Self-rated health status as a health measure: the predictive value of self-reported health status on the use of physician services and on mortality in the working-age population

The validity of various self-reported health assessments in predicting physician contracts and all-cause mortality was investigated in a prospective study in Finland. The follow-up periods were one year for the use of physician services and ten years ten months for the mortality. The study cohort comprised 1340 men and 1500 women, 35-63 years of age at the beginning of the study. The initial health assessments were derived from postal questionnaires in 1980 (response rate 77.5%). The survey was repeated one year later to verify the stability of the respondents' perceived health status. The data on the physician contacts and mortality were registered independently. The stability of perceived health status was relatively good and the perceived health was inversely associated with the number of physician contacts per year. A consistent inverse association, standardized by age, sex and social status, was observed between perceived health status and perceived physical fitness and mortality, while the predictive value of self-reported chronic diseases was low. The results suggest that the subjective health assessments are valid health status indicator in middle-aged populations, and they can be used in cohort studies and population health monitoring.

Epidemiology of hip fractures

There were an estimated 1.66 million hip fractures world-wide in 1990. According to the epidemiologic projections, this worldwide annual number will rise to 6.26 million by the year 2050. This rise will be in great part due to the huge increase in the elderly population of the world. However, the age-specific incidence rates of hip fractures have also increased during the recent decades and in many countries this rise has not leveled off. In the districts where this increase has either showed or leveled off, the change seems to especially concern women's cervical fractures. In men, the increase has continued unabated almost everywhere. Reasons for the age-specific increase are not known: increase in the age-adjusted incidence of falls of the elderly individuals with accompanying deterioration in the age-adjusted bone quality (strength, mineral density) may partially explain the phenomenon. The growth of the elderly population will be more marked in Asia, Latin America, the Middle East, and Africa than in Europe and North America, and it is in the former regions that the greatest increments in hip fracture are projected so that these regions will account for over 70% of the 6.26 million hip fractures in the year 2050. The incidence rates of hip fractures vary considerably from population to population and race to race but increase exponentially with age in every group. Highest incidences have been described in the whites of Northern Europe (Scandinavia) and North America. In Finland, for example, the 1991 incidence of hip fractures was 1.1% for women and 0.7% for men over 70 years of age. Among elderly nursing home residents, the figures can be as high as 6.2% and 4.9%. The lifetime risk of a hip fracture is 16%-18% in white women and 5%-6% in white men. At the age of 80 years, every fifth woman and at the age of 90 years almost every second woman has suffered a hip fracture. Since populations are aging worldwide, the mean age of the hip fracture patients are increasing rapidly, too. Between 1970 and 1991, the mean age of male Finnish patients increased dramatically from 52.9 years to 69.0 years. In women, the corresponding figures were 71.6 and 78.9 years. This change is likely to cause increasing problems in the treatment and rehabilitation of the patients. In 1990, 72% of the hip fractures worldwide occurred in women. All over the world, the hip fracture incidences are about two times higher in women than in men. Women's overrepresentation has been explained by women's lower bone mass and density and higher frequency of falling. Epidemiologic studies show that trochanteric fractures are an increasing problem since compared with cervical fractures their relative number increases progressively with age in women after the age of 60 years and since their incidence has been shown to increase in both sexes and all age groups during the recent decades. This may have direct public health implication since mortality, morbidity, and costs caused by trochanteric fractures are higher than those of the cervical fractures. Reduced bone density (strength) by age and over the recent decades has been the most frequently mentioned reason for the increase of trochanteric fractures. Also, the fall characteristics of the elderly may have changed during the recent decades resulting in increasing numbers of this type of hip fractures since the type of the hip fracture (cervical or trochanteric) also depends on the impact angle of the greater trochanter at the moment of the floor contact.

Effect of starting age of physical activity on bone mass in the dominant arm of tennis and squash players

OBJECTIVE

To determine in female tennis and squash players the effect of biological age (that is, the starting age of playing relative to the age at menarche) at which tennis or squash playing was started on the difference in bone mineral content between the playing and non-playing arms.

DESIGN

Cross-sectional study.

SETTING

Finnish tennis and squash federations.

PARTICIPANTS

105 female Finnish national-level players and 50 healthy female controls.

MAIN OUTCOME MEASURES

Differences in bone mineral content in playing and nonplaying (dominant to nondominant) arms (proximal humerus, humeral shaft, radial shaft, and distal radius) were compared in the players and controls and among six groups of players. Players were divided into groups according to the biological age (years before or after menarche) at which their playing careers began: more than 5 years before; 3 to 5 years before; 2 to 0 years before; 1 to 5 years after; 6 to 15 years after; and more than 15 years after.

RESULTS

Compared with controls (whose mean +/- SD differences in bone mineral content were 4.6% +/- 4.6%, 3.2% +/- 2.3%, 3.2% +/- 3.8%, and 3.9% +/- 4.3% at the previously noted anatomical sites), the players had a significantly (P < 0.001) larger side-to-side difference in every measured site (15.5% +/- 8.4%, 16.2% +/- 9.8%, 8.5% +/- 6.6, and 12.5% +/- 7.1%). Among players, the group differences in bone mineral content were significant (P < 0.001 to P = 0.005), with the group means clearly decreasing with increasing starting biological age of playing. The difference was two to four times greater in the players who had started their playing careers before or at menarche (lowest mean difference in bone mineral content, 10.5% +/- 7.2%; highest difference, 23.5% +/- 7.2%) than in those who started more than 15 years after menarche (lowest difference, 2.4% +/- 4.8%; highest difference, 9.6% +/- 4.9%). Adjustment for potential confounding factors (age and height) did not change these trends.

