Grip strength in men and women aged 50-79 years is associated with non-vertebral osteoporotic fracture during 15 years follow-up: The Tromsø Study 1994-1995

In 50-79-year-olds who participated in the Tromsø Study (1994-1995), the risk of non-vertebral osteoporotic fractures during 15 years follow-up increased by 22% in men and 9% in women per 1 SD lower grip strength. The strongest association was observed in men aged 50-64 years.

INTRODUCTION

We aimed to explore whether low grip strength was associated with increased risk of non-vertebral osteoporotic fracture in the population-based Tromsø Study 1994-1995.

METHODS

Grip strength (bar) was measured by a Martin Vigorimeter and fractures were retrieved from the X-ray archives at the University Hospital of North Norway between 1994 and 2010. At baseline, weight and height were measured, whereas information on the other covariates were obtained through self-reported questionnaires. Cox regression was used to estimate the hazard ratio (HR) of fracture in age- and gender-specific quintiles of grip-strength, and per 1 SD lower grip strength. Similar analyses were done solely for hip fractures. Adjustments were made for age, height, body mass index (BMI), marital status, education, smoking, physical activity, use of alcohol, self-perceived health, and self-reported diseases.

RESULTS

In 2891 men and 4002 women aged 50-79 years, 1099 non-vertebral osteoporotic fractures-including 393 hip fractures-were sustained during the median 15 years follow-up. Risk of non-vertebral osteoporotic fracture increased with declining grip strength: hazard ratios per SD decline was 1.22 (95% CI 1.05-1.43) in men and 1.09 (95% CI 1.01-1.18) in women. HR for fracture in lower vs. upper quintile was 1.58 (95% CI 1.02-2.45) in men and 1.28 (95% CI 1.03-1.59) in women. The association was most pronounced in men aged 50-64 years with HR = 3.39 (95% CI 1.76-6.53) in the lower compared to the upper quintile.

CONCLUSIONS

The risk of non-vertebral osteoporotic fracture increased with declining grip-strength in both genders, particularly in men aged 50-64 years.

Excess mortality following hip fracture: impact of self-perceived health, smoking, and body mass index. A NOREPOS study

Self-perceived health, smoking, and body mass index measured years before the hip fracture predicted excess post-hip fracture mortality, and even hip fracture patients with the most favorable levels of these risk factors had higher mortality than subjects who did not fracture.

INTRODUCTION

This study aimed to investigate the impact of pre-fracture self-perceived health, smoking, and body mass index (BMI) on excess post-hip fracture mortality using matched peers without hip fracture as reference.

METHODS

The study was based on the Cohort of Norway (CONOR) consisting of 10 regional health studies (1994-2003) and the NOREPOS hip fracture database (1994-2008). A matched cohort design was used to compare survival between hip fracture patients and subjects without fracture (matched on gender, age at participation in CONOR, and study site). Subjects aged ≥60 years were included. Hazard ratios were estimated using stratified Cox regression. Age-standardized mortality was also calculated.

RESULTS

Overall, hip fracture patients (N = 3177) had a 2.26-fold (95 % CI 2.13, 2.40) increased mortality compared to matched subjects (N = 20,282). The highest excess mortality was found in hip fracture patients reporting poor health (HR 4.08, 95 % CI 3.17, 5.26) and daily smoking (HR 3.25, 95 % CI 2.89, 3.66) and in patients with BMI <18.5 (HR 3.07, 95 % CI 2.11, 4.47) prior to the fracture. However, excess mortality was also observed in hip fracture patients in all other categories of BMI, self-perceived health, and smoking.

CONCLUSIONS

Information on self-perceived health, smoking, and BMI collected years before hip fracture predicted excess post-hip fracture mortality, and even hip fracture patients with the most favorable levels of these risk factors had higher mortality than the matched subjects who did not fracture. This suggests that both pre-fracture health status and factors related to the hip fracture itself might affect post-hip fracture mortality.

Forecasting the burden of future postmenopausal hip fractures

SUMMARY

A growing elderly population is expected worldwide, and the rate of hip fractures is decisive for the future fracture burden. Significant declines in hip fracture rates in Norway, the USA, France, Germany, and the UK are required to counteract the impact of the ageing effects.

INTRODUCTION

This study aims to evaluate the consequences of the expected growth of the elderly population worldwide on the hip fracture burden using Norway as an example. Furthermore, we wanted to estimate the decline in hip fracture rates required to counteract the anticipated increase in the burden of hip fracture for Norway, the USA, France, Germany, and the UK.

METHODS

The burden of future postmenopausal hip fractures in Norway were estimated given (1) constant age-specific rates, (2) continued decline, and (3) different cohort scenarios. Based on population projection estimates and population age-specific hip fracture rates in women 65 years and older, we calculated the required declines in hip fracture rates needed to counteract the growing elderly populations in Norway, the USA, France, Germany, and the UK.

RESULTS

The level of age-specific hip fracture rates had a huge impact on the future hip fracture burden in Norway. Even if the hip fracture rates decline at the same speed, a 22 % increase in the burden of hip fractures can be expected by 2040. An annual decline in hip fracture rates of 1.1-2.2 % until 2040 is required to counteract the effects of the growing elderly population on the future burden of hip fractures in Norway, the USA, France, Germany, and the UK.

CONCLUSIONS

Hip fracture rates have a great impact on the burden of hip fractures. The rates will have to decline significantly to counteract the impact of a growing elderly population. A change in preventive strategies and further studies are warranted to identify the complex causes associated to hip fractures.

Does using lower limit of normal values enhance the ability of a single bone mineral density measure to predict fractures?

Using a single bone mineral density (BMD) measure, we demonstrated that the lower limit of normal (LLN) method is more consistent in predicting osteoporosis fractures than the T-score in white menopausal women from the Study of Osteoporosis Fracture (SOF).

