium, serum parathyroid hormone, and blood pressure. The Tromsø study.

OBJECTIVE: To study associations between serum ionised calcium, serum parathyroid hormone (PTH) and blood pressure. DESIGN: A population based, cross-sectional study was used. METHODS: Blood pressure, body mass index, serum ionised calcium and serum PTH were measured in 460 males and 486 females in the Tromso study in 1994/1995. None were on medication for hypertension. The data were analysed with a multiple linear regression model. RESULTS: When looking at subjects with serum ionised calcium<1.39mmol/l, there was a significant negative association (P<0.01) between serum ionised calcium and PTH. There was no association between blood pressure and serum ionised calcium. In both sexes there was a significant positive association between age and serum PTH (P<0.01). For women, but not for men, there was a significant positive association between serum PTH and systolic and diastolic blood pressure (P<0.01). Within each age group there was a difference in both systolic and diastolic blood pressure of 3-10mmHg between the upper and lower serum PTH halves of the female population. Females with hypertension had significantly higher serum PTH levels than the normotensive females (P<0.01). CONCLUSION: Serum PTH is strongly and positively associated with blood pressure in women.

Adult↗

Ability of patients with type 1 diabetes mellitus to predict changes in HbA1c levels.

Forty patients with Type 1 diabetes mellitus were examined on five occasions, three months apart. Their mean (+/- SD) age was 38.9 (13.2) years. At each visit they participated in a teaching program and also filled out a questionnaire on average morning and daytime blood glucose levels, weekly number of blood glucose measurements and hypoglycaemias. They were then told their last HbA1c value and asked whether they believed the present one would be unchanged (+/- 0.3%), slightly higher/lower (0.4-1.0%), or much higher/lower (more than 1.0%). They did infrequent home blood glucose monitoring [mean weekly number of measurements 6.9 (6.7)] and did not do systematic self-adjustment of insulin doses. Their HbA1c at inclusion was 9.0 (1.6)% and 8.4 (1.3)% at the end of the study (p < 0.05). Generally, the changes in HbA1c were few, and only more than 1.0% in 22.5% of tests. The kappa values for agreement between predicted and actual HbA1c values at the five visits were between 0.27 and 0.12. The ability to predict HbA1c changes did not improve during the study. A correct prediction (direction of change or no change) was seen in only 45.0% at the start and 42.5% at the end of the study. Those predicting correctly did no more home blood glucose measurements than the others. In conclusion, the patients' own perception of glycaemic control is a poor indicator of HbA1c changes over time.

Adult↗

Quantitative EEG during controlled hypoglycaemia in diabetic and non-diabetic children.

We investigated quantitative EEG in 19 diabetic children (mean age 14.2 (SD 1.4) years, mean HbA1c 9.8 (SD 1.2)% and 17 non-diabetic children (14.3 (1.1) years) during and after a gradual reduction in plasma glucose with the glucose clamp technique. The amplitudes of the EEG frequency bands at each glucose level were compared to the registration prior to hypoglycaemia. At plasma glucose approximately 4 mmol l(-1), a small increase in delta (p < 0.05) and theta (p < 0.01) amplitude appeared in the combined diabetic and control group. At approximately 3 mmol l(-1), and at glucose nadir, a further and widespread increase in low-frequency EEG activity was observed. In diabetic and non-diabetic subgroups with similar glucose nadirs, the diabetic children had more delta (p < 0.01) and theta (p < 0.01) activity, and more epileptiform activity (p < 0.05), than the non-diabetic children. In the non-diabetic subjects, but not in the diabetic subjects, the increase in delta and theta activity correlated with a hypoglycaemic symptom score (r = 0.75, p = 0.001 and r = 0.77, p < 0.0005, respectively). In conclusion, EEG changes are detectable already at plasma glucose approximately 4 mmol l(-1) in children. EEG deterioration during hypoglycaemia is more pronounced in diabetic than in non-diabetic children. The increase in cerebral disturbances is not accompanied by an increment in hypoglycaemic symptoms in diabetic children.

Adolescent↗

Mutation analysis of the MEN1 gene in multiple endocrine neoplasia type 1, familial acromegaly and familial isolated hyperparathyroidism.

Multiple endocrine neoplasia type 1 (MEN 1) is an autosomal dominant disease characterized by neoplasia of the parathyroid glands, the endocrine pancreas, and the anterior pituitary gland. In addition, families with isolated endocrine neoplasia, notably familial isolated hyperparathyroidism (FIHP) and familial acromegaly, have also been reported. However, whether these families constitute MEN 1 variants or separate entities remains speculative as the genetic bases for these diseases are unclear. The gene for MEN 1 has recently been cloned and characterized. Using single strand conformation analysis (SSCA) and sequencing, we performed mutation analysis in: a) a total of 55 MEN 1 families from 7 countries, b) 13 isolated MEN 1 cases without family history of the disease, c) 8 acromegaly families, and d) 4 FIHP families. Mutations were identified in 27 MEN 1 families and 9 isolated cases. The 22 different mutations spread across most of the 9 translated exons and included frameshift (11), nonsense (6), splice (2), missense mutations (2), and in-frame deletions (1). Among the 19 Finnish MEN 1 probands, a 1466del12 mutation was identified in 6 families with identical 11q13 haplotypes and in 2 isolated cases indicating a common founder. One frameshift mutation caused by 359del4 (GTCT) was found in 1 isolated case and 4 kindreds of different origin and haplotypes; this mutation therefore represents a common "warm" spot in the MEN1 gene. By analyzing the DNA of the parents of an isolated case one mutation was confirmed to be de novo. No mutation was found in any of the acromegaly and small FIHP families, suggesting that genetic defects other than the MEN1 gene might be involved and that additional such families need to be analyzed.

