Primary hyperparathyroidism detected in a health screening. The Trømsø study

Serum calcium was measured in 12,339 men and 13,394 women ages 25 to 75. Primary hyperparathyroidism, defined as a combination of serum calcium and parathyroid hormone (PTH) levels within the extreme or upper normal range, was diagnosed in 17 men and 47 women. The prevalence in both sexes increased with age. When 42 subjects with asymptomatic primary hyperparathyroidism were followed for 3 years, no significant increase in serum calcium or PTH was seen. In a subgroup of 473 men and 517 women ages 50 to 75, serum PTH was measured along with serum calcium. Depending on the criteria used to define primary hyperparathyroidism, the prevalence in older women within this subgroup ranged from 3.6% to 13.9%. The study concluded that a high prevalence of primary hyperparathyroidism exists in older women, although the progression of the disease, judging by serum calcium and PTH measurements, appears to be very slow.     

The Tromsø study: determinants of precision in bone densitometry

Studies of precision determinants in bone densitometry are scarce. A total of 111 subjects recruited from the population-based multipurpose Troms? Study (Norway), 27-75 years of age, had repeated forearm bone single X-ray absorptiometry (SXA) measurements. Measurement conditions were systematically varied in series up to eight scans. Median coefficients of variation (CV) for two scans performed 1 week apart, by two different operators were 0.79% and 0.98% at distal and ultradistal sites, respectively. The CV distribution was skewed: 5% of the subjects had individual CVs above 2.2% (distal) and 3.4% (ultradistal). Age (P = 0.0097) and repositioning were important determinants of precision. The SXA bone mineral density (BMD)-measurement method is sufficiently precise to establish BMD level. The minimal individual percentage BMD change that can be detected with 95% certainty was 2% and 3% at distal and ultradistal sites, respectively. Detection of BMD changes less than this should rely on multiple repeat measurements at each point in time.     

Determinants of serum calcium in men and women. The Tromsø Study

The level of serum calcium appears to be associated with blood pressure and metabolic risk factors for cardiovascular disease. Determinants of serum calcium may therefore be of interest. In a health survey in Tromsø in 1994–1995, 27,159 subjects were examined. The survey included measurements of serum calcium and questionnaires on diet and lifestyle factors. In males mean serum calcium declined from 2.41 mmol/l for those in their 20s to 2.34 mmol/l for those in their 80s. In females mean serum calcium was stable at a level of 2.35 mmol/l before the menopause, and thereafter reached a plateau of 2.39 mmol/l. In both sexes serum calcium showed a positive association with body mass index (BMI) and coffee consumption that persisted after correcting for other variables in a multiple regression model (p < 0.05). Physical activity had no significant association with serum calcium. In females alcohol consumption was negatively, and cigarette smoking positively associated with serum calcium (p < 0.01). No significant effect on the serum calcium levels was found for the intake of calcium or vitamin D, except for males with a calcium intake below 200 mg/day. Some of the observed effects, like the variation with age, may partly be explained by alterations in levels of serum albumin to which approximately 40% of circulating calcium is bound and which was not adjusted for in this study, whereas that is hardly the case for the association with BMI and coffee consumption. However, none of these factors could affect the serum calcium level more than 0.02 mmol/l, and the biological significance of the observed associations questionable.     

Serum osteoprotegerin levels are related to height loss: The Tromsø Study

Severe loss of body height is often a consequence of osteoporotic vertebral fractures. Osteoprotegerin (OPG) and receptor activator of nuclear factor-kB ligand (RANKL) are cytokines essential for the regulation of bone resorption. The aim of this study was to assess the relationship between the OPG/RANKL system and height loss. A total of 4,435 inhabitants from the municipality of Tromsø, Norway (2,169 men and 2,266 women) were followed for 6 years. Baseline measurements included height, weight, bone mineral density, OPG, RANKL, serum parathyroid hormone and information about lifestyle, prevalent diseases and use of medication. Height was measured again at follow-up, and the loss of height was categorized into 4 groups: ≤1, 1.1–2, 2.1–3, >3 cm. We found increasing height loss with increasing baseline OPG levels in both men and women (P trend = 0.02 and 0.001, respectively), after adjustments for age and other confounders. However, when the women were stratified according to menopausal status and use of hormone replacement therapy (HRT), a significant relationship was present only among postmenopausal women not using HRT (P trend = 0.02). No relations between OPG and height loss were found in post-menopausal HRT-users and premenopausal women (P trend ≥0.39). We conclude that height loss is positively associated with OPG in men and in postmenopausal women not using HRT. No relationship was found between RANKL and height loss.     