CONCLUSIONS

Bones of the playing extremity clearly benefit from active tennis and squash training, which increases their mineral mass. The benefit of playing is about two times greater if females start playing at or before menarche rather than after it. The minimal level and minimum number of years of activity necessary to produce these results, the extent to which this benefit is sustained after cessation of intensive training, and the degree to which these results can be extended to other forms of physical activity and other bone sites should be studied further.

Prevention of hip fracture in elderly people with use of a hip protector

BACKGROUND

Hip fractures are common in frail elderly adults worldwide. We investigated the effect of an anatomically designed external hip protector on the risk of these age-related fractures.

METHODS

We randomly assigned 1801 ambulatory but frail elderly adults (1409 women and 392 men; mean age, 82 years), in a 1:2 ratio, either to a group that wore a hip protector or to a control group. Fractures of the hip and all other fractures were recorded until the end of the first full month after 62 hip fractures had occurred in the control group. The risk of fracture in the two groups was compared, and in the hip-protector group the risk of fracture was also analyzed according to whether the protector had been in use at the time of a fall.

RESULTS

During follow-up, 13 subjects in the hip-protector group had a hip fracture, as compared with 67 subjects in the control group. The respective rates of hip fracture were 21.3 and 46.0 per 1000 person-years (relative hazard in the hip-protector group, 0.4; 95 percent confidence interval, 0.2 to 0.8; P=0.008). The risk of pelvic fracture was slightly but not significantly lower in the hip-protector group than in the control group (2 subjects and 12 subjects, respectively, had pelvic fracture) (relative hazard, 0.4; 95 percent confidence interval, 0.1 to 1.8; P > or = 0.05). The risk of other fractures was similar in the two groups. In the hip-protector group, four subjects had a hip fracture (among 1034 falls) while wearing the protector, and nine subjects had a hip fracture (among 370 falls) while not wearing the protector (relative hazard, 0.2; 95 percent confidence interval, 0.05 to 0.5; P=0.002).

CONCLUSIONS

The risk of hip fracture can be reduced in frail elderly adults by the use of an anatomically designed external hip protector.

Majority of hip fractures occur as a result of a fall and impact on the greater trochanter of the femur: a prospective controlled hip fracture study with 206 consecutive patients

The objectives of this study were to learn how hip fracture patients fall, and to compare the mechanics of their falls with those falls that did not result in hip fracture. In this way we sought to obtain reliable insight into the etiology and pathogenesis of hip fracture and fracture prevention. A total of 206 consecutive patients with fresh hip fracture and 100 controls were interviewed and examined between October 1994 and May 1996. The only inclusion criterion was that the fracture had occurred within 24 hours of hospital admittance. The control subjects were admitted from the same community after an accidental fall that did not result in hip fracture. The characteristics of the accident were determined by personal interview and examination of the patients within 24 hours of the event. In 98% of the hip fracture patients, the fracture was a result of a fall. The majority of the patients (76%) reported that they had fallen directly to the side. Forty-eight fracture cases had one or more eyewitnesses and their reports supported this observation. In 56% of the hip fracture patients, a fresh subcutaneous hematoma was seen on the greater trochanter of the proximal femur; such a hematoma was rare in the controls (6%) (P < 0. 001), and this gave evidence for the direct impact of the greater trochanter during the fall of the hip fracture subjects. Most of the elderly fallers who fractured a hip did not manage to break the fall, e.g., with an outstretched arm. In conclusion, our results suggest that a typical hip fracture is the result of a fall and a subsequent impact on the greater trochanter of the proximal femur. The clinical implication of this finding is that effective prevention of hip fractures could be achieved by the diminution of the number and severity of falls of the elderly. We suggest that the severity of the falls (impacts on the greater trochanter) could be decreased by an external hip protector.

Fall-induced injuries and deaths among older adults

CONTEXT

Although various fall-induced injuries and deaths among older adults are increasing, little is known about the epidemiology of these events.

OBJECTIVE

To determine the trends in the number and incidence of fall-induced injuries and deaths of older adults in a well-defined white population.

DESIGN AND SETTING

Secular trend analysis of the population of Finland, using the Finnish National Hospital Discharge Register and the Official Cause-of-Death Statistics of Finland.

PARTICIPANTS

All persons aged 50 years or older who were admitted to hospitals in Finland for primary treatment of a first fall-induced injury from the years of 1970 to 1995, and for comparison, all fall-induced deaths in the same age group from the years 1971 to 1995.

MAIN OUTCOME MEASURE

The number and the age-specific and age-adjusted incidence rate (per 100000 persons) of fall-induced injuries and deaths in each year of the study.

RESULTS

For the study period, both the total and population-adjusted number (per 100000 persons) of Finns aged 50 years or older with fall-induced injury increased substantially. Total fall-induced injuries increased from 5622 in 1970 to 21 574 in 1995, a 284% increase, and the rate increased from 494 to 1398 per 100000 persons, a 183% increase. The age-adjusted incidence also increased in both women (from 648 in 1970 to 1469 in 1995, a 127% increase) and men (from 434 in 1970 to 972 in 1995, a 124% increase). Moreover, the number of deaths due to falls in the overall population increased from 441 in 1971 to 793 in 1995, an 80% increase, and the rate increased from 38 in 1971 to 51 in 1995, a 34% increase. However, after age adjustment the incidence of fall-induced death did not show a clear upward trend.

CONCLUSIONS

In a well-defined white population, the number of older persons with fall-induced injuries is increasing at a rate that cannot be explained simply by demographic changes. Preventive measures should be adopted to control the increasing burden of these injuries. Fortunately, the age-adjusted incidence of the fall-induced deaths shows no increasing trend over time.

