Symptomatic Fracture Incidence in Southern Tasmania: Does Living in the Country Reduce Your Fracture Risk?

There are limited data describing urban–rural differences in fracture incidence and the overall effect remains controversial. The aim of this study was to compare symptomatic fracture incidence occurring in geographically defined rural (n= 34 619) and urban (n = 194 974) populations of Southern Tasmania from July 1, 1997 to June 30, 1999. Fractures were ascertained by reviewing reports from all the radiology providers within the area. In the 2-year study time frame there were 3644 fractures in males and 2657 fractures in females. Fracture incidence was significantly higher in urban compared with rural populations in both sexes (male: RR 1.60, 95% CI 1.47–1.75; female: RR 1.77, 95% CI 1.58–1.98). This higher urban fracture incidence was present across all age groups and all fracture types with the exception of knee and pelvis fractures in males (although not all were statistically significant). In addition, urban men >50 years old had a higher fracture incidence than rural women >50 years old (RR 1.25, 95% CI 1.05–1.50), suggesting that in later life the factors responsible for the urban–rural difference are able to offset completely the effect of gender. While some of the reduced fracture incidence in the rural population may be explained by urban drift and underreporting of minor fractures such as foot fractures, the overall pattern of higher fracture risk was very consistent, suggesting a real difference in whole-of-life symptomatic fracture incidence. Further research at an individual level is required to determine what factors account for these large urban–rural differences, as they imply a substantial potential for fracture prevention. Received: 28 November 2001 / Accepted: 5 April 2001     

Prevalent Vertebral Deformity Predicts Incident Hip though not distal Forearm Fracture: Results from the European Prospective Osteoporosis Study

The presence of a vertebral deformity increases the risk of subsequent spinal deformities. The aim of this analysis was to determine whether the presence of vertebral deformity predicts incident hip and other limb fractures. Six thousand three hundred and forty-four men and 6788 women aged 50 years and over were recruited from population registers in 31 European centers and followed prospectively for a median of 3 years. All subjects had radiographs performed at baseline and the presence of vertebral deformity was assessed using established morphometric methods. Incident limb fractures which occurred during the follow- up period were ascertained by annual postal questionnaire and confirmed by radiographs, review of medical records and personal interview. During a total of 40 348 person-years of follow-up, 138 men and 391 women sustained a limb fracture. Amongst the women, after adjustment for age, prevalent vertebral deformity was a strong predictor of incident hip fracture, (rate ratio (RR) = 4.5; 95% CI 2.1–9.4) and a weak predictor of ‘other’ limb fractures (RR = 1.6; 95% CI 1.1–2.4), though not distal forearm fracture (RR = 1.0; 95% CI 0.6–1.6). The predictive risk increased with increasing number of prevalent deformities, particularly for subsequent hip fracture: for two or more deformities, RR = 7.2 (95% CI 3.0–17.3). Amongst men, vertebral deformity was not associated with an increased risk of incident limb fracture though there was a nonsignificant trend toward an increased risk of hip fracture with increasing number of deformities. In summary, prevalent radiographic vertebral deformities in women are a strong predictor of hip fracture, and to a lesser extent humerus and ‘other’ limb fractures; however, they do not predict distal forearm fractures. Received: 23 February 2000 / Accepted: 11 August 2000     

Survival after Hip Fracture: Short- and Long-Term Excess Mortality According to Age and Gender