Acromegaly↗

Effects of exercise on hypoglycaemic responses in insulin-dependent diabetes mellitus.

This study sought to determine whether moderate exercise influences hypoglycaemic responses in insulin-dependent diabetes mellitus (IDDM). Ten patients with IDDM and no history of hypoglycaemia unawareness or autonomic neuropathy were included. The patients were studied in random order on 4 occasions: twice during euglycaemia (once at rest and once on a treadmill) and twice during a gradual drop in blood glucose from 5 to 2 mmol/l (once at rest and once on a treadmill). Blood samples for hormones and glucose were drawn, and a symptom questionnaire was filled out every 5 min. Cognitive tests were performed at the start and end of each study. Glucose thresholds for hormones and symptoms are reported as the plasma glucose level at which responses were more than two standard deviations above basal level and continued to increase. The thresholds for adrenaline and noradrenaline release came at a significantly higher blood glucose level during exercise than at rest: 2.7 +/- 0.2 vs 2.1 +/- 0.2 mmol/l (p < 0.05) for adrenaline and 2.7 +/- 0.2 vs 2.0 +/- 0.1 mmol/l (p < 0.01) for noradrenaline. Thresholds for neuroglycopenic symptoms were also at a significantly higher blood glucose level during exercise: 2.6 +/- 0.2 vs 2.0 +/- 0.2 mmol/l (p < 0.05). During hypoglycaemia, patients showed a non-significant trend towards a lower score on cognitive tests during exercise than at rest. It is concluded that moderate exercise during a gradual drop in blood glucose does not mask hypoglycaemic responses in patients with IDDM.

Adult↗

Counterregulatory hormone and symptom responses to hypoglycaemia in diabetic children.

The hormonal responses to, and symptoms of, hypoglycaemia were investigated in 19 diabetic children (mean age 14.2 (SD 1.4) years, mean HbA1c 9.8 (SD 1.2)%) and 16 non-diabetic children (14.4(1.0) years) during a gradual reduction in plasma glucose with the glucose clamp technique. Plasma glucose was reduced from approximately 5.7 to approximately 2.6 mmol l(-1) in the diabetic children and from approximately 5.7 to approximately 2.9 mmol l(-1) in the non-diabetic children over 200 min. The mean glycaemic thresholds for adrenaline, and for autonomic and total symptom score, were similar in the diabetic and non-diabetic groups, and were found at plasma glucose levels between 3.4 and 3.7 mmol l(-1). The mean glucose levels which elicited increase of cortisol, growth hormone, and glucagon were lower (p < 0.01), and the mean incremental responses of adrenaline, cortisol, and glucagon were smaller in the diabetic than in the non-diabetic children. In the diabetic children, a correlation was found between Body Mass Index (BMI) and the hypoglycaemic thresholds for autonomic and total symptom scores (r = 0.64, p < 0.01 and r = 0.72, p = 0.001, respectively). We conclude that counterregulatory hormone responses are attenuated in diabetic as compared to non-diabetic children, whereas recognition of autonomic symptoms is similar in the two groups. Diabetic children with a higher BMI seem to have increased awareness of a declining plasma glucose level.

Adolescent↗

Return of beta-adrenergic sensitivity in a patient with insulinoma after removal of the tumour.

Beta-adrenergic sensitivity and counterregulatory hormone and symptomatic responses to hypoglycaemia were studied in a 22-year-old man before and 3 and 34 weeks after removal of an insulinoma. The beta-adrenergic sensitivity was measured by the effect of an isoprenaline infusion on the heart rate, and the dose needed to increase the heart rate by 25 beats min(-1) (I25) calculated from regression lines. The glucose thresholds for the hormonal responses and symptoms were studied during a gradual fall in plasma glucose using a hypoglycaemic clamp technique. As compared with preoperative values, beta-adrenergic sensitivity was unchanged 3 weeks after surgery, but showed a marked improvement after 34 weeks, the I25 (in microg isoprenaline) being 0.96, 0.86, and 0.56, respectively. The hormone responses to hypoglycaemia were earlier, but with no improvement in symptom generation at 3 weeks. After 34 weeks, the thresholds for both hormone release and symptom generation occurred at a plasma glucose approximately 1 mmol l(-1) higher than before surgery. Thus, in our patient, there was a marked improvement in beta-adrenergic sensitivity, an earlier release of counterregulatory hormones, and an earlier recognition of hypoglycaemic symptoms after surgery. However, the restoration of these responses took more than 3 weeks.

