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Biomedical subjects

H Ibsen

Publications and source records attributed to H Ibsen.

At least 55 records · Page 3Linked to original sources
PubMed1998

Normal values for ambulatory blood pressure and differences between casual blood pressure and ambulatory blood pressure: results from a Danish population survey.

OBJECTIVE: To determine normal values for 24 h ambulatory blood pressure in a Danish population and to study the relationship to casual blood pressure. STUDY POPULATION: A random sample of 2656 Danish men and women participated in a population survey. The participants were selected in age groups and were aged 41-42, 51-52, 61-62 or 71-72 years during the survey. METHODS; Casual blood pressure (standard mercury sphygmomanometer) and 24 h ambulatory blood pressure (Takeda TM-2421) were measured successfully in 2082 subjects. All subjects under antihypertensive treatment (247) were excluded, restricting the study population to 1835 participants. RESULTS: Casual and 24 h ambulatory blood pressure were correlated (P < 0.0001) in all age and sex groups. Casual systolic/diastolic blood pressures were 129.6+/-17.8/82.6+/-10.3 for men and 125.1+/-18.2/79.7+/-9.9 mmHg for women. Twenty-four-hour average blood pressures were 130.8+/-14.2/75.3+/-8.6 for men and 122.4+/-14.9/69.6+/-8.3 mmHg for women. A multivariate linear logistic regression model confirmed that a high casual blood pressure (odds ratios 11/7 for systolic/diastolic blood pressure; P=0.001) was the major determinant of a lower ambulatory than casual blood pressure; age and sex were less important. CONCLUSION: The relationship between casual blood pressure on the one hand and the difference in casual and 24 h ambulatory blood pressure on the other hand suggests that ambulatory blood pressure represents a regression towards the mean compared to casual blood pressure. Any definition of an upper normal level of 24 h ambulatory blood pressure that is derived from a correlation between casual and ambulatory measurements will be inaccurate, and must await long-term studies of the relationship between ambulatory blood pressure and subsequent cardiovascular events.

Adult↗
PubMed1998

AT1 and AT2 receptor blockade and epinephrine release during insulin-induced hypoglycemia.

Angiotensin II facilitates epinephrine release during insulin-induced hypoglycemia, and this effect appears to be independent of type 1 angiotensin II (AT1) receptors in man. In the present study, we hypothesized that the action of angiotensin II on adrenomedullary epinephrine release is mediated by an AT2 receptor-dependent mechanism. In conscious chronically instrumented rats, we measured plasma concentrations of catecholamines during acute insulin-induced hypoglycemia in groups of rats pretreated with the AT1 receptor antagonist losartan (10 mg/kg i.v.), the AT2 receptor antagonist PD123319 (30 mg/kg i.v.), combined losartan + PD123319, the converting enzyme inhibitor enalapril (1 mg/kg i.v.), or vehicle. In vehicle-treated rats, the area under the curve for changes in plasma epinephrine concentration [AUC(plasma epinephrine)] during insulin-induced hypoglycemia was 111+/-8 nmolXh/L (+/-SEM). Pretreatment with losartan alone did not affect AUC(plasma epinephrine) (113+/-17 nmol x h/L), while pretreatment with PD123319 tended to reduce the response (87+/-10 nmol x h/L; P=.08 versus vehicle). However, AUC(plasma epinephrine) was significantly reduced in rats that were pretreated with combined losartan + PD123319 (68+/-5 nmol x h/L; P<.001 versus vehicle) or enalapril: 86+/-10 nmol x h/L (P<.05 versus vehicle). Thus, combined treatment with losartan + PD 123319 proved more effective in attenuating the reflex increase in plasma epinephrine concentration during hypoglycemia than either of the two AT receptor antagonists given alone. We speculate that angiotensin II through binding to both receptor subtypes facilitates the sympathoadrenal reflex response by actions at several anatomical levels of the neural pathways involved in the sympathoadrenal reflex response elicited during insulin-induced hypoglycemia.

Angiotensin Receptor Antagonists↗
PubMed1998

Characteristics of 9194 patients with left ventricular hypertrophy: the LIFE study. Losartan Intervention For Endpoint Reduction in Hypertension.