Tracking of cardiovascular risk factors: the Tromsø study, 1979-1995

Tracking of cardiovascular risk factors (blood pressure, body mass index (BMI), and serum lipids) has not been studied much in a general, adult population. No known study has compared tracking of these factors for both sexes. In the present study, 17,710 men and women aged 20-61 years at baseline attended two or three population-based health surveys in Troms?, Norway, over 16 years (between 1979-1980 and 1994-1995). Tracking coefficients were estimated by using different methods, and possible predictors of tracking were found. There was a high degree of tracking for BMI (overall tracking coefficients: 0.85 for men, 0.80 for women). Relatively high (or moderate) tracking was found for systolic blood pressure (respective sex-specific coefficients: 0.52, 0.54), diastolic blood pressure (0.48, 0.48), high density lipoprotein cholesterol (0.55, 0.64), and total cholesterol (0.77, 0.65). The lowest coefficients were for triglycerides (0.43, 0.39). Analysis of tracking in the upper sextile confirmed these results. Although some baseline predictors were associated with tracking, the effects were relatively weak. When predictors for tracking in the upper sextile were assessed, significant associations were found with relatively strong effects. No major sex differences were observed in tracking. However, women were more likely than men to remain in the upper sextile of systolic and diastolic blood pressures and of BMI.     

Mental disorder and caregiver burden in spouses: the Nord-Trøndelag health study

Background  

Researchers generally agree that mental disorder represents a burden to the family. The present study concerns the subjective burden of living with a person with mental disorder, more specifically the association between mental disorder in the index person and subjective well-being and symptoms of anxiety and depression in the spouse.     

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 ≥ 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.     

Body mass index and disease burden in elderly men and women: The Tromsø Study

Chronic health problems may be related to body mass index (BMI, kg/m²), but this has been best documented in overweight and obese adults. The primary objective of this study was to identify factors associated with different categories of BMI in elderly men and women from the general population, also including the lower categories of BMI. In a cross-sectional population survey from the municipality of Tromsø, Norway we analyzed associations between BMI and a wide range of chronic disease conditions, lifestyle and socioeconomic factors. BMI was categorized into six groups (<20, 20.0–22.4, 22.5–24.9, 25.0–27.4, 27.5–29.9, ≥30.0 kg/m²). The study included 4,259 men and women aged 65 years and older from the general population. We found low relative weight (BMI < 20 kg/m²) to be associated with increasing prevalence of mental distress, hip fracture, smoking and low handgrip strength. A U-shaped relation to BMI was found for asthma and chronic bronchitis, poor current health and low physical activity. The higher categories of BMI were associated with low education level, a difficult economical situation, diabetes mellitus and ischemic heart disease. These results demonstrate that both low and high BMI are associated with a wide range of prevalent conditions and diseases in elderly men and women. For the clinician the findings emphasize the importance of nutritional assessment as part of the medical evaluation of elderly patients.     

Association of low blood pressure with anxiety and depression: the Nord-Trøndelag Health Study

Background

Low blood pressure has mainly been regarded as ideal, but recent studies have indicated an association with depression in elderly people.

Objective

To investigate whether low blood pressure is associated with anxiety and depression in the general population.

Design

Cross‐sectional study.

Setting

Participants in the population‐based Nord‐Trøndelag Health Study (HUNT‐2, 1995–7), Norway.

Participants

60 799 men and women aged 20–89 years filled in the Hospital Anxiety and Depression Scale as part of a general health study. Systolic and diastolic blood pressure was classified in age‐stratified and sex‐stratified centile groups.