The purpose of this study was to analyze the excess mortality after hip fracture and to reveal whether, and eventually when, the excess mortality vanished in different groups of age and gender. A population-based, prospective, matched-pair, cohort study among persons 50 years of age and older was conducted involving 1338 female and 487 male hip fracture patients with 11 086 and 8141 controls respectively. Occurrence of hip fracture and mortality were recorded from 1986 until 1995. We studied the excess mortality of the hip fracture patients versus controls by using Kaplan–Meier curves and extended Cox regression with hip fracture (yes/no) as time-dependent covariate. The male hip fracture patients had higher mortality than the women the first year after the injury, irrespective of age, both in absolute terms (31% and 17% respectively) and relative to their age-matched controls. The relative risk (RR) of dying within 1 year for hip fracture patients versus controls was 3.3 (95% confidence interval (CI) 2.1–5.2) for women and 4.2 (95% CI 2.8–6.4) for men below 75 years of age. The corresponding figures for persons 85 years and older were 1.6 (95% CI 1.2–2.0) for women and 3.1 (95% CI 2.2–4.2) for men. All groups of age and gender, except women 85 years and older, had a large and significant excess mortality lasting for many years after the hip fracture – at least 5–6 years for women below 75 years of age (RR = 3.2, 95% CI 1.9–5.6). The excess mortality after hip fracture for women 85 years and older had vanished after 3 months (RR = 1.0, 95% CI 0.8–1.1). When referring to the excess mortality after hip fracture it is therefore necessary to specify sex, age and time since injury. Received: 15 September 1998 / Accepted: 23 December 1998     

Changes in Hip Fracture Epidemiology: Redistribution Between Ages, Genders and Fracture Types

After several reports of increasing hip fracture incidence some studies have suggested a trend-break. In a previous study of hip fractures we forecast a 70% increase in the total number of fractures from 1985 up to year 2000. We therefore studied the incidence trend for the last 15 years and supply a new prognosis up to year 2010. We recorded all incident hip fractures treated in the county of ?sterg?tland, Sweden (≈ 400 000 inhabitants) 1982–96. A total of 11 517 hip fractures in men and women aged 50 years and above were included in the study after cross-validation between a computerized register of radiologic investigations and the hospital records. The projected number of fractures up to year 2010 was estimated by a Poisson regression model, considering both age and year of fracture in every single year 1982–96 for the respective fracture type and gender, and applied to the projected population. The annual number of hip fractures increased by 39% in men and 25% in women during the study period. Amongst men, the age-adjusted incidence of cervical fractures increased from 188 to 220/100 000 and of trochanteric fractures from 138 to 170/100 000. In women the incidence of cervical fractures decreased from 462/100 000 to 418/100 000 and of trochanteric fractures from 407/100 000 to 361/100 000. Cervical/trochanteric fracture incidence rate ratio leveled off, and also the female/male fracture rate ratio declined. A prognosis assuming that the incidence development will continue as during 1982–96, and a population in agreement with the forecast, predicts that the total age- and sex-adjusted number of hip fractures will decrease by 11% up to year 2010 compared with 1996. In women and men, however, a decrease of 19% and an increase of 7% respectively were projected. If the age- and sex-specific incidence remains at the same level as at the end of the study period, no significant change in the total numbers will occur. A trend-break was thus found in hip fracture incidence for women but not for men. Whether this is due to therapeutic and/or preventive measures in women is unknown. According to the most probable scenario a substantial increase in male trochanteric fractures (36%) is expected up to 2010, while all other hip fractures in both genders will decrease by 4–32% resulting in a total reduction of 11%. Received: 17 November 2000 / Accepted: 2 July 2001     

Hip Fracture Incidence Rates in Singapore 1991–1998

In this population-based study, we determined the incidence rates of hip fracture among Singapore residents aged 50 years and above. Information was obtained from a centralized database system which captured admissions with the primary diagnosis of a closed hip fracture (ICD-9 codes 820, 820.0, 820.2 and 820.8, n= 12 927) from all health care establishments in the country from 1991 to 1998 inclusive. After removing duplicates, hospital transfers, readmissions and non-acute care admissions, the total number of hip fractures was 9406. Based on the national population census 1990 (n= 464 100) and yearly population estimates, the age-adjusted hip fracture rates for 1991–1998 (per 100 000) were 152 in men and 402 in women. This was 1.5 and over 5 times higher than corresponding rates in the 1960s. From 1991 to 1998, these hip fracture rates tended to increase by 0.7% annually in men and by 1.2% annually in women. Among the three major racial groups, in men, the Chinese had significantly higher age-adjusted hip fracture rates (per 100 000): 168 (95% confidence interval (CI) 158–178) compared with 128 (95% CI 105–152) for Indians and 71 (95% CI 54–88) for Malays. A similar pattern occurred in women: 410 (95% CI 395–425), for Chinese compared with 361 (95% CI 290–432) for Indians and 264 (95% CI 225–303) for Malays. Since the 1960s, the main increases in hip fracture rates have been seen in the Chinese and Malays, with the rates in Indians appearing to decrease. Hip fracture incidence rates in Singapore have risen rapidly over the past 30–40 years, particularly in women, and are now among the highest in Asia. Significant racial differences in hip fracture rates occur within the same community. Time trends in hip fracture rates differed between races. Received: 9 March 2000 / Accepted: 5 September 2000     