-Losartan was the first available orally administered selective antagonist of the angiotensin II type 1 receptor developed for the treatment of hypertension. The Losartan Intervention For Endpoint (LIFE) Reduction in Hypertension Study is a double-blind, prospective, parallel group study designed to compare the effects of losartan with those of the beta-blocker atenolol on the reduction of cardiovascular morbidity and mortality. Patients with essential hypertension, aged between 55 and 80 years, and ECG-documented left ventricular hypertrophy (LVH) were included. Altogether, 9223 patients in Scandinavia, the United Kingdom, and the United States were randomized from June 1995 through April 1997, and 9194 remain after exclusion of a study center at which irregularities were discovered. This population of hypertensives (mean systolic/diastolic blood pressure, 174.4/97.8 mm Hg) with LVH comprises women (54.1%) and men, mostly retired from active work (mean age, 66.9 years), with a high prevalence of overweight (mean body mass index, 28.0 kg/m2), diabetes mellitus (12.3%), lipid disorders (18.0%), and symptoms or signs of coronary heart disease (15.1%). There were fewer current smokers (<17%) than in the general population, and approximately 7% were nonwhite. Almost 30% of participants had been untreated for at least 6 months when screened for the study. Only 1557 persons who entered the placebo run-in period of 14 days were excluded, predominantly because of sitting blood pressures above or below the predetermined range of 160-200/95-115 mm Hg and ECG-LVH criteria not met. By application of simple 12-lead ECG criteria for LVH (Cornell voltage QRS duration product formula plus Sokolow-Lyon voltage read by a core laboratory), hypertensive patients with LVH with an average 5-year coronary heart disease risk of 22.3% according to the Framingham score were identified. This population is now being treated (goal, <140/90 mm Hg) in adherence with the protocol for at least 4 years after final enrollment (ie, through April 2001) and until at least 1040 patients suffer myocardial infarction, stroke, or cardiovascular death.

Aged↗
PubMed1998

Analysis of the relationship between fasting serum uric acid and the insulin sensitivity index in a population-based sample of 380 young healthy Caucasians.

AIM: To determine whether fasting serum uric acid is associated with the insulin sensitivity index or with other anthropometric, metabolic or environmental features of the insulin resistance syndrome in a population-based sample of young healthy Caucasians. METHODS: The protocol included 380 unrelated Caucasian subjects (age 18-32 years) who had their insulin sensitivity index and glucose effectiveness measured during a combined intravenous glucose (0.3 g/kg body weight) and tolbutamide (3 mg/kg body weight) tolerance test. A number of anthropometric and biochemical tests, including the level of fasting serum uric acid, were carried out. RESULTS: In univariate analyses the concentration of fasting serum uric acid was negatively correlated to the insulin sensitivity index in both men (r2 = -0.25, P = 0.001) and women (r2 = -0.25, P < 0.001). In multivariate analysis controlling for age, gender, body mass index, waist to hip ratio, maximal aerobic capacity, fasting serum triglyceride and creatinine, daily intake of alcohol, smoking, use of oral contraceptives, and disposition for non-insulin dependent diabetes mellitus, the insulin sensitivity index was not significantly associated with fasting serum uric acid. However, 51% of the variation in the fasting serum uric acid level could be explained, and fasting serum triglyceride was the most important determinant of fasting serum uric acid. CONCLUSION: The major determinant of the fasting serum uric acid level in young healthy Caucasians is the fasting concentration of serum triglyceride, which has been shown to be a biochemical feature of the insulin resistance syndrome. Thus, hyperuricaemia appears to be an indirect part of the insulin resistance syndrome through its association with fasting hypertriglyceridaemia.

Adult↗
PubMed1997

[Occurrence of renal artery stenosis in patients with peripheral arteriosclerosis and hypertension].