Main results

Compared with participants with systolic blood pressure within the 41–60 centile (reference) group, the odds ratio for anxiety was 1.31 (95% confidence intervals (CI) 1.16 to 1.49), for depression 1.22 (95% CI 1.03 to 1.46), and for comorbid anxiety and depression 1.44 (95% CI 1.24 to 1.68) in the group with ⩽5 centile systolic blood pressure. Slightly weaker associations were found of low diastolic blood pressure with anxiety and depression. These associations were similar across sex and age groups. Physical impairment, smoking and angina pectoris influenced the associations only marginally, whereas stroke, myocardial infarction, use of drugs for hypertension, body mass index and several other covariates had no influence.

Conclusions

This study represents epidemiological evidence for an association of low blood pressure with anxiety and depression, which is not caused by cardiovascular disease.The global burden of hypertension as a leading risk factor for cardiovascular and kidney disease, and for mortality,¹ has overshadowed possible health problems associated with chronic low blood pressure. Through decades, medicine has viewed hypotension as an ideal blood pressure level,² and as an example of a non‐disease.³ Earlier, however, low blood pressure was associated with neurasthenic symptoms such as tiredness, weakness, dizziness and headache,⁴ and with sleep disturbances, anxiety and depression.⁵ Although chronic low blood pressure can still be used in some continental European countries to explain a variety of constitutional symptoms, the prevailing attitude in English‐speaking countries has been that low blood pressure does not produce symptoms.^5,6Psychosomatic research on blood pressure has mainly focused on hypertension.^7,8,9 Several studies have indicated an association between hypertension and psychological factors. However, the psychometric properties of the scales used have often been less well established,⁹ and most previous studies have not explored the lower range of blood pressure. By contrast, some studies have indicated that low blood pressure is associated with various somatic and psychological symptoms.^5,10,11,12 Four of six geriatric studies, using standardised screening inventories for depression, found an association between low blood pressure and depression,^6,13,14,15 one study found no association,¹⁶ whereas a recent study found an association between hypertension and depression.¹⁷ However, the design and findings in some of the studies have been contested.¹⁸ In the absence of a commonly accepted definition of low blood pressure, various boundaries have been used. Four geriatric studies defined blood pressure <120/75 mm Hg as hypotensive, 120–139/75–84 mm Hg as normal and ⩾140/85 mm Hg as hypertensive.^6,13,15,16As most previous studies have limitations, and as their results are inconsistent, we wanted to examine the association of blood pressure with anxiety and depression in the general population using a standardised screening inventory. Our large sample size and broad age range gave an opportunity to explore both tails of the blood pressure distribution, and to control for body weight, cigarette smoking, cardiovascular disease and other relevant covariates.     

Myocardial infarction and future risk of cancer in the general population—the Tromsø Study

The association between myocardial infarction (MI) and future risk of incident cancer is scarcely investigated. Therefore, we aimed to study the risk of cancer after a first time MI in a large cohort recruited from a general population. Participants in a large population-based study without a previous history of MI or cancer (n = 28,763) were included and followed from baseline to date of cancer, death, migration or study end. Crude incidence rates (IRs) and hazard ratios (HRs) for cancer after MI were calculated. During a median follow-up of 15.7 years, 1747 subjects developed incident MI, and of these, 146 suffered from a subsequent cancer. In the multivariable-adjusted model (adjusted for age, sex, BMI, systolic blood pressure, diabetes mellitus, HDL cholesterol, smoking, physical activity and education level), MI patients had 46% (HR 1.46; 95% CI: 1.21–1.77) higher hazard ratio of cancer compared to those without MI. The increased cancer incidence was highest during the first 6 months after the MI, with a 2.2-fold higher HR (2.15; 95% CI: 1.29–3.58) compared with subjects without MI. After a 2-year period without higher incidence rate, MI patients displayed 60% (HR 1.60; 95% CI: 1.27–2.03) higher HR of future cancer more than 3 years after the event. The increased IRs were higher in women than men. Patients with MI had a higher short- and long-term incidence rate of cancer compared to subjects without MI. Our findings suggest that occult cancer and shared risk factors of MI and cancer may partly explain the association.     

