Biomedical subjects

Rolf Jorde

Publications and source records attributed to Rolf Jorde.

17 recordsLinked to original sources

PubMed2006

Serum levels of vitamin D and haemostatic factors in healthy subjects: the Tromsø study.

BACKGROUND: Receptors for vitamin D have been found in various tissues, including the vascular endothelium. The role of vitamin D in the haemostatic process is uncertain, but in vitro studies may indicate a pro-fibrinolytic effect. METHODS: Two hundred and six subjects (105 males) were included in the study. The relations between indices of calcium metabolism and haemostatic factors [tissue plasminogen activator antigen (tPA Ag), plasminogen activator inhibitor 1 (PAI-1), prothrombin fragment 1+2, activated factor VII and total factor VII coagulant activity] and high-sensitivity C-reactive protein (HS-CRP) were examined. RESULTS: There were significant and negative correlations between serum 25(OH) vitamin D and PAI-1 and tPA Ag, and between serum 1,25(OH)2 vitamin D and tPA Ag and HS-CRP. In a multiple linear regression model with age, gender, body mass index and smoking status as covariables, only the relation between 25(OH) vitamin D and tPA Ag was significant. There were no significant relations between any of the haemostatic factors tested and serum parathyroid hormone. CONCLUSION: It appears that the serum level of vitamin D is related to fibrinolytic activity and to the integrity of the vascular endothelium, but the clinical importance of this observation remains to be determined.

Adult↗

PubMed2006

Endogenous testosterone levels and smoking in men. The fifth Tromsø study.

Smoking is a risk factor of coronary heart disease (CHD), while the role of testosterone in the development of CHD is controversial. The reported effects of cigarette smoking on testosterone levels in men are conflicting, and smoking may be an important confounding factor when evaluating the relationship between testosterone levels and CHD. Thus, the objective of the present study was to examine the associations of smoking status and number of cigarettes smoked per day with total and free testosterone levels in a cross-sectional population-based study of 3427 men participating in the fifth Tromsø study. Total testosterone, luteinizing hormone, follicle-stimulating hormone and sex hormone-binding globulin levels were measured with immunoassay while free testosterone levels were calculated. Waist circumference was also measured and two standardized questionnaires were completed, including smoking status and number of cigarettes smoked. The data were analysed with analysis of variance and covariance and multiple regression analysis. Smoking men had significantly higher levels of total and free testosterone compared with men who never smoked (p < 0.001 and <0.01 respectively). Both total and free testosterone levels increased significantly with increasing number of cigarettes smoked daily (p < 0.001). Smoking men had 15% higher total and 13% higher free testosterone levels compared with men who never smoked. Thus, smoking seems to be an important confounding factor when evaluating testosterone levels, and could possibly mask borderline hypogonadism.

Adult↗

PubMed2006

Causes of secondary hyperparathyroidism in a healthy population: the Tromsø study.

Secondary hyperparathyroidism (SHPT) develops as a compensatory mechanism when the body is in calcium deficit. SHPT may be harmful and has been associated with elevated blood pressure. The cause of SHPT could be low calcium intake, reduced intestinal calcium absorption, or increased excretion. However, the relative importance of these factors for the development of SHPT is not known. During the 5th Tromsø study, serum PTH and calcium were measured in 7954 subjects. Then 96 subjects with SHPT (defined as serum PTH above 6.4 pmol/l together with serum calcium below 2.40 mmol/l) and 106 control subjects were examined at follow-up with a food frequency questionnaire, calcium absorption test, measurement of 24-h urinary calcium excretion, and serum vitamin D status. The statistical analyses showed several interactions necessitating subgroup analysis. It was found that the calcium intake was significantly lower in the SHPT group, but only in nonsmoking males; the calcium absorption was nonsignificantly higher in the SHPT group; the serum 25-hydroxyvitamin D levels were significantly lower in the SHPT group but only in nonsmokers; and the 24-h urinary calcium excretion was significantly lower in the SHPT group but only in those not on blood pressure medication. The most frequent cause of SHPT appeared to be low calcium intake (18%) and a low serum 25-hydroxyvitamin D level (18%). However, in most subjects with SHPT all tests were within the normal range, and the cause is therefore probably a combination of several factors.