The aim of this study was to evaluate the prevalence of renal artery stenosis in patients with clinical signs of peripheral vascular disease and hypertension. One hundred patients, mean age 69 years (range 45-88) with symptoms and clinical signs of severe peripheral ischaemia, underwent aortography to determine the degree of peripheral vascular disease and possible renal artery stenosis. History of claudication and measurement of systolic distal blood pressure and calculation of the Ankle Brachial Index was used to define the severity of peripheral vascular disease. Thirty-one percent had renal artery stenosis (14% greater than 50% reduction in luminal diameter). In a subgroup of patients with hypertension and peripheral vascular disease (n = 74), 34% had renal artery stenosis. In the subgroup of patients with renal artery stenosis, 81% had hypertension. Among patients with renal artery stenosis and lumen reduction of more than 50%, 93% had hypertension (p < 0.001). In conclusion this study shows that the combination of peripheral vascular disease and hypertension is an important clinical clue for renovascular disease. Examination for renovascular disease in this population should be considered, since the prevalence of the condition is high. Furthermore, examination for renal vascular disease in this population is mandatory, before treatment with angiotensin converting enzyme inhibitors is initiated, since treatment might lead to serious renal function impairment.

Aged↗
PubMed1997

Basal insulin-level oscillations in normotensive individuals with genetic predisposition to essential hypertension exhibit an irregular pattern.

BACKGROUND: Insulin is secreted in regular pulses at intervals of 12-14 min in normal fasting subjects. An abnormal pattern has been found in subjects with non-insulin-dependent diabetes mellitus (NIDDM) and in young individuals predisposed to NIDDM. It has been suggested that there might be a causal relationship between insulin-secretion abnormalities and insulin resistance. OBJECTIVE: To examine whether insulin-secretion abnormalities are also present in offspring of patients with essential hypertension. METHODS: Eleven young (aged 18-35 years) normotensive individuals each of whom had two parents with essential hypertension were compared with 10 age- and sex-matched controls each of whom had two normotensive parents. We verified that diabetes and morbid obesity were absent among the subjects and their parents. We studied basal insulin-secretion patterns during a 60 min period, glucose tolerance by administering an oral glucose-tolerance test, insulin resistance by using an isoglycaemic hyperinsulinaemic clamp and basal plasma catecholamine levels. RESULTS: Autocorrelation analysis of insulin concentrations showed that the hypertension-prone subjects had a significantly reduced or irregular oscillatory pattern compared with the regular insulin-level oscillations with a period of 12-14 min in control subjects. The hypertension-prone subjects had significantly higher systolic blood pressures and tended to be insulin-resistant. CONCLUSION: This is the first evidence of early insulin-secretion abnormalities in young normotensive individuals with a genetic predisposition to essential hypertension, but with a normal glucose tolerance and without a genetic predisposition to NIDDM. Early insulin-secretion abnormalities may be the very first step towards the development of insulin resistance and an important factor initiating the hypertension in hypertension-prone individuals.

Adolescent↗
PubMed1997

AT1 receptor blockade and the sympathoadrenal response to insulin-induced hypoglycemia in humans.

An important facilitating effect of angiotensin II on adrenal catecholamine release has been demonstrated in several species. To determine whether specific AT1 receptor blockade affects medullary epinephrine secretion and musculocutaneous norepinephrine release during insulin-induced hypoglycemia, 16 healthy volunteers received losartan vs. placebo followed by an intravenous insulin bolus and measurement of effect variables at short intervals for 150 min. AT1 receptor blockade was effective, as evidenced by substantially increased circulating renin and angiotensin II levels, a 60% inhibition of circulating aldosterone, and an 8.5% decrease of mean arterial pressure over time compared with placebo. Arterial glucose concentration fell to a nadir of 1.9 mM, arterial epinephrine concentration increased 23-fold, forearm musculocutaneous norepinephrine release increased 4-fold, heart rate increased 40%, and forearm blood flow increased 3-fold. All absolute values and the time course of these changes were independent of AT1 receptor blockade. It is concluded that a putative interaction between angiotensin II and the sympathoadrenal axis may not be mediated by AT1 receptors in humans.

Adrenal Medulla↗
PubMed1997

Captopril does not blunt the sympathoadrenal response to cigarette smoking in normotensive humans.