INTRODUCTION

In order to circumvent the inconsistencies and limitations with using the T-score when defining osteoporosis, we propose using 95% LLN values derived from centered polynomial models using the NHANES III BMD measures. The main aim of this study was to compare the two methods in prediction of fracture and agreement in osteoporosis classification using cohort data.

METHODS

We compared the fracture prediction ability of the two methods using a single BMD measurement in 4,948 white women aged 67-74 years in the SOF employing kappa statistics, sensitivity, and specificity.

RESULTS

The T-score provided inconsistent osteoporosis classification (46.6%) across the five hip regions of interest (ROIs) and this was significantly (p<0.0001) reduced when using the LLN method (36.5%). Kappa statistics of incident fracture during 12 years of follow-up related to the prevalence of osteoporosis at baseline was significantly improved using the LLN method compared to using T-score. Sensitivity and specificity for fracture based on a single BMD measurement of different hip ROIs were more consistent using the LLN method.

CONCLUSION

The LLN method provides a more consistent and efficient method for osteoporosis fracture prediction than the T-score in 67- to 74-year-old white women.

Urinary cadmium, osteopenia, and osteoporosis in the US population

SUMMARY

The association between cadmium and osteoporosis in a multiethnic population is unclear. We found that urinary cadmium is consistently associated with osteopenia and osteoporosis in the Third National Health and Nutrition Examination Survey, regardless of age, sex, race, and smoking status. Cadmium exposure may be an independent risk factor for osteoporosis.

INTRODUCTION

Our purpose was to test whether cadmium exposure is associated with a higher prevalence of osteopenia and osteoporosis in the general US population and selected subgroups.

METHODS

We used multinomial logistic regression to analyze data on 10,978 subjects (aged 30-90) from the Third National Health and Nutrition Examination Survey. We studied the association of urinary cadmium levels (adjusted for urinary creatinine) and the prevalence of osteopenia and osteoporosis as defined by the World Health Organization.

RESULTS

After adjustment for age, sex, ethnicity, body mass index, calcium intake, and physical inactivity, odds ratios (ORs) for osteopenia and osteoporosis increased dose dependently with two urinary cadmium levels (in micrograms of urinary cadmium per grams of urinary creatinine: level I, 1.00-1.99 mcg/g; level II, > or =2.00 mcg/g). Osteopenia results were as follows: level I OR, 1.49 (95% confidence interval [CI], 1.24-1.80); level II OR, 2.05 (95% CI, 1.52-2.78). Osteoporosis results were as follows: level I OR, 1.78 (95% CI, 1.26-2.52); level II OR, 3.80 (95% CI, 2.36-6.14). The association was consistent in all age, sex, race, and smoking status subgroups.

CONCLUSIONS

Cadmium exposure may be a potential risk factor for osteopenia and osteoporosis in the general US population.

Depression and low bone mineral density: a meta-analysis of epidemiologic studies

SUMMARY

The association between depression and loss of bone mineral density (BMD) has been reported inconsistently. This meta-analysis, which pooled results from 14 qualifying individual studies, found that depression was associated with a significantly decreased BMD, with a substantially greater BMD decrease in depressed women and in cases of clinical depression.

INTRODUCTION

The reported association between depression and loss of BMD has been controversial. This meta-analysis was conducted to determine whether depression and BMD are associated and to identify the variation in some subgroups.

METHODS

English-language articles published before October 2008 were used as the data source. A total of six case-controlled and eight cross-sectional studies met prestated inclusion criteria (N = 10,523). Information on study design, participant characteristics, measurements of BMD and depression, and control for potential confounders was abstracted independently by two investigators using a standardized protocol.

RESULTS

Overall, depression was associated with a significant decrease in mean BMD of spine (-0.053 g/cm(2) [95% confidence interval {CI} -0.087 to -0.018 g/cm(2)]) and hip (-0.052 g/cm(2) [95% CI -0.083 to -0.022 g/cm(2)]). A substantially greater BMD decrease was observed in depressed women (-0.076 g/cm(2) in spine; -0.059 g/cm(2) in hip) and in cases of clinical depression (-0.074 g/cm(2) in spine; -0.080 g/cm(2) in hip).

CONCLUSION

Depression is associated with low BMD, with a substantially greater BMD decrease in depressed women and in cases of clinical depression. Depression should be considered as an important risk factor for osteoporosis.

Long-term mental distress, bone mineral density and non-vertebral fractures. The Tromsø Study

The purpose of this study was to examine, prospectively, the risk of non-vertebral fractures and low bone mineral density in a population-based cohort with respect to indicators of subjective mental distress. In 1979-1980 all males born 1925-1959 and all females born 1930-1959 living in Tromsø were invited (21,441; response rate, 78%). The same individuals were invited to the subsequent studies in 1986-1987 and 1994-1995 (74% attended the first two, and 71% attended all three surveys). Non-vertebral fractures were registered by linkage to the hospital X-ray register for the period 1988-1995, and forearm bone mineral density (BMD) was available in a subsample of 4,690 who had attended three times. Questions about mental distress (depression, insomnia and coping problems) were repeated three times and analyzed as cumulated exposure. Women who reported being depressed at two time points had an adjusted odds ratio (OR) =2.5 (95% confidence interval [CI] 1.3-4.9) for sustaining a non-vertebral fracture and OR=3.1 (95% CI 1.3-7.2) for sustaining an osteoporotic fracture, compared with those without depression on any occasion. The corresponding odds ratios for those with coping problems at two time points were slightly higher, whereas sleeping problems seem only to be weakly associated with non-vertebral fractures. The pattern of associations and the magnitude of OR estimates were mainly the same in women younger than 50 years and those 50 years and older. Women using nerve medicine and reporting depression twice had an odds ratio of 4.4 (95% CI 1.1-17.7) for sustaining a non-vertebral fracture, and those using nerve medicine and reporting coping problems twice had a corresponding OR 4.7 (95% CI 1.2-18.4). Among men no significant associations were found for either fracture type. No association was found between mean BMD and number of times reporting depression, insomnia or coping problems, in women or men. Long-term mental distress is associated with risk of all non-vertebral fractures and osteoporotic fractures in middle-aged women, but not in men. Mental distress itself seems to be more important than the use of nerve medicine.