Population-based study of age at menopause and ultrasound assessed carotid atherosclerosis: The Tromsø Study

Early menopause has been associated with higher prevalence and incidence of cardiovascular disease and death than late menopause, indicating that early loss of ovarian function and subsequent deficiency of estrogen may promote such diseases. No population-based studies have, however, examined the relation between age at menopause and atherosclerosis. We assessed the prevalence and the extent of carotid atherosclerosis by high-resolution B-mode ultrasound in 2588 postmenopausal women who participated in a population health survey. Information about age at menopause and menarche, parity, use of hormone replacement therapy, and prevalent diseases was collected, and cardiovascular risk factor levels were measured. Women with late menopause and women who ever had used postmenopausal estrogens had significantly less atherosclerosis than women with early menopause and those with never use of estrogen. This study provides further support for the hypothesis that estrogen protects women against cardiovascular disease.     

Correlates of forearm bone mineral density in young Norwegian women: the Nord-Trøndelag Health Study

Maximizing attainment of optimal peak bone mineral density (BMD) is a potential osteoporosis prevention strategy. The main objective of this study was to identify correlates of forearm BMD in young adult women. Population-based data derived from standardized questionnaires administered to healthy women aged 19-35 years in Nord-Tr?ndelag, Norway (n = 963), were collected in 1995-1997. Forearm BMD was assessed by single x-ray absorptiometry. Multiple linear and logistic regression analyses were used to determine correlates of BMD (g/cm(2)) and lowest quintile of BMD, respectively, at the ultradistal and distal sites. The mean age and weight of the cohort were 29.7 years (standard deviation 4.7) and 68.6 kg (standard deviation 12.5), respectively. Age and weight were positively associated with BMD at both forearm sites. When data were controlled for age and weight, later age at menarche and lack of milk consumption were associated with lower BMD values. In both linear models and logistic models, none of the factors vitamin D intake, physical activity, smoking, alcohol consumption, amenorrhea, oral contraceptive use, number of pregnancies, history of breastfeeding, and family history of osteoporosis were found to be significantly associated with BMD. Prior studies have suggested that calcium supplementation in children is useful for optimizing peak BMD. Further studies exploring the relation between lifestyle factors and BMD are warranted to search for ways to maximize attainment of peak BMD.     

Reliability and validity of self-reported physical activity in the Nord-Trøndelag Health Study: HUNT 1

BACKGROUND: A large health survey was previously conducted in 1984-86, the Nord-Tr?ndelag Health Study (HUNT 1), and another was conducted in 1995-97 (HUNT 2). A third, HUNT 3, started in 2006. However, the physical activity (PA) questionnaires have not yet been validated. AIMS: To assess the reliability and validity of the self-reported physical activity questionnaire in the Nord-Tr?ndelag Health Study (HUNT 1). METHODS: The HUNT 1 questionnaire was administered to a random sample of 108 healthy men aged 20-39 years. Repeatability was assessed with a repeat questionnaire after one week, and validity by comparing results with direct measurement of VO(2) during maximal work on a treadmill, with ActiReg, an instrument that measures PA and energy expenditure (EE) and with the International Physical Activity Questionnaire (IPAQ). ActiReg records the main body positions (stand, sit, bent forward and lie) together with the motion of the trunk and/or one leg each second. RESULTS: The results indicated strong, significant agreement on test-retest (weighted kappa frequency, r=0.80, intensity, r=0.82, and duration, r=0.69). We found a moderate, significant correlation, r=0.48 (p< or =0.01), between the index based on questionnaire responses and VO(2max.) Metabolic equivalent (MET) values of 6 or more from ActiReg and "vigorous activity' from the IPAQ most strongly correlated with the index (r=0.39, r=0.55, respectively). Associations of other measures obtained from ActiReg with questionnaire responses were weaker. CONCLUSIONS: Our results indicate that the PA questionnaire in HUNT 1 is reproducible and provides a useful measure of leisure-time PA for men. The questionnaire is very short, and compared favourably with much longer instruments for assessment of more vigorous PA. It should be an appropriate tool for use in further epidemiological studies, particularly when the interest is in aspects of PA reflected in fitness or METs greater than 6.     