The aim of this study was to assess whether an interaction exists between the renin-angiotensin system and the sympathetic nervous system at the level of the adrenal medulla during smoking in normal humans. Thirteen habitual smoking volunteers were studied in a randomized, single-dose, double-blind, cross-over fashion using 50 mg captopril vs placebo followed by smoking of two high nicotine content cigarettes within 15 min. Blood samples were obtained at frequent intervals before, during and after smoking. We found that the increase in plasma adrenaline concentration during cigarette smoking was modest. There was no difference between captopril treatment as compared to placebo. Thus, the adrenaline response to cigarette smoking was not blunted by acute blockade of angiotensin II generation. A significant increase in heart rate, and blood pressure was found as well. No increase in plasma noradrenaline concentration was found. Plasma renin concentration increased significantly during captopril treatment, whereas it decreased throughout the study period in the placebo phase. Plasma angiotensin II concentration decreased in both the captopril treatment and the placebo phase throughout the study period, but this was more pronounced during captopril treatment. In conclusion, cigarette smoking-induced activation of the sympathetic nervous system was not blunted by acute ACE-inhibition by captopril. This indicates that angiotensin II does not facilitate smoking-induced activation of sympathoadrenal activity in humans.

Adrenal Medulla↗
PubMed1997

The Losartan Intervention For Endpoint reduction (LIFE) in Hypertension study: rationale, design, and methods. The LIFE Study Group.

The treatment of hypertension mainly with diuretics and beta blockers reduces cardiovascular mortality and morbidity, largely due to a decreased incidence of stroke, whereas the beneficial effects of antihypertensive therapy on the occurrence of coronary events have been less than expected from epidemiological studies. Furthermore, treated hypertensive patients still have a higher cardiovascular complication rate, compared with matched normotensives. This is particularly evident in patients with left ventricular hypertrophy (LVH), a major independent risk indicator for cardiovascular disease. In addition to elevating blood pressure, angiotensin II (A-II) exerts an important influence on cardiac structure and function, stimulating cell proliferation and growth. Thus, to further reduce morbidity and mortality when treating hypertensive patients, it may be important to effectively block the effects of A-II. This can be achieved directly at the A-II receptor level by losartan, the first of a new class of antihypertensive agents. It therefore seems pertinent to investigate whether selective A-II receptor blockade with losartan not only lowers blood pressure but also reduces LVH more effectively than current therapy, and thus improves prognosis. The Losartan Intervention For Endpoint reduction (LIFE) in Hypertension study is a double-blind, prospective, parallel group study designed to compare the effects of losartan with those of the beta-blocker atenolol on the reduction of cardiovascular morbidity and mortality in approximately 8,300 hypertensive patients (initial sitting diastolic blood pressure 95 to 115 mm Hg or systolic blood pressure 160 to 200 mm Hg) with electrocardiographically documented LVH. The study, which will continue for at least 4 years and until 1,040 patients experience one primary endpoint, has been designed with a statistical power that will detect a difference of at least 15% between groups in the incidence of combined cardiovascular morbidity and mortality. It is also the first prospective study with adequate power to link reversal of LVH to reduction in major cardiovascular events. The rationale of the study, which will involve more than 800 clinical centers in Scandinavia, the United Kingdom, and the United States, is discussed, and the major features of its design and general organization are described. On April 30, 1997, when inclusion was stopped, 9,218 patients had been randomized.

Adrenergic beta-Antagonists↗
PubMed1996

[Salt--an analysis of the connection between intake and health].

The average salt intake (sodium chloride) in Denmark is about 10 g/person/day, which is approximately 8 times higher than the estimated need. Salt added during industrial processing of foods constitutes more than 50% of the daily salt intake. Observational and experimental epidemiological studies indicate no decisive effects on blood pressure in humans caused by considerable variations in the daily salt intake. However, a small group of patients with hypertension may lower their blood pressure by reducing the daily intake of salt to 5 g. It has not been convincingly documented that high salt intake is an independent risk factor in the pathogenesis of asthma, osteoporosis, toxaemia of pregnancy or apoplectic stroke. On the other hand, several epidemiological studies point to the fact that the intake of salted foods may increase the risk of gastric cancer. It is recommended 1) that the food industry as far as possible limits the addition of salt, 2) that foods are supplied with a declaration of the salt content, and 3) that the research in this field is strengthened to facilitate the identification of persons at increased risk of developing disorders associated with high salt intake.

Denmark↗
PubMed1996

Insulin sensitivity index, acute insulin response, and glucose effectiveness in a population-based sample of 380 young healthy Caucasians. Analysis of the impact of gender, body fat, physical fitness, and life-style factors.

