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Biomedical subjects

H R Christensen

Publications and source records attributed to H R Christensen.

At least 37 records · Page 2Linked to original sources
PubMed1997

Smoking related to 24-h ambulatory blood pressure and heart rate: a study in 352 normotensive Danish subjects.

This study shows the association between smoking and both office and ambulatory blood pressure. By means of stratification, a uniform number of subjects of both sexes and spanning 6 decades (aged 20 to 79 years) were recruited randomly from the local community register. A total of 352 subjects participated, including 161 smokers. Smokers (both sexes and all age groups summed), as compared with nonsmokers had statistically significant lower office blood pressure as follows (mean systolic +/- SED/mean diastolic +/- SED): (systolic and diastolic, -6.8 +/- 2.1/-3.9 +/- 1.3); day ambulatory blood pressure (diastolic, /-2.8 +/- 1.0); and night ambulatory blood pressure (systolic and diastolic, -4.2 +/- 1.8/-3.9 +/- 1.1). The intraperson variability of the day ambulatory blood pressure (as measured every 15 min) was identical for the smokers and the nonsmokers. Smokers were found to have a diminished "white coat" effect; this diminished white coat effect has not previously been described. The major white coat effect was seen in the older nonsmokers, whereas the diminished white coat effect was most pronounced in the older male smokers and in the younger female smokers. Smokers seem to have a diminished white coat effect, as well as a lower ambulatory blood pressure throughout the day (diastolic) and at night (systolic and diastolic). The similar intraperson variability found in the smokers' and nonsmokers' blood pressure further speaks for a consistently lower blood pressure in smokers as compared with nonsmokers.

Adult↗
PubMed1996

[Round-the-clock blood pressure measurements in 352 persons--a reference material].

The aim of this study was to establish reference values for 24-hour ambulatory blood pressure in a Danish population stratified for gender and age in the decades from 20 to 79 years of age. A sample of 352 persons, 179 men and 173 women randomly selected from the local community register, age 20-79 years underwent 24-h ambulatory blood pressure monitoring. For men age < 50 daytime ambulatory blood pressure (median) was 125/79 mmHg and night time was 106/65 mmHg, for women the respective pressures were 113/77 mmHg and 97/64 mmHg. For men age > or = 50 daytime ambulatory blood pressure was 133/83 mmHg and night time was 124/86 mmHg, for women the respective pressures were 122/83 mmHg and 105/65 mmHg. Presently, we can only relate cardiovascular risk to clinic blood pressure. Therefore we have calculated corresponding ambulatory blood pressure values to WHO's upper limit 160/90 mmHg for normal blood pressure in the clinic and found 154/87 mmHg for daytime and 134/74 mmHg at night. For a clinic pressure of 95 mmHg the corresponding daytime value was 91 mmHg, for 100 mmHg it was 95 mmHg.

Adult↗
PubMed1995

Aminoglycosides: single or multiple daily dosing? A meta-analysis on efficacy and safety.

A number of randomised studies indicate that a single high dose of aminoglycoside every 24 h may be more efficient and less toxic than the same dose divided into multiple daily doses. In the meta-analysis of 16 studies described here, which included more than 1200 patients, the relative chance (i.e. the relative risk, RR) of cure of the single-dose regime compared with the multiple-dose regime was 1.027, indicating that the single daily dose regime had a 2.7% higher cure rate (NS). The RR of avoiding nephrotoxicity was 1.001 (NS) and the RR of avoiding ototoxicity was 1.001 (NS). It is concluded that there is no difference concerning efficacy and safety between single-dose and multiple-dose regimes for administration of aminoglycosides.

Aminoglycosides↗
PubMed1995

24-h ambulatory blood pressure in 352 normal Danish subjects, related to age and gender.