The Tromsø study: registration of fractures, how good are self-reports, a computerized radiographic register and a discharge register?

In order to compare different methods of fracture registration, we sought all nonvertebral fractures suffered during 8 years (1988-95) among 21,441 persons invited to a survey in 1979/80. We registered a total of 54 hip fracture cases through three separate sources (self-report, computer linkage to the local radiographic archives, discharge register), whereas forearm fractures (a total of 291 cases) were registered through two separate sources (self-report, computer linkage to the radiographic archives). The registration of fractures at other sites (a total of 1321 cases) were from one source (computer linkage to the local radiographic archives), and we have compared three ways of obtaining data from this single source (no ascertainment, ascertainment of records coded as fracture, ascertainment of all records). Ninety-three percent of all hip fractures and 97% of all wrist fractures in the entire study population were found by computer linkage to the radiographic archives, whereas the discharge register detected 87% of all the hip fractures. Computer linkage with ascertainment gave no overreporting of fractures. Among the 11,626 persons who answered a follow-up questionnaire in 1994/95, 97% (CI 84-100%) of all hip fractures and 72% (CI 66-78%) of all wrist fractures were self-reported. We conclude that a computerized search of radiographic archives is a viable method of fracture registration.

Academic models of clinical care for women: the National Centers of Excellence in Women's Health

Between 1996 and 1999, 18 academic health centers were awarded the designation of National Center of Excellence (CoE) in Women's Health by the Office on Women's Health within the Department of Health and Human Services and were provided with seed monies to develop model clinical services for women. Although the model has evolved in various forms, core characteristics that each nationally designated CoE has adopted include comprehensive, women-friendly, women-focused, women-relevant, integrated, multidisciplinary care. The permanent success of these comprehensive clinical programs resides in the ability to garner support of leaders of the academic health centers who understand both the importance of multidisciplinary programs to the clinical care they provide women and the education they offer to the future providers of women's healthcare.

Forearm bone mineral density by age in 7,620 men and women: the Tromsø study, a population-based study

Population-based studies of adult forearm bone mineral density (BMD) by age are scarce, and standardized reference values are lacking. In this cross-sectional study, men aged 55-74 years, women aged 50-74 years, and representative 5-10% samples of remaining age groups between 25 and 84 years living in Tromsø, Norway, were invited for forearm BMD measurement in 1994-1995. The authors measured 3,062 men and 4,558 women (response rate, 78%) by single x-ray absoptiometry at distal and ultradistal forearm sites. Up to age 50, the mean BMD difference was -0.1% per 1-year age group in both sexes. After age 50, the mean BMD difference per 1-year age group was -0.6% in men and -1.3% (distal) and -1.5% (ultradistal) in women. The BMD by age curve was linear for men throughout senescence, but women had a slope change to -0.7% (distal) and -0.8% (ultradistal) per 1-year age group from the 65- to 69-year age group. BMD levels and BMD by age association in the general population (n = 7,620) and in the population without bone-threatening diseases or medication (n = 5,179) were similar. Only longitudinal studies can clarify whether cohort effects or longitudinal BMD development patterns explain these cross-sectional results.

The Tromsø Study: a population-based study on the variation in bone formation markers with age, gender, anthropometry and season in both men and women

Background information on how biological factors influence the level of bone turnover markers is crucial in order to make proper use of these measurements. In the present study, which is part of the fourth survey of a general population in Tromsø, Norway, we evaluated the variation in the bone formation markers bone alkaline phosphatase (S-BAP) and osteocalcin (S-OC) in 528 men and 605 women, age 25-74 years. In the Tromsø Study in 1994/5, the whole population above 25 years was initially invited and 7948 individuals attended an extended examination (76.4% of the invited population). The present study population is a random sample of these attendees. The variation with age, gender, height, weight, body mass index and season, and with menopausal status in women, was examined. In men there was a decrease in S-OC up to the age of 56 years with little further change, while S-BAP showed no change with age. Among women, variation in bone markers was mainly observed to change with menopause, with a 41% and 21% increase in the mean level of S-BAP and S-OC, respectively. There was a negative trend in S-OC with body mass index in both men and women. A seasonal change of 20% in the level of both bone markers in men and of S-BAP in postmenopausal women was observed in this region at a far northern latitude. We conclude that, of the factors examined, season and menopausal status must be taken into account when measuring these bone formation markers.

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 Tromsø 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.

Hormone replacement therapy: knowledge, attitudes, self-reported use - and sales figures in Nordic women

OBJECTIVES

To evaluate knowledge about, attitudes towards and use of hormone replacement therapy (HRT) in Norwegian women - and to compare self-reported use with sales statistics of HRT in the Nordic countries during recent years.

MATERIAL AND METHODS

Random samples of Norwegian women age 16-79 were interviewed by the Central Bureau of Statistics in 1994 (n=737), in 1996 (n=665) and in 1998 (n=680). Statistics on the sale of estrogen were provided by the Norwegian Medical Depot and Nordic Council on Medicines.