Agreement between questionnaire data and medical records of chronic diseases in middle-aged and elderly Finnish men and women

The agreement between self-reported diseases in a questionnaire survey and data from medical records was assessed in a representative sample of Finnish men and women (n = 596) aged 45-73 years. The accumulated medical record information was abstracted from the records in the health centers and the central hospital in the study region. The agreement between the two information sources was substantial (kappa 0.73-0.80) for cardiovascular diseases as a group, hypertension, angina pectoris, myocardial infarction, and diabetes. The lowest agreement (kappa < 0.55) was found for lower back disorder, hip and knee arthrosis, and claudication. These results showed that the agreement between questionnaire data and medical records was good for well-known chronic diseases that have clear diagnostic criteria and are easily communicated to the patient. Conversely, the agreement was poor for diseases with nonestablished diagnostic criteria and a fluctuating course.

Exercise-induced bone gain is due to enlargement in bone size without a change in volumetric bone density: a peripheral quantitative computed tomography study of the upper arms of male tennis players

Bilateral bone characteristics of the humerus (proximal, shaft, and distal sites) and radius (shaft and distal sites) in 12 former Finnish national-level male tennis players (mean age 30 years) and their 12 age-, height-, and weight-matched controls were measured with peripheral quantitative computed tomography (pQCT). The pQCT variables analyzed were bone mineral content (BMC), total cross-sectional area of bone (Tot.Ar), cross-sectional area of the marrow cavity (M.Cav.Ar), cortical bone (Co.Ar) and trabecular bone (Tr.Ar), volumetric density of cortical (Co.Dn) and trabecular (Tr. Dn) bone, cortical wall thickness (Co.Wi.Th), bone strength index (BSI), and principal moments of inertia (I(min) and I(max)). In the players, significant side-to-side differences, in favor of the dominant (playing) arm, were found in BMC (ranging 14%-27%), Tot.Ar (16%-21%), Co.Ar (12%-32%), BSI (23%-37%), I(min) (33%-61%), and I(max) (27%-67%) at all measured bone sites, and in Co.Wi.Th. (5%-25%) at the humeral and radial shafts, and distal humerus. The side-to-side M.Cav.Ar difference was significant at the proximal humerus (19%) and radial shaft (29%). Concerning the players' Co.Dn and Tr.Dn, the only significant side-to-side difference was found in the Co.Dn of the distal humerus, with the playing arm showing a slightly smaller Co.Dn than the nonplaying arm (-2%). In controls, significant dominant-to-nondominant side differences were also found, but with the majority of the differences being rather small, and significantly lower than those of the players. In conclusion, despite the large side-to-side differences in BMC, the volumetric bone density (Co.Dn, Tr.Dn) was almost identical in the dominant and nondominant arms of the players and controls. Thus, the players' high playing-arm BMC was due to increases in the Tot.Ar, M.Cav.Ar, Co.Ar, and CW.Th. In other words, the playing arm's extra bone mineral, and thus increased bone strength, was mainly due to increased bone size and not due to a change in volumetric bone density. These upper arm results may not be generalized to the entire skeleton, but the finding may give new insight into conventional dual-energy X-ray absorptiometry (DXA)-based bone density measurements when interpreting the effects of exercise on bone.

Randomised controlled trial of effect of high-impact exercise on selected risk factors for osteoporotic fractures

BACKGROUND

Osteoporotic fractures among the elderly are common, and without preventive measures the burden of these fractures on health-care systems will increase further. The purpose of this randomised controlled study was to evaluate, in premenopausal women, the effects of high-impact loading on several determinants osteoporotic fractures.

METHODS

98 healthy, sedentary female volunteers aged 35-45 years were randomly assigned to either a training (n = 49) or a control group (n = 49). Progressive high-impact exercises were done three times per week for 18 months. We measured bone mineral density (BMD) in specific axial and lower-limb sites, by dual-energy X-ray absorptiometry, at baseline and after 12 and 18 months. Maximum isometric strength, muscular and cardiovascular performance, and dynamic balance were also assessed.

FINDINGS

BMD at the femoral neck, a weightbearing site, increased significantly more in the training group (mean 1.6% [95% CI 0.8-2.4]) than in the control group (0.6% [-0.2 to 1.4], p = 0.006). By contrast, at non-weightbearing sites, such as the distal radius, there was no significant difference between the training and control groups (-1.5% [-2.7 to -0.3] vs -0.7% [-1.9 to -0.5], p = 0.60). In the training group there was a significant improvement in vertical jump and predicted oxygen consumption per min at maximum exercise compared with controls.

INTERPRETATION

High-impact exercises that load bones with a rapidly rising force profile in versatile movements improve skeletal integrity, muscular performance, and dynamic balance in premenopausal women. If done on a regular basis, this type of exercise may help decrease the risk of osteoporotic fractures in later life. Long-term studies are required to show whether these 18-month results can be translated into long-term benefit.

Hip fractures in Finland between 1970 and 1997 and predictions for the future

BACKGROUND

Hip fractures in elderly people are common worldwide, and the predicted ageing of populations is increasing the burden of these fractures on health-care systems. However, prediction of the true increases in number of patients needing treatment requires exact knowledge of whether the number of hip fractures is rising more rapidly than can be accounted for by demographic changes alone. We aimed to make such a prediction for people aged 50 years or more in Finland.

METHODS

All patients aged 50 years or more, who were admitted to hospitals in Finland during 1970-97 for primary treatment of first hip fracture were selected from the National Hospital Discharge Register. The age-specific and age-adjusted fracture incidences were expressed as the number of patients per 100,000 individuals per year, and prediction of the number, and incidence of hip fractures in Finland (population 5 million) until the year 2030 was calculated with a regression model.