BACKGROUND: Insulin sensitivity and insulin secretion are traits that are both genetically and environmentally determined. AIM: The aim of this study was to describe the distribution of the insulin sensitivity index (Si), the acute insulin response, and glucose effectiveness (Sg) in young healthy Caucasians and to estimate the relative impact of anthropometric and environmental determinants on these variables. METHODS: The material included 380 unrelated Caucasian subjects (18-32 yr) with measurement of Si, Sg and insulin secretion during a combined intravenous glucose (0.3 grams/kg body weight) and tolbutamide (3 mg/kg body weight) tolerance test. RESULTS: The distributions of Si and acute insulin response were skewed to the right, whereas the distribution of Sg was Gaussian distributed. Sg was 15% higher in women compared with men (P < 0.001). Waist circumference, body mass index, maximal aerobic capacity, and women's use of oral contraceptives were the most important determinants of Si. Approximately one-third of the variation of Si could be explained by these factors. Compared with individuals in the upper four-fifths of the distribution of Si, subjects with Si in the lowest fifth had higher waist circumference, higher blood pressure, lower VO2max, and lower glucose tolerance and fasting dyslipidemia and dysfibrinolysis. Only 10% of the variation in acute insulin response could be explained by measured determinants. CONCLUSION: Estimates of body fat, maximal aerobic capacity, and women's use of oral contraceptives explain about one-third of the variation in Si in a population-based sample of young healthy Caucasians.

Adolescent↗
PubMed1996

Association of body mass index, blood pressure and serum levels of triglycerides and high-density lipoprotein cholesterol in childhood with the insulin sensitivity index in young adulthood: a 13-year follow-up.

BACKGROUND: Tracking of body mass index (BMI), blood pressure and serum lipids from childhood to adulthood has been demonstrated in previous studies. Whether these factors are associated with the insulin-sensitivity index measured in young adulthood (ISIadult) remains undetermined. OBJECTIVES: To determine whether any association exists between the ISIadult and BMI, blood pressure and plasma lipids measured in childhood (1979). METHODS: The study included 227 unrelated white subjects (aged 18-32 years). Their ISIadult were measured in 1992/93 with a combined intravenous glucose (0.3 gl/kg body weight) and tolbutamide (3 mg/kg body weight) tolerance test. BMI, blood pressure and blood lipids were measured in 1979 and again in 1992/93. RESULTS: In men, plasma high-density lipoprotein cholesterol (HDLC) in 1979 (rs = 0.25, F = 0.006) was positively associated with ISIadult and plasma triglyceride measured in 1979 (rs = -0.34, P = 0.001). BMI (rs = -0.29, P = 0.002) and systolic blood pressure, both measured in 1979 (rs = -0.29, P = 0.002) were associated negatively with ISIadult. In women, plasma HDLC measured in 1979 was associated positively and significantly with ISIadult (rs = 0.21, P = 0.024) and BMI measured in 1979 was associated significantly and negatively with ISIadult (rs = -0.22, P = 0.018). Plasma triglyceride or systolic blood pressure, both measured in 1979, were not associated with ISIadult. In gender-stratified multiple-regression analyses [controlling for waist circumference(adult) maximal aerobic capacity (VO2max(adult)), age and women's use of oral contraceptives], plasma HDLC measured in 1979 was associated significantly with ISIadult in men (P = 0.026) but not in women (P = 0.066). A negative association was found between plasma triglyceride measured in 1979 and ISIadult (P = 0.045) in men, but not in women (P = 0.30). BMI, total cholesterol and systolic and diastolic blood pressure, all measured in 1979, were not associated with ISIadult. CONCLUSION: Low plasma HDLC, high plasma triglyceride and high BMI in childhood are associated with low insulin-sensitivity index values in young adulthood.

Adolescent↗
PubMed1996

Prevalence of renal artery stenosis in patients with peripheral vascular disease and hypertension.