RESULTS

One in three women had received information about HRT during the last 2 years (1994), mainly through weekly magazines and physicians. The proportion answering in accordance with the prevailing view of HRT's effects ('correct knowledge') varied from 36.4 to 47.2%. Those informed by a physician possessed correct knowledge, had positive attitudes towards HRT and were willing to use HRT more often than women informed through other channels. Women with a high level of education had received information and had correct knowledge more often than others, but they were still less willing to use HRT and did not use HRT more often than the less educated. In the age group 45-69 years the use of HRT was 16.3% in 1994, 19.1% in 1996 and 19. 1% in 1998 (P=0.421, trend). In addition to received information, attitudes towards and knowledge about estrogen were the most important factors predicting use of HRT after adjusting for other variables. According to sales figures, the use of systemic estrogen in Norway has increased more than 360% since 1990. Although no other Nordic country has experienced a corresponding increase, Iceland had the highest sales figures in 1997.

CONCLUSIONS

Based on the limited proportion of women receiving information on HRT and the ambivalence found in groups of educated women, we suggest that more and better information should be given middle-aged women to make them better able to make informed choices regarding use of HRT.

Walking after stroke: does it matter? Changes in bone mineral density within the first 12 months after stroke. A longitudinal study

Stroke patients have increased risk of hip fractures. Nearly all fractures occur on the hemiplegic side, and reduced bone mineral density (BMD) may be an important predisposing factor. The aim of this study was to investigate the degree of demineralization within the first year after stroke, and to elucidate a possible difference in patients with high versus low ambulatory levels. Forty acute stroke patients were followed (17 initially wheelchair-bound and 23 initially ambulatory). BMD was measured in the proximal femur bilaterally at a mean 6 days, 7 months and 1 year after stroke onset using dual-energy X-ray absorptiometry. Ambulatory status was independently associated with changes in BMD (p < or = 0.005) 1 year after stroke. The 17 initially wheelchair-bound patients had a significant 10% reduction in BMD at the paretic side and 5% reduction at the non-paretic side (p < 0.001), while the 23 patients initially able to walk had a significant loss (3%) only at the paretic side (p = 0.01). The analysis also indicated that the major reduction in BMD took place within the first 7 months. Two months after stroke 12 of the wheelchair-bound patients had relearned to walk. At the paretic side the 1 year changes in BMD in the patients who stayed wheelchair-bound, the patients who re-learned to walk within the first 2 months and the patients who were able to walk throughout the study were 13%, 8% and 3%, respectively, and a statistically significant trend with ambulatory level was found (p = 0.007). This study provides clear evidence that lack of mobility and weight-bearing early after stroke is an important factor for the greater bone loss in the paretic leg, but that relearning to walk within the first 2 months after stroke, even with the support of another person, may reduce the bone loss after immobilization.

The Tromsø Study: artifacts in forearm bone densitometry--prevalence and effect

Suboptimal performance of bone densitometer, operator and/or subject may cause artifacts of consequence both for individual patient management and research. The prevalence and effects of such artifacts are largely unknown in densitometry. A cross-sectional population-based study was carried out of artifacts in forearm bone densitometry with single X-ray Absorptiometry (SXA) of the nondominant hand (distal and ultradistal site). After the screening, all scans were reviewed for artifact detection and reanalysis. The effect on the bone mineral density (BMD) result was found by comparing artifactual scans with a reanalyzed version or with normal repeat scans. All women aged 50-74 years, all men aged 55-74 years and 5-10% samples of other age groups aged >/=25 years attending the fourth Tromso health study were invited to have bone densitometry. The response rate from the background population was 80% (n = 7948). Fourteen percent of subjects had a movement artifact at either the distal or ultradistal site. The individual BMD variation was twice as large in scans with a movement artifact (0.94%) compared with normal scans (0.58%) (p = 0.0027). The radial endplate was inaccurately detected in 74% of the scans. Reanalysis of these scans led to a mean 3.8% decrease in the BMD value and an increase in the prevalence of osteoporosis of 10%. Artifacts were thus common, and their effects were clinically relevant in forearm bone densitometry. Artifacts and their effects need to be characterized in other bone densitometry settings also.

The Tromsø Study: physical activity and the incidence of fractures in a middle-aged population

We have studied the relation of occupational and recreational physical activity to fractures at different locations. All men born between 1925 and 1959 and all women born between 1930 and 1959 in the city of Tromsø were invited to participate in surveys in 1979-1980 and 1986-1987 (The Tromsø Study). Of 16,676 invited persons, 12,270 (73.6%) attended both surveys. All nonvertebral fractures (n = 1435) sustained from 1988 to 1995 were registered in the only hospital in the area. Average age in the middle of the follow-up period (December 31, 1991) was 47.3 years among men and 4501 years among women, ranging from 32 to 66 years. Fracture incidence increased with age at all locations among women, but it decreased with or was independent of age among men. Low-energetic fractures constituted 74.4% of all fractures among women and 55.2% among men. When stratifying by fracture location, the most physically active persons among those 45 years or older suffered fewer fractures in the weight-bearing skeleton (relative risk [RR] 0.6, confidence interval [CI] 0.4-0.9, age-adjusted), but not in the non-weight-bearing skeleton (RR 1.0, CI 0.7-1.2, age-adjusted) compared with sedentary persons. The relative-risk of a low-energetic fracture in the weight-bearing skeleton among the most physically active middle-aged was 0.3 (CI 0.1-0.7) among men and 0.9 (CI 0.4-1.8) among women compared with the sedentary when adjusted for age, body mass index, body height, tobacco smoking, and alcohol and milk consumption. It seems that the beneficial effect on the skeleton of weight-bearing activity is reflected also in the incidence of fractures at different sites.

[Can biochemical markers for bone density be recommended as diagnostic and prognostic tools in osteoporosis?]

