Hip fractures are recognized to be a major public health problem in many Western nations, most notably those in North America, Europe and Oceania. Incidence rates for hip fracture in other parts of the world are generally lower than those reported for these predominantly Caucasian populations, and this has led to the belief that osteoporosis represents less of a problem to the nations of Asia, South American and Africa. Demographic changes in the next 60 years, however, will lead to huge increases in the elderly populations of those countries. We have applied available incidence rates for hip fracture from various parts of the world to projected populations in 1990, 2025 and 2050 in order to estimate the numbers of hip fractures which might occur in each of the major continental regions. The projections indicate that the number of hip fractures occurring in the world each year will rise from 1.66 million in 1990 to 6.26 million by 2050. While Europe and North America account for about half of all hip fractures among elderly people today, this proportion will fall to around one quarter in 2050, by which time steep increases will be observed throughout Asia and Latin America. The results suggest that osteoporosis will truly become a global problem over the next half century, and that preventive strategies will be required in parts of the world where they are not currently felt to be necessary.

Vertebral fractures are the classic hallmark of osteoporosis, yet little is known of their epidemiology. The incidence of clinically diagnosed vertebral fractures was therefore directly assessed in the predominantly white (European descent) population of Rochester, Minnesota. Altogether, 341 Rochester residents were radiologically diagnosed for the first time with one or more vertebral fractures in the 5 year study period, 1985-1989. The overall age- and sex-adjusted incidence rate was 117 per 100,000 person-years (95% CI, 105 to 130). The age-adjusted rate in women (145 per 100,000 person-years) was almost twice that in men (73 per 100,000 person-years). Of all fractures, 47 (14%) followed severe trauma, 282 (83%) followed moderate or no trauma, and 12 (3%) were pathologic. Incidence rates for fractures following moderate trauma were higher in women than in men and rose steeply with age in both genders. In contrast, fractures following severe trauma were more frequent in men, and their incidence increased less with age. These Rochester rates are greater than those previously reported from studies in Britain and Sweden but lower than the incidence rates extrapolated from a prevalence study in this population.

There is a need to identify vertebral fractures from radiographs taken at a single point in time, but considerable controversy surrounds the methods to be used. We extended a data set to comprise baseline radiographs of the thoracic and lumbar spine on an age-stratified random sample of 762 Rochester, Minnesota, women and used revised methods to define vertebral deformities morphometrically. Changes in the method of measuring vertebral heights, changes in the source of normal values for vertebral measurements and changes in the criteria for assessing vertebral deformity had little impact on estimated prevalence and incidence in this population. The prevalence of any vertebral deformity was estimated at 25.3 per 100 Rochester women aged 50 years and over (95% CI, 22.3-28.2), while the incidence of a new deformity in this group was estimated at 17.8 per 1000 person-years (95% CI, 16.0-19.7). Projected nationally, these data suggest that over 500,000 white women in the United States develop vertebral deformities for the first time each year and that over 7 million white women aged 50 years and over might be affected at any given time. These estimates are limited by the absence of a reliable 'gold standard' with which to determine false positive and false negative rates associated with this or any other morphometric method. Information on the health consequences of vertebral deformities of various sorts would be most helpful in choosing between alternative approaches to defining them.

This population-based study documents an increase in most types of fractures following the occurrence of a clinically recognized vertebral fracture among 820 Rochester, Minnesota, residents. During 4349 person-years of follow-up, 896 new fractures were observed. Relative to incidence rates in the community, there was a 2.8-fold increase in the risk of any fracture, which was greater in men (standardized incidence ratio (SIR), 4.2; 95% CI, 3.2-5.3) than women (SIR, 2.7; 95% CI, 2.4-3.0). The estimated cumulative incidence of any fracture after 10 years was 70%. The greatest increase in risk was for subsequent fractures of the axial skeleton, in particular a 12.6-fold increase (95% CI, 11-14) in additional vertebral fractures. There was a lesser increase in most limb fractures, including a 2.3-fold increase (95% CI, 1.8-2.9) in hip fractures and a 1.6-fold increase (95% CI, 1.01-2.4) in distal forearm fractures. There was a slightly greater association with distal forearm fractures among those whose first vertebral fracture occurred before age 70 years but a similar relationship with hip fractures, including cervical and intertrochanteric hip fractures separately, regardless of age at the initial vertebral fracture. There was also an equivalent increase in subsequent fracture risk whether the initial vertebral fracture was attributed to severe or moderate trauma. These data show that vertebral fractures represent an important risk factor for fractures in general, not just those of the spine and hip.

Objective-The aim was to describe the sex and socioeconomic differences in patterns of physical activity at work and in leisure time of men and women aged 36 years, and to investigate factors in childhood and adolescence which predict high rates of participation in sports and recreational activities in later life.Design-Data collected in childhood, adolescence, and at 36 years on members of a national prospective birth cohort study were used.Setting-The population sample was resident in England, Scotland, and Wales.Subjects-A stratified sample of about 3500 men and women was studied regularly from birth until 43 years.Measurements and main results-More men than women reported high rates of sports and recreational activities, gardening, and do-it-yourself. In contrast women reported higher rates of bicycling and walking. Higher levels of education were associated with frequent participation in sports. Individuals often engaged in one type of activity without necessarily engaging in other types. Those who were most active in sport had been above average at sports in school, more outgoing socially in adolescence, had fewer health problems in childhood, were better educated, and had more mothers with a secondary education than those who were less active.Conclusions-Studies that examine the relationship between physical activity and chronic disease should consider a broad range of pursuits rather than extrapolating from only one area of physical activity, and in their explanations should take account of the possible role of childhood characteristics. The findings suggest the importance of developing skills and habits in childhood as well as of encouraging healthier exercise habits in adults who may have had few opportunities or low motivation previously.