FINDINGS

The number of hip fractures in Finnish people aged 50 or more rose during the study period, from 1857 in 1970 to 7122 in 1997. The corresponding fracture incidence (per 100,000 people) increased from 163 to 438. The age-adjusted incidence of hip fractures also showed a steady increase from 1970 to 1997: in women, from 292 to 467, and in men, from 112 to 233. If this trend continues, the number of hip fractures in Finland will be almost three-fold higher in the year 2030 than in 1997.

INTERPRETATION

The number of hip fractures in elderly Finnish men and women is increasing at a rate that cannot be explained merely by demographic changes. The precise reasons for this are not known, but deterioration in age-adjusted bone-mineral density and strength, with accompanying increase in the age-adjusted incidence of injurious falls of the elderly, could partly account for the development.

Bone mineral density in female athletes representing sports with different loading characteristics of the skeleton

To address the hypothesis that osteogenic effect of physical loading increases with increasing strain rates and peak forces, we examined 59 competitive Finnish female athletes (representing three sports with different skeletal loading characteristics), physically active referents (they reported an average of five various types of exercise sessions per week), and sedentary referents (two sessions per week) using dual energy X-ray absorptiometry. The measured anatomic sites were at the lumbar spine, femoral neck, distal femur, patella, proximal tibia, calcaneus, and distal radius. The athlete group consisted of aerobic dancers (N = 27), squash players (N = 18), and speed skaters (N = 14). The squash players had the highest values for weight-adjusted bone mineral density (BMD) at the lumbar spine (13.8% p < 0.001 as compared with the sedentary reference group), femoral neck (16.8%, p < 0.001), proximal tibia (12.6%, p < 0.001) and calcaneus (18.5%, p < 0.001). Aerobic dancers and speed skaters also had significantly higher BMD values at the loaded sites than the sedentary reference group, the difference ranging from 5.3% to 13.5%. The physically active referents' BMD values did not differ from those of the sedentary referents at any site. The results support the concept that training, including high strain rates in versatile movements and high peak forces, is more effective in bone formation than training with a large number of low-force repetitions.

Peripheral quantitative computed tomography in human long bones: evaluation of in vitro and in vivo precision

Despite the excellent performance in clinical practice and research, the dual-energy X-ray absorptiometry is restricted by the inherent planar nature of the measurement and the inability to discriminate between trabecular and cortical components of bone. Recently, a new peripheral tomographic scanner (Norland/Stratec XCT 3000) was introduced for versatile measurements of human long bone characteristics in vivo, including trabecular and cortical density (TrD and CoD, respectively), respective cross-sectional areas (TrA and CoA), bone strength index (BSI), and bone mineral content (BMC). We evaluated the technical performance of the scanner using different phantoms and determined the in vivo precision of the above-noted applications by measuring twice several sites of upper and lower limbs of 19 and 36 volunteers aged 23-60 years. The bone scans were performed, with intermediate positioning of the subject, at two different anatomic sites of the forearm, three sites of the upper arm, three sites of the shank, and two sites of the thigh, with the respective skeletal sites representing different bone compositions and sizes. According to phantom measurements, the XCT 3000 appeared to be a highly linear, stable, and precise (coefficient of variation [CV] about 0.2%) system in vitro. The soft tissue thickness, however, had a linear effect on density values and a nonlinear effect on BMC, whereas the effect on cross-sectional area was marginal. The in vivo root mean square CV (CVrms) values for the long bone ends ranged from 0.9% (distal tibia) to 2.7% (distal femur) for TrD, from 1.8% (distal femur) to 7.6% (distal radius) for TrA, from 2.0% (distal tibia) to 6.8% (proximal tibia) for CoD, from 1.8% (distal femur) to 4.9% (proximal tibia) for CoA, and from 4.2% (distal tibia) to 7.7% (distal radius) for BSI. The corresponding CVrms values for the long bone shafts ranged from 0.5% (midshaft of humerus) to 1.4% (midshaft of fibula) for CoD, from 1.7% (midshaft of tibia) to 4.6% (proximal shaft of humerus) for CoA, and from 2.5% (midshaft of tibia) to 7.5% (proximal shaft of humerus) for BSI. There was no interoperator effect on precision. This study provided, for the first time, independent precision data for the new XCT 3000 peripheral quantitative computed tomography (pQCT) scanner in various applications of human long bones (radius, ulna, humerus, tibia, fibula, and femur) and gave practical guidelines and procedures on how to employ this versatile method in clinical and research applications. The technical performance of the tested system was excellent and it allowed, with a low radiation dose, precise in vivo evaluation of trabecular and cortical density, cross-sectional area, and BMC of selected skeletal sites. The potential effect of the soft tissue thickness on density and mineral content values need to be recognized. The pQCT measurement seems to be useful in supplementing the integral, planar DXA data and obviously opens new possibilities for clinical practice and research.

Association of leisure time physical activity with the risk of coronary heart disease, hypertension and diabetes in middle-aged men and women

BACKGROUND

The association of physical activity and the risk of coronary heart disease (CHD), hypertension and diabetes has previously been studied mostly in separate follow-up studies. The present analysis focuses on the association between physical activity and these three metabolic diseases in a representative adult cohort.

METHODS

The effect of the total amount and intensity of leisure time physical activity on the risk of the three diseases was studied in a cohort of 1340 men and 1500 women aged 35-63 years.