Biochemical markers of bone metabolism have potential clinical value in osteoporosis, rheumatic diseases, metabolic bone diseases, and skeletal metastasis. The markers are measured in serum or urine and reflect bone synthesis or bone resorption. Knowledge of the markers' analytical and biological variation, sensitivity, and specificity is necessary to make use of these measurements. This article gives a review of the new bone markers available today: osteocalcin, bone alkaline phosphatase, procollagen peptides, pyridinolines, and telopeptides. Bone markers are clearly useful in research and in epidemiological studies, but routine clinical use is still controversial. We discuss the consequences of making use of bone markers in the diagnostics of osteoporosis, as a prognostic factor of bone loss or fractures, or to monitor therapy. We conclude that we still lack sufficient knowledge to justify use in clinical practice.

[Normal bone remodelling--what can go wrong in osteoporosis?]

The skeleton is a metabolically active organ in constant change and renewal. Specialised cells are responsible for resorbing and synthetizing bone matrix. The process of bone remodelling, by removing old and damaged bone tissue and replacing it with new, is necessary for conserving the integrity of bone. In recent years, research has given new insight into the fine relationship between different cell types in bone tissue. This has enhanced our understanding of the pathophysiology behind osteoporosis and other metabolical bone diseases. This article gives a summary of our present knowledge of the normal cell biology of bone and what contributes to its regulation. How this helps the understanding of normal and pathological bone loss is illustrated. It is important to understand bone remodelling in order to interpret measurements of bone mineral density and biochemical markers accurately.

[Estrogen replacement]

Recent research on long-term postmenopausal hormone replacement therapy (HRT) indicates a positive effect on both total mortality and morbidity. This has raised the question of widespread preventive long-term use of HRT. Possible side-effects and ideological issues related to preventive HRT have led to debate and uncertainty among health professionals, in the media, and in the population at large. In order to evaluate the level of knowledge about and attitudes towards HRT, a randomly selected group of 737 Norwegian women aged 16-79 was interviewed by the Central Bureau of Statistics. One in three women had received information about HRT in the last two years, mainly through weekly magazines and physicians. The proportion who answered the questions on knowledge correctly varied from 36% to 47%. Those who had been given information by a physician possessed accurate knowledge, had more positive attitudes towards HRT and were more willing to use HRT than women who had reviewed information through other channels. Women with a higher level of education were better informed and more knowledgeable than others, but were nevertheless more reluctant to use HRT than those who were less educated. The limited number of women who actually receive information on HRT, the low level of knowledge and the ambivalent attitudes toward HRT are a major challenge to the public health service.

[Hormone replacement therapy among Norwegian women. Self-reported use and sales of estrogen preparations]

In order to analyse the use of hormone replacement therapy (HRT) and the predicting factors for its use, two random samples of Norwegian women (30-79 years) were interviewed by the Central Bureau of Statistics in 1994 (n = 565) and in 1996 (n = 470). The extent of use of HRT was compared with statistics for sales of oestrogen in Norway and the Nordic countries. In the age group 45-69 years the use of hormone replacement therapy increased from 16.3% in 1994 to 19.1% in 1996. The proportion of users did not increase with a higher level of education. In addition to information received, and after adjusting for other variables, attitudes towards oestrogen and knowledge about it were the most important contributing factors for using HRT. Sales figures show that the use of systemic oestrogen in Norway has increased more than 280% since 1990. None of the Nordic countries have had a corresponding increase, but the Norwegian figures are still low compared to most other Nordic countries. In 1996 14.5% of Norwegian women (50-79 years) used oestrogen for urogenital disorders. Norwegian women need to be better informed and more knowledgeable to enable them to make conscious choice regarding use of hormone replacement therapy.

The Tromsø Study: body height, body mass index and fractures

Tall persons suffer more hip fractures than shorter persons, and high body mass index is associated with fewer hip and forearm fractures. We have studied the association between body height, body mass index and all non-vertebral fractures in a large, prospective, population-based study. The middle-aged population of Tromsø, Norway, was invited to surveys in 1979/80, 1986/87 and 1994/95 (The Tromsø Study). Of 16,676 invited to the first two surveys, 12,270 attended both times (74%). Height and weight were measured without shoes at the surveys, and all non-vertebral fractures in the period 1988-1995 were registered (922 persons with fractures) and verified by radiography. The risk of a low-energy fracture was found to be positively associated with increasing body height and with decreasing body mass index. Furthermore, men who had gained weight had a lower risk of hip fractures, and women who had gained weight had a lower risk of fractures in the lower extremities. High body height is thus a risk factor for fractures, and 1 in 4 low-energy fractures among women today might be ascribed to the increase in average stature since the turn of the century. Low body mass index is associated with a higher risk of fractures, but the association is probably too weak to have any clinical relevance in this age category.

Physical activity and predisposition for hip fractures: a review

Studies on the association between physical activity and hip fractures are reviewed. All the studies, which comprise four follow-up studies, one nested case-control study and 17 case-control studies, suggest a protective effect of physical activity with regard to hip fractures. The association is strong and consistent with physical activity in leisure, weaker with respect to physical activity at work. The association is present for physical activity from childhood to adult age, and it is consistent in study populations from the USA, Australia, Asia and Northern and Southern Europe, in spite of very different hip fractures incidences in these populations. The magnitude of the association is difficult to assess because of varying criteria for exposure, but to be among the physically active seems to reduce the risk of later hip fracture by up to 50%. It seems that even daily chores, such as climbing stairs and walking, protect against hip fracture.

[Osteoporosis. Knowledge and attitudes of the Norwegian population]

In March 1994, a random sample of 1,514 Norwegians aged 16-79 years were interviewed about their knowledge of osteoporosis and their attitudes towards prevention of this disease. About 85% answered correctly that osteoporosis can be prevented, but only 57% knew that it cannot be cured. Women had better knowledge of osteoporosis than men had. Two thirds of the women were positive to the use of long-term hormone replacement therapy to prevent osteoporosis. The majority of women aged 60 years or more preferred walking to other physical activities to prevent the disease. Although the data demonstrated fairly good general knowledge of osteoporosis in the population, the oldest women, those at the highest risk of developing the disease, knew less about osteoporosis than the younger women did.