Absorption↗

PubMed2005

Neuropsychological function in relation to serum parathyroid hormone and serum 25-hydroxyvitamin D levels. The Tromsø study.

There are receptors for parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D in the brain, and there are clinical and experimental data indicating that PTH and vitamin D may affect cerebral function. In the present study 21 subjects who both in the 5th Tromsø study and at a follow-up examination fulfilled criteria for secondary hyperparathyroidism (SHPT) without renal failure (serum calcium < 2.40 mmol/L, serum PTH > 6.4 pmol/L, and normal serum creatinine) and 63 control subjects were compared with tests for cognitive and emotional function. Those in the SHPT group had significantly impaired performance in 3 of 14 cognitive tests (Digit span forward, Stroop test part 1 and 2, and Word association test (FAS)) as compared with the controls, and also had a significantly higher depression score at the Beck Depression Inventory (BDI) (items 1-13). In a multiple linear regression model, a high serum PTH level was significantly associated with low performance at the Digit span forward, Stroop test part 1 and 2, and Digit Symbol tests. A low level of serum 25-hydroxyvitamin D was significantly associated with a high depression score. In conclusion, a deranged calcium metabolism appears to be associated with impaired function in several tests of neuropsychological function.

Adult↗

PubMed2005

Neuropsychological function and symptoms in subjects with subclinical hypothyroidism and the effect of thyroxine treatment.

OBJECTIVE: Our objective was to examine the relation between neuropsychological function and subclinical hypothyroidism (SHT), defined as serum TSH of 3.5-10.0 mIU/liter and normal serum free T4 and free T3 levels, and to study the effect of T4 supplementation. SUBJECTS: A total of 89 subjects (45 males) with SHT and 154 control subjects (72 males) were recruited from a general health survey (the fifth Tromsø study). Sixty-nine of those with SHT were included in a placebo-controlled, double-blind intervention study with T4 medication for 1 yr. MAIN OUTCOME MEASURES: We used fourteen tests of cognitive function, Beck Depression Inventory, General Health Questionnaire, and a questionnaire on hypothyroid symptoms. RESULTS: The mean +/- sd serum TSH in the SHT and control group were 5.57 +/- 1.68 and 1.79 +/- 0.69 mIU/liter, respectively. There were no significant differences in cognitive function and hypothyroid symptoms between the two groups, but those with SHT scored significantly better than the controls on the GHQ-30. At the end of the intervention study, serum TSH in the T4 group (n = 36) and the placebo group (n = 33) were 1.52 +/- 1.51 and 5.42 +/- 1.96 mIU/liter, respectively. T4 substitution had no effect on any of the parameters measured. CONCLUSION: In subjects with SHT where the serum TSH level is in the 3.5-10.0 mIU/liter range, there is no neuropsychological dysfunction, and compared with healthy controls, there is no difference in symptoms related to hypothyroidism.

Adult↗

PubMed2005

Left ventricular dysfunction in subjects with mild secondary hyperparathyroidism detected with pulsed wave tissue Doppler echocardiography.

AIMS: To assess left ventricular function by conventional and pulsed wave tissue Doppler (PWTD) echocardiography in subjects with mild secondary hyperparathyroidism, and to evaluate whether PWTD would be more sensitive than conventional echocardiography in detecting subtle changes in LV systolic and diastolic function. METHODS: In the fifth Tromsø study (2001) serum PTH and calcium were measured in 7,954 subjects. One hundred subjects with secondary hyperparathyroidism (SHPT; serum PTH >6.40 pmol/l and serum calcium <2.40 mmol/l) and 106 control subjects with normal PTH and calcium levels and with no history of cardiovascular disease were examined at the follow-up 6-12 months later. RESULTS: Conventional transthoracic echocardiography and PWTD of mitral annulus were successfully performed in 83 cases and 88 controls. At follow-up mean serum PTH values were 6.0 +/- 2.2 versus 3.2 +/- 1.3 pmol/l (p < 0.05) and mean calcium 2.28 +/- 0.10 versus 2.33 +/- 0.08 mmol/l (p < 0.05) in cases and controls, respectively. Unpaired t test and multiple linear regression analyses were used. No significant differences in conventional echocardiographic parameters were found. However, PWTD showed reduced systolic velocity in septal, lateral and anterior mitral annulus (p < 0.05) and also reduced early diastolic velocity in septal and anterior mitral annulus (p < 0.05). CONCLUSION: Subjects with mild SHPT have impaired left ventricular long axis function as evaluated by PWTD compared to conventional echocardiography. PWTD seems to be a more sensitive tool in detecting minor changes in left ventricular function and the new modality should routinely be included in studies evaluating left ventricular function, especially the long axis function.