The aim of this study was to evaluate the prevalence of renal artery stenosis in patients with clinical signs of peripheral vascular disease and hypertension. One hundred patients, mean age 69 years (range 45-88) with symptoms and clinical signs of severe peripheral ischemia, underwent aortography to determine the degree of peripheral vascular disease and possible renal artery stenosis. History of claudication, and measurement of systolic distal blood pressure (BP) and calculation of the Ankle Brachial Index was used to define the severity of peripheral vascular disease. A total of 31% had renal artery stenosis (14% greater than 50% reduction in luminal diameter). In a subgroup of patients with hypertension and peripheral vascular disease (n = 74), 34% had renal artery stenosis. In the subgroup of patients with renal artery stenosis, 81% have hypertension. Patients with renal artery stenosis and lumen reduction of more than 50%, 93% have hypertension (P < or = 0.001). In conclusion this study shows that the combination of peripheral vascular disease and hypertension is an important clinical clue for renovascular disease. Examination for reno-vascular disease in this population should be considered, since the prevalence of the condition is high. Furthermore examination for renal vascular disease in this population is mandatory, before treatment with angiotensin converting enzyme (ACE) inhibitors is initiated, since treatment might lead to serious renal function impairment.

Aged↗
PubMed1995

The importance of adrenaline, insulin and insulin sensitivity as determinants for blood pressure in young Danes.

OBJECTIVE: To study the influence of the adrenergic system, fasting serum insulin level and insulin sensitivity on systolic (SBP) and diastolic blood pressure (DBP) in young individuals. DESIGN AND METHODS: In a population survey we measured SBP and DBP (using the London School of Hygiene sphygmomanometer) and fasting levels of serum catecholamines, serum insulin and insulin sensitivity in 383 randomly recruited subjects (mean age 25.0 years) of both sexes. Insulin sensitivity was estimated from a combined intravenous glucose and tolbutamide tolerance test and calculated using Bergman's minimal model. Confounders were body mass index, waist:hip ratio, maximal aerobic capacity, age, sex, and consumptions of tobacco and alcohol. RESULTS: In a multiple regression analysis including the above factors, the most important determinant of SBP, after sex, was the plasma adrenaline level (partial correlation coefficient, rp = 0.23, P < 0.01). No significant association was found between plasma noradrenaline level and SBP. A significant association was found between plasma adrenaline level and DBP in females only (rp = 0.15, P < 0.05). Overall, the plasma adrenaline level was more important than the plasma noradrenaline level. Fasting serum insulin level and insulin sensitivity were each significantly correlated with both SBP and DBP in univariate analyses, but not in a multiple regression analysis. A family history of hypertension was associated with higher SBP level, body mass index and fasting serum insulin level, and with lower insulin sensitivity, but with no difference in circulating plasma adrenaline or noradrenaline compared with individuals without a family history. In a multiple regression analysis with the above confounders, no significant association between SBP and plasma adrenaline level could be found in either sex for subjects with a family history of hypertension. Both male (rp = 0.41, P < 0.001) and female (rp = 0.18, P < 0.05) subjects with no history of family hypertension had a significant association between SBP and plasma adrenaline level in a multiple regression analysis. CONCLUSION: In young healthy Caucasians adrenergic activity is an important determinant for SBP. The importance of fasting serum insulin level and insulin sensitivity on blood pressure level is minor when confounders are considered.

Adolescent↗
PubMed1995

The etiology of hypertension in nonrenovascular unilateral renal disease--two cases of renin induced hypertension in congenital renal dysplasia.

We report two cases of severe hypertension and unilateral renal dysplasia. No renal artery stenosis and no other urogenital malformations were found. In both cases we found substantially enhanced secretion of renin from the dysplastic kidney. After nephrectomy both patients obtained a distinctive and permanent reduction or normalization of blood pressure. In the two cases reported, regional renin release induced by ischemia is a very likely etiological factor.

Adult↗
PubMed1993

Norwegian industry and health promotion 1910-1967.

The development of occupational health services in Norway is explored by making a case study of both a chocolate factory and a cement factory. The study shows how different motives and ideological positions promoted the industrial health service. Prominent among them were a social and political philosophy, those of welfare capitalism, as an alternative to socialism and state policy in building the affluent society and the move toward improvements of production. All leading to a growing interest in the human factor in industry, where the medical officer should help to shape a satisfied, rational and productive worker in a healthy work environment.

History, 20th Century↗