What do Norwegian women and men know about osteoporosis?

A survey of a random sample of 1514 Norwegian women and men aged 16-79 years was undertaken to investigate knowledge of osteoporosis and attitudes towards methods for preventing this disease. The interviews were carried out by Central Bureau of Statistics of Norway as part of their monthly national poll using a structured questionnaire. Women knew more about osteoporosis than did men (p < 0.001). In both men and women increased knowledge of osteoporosis was correlated to a high level of education. Furthermore it was clearly demonstrated that knowing someone with osteoporosis or suffering from it oneself increased the knowledge of osteoporosis significantly in both women and men. Multiple regression analysis confirmed the univariate analyses, and education was the strongest predictive factor for knowledge. To a hypothetical question as many as two-thirds of the women answered that they would use long-term hormone replacement therapy (HRT) to prevent osteoporosis on the recommendation of their general practitioner. Their attitudes towards the use of estrogen therapy did not show any significant relation to age, but their reluctance towards HRT increased with education (p < 0.001). When asked a question about their preferences regarding the use of physical activity as a means to prevent osteoporosis, older women preferred walking (p < 0.001), whereas younger women wanted more organized athletic activity (p < 0.001). The data demonstrated that there was a high degree of general knowledge of osteoporosis and its consequences in the general population.

A prospective evaluation of antithyroid antibody prevalence in 100 patients with rheumatoid arthritis

The prevalence of thyroid antibodies in 100 patients with rheumatoid arthritis in Northern Norway was studied. The serological data were compared with those from a major population survey in the same area. Compared to the prevalence in the normal population, the present study demonstrates that patients with rheumatoid arthritis have a higher prevalence of antibodies to both thyroid microsomal antigen and thyroglobulin.

Characterization of proteoglycans associated with mouse splenic AA amyloidosis

We here report for the first time on the chemical characteristics of proteoglycans associated with mouse splenic reactive AA amyloid. Amyloid was induced in CBA/J mice by two different procedures; conventional casein treatment and by employing Freund's complete adjuvant, accelerated by Trypan Blue. Pulse-labelling was employed at distinct stages during amyloid development, followed by [35S]proteoglycan characterization of organ extracts. Repetitive 35S injections were also administered during the phase where amyloid deposition occurred most rapidly. Proteoglycans were extracted with guanidine in the presence of protease inhibitors and purified. The results showed that the production of proteoglycans is dramatically enhanced during amyloidogenesis, the glycosaminoglycan and proteoglycan accumulation being not only dependent on alterations in proteoglycan catabolism, but rather on increased synthesis. The increment could be demonstrated even at the stage before microscopic detection of amyloid deposits, clearly suggesting that the upregulation of proteoglycan expression precedes amyloid fibril formation. Two major proteoglycans were found to accumulate in advanced splenic amyloid; one a heparan sulphate proteoglycan of approx. 200 kDa with a core protein of 70 kDa, the other a chondroitin sulphate proteoglycan of smaller size. Moreover, free dermatan sulphate chains seemed to specifically accumulate in the organs during amyloid fibrillogenesis. We suggest that free glycosaminoglycans may be a specific feature of amyloidosis and that different proteoglycans and glycosaminoglycans play a role in formation and stabilization of amyloid fibrils in vivo.

[Rheumatic fever--does it exist in Norway today?]

During the last 30 years, acute rheumatic fever has been a curiosity in Norway, and only five cases have been reported to MSIS (National Notification System for Infectious Diseases, Norway) in the 1990s. Even so, during the period 1990 to 1992 99 patients were discharged from Norwegian hospitals with the diagnosis acute rheumatic fever. Could the increase in the number of group A-streptococci in the last years have led to a corresponding increase in the incidence of acute rheumatic fever? If so, could such an increase have escaped our attention? We present an updated review of acute rheumatic fever and the case of a young soldier.

[Polymyalgia rheumatica and temporal arteritis. New aspects of diagnosis, treatment, prognosis and risk of cancer]

The incidence of polymyalgia rheumatica and temporal arteritis is increasing, mainly in elderly people. The risk of cancer during a lifetime is high in patients with positive biopsy of the temporal artery, but polymyalgia rheumatica and temporal arteritis are not to be considered as paraneoplastic syndromes. Temporal arteritis can appear in patients under treatment for polymyalgia rheumatica, and polymyalgia rheumatica can be accompanied by arthritis. Various new aspects of diagnoses and treatment are discussed.

[The significance of proteoglycans in several diseases]

A prominent feature in several diseases is the accumulation of connective tissue. The ultimate result of high levels of extracellular matrix is organ failure and death, evident in diseases such as liver fibrosis, diabetes and amyloidosis. Among the extracellular matrix components, proteoglycans play a basic role in several pathological conditions. In the development of atherosclerosis they provide an anchor for lipoprotein lipase on the endothelial wall, sequester lipoproteins in the subendothelial matrix and present lipoproteins to macrophages. In diabetes these proteoglycans have a lower charge, such that the network has a reduced capacity to retain negatively charged proteins. In fibrosis and amyloidosis the synthesis of proteoglycans and matrix is increased and large amounts are deposited at the expense of tissue-specific cells. Some of the conditions mentioned can be ameliorated by changes in the diet.