RESULTS

During the 10 years of follow-up the incidence rates per 1000 person-years for CHD, hypertension and diabetes were 108, 142 and 64 for men and 75, 117 and 54 for women, respectively. In the Cox proportional hazards model the men's total amount of activity was inversely associated with the risk of CHD and hypertension. An age- and smoking-adjusted relative risk of 1.98 (95% confidence interval [CI]: 1.22-3.23) for CHD and age-adjusted risk of 1.73 (95% CI: 1.13-2.65) for hypertension were found for the lowest third total activity group compared with the highest third of total activity. Vigorous activity once or more often a week was inversely associated with the risk of hypertension. For the women both a higher total amount of activity and weekly vigorous activity had an inverse association with the risk of diabetes. An age-adjusted relative risk of 2.64 (95% CI: 1.28-5.44) for diabetes was found for the lowest third activity group compared with the highest third.

CONCLUSIONS

The results suggest a preventive effect of leisure time physical activity on CHD, hypertension and diabetes. This effect may differ among middle-aged men and women and the relative importance of the total amount and the intensity may vary depending on the outcome measure.

High-impact exercise and bones of growing girls: a 9-month controlled trial

The maximum amount of bone a person can obtain during the first two decades of life is an important determinant of bone mass in later life, and an increase in peak bone mass has been associated with decreased risk for osteoporotic fractures. It is known that growth of bone and thus development of peak bone mass are strongly controlled by genetic factors, but information on the role of environmental factors, such as exercise and nutrition, (e.g., exercise) on growing bone is limited. We tested a hypothesis that in growing girls the benefit of mechanical loading on bone mineral mass and bone strength is better before rather than after the menarche. Sixty-four girls (25 premenarcheal, 39 postmenarcheal) carried out a supervised 9-month step-aerobic program (two sessions per week), each session complemented with additional jumps. Sixty-two girls (33 premenarcheal, 29 postmenarcheal) served as controls. Bone mineral content (BMC) at the lumbar spine and proximal femur was measured by dual-energy X-ray absorptiometry (DXA). In addition, the cortical density (CoD, mg/cm3) and cortical cross-sectional area (CoA, mm2) and the density-weighted polar section modulus (BSI, mm3) of the tibial midshaft were determined by peripheral quantitative tomography (pQCT). In the premenarcheal girls, BMC increased statistically significantly more in the trainees than controls at the lumbar spine (p = 0.012) (8.6% vs 5.3%) and femoral neck (p = 0.014) (9.3% vs 5.3%). In the tibial midshaft, the intergroup differences (CoD, CoA and BSI) were not significant. The postmenarcheal girls showed no significant post-training intergroup differences in any of the bone parameters (BMC increased in the lumbar spine 6.0% vs 4.9%; femoral neck 3.4% vs 3.2%; and trochanter 2.6% vs 3.5%). Although a large proportion of bone mineral increase in the growing girls of this study was attributable to growth itself, this 9-month exercise intervention showed that a clear and large additional bone gain could be obtained in exercising premenarcheal girls, but not in exercising postmenarcheal girls. In other words, exercise seemed more beneficial for additional bone mineral acquisition before menarche (i.e., during the growth spurt) rather than after it.

Heat related mortality in warm and cold regions of Europe: observational study

OBJECTIVES

To assess heat related mortalities in relation to climate within Europe.

DESIGN

Observational population study.

SETTING

North Finland, south Finland, Baden-Württemberg, Netherlands, London, north Italy, and Athens.

SUBJECTS

People aged 65-74.

MAIN OUTCOME MEASURES

Mortalities at temperatures above, below, and within each region's temperature band of minimum mortality.

RESULTS

Mortality was lowest at 14.3-17.3 degrees C in north Finland but at 22.7-25.7 degrees C in Athens. Overall the 3 degrees C minimum mortality temperature bands were significantly higher in regions with higher than lower mean summer temperatures (P=0.027). This was not due to regional differences in wind speeds, humidity, or rain. As a result, regions with hot summers did not have significantly higher annual heat related mortality per million population than cold regions at temperatures above these bands. Mean annual heat related mortalities were 304 (95% confidence interval 126 to 482) in North Finland, 445 (59 to 831) in Athens, and 40 (13 to 68) in London. Cold related mortalities were 2457 (1130 to 3786), 2533 (965 to 4101), and 3129 (2319 to 3939) respectively.

CONCLUSIONS

Populations in Europe have adjusted successfully to mean summer temperatures ranging from 13.5 degrees C to 24.1 degrees C, and can be expected to adjust to global warming predicted for the next half century with little sustained increase in heat related mortality. Active measures to accelerate adjustment to hot weather could minimise temporary rises in heat related mortality, and measures to maintain protection against cold in winter could permit substantial reductions in overall mortality as temperatures rise.

Effect of long-term unilateral activity on bone mineral density of female junior tennis players