Aged↗

PubMed2005

Serum parathyroid hormone as a predictor of increase in systolic blood pressure in men.

BACKGROUND: In cross-sectional studies there appears to be a link between calcium metabolism and blood pressure, and most studies have found a positive association between serum parathyroid hormone (PTH) and hypertension. OBJECTIVE: To determine the prognostic value of serum PTH regarding a future increase in blood pressure. DESIGN: A prospective cohort study. SUBJECTS: A total of 1784 individuals who had measurements of PTH in serum samples from both the fourth (1994) and fifth (2001) Tromsø studies, who did not use blood pressure medication during the observation period, and had serum calcium less than 2.61 mmol/l, were included. MAIN OUTCOME MEASURE: Delta blood pressure (blood pressure from 2001 minus blood pressure from 1994). RESULTS: The mean delta systolic blood pressure in the men and women during these 7 years was 5.8 and 8.1 mmHg, respectively. In a sex-specific linear regression model correcting for age, body mass index (BMI), and smoking status, serum PTH from 1994 was a significant predictor of delta systolic blood pressure in men (P < 0.01), but not in women. The difference in delta systolic blood pressure between those in the highest and those in the lowest PTH quartile was 3.5 mmHg. Similarly, delta serum PTH (serum PTH from 2001 minus serum PTH from 1994) was a significant predictor of delta systolic blood pressure in men (P < 0.05). CONCLUSIONS: Although these findings do not prove a causal relationship between PTH and blood pressure, it adds to the growing number of indications that PTH is involved in the development of hypertension.

Age Factors↗

PubMed2004

Waist circumference and testosterone levels in community dwelling men. The Tromsø study.

To examine the relationship of total and free testosterone and sex hormone-binding globulin (SHBG) with central obesity in men, we studied 1548 men aged 25-84 years that took part in the 1994--1995 survey of the Tromsø study. Total testosterone and SHBG were measured by immuno-assay and the free testosterone fraction was calculated. These measurements were analyzed in relation to anthropometric data and lifestyle factors. The age-adjusted correlation between waist circumference (WC) and total testosterone was -0.34 (p < 0.001), between WC and free testosterone -0.09 (p < 0.001) and, between WC and SHBG -0.44 (p < 0.001). Adjusting for BMI and lifestyle factors weakened, but did not eliminate these associations. All hormone and SHBG associations were stronger for WC than for waist-hip ratio or BMI. In age- and BMI-adjusted analyses men with a WC > or = 102 cm had significantly lower levels of total testosterone and SHBG compared to men with an optimal WC, defined as < 94 cm (12.3 vs. 13.9 nmol/l; p < 0.01 and 48.5 vs. 55.1 nmol/l; p < 0.001, respectively). The lowest levels of total and free testosterone were observed in men with relatively high WC despite relatively low overall obesity (BMI), suggesting that WC should be the preferred anthropometric measurement in predicting endogenous testosterone levels.

Adult↗

PubMed2004

Serum parathyroid hormone levels predict coronary heart disease: the Tromsø Study.