Interaction between circulating amyloid fibril protein precursors and extracellular tissue matrix components in the pathogenesis of systemic amyloidosis

Amyloidosis is a heterogeneous group of diseases characterized by deposition of a fibrillar, proteinaceous material, amyloid, in various tissues and organs. Increasing knowledge about the different proteins that constitute the amyloid fibrils has made it possible to classify amyloidosis by the fibril protein, which appears more rational than the traditional classification by its clinical expression. A serum protein is the precursor of the amyloid fibril protein in the various systemic forms of amyloidosis. Although the chemical composition of amyloid is presently well known, the pathogenetic processes that convert such proteins into a fibrillar form and lay them down in the tissues are far from clarified. We suggest some pathogenetic mechanisms for amyloid deposition, involving different types of fibril protein, their precursors, the extra-fibrillar amyloid P component, glycosaminoglycans, proteoglycans, and calcium with special reference to experimental work from our research group.

On the association between amyloid fibrils and glycosaminoglycans; possible interactive role of Ca2+ and amyloid P-component

We have previously reported the specific association of glycosaminoglycans (GAG) and proteoglycans (PG) with amyloid fibrils and characterized the polysaccharides directly extracted from amyloid-laden tissues. In the present study we further elucidate the association between purified amyloid fibrils and GAG/PG with special reference to those GAG/PG associated with amyloid P-component (AP) and the interactive role of Ca2+ ions. Amyloid fibrils were isolated from human hepatic AA amyloid employing water extraction with and without preceding removal of AP, an extrafibrillar protein component of all amyloids, using sodium citrate. GAG/PG co-isolated with the amyloid extracts, with and without AP, were isolated and characterized. Agarose-affinity chromatography of extracts containing AP was performed, and the GAG associated with this extrafibrillary protein were characterized as well. Several different GAG/PG populations were demonstrated in the various extracts. The abolition of calcium-dependent binding markedly influenced the amount of GAG/PG recovered in the fibril extracts, as well as the total amount of amyloid material obtained. Thus, it seems that calcium plays an important role in the association between the fibrils and the sugar moieties, and that a significant fraction of the GAG found in amyloid exhibits a Ca(2+)-dependent fibril-GAG interaction. No significant difference in the proportion between galactosaminoglycans and glucosamines was, however, disclosed when the two extraction protocols were compared, suggesting that no particular GAG species has a higher affinity for the fibrils themselves. Both dermatan/chondroitin sulphate and heparan sulphate identified in the present study exhibited a Ca(2+)-dependent interaction with AP, supporting previous findings. However, the amyloid-associated galactosaminoglycans found, especially the large PG appearing in small amounts, seemed to have a higher affinity for the extrafibrillar AP than the other GAG.

Writing a scientific paper as part of the medical curriculum

The curriculum at the Medical School, University of Tromsø reserves 23 weeks for optional studies, including a period of 12 weeks at the end of the fifth year when the students carry out an independent study and write a short thesis. Of the first 417 doctors (graduation year 1979-89) from Tromsø 84.6% answered a postal questionnaire asking them to evaluate this part of the curriculum. These postgraduates report high levels of satisfaction with and benefit from this part of the curriculum. A total of 26.8% started working on their thesis before the final 12-week period, 32.6% had also published their study, half of these in international journals, and 75.6% found that the skills acquired during the final optional period had been useful in their subsequent work, irrespective of specialty. In conclusion, postgraduates consider their work in preparing a scientific paper as an important and integral part of medical studies.

Rural doctor recruitment: does medical education in rural districts recruit doctors to rural areas?

The impact of the University of Tromsø Medical School on the distribution of doctors in rural areas in northern Norway was evaluated by a postal questionnaire. The survey covered 11 graduation years (417 doctors), and the response rate was 84.2%. The establishment of a new medical school in northern Norway has clearly had beneficial effects: a total of 56.1% of the graduates stay in these remote areas. Of those who also spent their youth in northern Norway the proportion is 82.0%, compared to graduates who lived in the southern parts of the country while growing up (37.7%). The results clearly demonstrate that one of the main goals for the Medical School at the University in Tromsø, to educate doctors who prefer to work in these rural areas, has been accomplished.

Purification of amyloid-associated heparan sulphate proteoglycans and galactosaminoglycan free chains from human tissues

Basement membrane-associated heparan sulphate proteoglycans have been demonstrated immunohistochemically in organs from patients afflicted with various types of amyloidosis. In a recent report, we were able to isolate and partly characterize a basement membrane-associated heparin sulphate proteoglycan from human hepatic amyloid. In the present study proteoglycans were extracted with guanidine from human amyloid-laden kidney, spleen and lymph nodes. All tissues extracted with guanidine contained both heparan sulphate proteoglycan (HSPG) and galactosaminoglycan (CS/DS) free chains. Tissue staining using a monoclonal antibody against basement membrane HSPG revealed the presence of HSPG in amyloid deposits in kidney and spleen. Furthermore, following SDS-PAGE of HSPG from kidney after deaminative cleavage of the HS chains, a 15-kDa and 80-kDa protein appeared, probably representing the core protein(s). In lymph node HSPG, three core proteins of 65, 30 and 25 kDa could be demonstrated on SDS-PAGE, the first reacting with the anti-basement membrane HSPG antibody when subjected to Western blotting subsequent to SDS-PAGE. By immunohistochemistry, we failed to demonstrate any staining of the renal and splenic tissue sections employing an antibody against the decorin core protein.

[Evaluations and examinations at the Tromsø medical school. Evaluation by students after graduation]

The medical curriculum at the University of Tromsø is based on an organ-system model with full integration of the three main disciplines (basic science, clinical and community medicine). There are only three examinations during the six-year course. We present the results of a survey among the first 417 physicians educated at the Medical School in Tromsø. A mailed questionnaire was answered by 84.2%. More than 80% stated that it was of great importance to evaluate the form and contents of the lectures and their supervisors' teaching abilities. More than 96% found that integration of the examinations was achieved in accordance with the intention. Furthermore, the examinations were also relevant for them as physicians.

[Elective periods in the medical curriculum. Madness or academic challenge?]