UNLABELLED: The study was conducted to determine age and sex stratified normal values for 24-h ambulatory blood pressure. A sample of 352 healthy subjects (all white) were randomly selected from the community register and stratified by sex and age groups in decades from 20 to 79 years of age. Persons with a history of hypertension, cerebral apoplexy, diabetes, myocardial or renal disease, and who were taking blood pressure-influencing medication were excluded. Ambulatory blood pressure was recorded over 24 h, with measurements taken every 15 min from 07:00 to 22:59, and every 30 min from 23:00 to 6:59. Systolic blood pressure increased only slightly with age and was significantly higher in men than in women. The diastolic blood pressure increased only slightly with age in both sexes until the 50 to 59 years age group and declined thereafter. The diastolic blood pressure was not different for the two sexes. Both systolic and diastolic blood pressure were approximately 15% lower during the night regardless of age or sex. Ambulatory blood pressure during the daytime was on an average of 5 mm Hg lower than office blood pressure, but the mean difference between the two measurements increased with age. The variability of the difference also increased with age. IN CONCLUSION: Normal values for ambulatory blood pressure are presented in a randomly selected age- and gender-stratified population. Differences between office blood pressure and ambulatory blood pressure increased with age suggesting that the previously observed higher blood pressure seen in the elderly partly might be explained by a greater impact of white coat hypertension in older people.

Adult↗
PubMed1993

Pharmacokinetics and dynamic response of plain and slow release isradipine formulations in moderately hypertensive patients.

The pharmacokinetic variables and antihypertensive effect of the calcium antagonist isradipine, were investigated in 30 hypertensive patients. Isradipine was given orally in parallel group design in plain and slow release formulations in doses of 2.5 mg twice daily and 5.0 mg once daily, respectively. Isradipine concentration in serum was measured by a sensitive RIA method after the first dose and after 6 weeks of treatment. The pharmacokinetics and concentration/effect relationship after the first dose and after 6 weeks of treatment were compared. No differences in pharmacokinetics were observed between single and multiple dosing. Data were in accordance with results from studies in healthy volunteers. Rate, but not extent of bioavailability differs between the two isradipine formulations. Antihypertensive efficacy of the two formulations was similar (16/11 and 19/15 mmHg), and a significant time dependent increase in Emax from 10/3 mmHg to 23/14 mmHg after 6 weeks of treatment was observed.

Blood Pressure↗
PubMed1993

Effect of oral calcium supplementation on blood pressure in patients with previously untreated hypertension: a randomised, double-blind, placebo-controlled, crossover study.

It has been claimed that calcium lowers BP. The present randomised, double-blind, placebo-controlled crossover study is the first to investigate the effect on BP of a high oral dose of calcium given for a long period to patients with previously untreated hypertension. Elemental calcium (2 g) was administered for 12 weeks interchanging with a period of 12 weeks of placebo. Twenty patients completed the protocol. There was no significant difference in change of BP during the period of additional calcium intake when compared with placebo (P = 0.33). The risk of not detecting a real BP-lowering effect of calcium of at least 3 mmHg was < 5%. No evidence for the existence of a subgroup of 'responders' was found. It is concluded that a high daily dose of calcium supplementation given for 12 weeks does not decrease BP in previously untreated patients with mild to moderate hypertension.

Administration, Oral↗
PubMed1992

[The synonymous preparation Andion vs. the original preparation becotide in the treatment of steroid-dependent bronchial asthma. A comparative double-blind cross-over trial].

Two different beclomethasone dipropionate inhalation aerosols (Andion and Becotide) were compared in a double-blind, cross-over study in patients with stable, steroid-dependent asthma. Fifty-two patients were included in the study, and 44 completed the two 6-week periods of treatment. The difference in therapeutic efficacy on FEV1 between Andion and Becotide was -0.018 1, and likewise no differences in therapeutic efficacy on FVC and peak expiratory flow were found. There were no significant differences between the two treatment periods regarding peak expiratory flow rates, symptoms, frequency of adverse effects, and amount of salbutamol and beclomethasone dipropionate employed. In conclusion, no significant differences could be demonstrated between Andion and Becotide with regard to pulmonary function, symptoms, and frequency of adverse effects in the treatment of patients with steroid-dependent bronchial asthma.