BACKGROUND: Primary hyperparathyroidism (PHPT) is associated with hypertension, coronary atherosclerosis and other cardiovascular diseases. We aimed to evaluate serum parathyroid hormone (PTH) levels as an independent risk factor for coronary heart disease (CHD) in subjects with serum calcium within the reference range. DESIGN: Population-based cross-sectional study. METHODS: The Tromsø Study was attended by 27159 subjects aged 25-79 years. Serum PTH was measured in 3570 subjects. They all completed a questionnaire on medical history, including questions on angina pectoris and myocardial infarction along with a food-frequency questionnaire. A total of 1459 men and 1753 women with serum calcium 2.20-2.60 mmol/l, serum creatinine<121 micromol/l and who did not use diuretics were included in the present study. Linear regression was used to reveal associations between PTH, age, body mass index, serum calcium, calcium intake, cholesterol, blood pressure, glycosylated haemoglobin (HbA1c) and smoking status. A logistic regression model was used to find the independent predictors of CHD. RESULTS: When stratified for age the rate of CHD was higher in the subjects with serum PTH > 6.8 pmol/l than in those with normal or low serum PTH levels [relative risk 1.67, 95% confidence interval (CI) 1.26-2.23 in men and 1.78, 95% CI 1.22-2.57 in women]. The highest PTH quartile (> 3.50 pmol/l in men and > 3.30 pmol/l in women) predicted CHD, with odds ratios of 1.70 (95% CI 1.08-2.70) for men and 1.73 (95% CI 1.04-2.88) for women, versus the lowest PTH quartile (< 1.90 pmol/l for men and <1.80 pmol/l for women). CONCLUSIONS: Serum PTH predicts CHD in subjects with calcium levels within the reference range. This may indicate a role for PTH in the development of CHD.

Adult↗

PubMed2004

Association of endogenous testosterone with blood pressure and left ventricular mass in men. The Tromsø Study.

OBJECTIVE: To test the hypothesis that lower endogenous testosterone levels are associated with higher blood pressure, left ventricular mass, and left ventricular hypertrophy. DESIGN: Population-based cross-sectional study. METHODS: Sex hormone levels, measured by immunoassay, anthropometric measurements and resting blood pressure were studied in 1548 men aged 25-84 Years; echocardiography was completed in 1264 of these men. Partial correlations and multiple regressions were used to estimate the associations between sex hormones, blood pressure and left ventricular mass by height. Analyses of variance and covariance were used to compare men with categorical hypertension and left ventricular hypertrophy. RESULTS: In age-adjusted partial correlations, total testosterone and sex hormone-binding globulin (SHBG) were each inversely associated with systolic blood pressure (SBP) (P<0.001). Men with categorical hypertension (SBP> or =140 or diastolic blood pressure (DBP)> or =90 mmHg) had lower levels of total and free testosterone and SHBG before (P<0.001, P=0.011 and P<0.001, respectively) and after (P<0.001, P=0.035 and P=0.002, respectively) adjusting for body mass index (BMI). Total testosterone and SHBG were each inversely associated with left ventricular mass (P<0.001), and men with left ventricular hypertrophy had significantly lower levels of total testosterone (P=0.042) and SHBG (P=0.006); these associations were no longer significant after adjusting for BMI. CONCLUSION: The results of the present study are consistent with the hypothesis that lower levels of testosterone in men are associated with higher blood pressure, left ventricular mass, and left ventricular hypertrophy. The reduced associations after adjusting for BMI suggest that the association of low testosterone levels with blood pressure and left ventricular mass is mediated by obesity.

Aged↗

PubMed2004

Serum parathyroid hormone level is associated with body mass index. The 5th Tromsø study.

OBJECTIVE: To study whether serum parathyroid hormone (PTH) and serum calcium are associated with body mass index (BMI), and their predicting role in obesity. DESIGN: Population based, cross-sectional study. METHODS: In 2001 a population-based health survey was held in Tromsø, North Norway. Questionnaires on medical history and life-style factors were completed and anthropometric data were collected. Calcium and vitamin D intakes and a physical activity score were calculated. Serum calcium and PTH were measured in a subset of 3447 men and 4507 women. Pearson correlation and linear regression were used to evaluate associations between BMI, PTH and serum calcium, and logistic regression was used to test PTH and serum calcium as predictors of obesity and to calculate odds ratio. Relative risk was calculated using frequency tables. RESULTS: For serum calcium and PTH there was a significant positive relation to BMI in both genders (P<0.001), which to our knowledge has not previously been reported on the basis of a large epidemiological study. Age, low calcium and vitamin D intakes were explanatory variables for serum PTH. The highest quartile of serum PTH (>4.20 pmol/l) was a significant predictor for obesity (P<0.001) in both genders, adjusted for age, physical activity and serum calcium. Obesity rates were higher in those with PTH levels in the highest quartile compared with those in the lower quartiles, which resulted in a relative risk of 1.40 (95% confidence interval (C.I.) 1.20-1.60) for men and 1.48 (95% C.I. 1.31-1.67) for women. CONCLUSIONS: Serum PTH, adjusted for age, physical activity and serum calcium, is positively associated with BMI in both sexes, and serum PTH is an independent predictor of obesity in our statistical model.