The medical curriculum at the University of Tromsø reserves 23 weeks, divided into four periods, for elective work, including 12 weeks at the end of the fifth year, when the student carries out an independent study and writes a short thesis. 84.2% of 417 physicians (graduation year 1979-89) answered a mailed questionnaire asking them to evaluate these periods. The postgraduates report high levels of satisfaction with this part of the curriculum, thought they had benefited from it. As many as 86.0% evaluate the gain from the first three periods as good or very good. 26.8% started working on their thesis before the final 12 week period. 88.1% found the fourth, and longest period, assigned for their thesis to be an important part of the curriculum. One third had also published their material, half of these in international journals. 75.6% found the skills acquired during the final elective period to be useful in their present work, independent of specialty.

[Graduates from Tromsø--do they stay in Northern Norway? Geographic origin determines selection of professional practice location in Northern Norway]

The impact of the Medical School, University of Tromsø on the distribution of physicians in rural areas in North Norway was evaluated by means of a mailed questionnaire. The survey covered eleven graduation classes (417 physicians), and the response rate was 84.2%. The establishment of a new medical school in North Norway has clearly had beneficial effects: A total of 56.1% of the graduates stay on as doctors in these areas. Among those who also grew up in the northern parts of Norway, the proportion is 82.0%, compared with graduates who grew up in the southern parts where the proportion is 37.7%. The results clearly demonstrate that one of the main objectives of the Medical School at the University of Tromsø, to educate physicians who prefer to work in these areas, has been achieved.

Facial palsy and partial accommodative insufficiency associated with sulphasalazine treatment in a patient with ankylosing spondylitis

We report on a patient with peripheral facial nerve palsy and blurred near vision in association with sulphasalazine treatment. The possibility of this being an adverse reaction to sulphasalazine is discussed.

Isolation and partial characterization of heparan sulphate proteoglycans from human hepatic amyloid

Proteoglycans were isolated from human amyloidotic liver by extraction with guanidine, followed by trichloroacetic acid precipitation, DEAE-Sephacel ion-exchange chromatography, and Sepharose CL-6B gel chromatography. A significant portion of the material was found to be free chondroitin/dermatan sulphate chains (30%), whereas the predominant part was heparan sulphate proteoglycan (HSPG) (70%). The approx. molecular mass of the HSPG was 200 kDa, as measured by gel electrophoresis and gel chromatography. The molecular mass of the core protein was shown to be 60 kDa by SDS/PAGE following de-aminative cleavage of the heparan sulphate chains. The heparan sulphate chains were liberated from the core protein by alkali treatment and found to have a molecular mass of approx. 35 kDa by Sepharose CL-6B gel chromatography. The core protein was shown, by immunoblotting, to react with a monoclonal antibody against bovine basement membrane HSPG. The presence of HSPG in amyloid deposits was further confirmed by immunohistochemistry on tissue sections from amyloidotic liver using the same antibody.

Macromolecular properties of glycosaminoglycans in primary AL amyloid fibril extracts of lymphoid tissue origin

We have previously demonstrated the presence of glycosaminoglycans (GAGs) in water extracts of secondary AA amyloid fibrils. In the present study we isolated significant quantities of GAGs from fibril extracts of immunoglobulin light chain (AL) type derived from the spleens from two patients afflicted with primary amyloidosis. Employing ion-exchange chromatography and gel filtration subsequent to various specific chemical and enzymatic treatments, different types of high molecular weight GAGs were found in both preparations, but not in the corresponding normal splenic extracts. The amyloid-associated GAGs of the extracts derived from one patient consisted of 60% dermatan sulphate and 40% heparan sulphate whereas those obtained from the second spleen were 25% dermatan sulphate and 75% heparan sulphate. The heparan sulphate fraction occurred in the form of proteoglycans, whereas the dermatan sulphate apparently occurred as free GAG chains, resembling the data recently obtained from AA amyloid fibril extracts.

High molecular weight glycosaminoglycans in AA type amyloid fibril extracts from human liver

Glycosaminoglycans have previously been identified in extracts of AA type hepatic amyloid fibril from a patient with amyloidosis associated with juvenile rheumatoid arthritis. The macromolecular properties of these polysaccharides are described here in more detail. By gel filtration and ion exchange chromatography glycosaminoglycans in the form of high molecular weight free chains were shown to coisolate with water extracted amyloid fibrils. About 60% of these were characterised as galactosamines (chondroitin sulphate/dermatan sulphate), whereas the remaining 40% consisted of N-sulphated glucosamines (heparin/heparan sulphate). The amyloid associated glycosaminoglycans were not part of intact proteoglycans in the fibril extracts.

Glycosaminoglycans in extracts of cardiac amyloid fibrils from familial amyloid cardiomyopathy of Danish origin related to variant transthyretin Met 111

We have previously demonstrated an association between secondary AA type amyloid fibrils and glycosaminoglycans (GAGs) in human liver. The present study was aimed at investigating whether a similar association could be demonstrated in isolated cardiac amyloid fibrils from a unique Danish family with amyloid cardiomyopathy related to variant transthyretin (TTR) with a single amino acid substitution of a methionin for leucine at position 111 (TTR Met 111). Using gel filtration and ion exchange chromatography, significant amounts of GAGs were detected in close association with purified myocardial amyloid fibrils, whereas only trace amounts of polysaccharides were present in the corresponding normal preparation. The GAGs were identified as 50% chondroitin sulfate, 33% heparin/heparan sulfate, and 17% hyaluronan. With the methods used the amyloid associated GAGs appeared as high molecular weight free polysaccharide chains, and not as part of intact proteoglycans (PGs) in the fibril extracts. We conclude that the association between purified amyloid fibrils and GAGs may be a general feature of amyloid deposits. Also, we suggest that the proportion of different GAGs in the amyloid deposits may depend both on the organ or tissues affected and the type of proteins making up the fibrils.