Does a Fracture at One Site Predict Later Fractures at Other Sites? A British Cohort Study

The extent to which a fracture at one skeletal site predicts further fractures at other sites remains uncertain. We addressed this issue using information from the UK General Practice Research Database, which contains the medical records of general practitioners; our study population consisted of all patients aged 20 years or older with an incident fracture during 1988 to 1998. We identified 222 369 subjects (119 317 women, 103 052 men) who had sustained at least one fracture during follow-up. There was a 2- to 3-fold increase in the risk of subsequent fractures at different skeletal sites. A patient with a radius/ulna fracture had a standardized incidence ratio (SIR) of 3.0 (95% confidence interval 2.9–3.1) for fractures at a different skeletal site; for initial vertebral fracture, this ratio was 2.9 (2.8–3.1) and for initial femur/hip fracture it was 2.6 (2.5–2.7). The SIRs were generally higher among men than women. Men aged 65–74 years with a radius/ulna fracture or vertebral fracture had substantially higher rates of subsequent femur/hip fractures than expected; SIRs were 6.0 (3.4–9.9) and 13.4 (7.3–22.5). Corresponding SIRs among women of similar age were 3.3 (2.8–3.9) and 5.8 (4.1–8.1), respectively. Men and women aged 65 years or older with a vertebral fracture had a 5-year risk of femur/hip fracture of 6.7% and 13.3%, respectively. Our results indicate that fractures at any site are strong risk factors for subsequent fractures, among both elderly men and women. Received: 19 November 2001 / Accepted: 13 February 2002     

Forearm Fractures as Predictors of Subsequent Osteoporotic Fractures

To assess the ability of distal forearm fractures to predict future fractures, we conducted a population-based retrospective cohort study among the 1288 residents (243 men, 1045 women) of Rochester, Minnesota age 35 years or older who experienced their first distal forearm fracture in 1975–94. During 9664 person-years of follow-up, 548 patients experienced 1109 subsequent fractures, excluding 195 that occurred on the same day as the index forearm fracture. The cumulative incidence of any subsequent fracture was 55% by 10 years and 80% by 20 years following the initial distal forearm fracture. Compared to expected fracture rates in the community, the risk of a hip fracture following the index forearm fracture was increased 1.4-fold in women (95% CI, 1.1–1.8) and 2.7-fold in men (95% CI, 0.98–5.8). In women, the risk of hip fracture differed by age, as we had found in a previous study. Women over age 70 had a 1.6-fold increase (95% CI, 1.2–2.0) in subsequent hip fracture risk whereas women who sustained their first forearm fracture before age 70 years did not have significantly increased risk. By contrast, vertebral fractures were significantly increased at all ages, with a 5.2-fold increase (95% CI, 4.5–5.9) in risk among women and a 10.7-fold increase (95% CI, 6.7–16.3) among men following a first distal forearm fracture. The increased risk in men suggests that a sentinel forearm fracture should not be ignored. Among the women, we also found a missed opportunity for intervention as hormone replacement therapy was underutilized. Received: 8 May 1998 / Accepted: 16 October 1998     

Quantitative Ultrasound and Bone Densitometry to Evaluate the Risk of Nonspine Fractures: A Prospective Study