Adult↗

PubMed2003

Intakes of calcium and vitamin d predict body mass index in the population of Northern Norway.

This study was designed to investigate whether there is any association between body mass index (BMI) and life-style factors, with a special emphasis on calcium and vitamin D intakes. In 1994/1995, men (n = 9252) and women (n = 9662) participated in the fourth Tromsø study and completed the food-frequency and life-style factor questionnaires. We measured BMI, coffee and alcohol consumption, physical activity, smoking, and calcium and vitamin D intakes. A negative association between physical activity, smoking and BMI, and a positive association between BMI and coffee intake were found in both sexes (P < 0.001). BMI and calcium intake were positively related in men (P < 0.001), but not in women. BMI and vitamin D intake were negatively associated in both sexes (P < 0.001), which to our knowledge has not been reported before. The lowest quartile of vitamin D intake was an independent predictor of obesity (defined as BMI >30 kg/m(2)) in men and women (P < 0.001 in both genders), resulting in odds ratios of 2.24 [95% confidence interval (CI) 1.80, 2.80] in men and 1.51 (95% CI 1.23, 1.85) in women compared with the highest quartile. In conclusion, calcium and vitamin D intakes may have opposing effects on body weight, which is difficult to explain given current knowledge of calcium metabolism.

Adult↗

PubMed2003

Seasonal variation of testosterone and waist to hip ratio in men: the Tromsø study.

Studies of seasonal variation in male testosterone levels show contradictory results. We report here a cross-sectional study of the seasonal variation in total and free testosterone, LH, and SHBG levels in 1548 men living in north Norway, a population exposed to a wide seasonal variation in temperature and daylight. Total testosterone showed a bimodal seasonal variation (P < 0.001) with a small peak in February, the nadir in June, and a more prominent peak in October and November. Free testosterone also showed a significant seasonal pattern (P < 0.001), with the peak in December and the nadir in August. These patterns persisted after adjusting for age and waist to hip ratio (P < 0.001). Lowest testosterone levels occurred in months with the highest temperatures and longest hours of daylight. Waist to hip ratio paralleled the change in daylight and temperature, with the highest values during the summer and was thus inversely related to the seasonal testosterone variation. The variations in hormone levels were large, with a 31% difference between the lowest and highest monthly mean level of free testosterone. Prospective studies are needed to establish the direction of the association and its etiology.

Adult↗

PubMed2003

The associations of age, lifestyle factors and chronic disease with testosterone in men: the Tromsø Study.

OBJECTIVE: To study whether lifestyle factors and/or chronic disease are associated with the age-related decline of total and free testosterone in men, or if these factors might be associated with the variation of total and free testosterone but not with their age-related decline. DESIGN: A population-based, cross-sectional study was used. METHODS: Total testosterone and sex hormone binding globulin (SHBG) levels were analyzed and free testosterone levels were calculated in 1563 men participating in the Tromsø study in 1994/1995. Anthropometric characteristics were also measured and two standardized questionnaires completed, including lifestyle factors and medical history. The data were analyzed with multiple linear regression analysis of covariance, and logistic regression. RESULTS: Total and free testosterone were inversely associated (P=0.001 and P<0.001), while SHBG was positively associated (P<0.001) with age. Body mass index (BMI) was inversely associated with total (P<0.001) and free (P=0.016) testosterone and SHBG (P<0.001). Both total and free testosterone were positively associated with tobacco consumption (P<0.001 and P=0.004) and total testosterone was positively associated with coffee consumption (P<0.001). SHBG was positively associated with smoking (P=0.004) and coffee consumption (P<0.001). Men who reported having had a stroke or having a cancer diagnosis had lower levels of total testosterone (P<0.001 and P<0.01) and free testosterone (P<0.01). CONCLUSIONS: BMI and smoking are independent contributors to the variation of total and free testosterone and SHBG levels, and coffee consumption to the variation of total testosterone and SHBG. Thus, lifestyle factors can have a direct effect on circulating levels of free endogenous sex hormones and to total levels due to the effect on SHBG levels.

Adult↗

PubMed2002

["Subclinical" thyroid disease].