Body mass index and coronary heart disease risk score: the Tromsø study, 1979 to 2001

PURPOSE: The purpose of the study is to examine the association between longitudinal change in body mass index (BMI) and change in coronary heart disease (CHD) risk score by using the Framingham risk score equation. METHODS: A general adult population in the municipality of Troms?, Norway, was invited to four consecutive examinations in 1979 to 1980, 1986 to 1987, 1994 to 1995, and 2001. A total of 10,214 men and women aged 20 to 61 years at baseline attended at least three times. Associations were examined by using fixed-effects regression methods for longitudinal data. RESULTS: We observed a significant association between BMI change and risk score change in all baseline age groups. The association was significantly strengthened by age in women, but not men. A BMI increase of 3 kg/m(2) in subjects aged 40 to 49 years was associated with risk score increases of 0.45 points (95% confidence interval [CI], 0.29-0.62) in men and 0.66 points (95% CI, 0.52-0.80) in women. CONCLUSIONS: The well-known increase in body weight is associated with adverse CHD risk in both men and women.     

Prevalence of and risk factors for abdominal aortic aneurysms in a population-based study : The Tromsø Study

In a population-based study of 6,386 men and women aged 25--84 years in Troms?, Norway, in 1994--1995, the authors assessed the age- and sex-specific distribution of the abdominal aortic diameter and the prevalence of and risk factors for abdominal aortic aneurysm. Renal and infrarenal aortic diameters were measured with ultrasound. The mean infrarenal aortic diameter increased with age. The increase was more pronounced in men than in women. The age-related increase in the median diameter was less than that in the mean diameter. An aneurysm was present in 263 (8.9%) men and 74 (2.2%) women (p < 0.001). The prevalence of abdominal aortic aneurysm increased with age. No person aged less than 48 years was found with an abdominal aortic aneurysm. Persons who had smoked for more than 40 years had an odds ratio of 8.0 for abdominal aortic aneurysm (95% confidence interval: 5.0, 12.6) compared with never smokers. Low serum high density lipoprotein cholesterol was associated with an increased risk for abdominal aortic aneurysm. Other factors associated with abdominal aortic aneurysm were a high level of plasma fibrinogen and a low blood platelet count. Antihypertensive medication (ever use) was significantly associated with abdominal aortic aneurysm, but high systolic blood pressure was a risk factor in women only. This study indicates that risk factors for atherosclerosis are also associated with increased risk for abdominal aortic aneurysm.     

History of and factors associated with diabetic foot ulcers in Norway: the Nord-Trøndelag Health Study

AIMS: To determine the proportion of people with diabetes mellitus reporting a history of foot ulcer and to investigate factors associated with this adverse outcome. METHODS: All inhabitants aged 20 years and older residing in a large geographic region were invited to participate in the Nord-Tr?ndelag Health Study, 71% (n=65,604) attended. Those reporting diabetes (n=1,972) were invited to take part in an ancillary study on diabetes. Based on 1,494 responses to the question: "Have you had a foot ulcer that required more than three weeks to heal', the proportion with a history of foot ulcer was estimated. RESULTS: The overall proportion with a history of foot ulcer was 10.4% (95% CI 8.8-11.9%). In the final multivariate logistic regression model, significant factors for a foot ulcer history included age > or =75 years (OR 1.8, 95% CI 1.2-2.8), height (men>175 cm, women>161 cm) (1.9, 95% CI 1.3-2.8), gender (male) (1.5, 95% CI 1.03-2.2), using insulin (1.6, 95% CI 1.1-2.4), and macrovascular complications (1.8, 95% CI 1.2-2.6). CONCLUSIONS: The proportion of people reporting a history of foot ulcer in this population-based study exceeded the proportion of foot ulcer history reported previously. Height as a correlate has been occasionally reported in previous studies and needs further attention. Associated factors for a foot ulcer history help identify individuals who may be at particular risk of this adverse outcome.