High peak bone mass in early adulthood is an important protective factor against osteoporotic fractures in later life, but little is known about the effects of exercise on growing bone. The purpose of this cross-sectional study was to determine at which state of maturity (Tanner stage), the areal bone mineral density (BMD) differences between the playing and nonplaying arms of junior tennis players become obvious, and to clarify in each developmental stage which training and background variables, if any, could explain the interindividual differences in bones' response to mechanical loading. Ninety-one 7- to 17-year-old female tennis players and 58 healthy female controls were measured. In each Tanner stage, differences in BMD in playing and nonplaying (dominant and nondominant) arms (proximal humerus, humeral shaft, and distal radius) and BMD of the lumbar spine and nondominant distal radius were compared between the controls and players. Within each Tanner stage of players, the associations between training and background variables and BMD differences were analyzed with Spearman rank correlation coefficients. In players, BMD differences between the playing and nonplaying arms were significant (P < 0.05- < 0.001) in all Tanner stages, with the mean difference ranging from 1.6 to 15.7%. In controls, these dominant-to-nondominant arm differences were clearly smaller (ranging from -0.2 to 4.6%), but significant at some measured sites. In comparison with the relative side-to-side arm differences between the players and controls (i.e., examination of the training effect), the mean difference was not obvious and significant until the adolescent growth spurt (i.e., the girls in Tanner stage III with a mean age of 12.6 years). In the lumbar spine, significant BMD differences between players and controls were not found until Tanner stage IV (mean age 13.5 years; 8.7%, P < 0.05) and V (mean age 15.5 years; 12.4%, P < 0.05). In a nonloaded site of the skeleton (nondominant distal radius), no significant BMD differences were found between the players and controls in any Tanner stage. In the correlation analysis, the Tanner I and II players (mean ages 9.4 and 10.8 years) showed no significant associations between any of the predictive variables and the side-to-side BMD differences, while in Tanner stages III, IV, and V, such associations could be found; the total amount of training hours during the playing career and the number of training sessions per week showed a significant and systematic correlation (rs ranging from 0.43 to 0.80) with the side-to-side BMD differences in several measured bone sites. In conclusion, this study suggests that in a majority of female junior tennis players, the benefit of unilateral activity on bone density does not become clearly evident until the adolescent growth spurt or Tanner stage III. The total amount of training during the player's career and the current training frequency (sessions per week) seem to best explain the training effect on bone tissue, leaving, however, room for speculation on the still unknown factors that modulate the loading response of a growing bone.

Effects of unilateral strength training and detraining on bone mineral density and content in young women: a study of mechanical loading and deloading on human bones

This study assessed the effect of unilateral strength training at 80% one repetition maximum and of detraining on bone mineral density (BMD, g/cm-2) and bone mineral content (sigma BMC, g) in young women. Twelve female physiotherapy students trained their left limb by leg press an average of four times per week for 1 year followed by 3 months of detraining. Twelve students served as controls. Repeated bone measurements were performed by dual energy X-ray absorptiometry of the lumbar spine, femoral neck, distal femur, patella, proximal tibia, and calcaneus. The training increased the muscle strength of the trained limb, and the BMD of the same limb showed a nonsignificant but systematic increase in distal femur, patella, and proximal tibia, and in sigma BMC of the five measured limb sites (considered an index of the total osteogenic effectiveness of the training). Simultaneously, the muscle strength increased in the untrained limb as an evidence of cross-training effect. A corresponding small but systematic increase was also seen in BMD of this limb as well as in sigma BMC. After the cessation of training, leg extension strength was retained but BMD and sigma BMC of the trained and untrained limbs declined towards baseline values in 3 months. The BMD and sigma BMC values in the control group showed an increasing tendency during the follow-up but the changes were less than 1%. The differences of the changes in BMD and sigma BMC between the left and right limb in the control group, as well as between the same limb in the training and control groups were nonsignificant.(ABSTRACT TRUNCATED AT 250 WORDS)

The injury mechanisms of osteoporotic upper extremity fractures among older adults: a controlled study of 287 consecutive patients and their 108 controls

The risk factors for falls in older adults are well known but knowledge on the direct injury mechanisms that result in various osteoporotic fractures has been very sparse. The purpose of this study was therefore to clarify the injury mechanisms of osteoporotic upper extremity fractures of older adults and to compare these mechanisms with those of the control fallers, and in this way to obtain reliable insight into the etiology and pathogenesis of upper extremity fractures and thus to enable fracture prevention. One hundred and twelve patients with a fresh fracture of the proximal humerus, 65 patients with an elbow fracture, 110 patients with a wrist fracture and 108 controls (no fracture, or a fracture other than the case fracture) were interviewed and examined between September 1995 and December 1997. The inclusion criteria of the subjects were that the patient was 50 years of age or older at the time of the accident, and that the fracture/injury had occurred as a result of low-energy trauma (typically a fall from standing height or less) within a week before the interview and examination. In 97% of patients with a proximal humerus or elbow fracture, and in all patients (100%) with a wrist fracture, the fracture was a result of a fall. In the control group this figure was 93%. In a polychotomous logistic regression analysis the intergroup differences in the fall directions (adjusted by gender, age and functional capacity) were statistically highly significant (chi 2 = 43.6, d.f. = 15, p < 0.001). Most of the patients with a proximal humerus fracture or elbow fracture reported that they had fallen 'obliquely forward' (43% and 38%) or 'to the side' (29% and 26%), whereas in the wrist fracture group the main fall direction was also 'obliquely forward' (34%) but the other fall directions (i.e., 'forward', 'to the side', 'obliquely backward' and 'backward') were quite equally represented (13-19%). The odds ratio (OR) for an obliquely forward fall resulting in a proximal humerus fracture was 3.5 [95% confidence interval (CI) 1.4-9.2), as compared with the fall directions of the controls and the 'obliquely backward' fall direction. In a logistic regression analysis the patients with a wrist fracture managed to break their fall (e.g., with an outstretched arm) more frequently than the patients in the other groups (OR 3.9; 95% CI 2.0-7.3). The patients with a proximal humerus fracture, in turn, managed to break their fall less frequently than the controls (OR 0.33; 95% CI 0.14-0.80). The same was true of the patients with an elbow fracture, although the difference was not significant (OR 0.49%; 95% CI 0.19-1.3). As objective evidence for a direct fall-induced impact on the fracture site, 68% of patients with a proximal humerus fracture revealed a fresh subcutaneous hematoma on the shoulder/upper arm, while such a hematoma was rare in the controls (2%) (p < 0.001). Correspondingly, 62% of patients with an elbow fracture showed a similar hematoma on the elbow area, while this was seen in none of the controls (p < 0.001). In patients with a wrist fracture a hand/wrist hematoma was seen in 58% of the victims, as compared with 18% of the controls (p < 0.001). The study shows that the most typical osteoporotic upper extremity fractures of older adults have their specific injury mechanisms. A great majority of these fractures occur as a result of a fall and a subsequent direct impact of the fractured site. Effective fracture prevention could be achieved by minimizing the obvious risk factors of falling and reducing the fall-induced impact force with injury site protection.