Adrenergic beta-Agonists↗

Late and transient increases in free T4 after radioiodine treatment for Graves' disease.

The objective of this retrospective study was to evaluate the fall in free T4 (FT4) in patients with Graves' disease after treatment with radioiodine in a fixed dose of 600 MBq. The study was performed at our outpatient clinic with patients referred from primary care during the time period January 1989 to January 1995. Only patients not given anti thyroid drugs after radioiodine were included. FT4 and TSH were measured every second week for the first three months, and thyroxine substitution started when the FT4 was at or below 15 pmol/l. Of the 60 patients thus available for evaluation, 7 required retreatment, giving a "success rate" of 88%. Of the 53 patients successfully treated with one dose of radioiodine, 36 had not been pretreated with anti thyroid drugs. Among these patients 13 (36%) had a transient increase in FT4 after radioiodine therapy, which mostly occurred after 4 to 6 weeks. The remaining 17 patients had been given carbimazole prior to radioiodine. In this group 8 (53%) had a transient increase in FT4, generally after 2 weeks. In conclusion, giving a fixed large dose of radioiodine and starting thyroxine substitution before hypothyroidism has developed is a workable clinical routine. Although a gradual fall in FT4 was the rule, a transient increase in FT4 was noticed in 30-50% of the patients 2 to 6 weeks after treatment.

Adult↗

Urinary excretion of adrenaline and noradrenaline during hypoglycaemic clamp in diabetic and non-diabetic adolescents.

The urinary excretion of non-conjugated adrenaline and noradrenaline during hypoglycaemic clamp was investigated in 16 diabetic and 15 non-diabetic adolescents. In the diabetic adolescents, the mean excretion of adrenaline was approximately nine times higher in clamp urine than in morning urine (p < 0.0001). In the non-diabetic adolescents, the mean excretion of adrenaline was 20-30 times higher in clamp urine than in morning urine (p < 0.0001). Plasma catecholamines were measured, and the area under the plasma concentration-time curve (AUC) and renal clearance of catecholamines were calculated. There was a linear correlation between the AUC and the urinary excretion of adrenaline (r = 0.57, p = 0.001) and noradrenaline (r = 0.49, p = 0.006) during the hypoglycaemic clamp. The renal clearance of adrenaline and noradrenaline did not differ between the diabetic and non-diabetic subjects. In the diabetic group, there was a positive correlation between HbA1c and the adrenaline excretion in clamp urine (r = 0.60, p = 0.015). The eight diabetic subjects with HbA1c < 10% had lower adrenaline excretion in clamp urine than the subjects with HbA1c > 10% and the non-diabetic subjects (all p values < 0.05). We conclude that there is a marked increase in urinary adrenaline excretion during hypoglycaemia in diabetic and non-diabetic adolescents. The increase in adrenaline excretion during hypoglycaemia was attenuated in the better-controlled diabetic adolescents in our study.

Adolescent↗

Cardiovascular responses to tests for autonomic dysfunction in patients with chronic obstructive pulmonary disease with and without continuous long-term oxygen therapy.

The aim of this study was to investigate autonomic neuropathy, with and without oxygen therapy, in patients with chronic obstructive pulmonary disease (COPD). Four cardiovascular tests for autonomic function were used, and in addition, basal pancreatic polypeptide (PP) was measured. The following COPD patients were studied: 10 normoxemic (mean PaO2 10.9 +/- SD 1.1 kPa), 10 hypoxemic (PaO2 7.6 +/- 0.7 kPa before, and 10.6 +/- 1.4 kPa after 24 h oxygen therapy), and 6 hypoxemic on long-term oxygen therapy (LTOT) (PaO2 10.3 +/- 1.3 kPa before, and 7.0 +/- 0.8 kPa after 4 h of low dose or oxygen free interval). Twenty healthy age-matched subjects served as controls. In the individual tests the hypoxemic and the LTOT groups had a significantly decreased heart rate response to the Valsalva manoeuvre (ratio 1.23 +/- 0.17 and 1.12 +/- 0.07 versus control's 1.45 +/- 0.26 (p < 0.01 and 0.005, respectively) and versus the normoxemic group 1.46 +/- 0.30 (p < 0.05)) and the hypoxemic as well as the LTOT group had a significantly decreased heart rate response to standing up (ratio 0.97 +/- 0.04 and 0.97 +/- 0.07, respectively, versus the controls 1.06 +/- 0.09 (p < 0.005 and 0.05)). The blood pressure response to standing up and to sustained handgrip did not differ significantly between the groups. In spite of apparent autonomic dysfunction, PP levels in the LTOT group were significantly higher than in the controls (p < 0.01-0.001) and the normoxemic group (p < 0.05-0.01). Twenty-four hours of oxygen treatment in the hypoxemic group or four hours of oxygen withdrawal in the LTOT group did not change the results significantly. In conclusion, our findings are consistent with the previous notion of neurological dysfunction from hypoxemia, but this may not be corrected by the use of short term oxygen treatment. This contrasts to previous findings in which longer term oxygen did correct some of these problems.

Adult↗