Adult↗
PubMed1992

[Diurnal blood pressure. Practical, prognostic and therapeutic aspects].

Outpatient blood pressure monitoring is now feasible employing good equipment which is easy to handle. However, some major problems must be solved before outpatient measurement of blood pressure (AMBP) can be employed routinely in the treatment of hypertension. Normal measurements, a satisfactory description of the AMBP curve and more prognostic studies with and without treatment are necessary.

Ambulatory Care↗
PubMed1992

Determination of isradipine and its pyridine metabolite in serum by capillary column gas chromatography with nitrogen-selective detection.

A relatively simple, sensitive and precise gas chromatographic method for the determination of isradipine, a calcium antagonist of the dihydropyridine type, and its main metabolite in serum is described. Using a one-step extraction procedure, a wide-bore column and a nitrogen-phosphorus detector, a limit of quantitation of 0.5 and 2.0 nM for isradipine and the metabolite was found. No interferences from several drugs were observed. The method was successfully used in a pharmacokinetic study in hypertensive women during pregnancy.

Calcium Channel Blockers↗
PubMed1992

Atrial natriuretic peptide (ANP) in chronic obstructive pulmonary disease (COPD): the relationship between plasma ANP and lung function. Effects of exercise and of the calcium antagonist, isradipine, on plasma ANP. A randomised, double-blind, placebo-controlled study.

In patients with severe chronic obstructive pulmonary disease (COPD) an increased pulmonary arterial pressure (PAP), a raised plasma level of atrial natriuretic peptide (ANP) and a correlation between increasing PAP and increasing plasma ANP have been shown. Furthermore, a negative correlation between lung function and PAP has been reported, and calcium antagonists have been claimed to decrease PAP. The purpose of the present study was to investigate whether 1) a negative correlation between lung function and plasma ANP could be demonstrated, whether 2) plasma ANP would increase during exercise in patients with COPD, and whether (3), in a randomised, placebo-controlled, double-blind design, a calcium antagonist was able to decrease plasma ANP at rest and modify the expected increase in plasma ANP during exercise. Eighteen patients with severe COPD were investigated. Plasma ANP was measured at rest and during exercise before and two hours after ingestion of either a single dose of 5 mg of isradipine, or a single dose of placebo. At rest, a correlation between lung function (forced vital capacity) and plasma ANP was found (rho = -0.49, P = 0.05). During the first exercise period, before ingestion of isradipine or placebo, the median level of ANP increased from 74 pg/ml at rest to 97 pg/ml at exhaustion (P less than 0.0002) (all patients). Administration of isradipine did not alter resting levels or exercise induced increases in plasma ANP. It is concluded, that in patients with severe COPD plasma ANP tends to be higher the more severely FVC is reduced. Plasma ANP increases during exercise. The calcium antagonist, isradipine, does not alter resting levels or exercise induced levels of plasma ANP.

Atrial Natriuretic Factor↗
PubMed1991

Interaction between digoxin and indomethacin or ibuprofen.

To study a potential interaction between digoxin and two non-steroid anti-inflammatory drugs, indomethacin (50 mg three times daily) and ibuprofen (600 mg three times daily) were given for 10 days to 10 and 8 patients, respectively, on chronic digoxin treatment. Serum digoxin measured by fluorescence polarisation immunoassay increased significantly (P less than 0.05) during treatment with indomethacin from pre-treatment values of 0.73 +/- 0.34 nmol l-1 (mean +/- s.d.) to a mean value of 1.02 +/- 0.43 nmol l-1, while administration of ibuprofen did not change the steady state serum concentration of digoxin. The result demonstrates that some non-steroidal anti-inflammatory drugs such as indomethacin increase serum digoxin to levels high in the therapeutic range. This should be taken into consideration when co-administering other drugs known to increase the serum concentration of digoxin such as several antiarrhythmics.