Dose-response of physical activity and low back pain, osteoarthritis, and osteoporosis

PURPOSE

The purpose of this study was to examine the evidence for causal relationships between physical activity (PA) and low back pain (LBP), osteoarthritis (OA), and osteoporosis (OP), and for dose-response relations involved.

METHODS

Computer database searches and personal retrieval systems were used to locate relevant literature.

RESULTS

PA can be effective in preventing LBP (Category A) but prolonged, heavy loading can lead to LBP (Category C). Specific exercises have not been found effective in treatment of acute LBP (Category A), but PA can be effective in chronic LBP (Category B), especially for diminishing the effects of deconditioning. No evidence indicates that PA directly prevents OA. Large amounts of intensive PA involving high impacts or torsional loadings or causing injuries increases risk of OA (Category C). Light or moderate PA does not increase the risk of OA (Category C). PA can be effective in the treatment and rehabilitation of OA (Category B). High-intensity loading is osteogenic and possibly useful in prevention of OP (Category A) at the loaded site, but low to moderate loading is not osteogenic (Category D). Static efforts and slow movements are ineffective or less effective than fast application of force (Category B). The types of PA to attain the effects mentioned above are known except in the case of prevention of LBP, but dose-response relationships are poorly known; at best, semiquantitatively on the basis of just a few studies.

CONCLUSION

Given the shown primary and/or secondary preventative effectiveness of PA regarding LBP, OA, and OP, research to elucidate the inadequately known dose-response relations should be given high priority.

Osteoporotic fractures of the proximal humerus in elderly Finnish persons: sharp increase in 1970-1998 and alarming projections for the new millennium

We determined the current trends in the number and incidence of osteoporotic fractures of the proximal humerus in Finland by collecting from the National Hospital Discharge Register all patients 60 years of age or more who were admitted to Finnish hospitals in 1970-1998 for primary treatment of such fractures. The fracture was defined osteoporotic if it was caused by a low-energy trauma only, i.e., a fall from standing height or less. The number and incidence (per 10(5) persons) of fractures increased sharply from 208 (number) and 32 (incidence) in 1970 to 1,105 and 110 in 1998. Even after the age-adjustment, the incidence of fractures showed a clear increase: in women from 50 in 1970 to 133 in 1998, and in men from 14 in 1970 to 49 in 1998. If this trend continues, there will be three times more osteoporotic fractures of the proximal humerus in Finland in the year 2030 than there were in 1998.

A 2-km walking test for assessing the cardiorespiratory fitness of healthy adults

A simple walking test was developed with 159 (females = 80, males = 79) healthy 20-65-year-old subjects. All the subjects first walked the distances of 1.0, 1.5 and 2.0 km on a flat dirt road. Half of the participants were tested in the laboratory for maximal oxygen uptake (VO2max), and the 2-km test was repeated again twice. In a comparison of the three distances, the 2-km test was repeatable, the most preferable subjectively and the most accurate in predicting VO2max. A sex-specific prediction model including walking time, heart rate at the end of the walk, age and body mass index predicted 73-75% of the variance in VO2max (ml.kg-1.min-1) and that with body weight 66-76%, with a standard error of estimate of the order of 9-15% of the mean. The cross-validation of the models yielded reasonable accuracy in obese men and women and in moderately active men, and less accuracy in moderately active women and highly active men. These results suggest that a fast 2-km walk supplemented with simple measurements is a feasible and accurate alternative for determining the cardiorespiratory fitness of healthy adults.

Dimensions and estimated mechanical characteristics of the humerus after long-term tennis loading

This study evaluated the effects of long-term unilateral physical activity (tennis) on the playing arm humerus. Total lengths of both humeri, site-specific widths, and the bone mineral contents (BMC) at the proximal, middle, and distal parts of the bones were measured using dual-energy X-ray absorptiometry (DXA). Bone mineral apparent density (BMAD), cortical wall thickness (CWT), cross-sectional moment of inertia (CSMI), and section modulus (Z) were approximated from the DXA data for describing the bone's mechanical characteristics more concretely. The study population consisted of 67 healthy, competitive tennis players (17 young men with a mean age [+/- SD] of 25 +/- 5 years, 30 young women with a mean age of 19 +/- 3 years, and 20 older women with a mean age of 43 +/- 5 years) and 57 sedentary controls (16 young men with mean age of 25 +/- 5 years, 25 years, 25 young women with a mean age of 21 +/- 3 years, and 16 older women with mean age of 39 +/- 6 years). All the players had competitive playing histories greater than 4 years. The young male and female players had started their playing careers in childhood (men at the age of 10 +/- 3 years, women 9 +/- 2 years), while the older female players started the training at adulthood (29 +/- 6 years). The playing-to-nonplaying or dominant-to-nondominant arm differences in humeral length ranged from +0.2 to +1.4%, the difference being significant in young male players (+1.4%), young female controls (+1.1%), and older female players (+0.7%). When comparing players' relative side-to-side length differences with those of the controls, no significant differences were found. Significant side-to-side differences in humeral width were observed in all groups except male controls. Compared with the controls, the relative side-to-side width differences were significantly larger at the proximal humerus of the young male players (controls +1.2%, players +3.7%) and the distal humerus of young female players (controls -0.2%, players +1.6%). Compared with the controls, the players' relative side-to-side differences in BMC (range, +7.6 to +25.2%), BMD (+5.8 to +22.5%), BMAD (+5.5 to +20.4%), CWT (+6.9 to +45.2%), CSMI (+7.8 to +26.4%), and Z (+3.0 to +21.7%) were significantly larger in all measured humeral sites except BMAD in the distal humeri of the older female players. These relative side-to-side differences were clearly and significantly larger in the young players (+11.7 to +45.2%) than in the older players (+3.0 to +12.4%). In conclusion, long-term intensive tennis playing, especially if started in childhood or adolescence, clearly increases the humeral BMC, BMD, and CWT but seems to have only a minor effect on the width of this particular bone. In this respect, there seems to be no sex difference. However, along with the increases in mineral mass and density, the changes in bone width are important in increasing the bending stiffness and strength of the humerus. In older players, the relative side-to-side differences are at the same level or only slightly larger than those in their age-matched controls. This suggests that even intense physical loading of a mature bone is only marginally better in increasing the bone mass, bone density, and CWT of the target bone than the normal daily use of the dominant extremity.