BACKGROUND: It is generally easy to diagnose and treat patients with thyroid diseases, though there has been considerable uncertainty over whether or not to treat patients with subclinical disease. MATERIAL AND METHODS: An overview of clinical symptoms and complications related to subclinical thyroid disease is presented on the basis of relevant literature. RESULTS: Patients with subclinical hypothyreosis (elevated TSH level and normal free T4) may benefit from treatment with thyroxine in relation to well-being, serum lipid levels, and possibly also blood pressure. Patients with subclinical hyperthyreosis (suppressed TSH level and normal free T4) have an increased risk of developing atrial fibrillation and possibly also dementia. INTERPRETATION: Subclinical thyroid disease is usually progressive. If a transient condition is ruled out, proper treatment should not be delayed.

Cardiovascular Diseases↗

PubMed2002

The effects of calcium supplementation to patients with primary hyperparathyroidism and a low calcium intake.

BACKGROUND: In patients with primary hyperparathyroidism (PHPT) a low calcium intake might cause increased bone loss and thus aggravate osteoporosis, and a high intake might increase serum calcium level and the risk of nephrolithiasis. AIM OF THE STUDY: Generally, guidelines recommend a normal calcium intake, and accordingly, those with a low intake might benefit from a modest calcium supplementation. This hypothesis was tested in the present study. METHODS: Thirty-one patients with asymptomatic PHPT were recruited from an epidemiological study (The Tromsø study 1994/95). Those with a daily calcium intake below 450 mg were given calcium supplementation (500 mg Ca(2+)), and those with an intake above 450 mg were followed without supplementation. The study was open and lasted 1 year. Serum levels of calcium, PTH, 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D, urinary calcium excretion, blood pressure, and bone mineral density (BMD) were measured. RESULTS: Three subjects dropped out without reason, 1 developed abdominal discomfort from the calcium supplementation, and 3 had an increase in serum calcium of more than 0.2 mmol/L and were therefore excluded. The latter three did not differ from the rest of the group at baseline. Of the remaining 24 that completed the study, 17 were given calcium. In this group there was a non-significant increase in serum calcium and urinary calcium excretion, a significant decrease in PTH after 4 weeks (13.2 (6.0) vs 9.4 (3.0) pmol/L, P < 0.05), and a significant increase in BMD at the femoral neck at the end of the study (0.849 (0.139) vs 0.870 (0.153) g/cm(2), P < 0.05). The blood pressure was not significantly affected. CONCLUSIONS: Most patients with mild PHPT and a low calcium intake tolerate a moderate calcium supplement. This may have beneficial effects on the bones, but the patients must be followed carefully.

Aged↗

PubMedDate not supplied

Pancreatic polypeptide is increased in patients with advanced malignant disease.

BACKGROUND: Augmented secretion of pancreatic polypeptide (PP) has been demonstrated in patients with severe systemic diseases or endocrine tumors. The aim of this study was to evaluate PP and autonomic neuropathy in patients with advanced malignant disease. MATERIALS AND METHODS: Basal PP assessments and five cardiovascular tests for autonomic function were used. Twenty patients, including 11 patients with lung cancer (69 yrs +/- 11, mean +/- SD) and 10 healthy age-matched controls, were studied. RESULTS: PP levels were significantly higher in the patients than in the controls (pmol/L 107.0 +/- 111.4 versus 28.2 +/- 13.4, p<0.05). In the parasympathetical tests, the patients showed significantly decreased heart rate response to the Valsalva manoeuvre (ratio 1.20 +/- 0.19 versus 1.46 +/- 0.23, p<0.005). Also, in the sympathetical tests, the blood pressure response to standing up was significantly decreased (mmHg -3.84 +/- 17.53 versus 10.80 +/- 8.89, p<0.05). The heart rate response to standing up and deep breathing as well as the blood pressure response to sustained handgrip, did not differ significantly between the groups. In spite of the apparent autonomic dysfunction among cancer patients with advanced malignant disease, PP levels were significantly higher in these patients when compared with healthy controls. CONCLUSION: PP levels were significantly higher in patients with advanced cancer than controls, regardless of autonomic dysfunction in the cancer patients. This finding supports the hypothesis that PP may, in some cancer patients, be a marker of advanced malignant disease.

Adult↗