Aged↗
PubMed1991

A randomized comparison of isradipine slow release given once daily with isradipine twice daily on 24 hour blood pressure in hypertensive patients.

Isradipine, a new calcium channel blocker, was given to 32 patients with mild to moderate essential hypertension. After a run-in period of three weeks, 32 patients were randomized double-blindly to six weeks' treatment with either isradipine 2.5 mg twice daily or isradipine 5.0 mg once daily in a modified release formulation. Based on conventional 'clinic' BP measurements 12 or 24 hours postdose, the two treatments resulted in clinically relevant BP reduction (16/11 and 19/15 mmHg) without reflex tachycardia. No differences were seen between the groups. Efficacy increased throughout the study period. By determination of the 24 hour BP profile with a noninvasive method, the two groups were comparable during the placebo period, and no differences were seen between the two treatments. Both treatments resulted in satisfactory BP reduction during 24 hours (daily reduction of 4/6 and 12/9 mmHg twice daily and once daily dosing respectively). One third of the patients had 'white-coat' hypertension based on ambulatory daytime mean BPs, compared with conventional measurements. No relationship was found between the initial BP lowering effect and the effect after long-term treatment with isradipine in either dose.

Adult↗
PubMed1991

[Physiotherapy and mask treatment of chronic bronchitis and chronic obstructive lung disease].

The literature concerning traditional chest physiotherapy (postural drainage, percussion, vibration, breathing exercises), treatments with masks (CPAP, IPPB, RMT, PEP, PEEP) and general physical training in the treatment of chronic bronchitis is reviewed. The mucociliary clearance is increased after postural drainage, cough, forced expiratory manoeuvres and general physical training, but the influence of this upon the course of the disease is unknown. Chest physiotherapy in the treatment of patients admitted due to acute exacerbation of chronic bronchitis seems of no help. The use of face masks in this population has only been subject to limited investigation, but results from controlled trials do not indicate any favourable effect. In contrast general physical training seems to increase physical endurance and decrease dyspnoea. Specific rehabilitation programmes comprising psychological assistance, cessation of smoking and general physical training seem promising.

Bronchitis↗
PubMed1990

[Physical therapy and mask treatment of chronic bronchitis and chronic obstructive lung disease (COPD)].

The literature concerning traditional chest physiotherapy (postural drainage, percussion, vibration, breathing exercises), treatments with masks (CPAP, IPPB, RMT, PEP, PEEP) and general physical training in the treatment of chronic bronchitis is reviewed. The mucociliary clearance is increased after postural drainage, cough, forced expiratory manoeuvres and general physical training, but the influence of this upon the course of the disease is unknown. Chest physiotherapy in the treatment of patients admitted on account of acute exacerbation of chronic bronchitis does not appear to help. The use of face masks in this population has only been subject to limited investigation, but results from controlled trials do not indicate any favourable effect. In contrast, general physical training seems to increase physical endurance and decrease dyspnoea. Specific rehabilitation programmes comprising psychological assistance, cessation of smoking and general physical training seem promising.

Bronchitis↗
PubMed1990

[Peroral terbutaline in the treatment of patients with severe irreversible obstructive pulmonary disease].

This investigation assesses the effect of oral terbutaline in doses of 7.5 mg twice daily as compared with placebo in patients with moderate to severe chronic airflow limitation (CAL) without reversibility. Seventeen patients completed this double-blind randomised cross-over trial. Diaries with reports of dyspnoea during activities of daily living and peak-flow measurements, were obtained. Measurement of pulmonary function, walking distance and various scorings of function after treatment for three and five weeks were assessed. The investigation demonstrates that in patients with CAL treatment with terbutaline tablets may lead to improvement of several subjective effect variables although no real improvement in the majority of objective effect variables is observed. In patients with irreversible obstructive reduction of pulmonary function, in whom no other form of treatment can be considered, oral treatment with beta-2-agonists may be attempted. If no effect is obtained, the treatment should be withdrawn after one to two months.

Administration, Oral↗