The site-specific effects of long-term unilateral activity on bone mineral density and content

This study assessed the site-specific effects of long-term tennis playing on the bone mineral density (BMD) and content (BMC) of upper extremities in male Finnish top-level players using a dual energy x-ray absorptiometric (DXA) scanner. In players (n = 20), the BMDs and BMCs were significantly higher in each bone of the playing right extremity (p < 0.05-0.001), the side-to-side difference being largest in the humeral shaft (BMD + 25.4%, BMC + 28.7%) and proximal humerus (BMD + 14.4%, BMC + 20.5%), and smallest in the ulnar shaft (BMD + 3.1%, BMC + 7.5%) and distal ulna (BMD + 6.3%, BMC + 7.8%). In sex-, age-, weight-, and height-matched controls (n = 20), the right-to-left differences were small ranging from 0.0% to + 6.4% (average +3%). The number of training sessions per week was the only variable in muscle strength and training history assessment which showed, in several anatomic sites, a significant correlation with the relative bone mineral variables (r = 0.460-0.627, p < 0.05-0.001). In conclusion, long-term unilateral tennis activity had a clearly positive effect on the BMD and BMC of the bones of the playing extremity. The effect was very site-specific, being greatest in the humerus and smallest in the ulna. The effect was always greater in BMC than BMD indicating that the excess mineral was used not only for condensation of the bone tissue, but also for enlargement of bone dimensions.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term unilateral loading and bone mineral density and content in female squash players

We examined 19 female Finnish national level squash players and 19 healthy female controls with a dual energy x-ray absorptiometric (DXA) scanner for the determination of the association between long-term unilateral activity and bone mineral density (BMD) and content (BMC) of the upper extremities. In players, the BMDs and the BMCs were significantly higher in each bone site of the playing extremity. The side-to-side difference was largest in the proximal humerus (BMD 15.6%, BMC 17.8%) and smallest in the ulnar shaft (BMD 5.6%, BMC 7.3%). In sex-, age-, weight-, and height-matched controls, the side-to-side differences were significantly smaller, ranging from 1.6% to 4.1%. The number of training years and elbow flexion strength correlated positively with the relative BMD and BMC in the humerus of the playing arm (r = 0.632-0.685). The starting age of training in turn correlated negatively (r = -0.483 to -0.577) with these bone parameters. Significantly larger side-to-side differences (average 22%) were found in players who had started their career before or during menarche than in those who had begun the training 1 year or more after the menarche (9%). These findings suggest that the bones of the playing extremity clearly benefit from active squash playing. The benefit is largest in humerus and smaller in the bone of the forearm. The benefit of playing is stronger if the athlete has started the training at or before menarche than after it.(ABSTRACT TRUNCATED AT 250 WORDS)

Association between leisure time physical activity and 10-year body mass change among working-aged men and women

OBJECTIVE

To determine whether habitual leisure time physical activity and body mass change of working-aged men and women are associated.

DESIGN

Prospective 10 y follow-up study.

SUBJECTS

A regionally representative cohort of 19-63 y old men (n = 2564) and women (n = 2695) in three municipalities in Finland.

MEASUREMENTS

The main outcome measures were average body mass change during the 10 y of follow-up and the clinically significant body mass gain defined as a body mass gain of 5 kg or more during the follow-up and a body mass index of 26 or higher at the end of the follow-up. Leisure time physical activity was determined from self-administered questionnaires.

RESULTS

After adjustment for the potential confounders, the logistic regression analysis showed that the men and women with no regular weekly activity at the end of the follow-up had an odds ratio of 2.59 (95% confidence interval, 1.69-3.97) and 2.67 (1.65-4.31), respectively for clinically significant body mass gain in comparison with the most active groups. The men who had decreased their activity during the 10 y follow-up had an odds ratio of 1.96 (1.39-2.75), and the men who were physically inactive all the time had an odds ratio of 1.62 (1.18-2.20) for clinically significant body mass gain when compared with the subjects who were active all the time. Among the women the odds ratios for clinically significant body mass gain after adjustment for potential confounders were 2.49 (1.72-3.60) and 1.61 (1.17-2.21), respectively.

CONCLUSION

These findings are consistent with the hypothesis that regular physical activity prevents body mass gain and physical inactivity is a risk factor for body mass gain and obesity among adults.