The ability of quantitative ultrasound (QUS) to estimate the risk of osteoporotic fractures was evaluated in a prospective study over a mean time of 5.47 years in 254 postmenopausal women (mean age 58.06 ± 7.67 years). Baseline measurements of ultrasound transmission velocity (UTV) and bone mineral density (BMD) were taken at the distal radius (DR). UTV was also measured at the patella (P). Fifty nonspine fractures due to minor trauma were detected during annual check-ups with an incidence of 3.59/year. Fractures occurred in older women with a lower BMD and QUS. Using Cox regression analysis the relative risk (RR) per 1 standard deviation (SD) decrease in the unadjusted QUS and BMD measurements was: BMD-DR = 3.56, 95% confidence interval (CI) 1.57–8.09; UTV-DR = 5.35, 95% CI 2.07–13.83; UTV-P = 4.49, 95% CI 2.08–9.68. The relationship between BMD and QUS variables and fracture risk persisted after adjusting for potential confounders apart from previous fractures, giving the following RR: BMD-DR = 2.99, 95% CI 1.06–8.41; UTV-DR = 3.69, 95% CI 1.18–11.49; UTV-P = 3.89, 95% CI 1.53–9.90. Correcting also for previous fractures, only UTV-P remained an effective predictor of fracture risk even after QUS measurement correction for BMD. Wrist fractures were best related to BMD-DR (RR 7.33, 95% CI 1.43–37.50) and UTV-DR (RR 10.94, 95% CI 1.10–108.45), while hip and ankle fractures were significantly associated only with UTV-P (hip: RR 32.14, 95% CI 1.83–562.80; ankle: RR 17.60, 95% CI 1.78–173.79). The combined use of BMD and QUS is a better predictor of fracture risk than either technique used separately. Comparison of the areas under the receiver operating characteristic (ROC) curves did not show differences in the ability of BMD and QUS to correctly distinguish fractures. In conclusion, QUS predicts fracture risk in osteoporotic women at least as well as BMD. UTV-DR and BMD-DR are good predictors of wrist fractures, while UTV-P is strongly related to hip and ankle fractures. QUS and BMD combined improve the diagnostic ability of each technique individually. Received: 27 April 1999 / Accepted: 3 December 1999     

Risk Factors for Perimenopausal Fractures: A Prospective Study

This prospective study was aimed at determining the risk factors for the development of fractures in perimenopausal women. The study group (n= 3068) was comprised of a stratified population sample of women aged between 47 and 56 years. During the follow-up period of 3.6 years, 257 (8.4%) of the women sustained a total of 295 fractures. After adjustment for covariates, the relative risk (RR) of sustaining a fracture was found to be 1.4 [95% confidence interval (CI) 1.2–1.6] for a 1 standard deviation (SD) decrease in the spinal and femoral neck bone mineral density (BMD). Women with a previous fracture history were found to have an increased risk of fracture [RR 1.7 (95% CI 1.3–2.2)] and those reporting three or more chronic illnesses exhibited a RR of 1.4 (95% CI 1.0–1.9). Women not using hormone replacement therapy (HRT) had a RR of 1.5 (95% CI 1.1–2.2) for all fracture types. When osteoporotic fractures (vertebral, hip, proximal humerus and wrist fractures; n= 98) were used as an endpoint, the independent risk factors were found to be a low BMD (RR for a 1 SD decrease in both spinal and femoral neck BMD was 1.6, 95% CI 1.3–2.0), a previous fracture history (RR 1.9, 95% CI 1.3–2.9) and nonuse of HRT (RR 2.2, 95% CI 1.3–4.0). The independent risk factors for all other fractures (n = 158) were a low BMD (RR for a 1 SD decrease in the spinal BMD was 1.4, 95% CI 1.2–1.6 and in the femoral neck BMD was 1.3, 95% CI 1.1–1.5), a previous fracture history (RR 1.6, 95% CI 1.1–2.2), smoking (RR 1.8, 95% CI 1.1–2.7) and having had three or more chronic illnesses (RR 1.6, 95% CI 1.1–2.2). Weight, height, age, menopausal status, maternal hip fracture, use of alcohol, coffee consumption or dietary calcium intake were not independently associated with the development of any particular type of fracture. We conclude that the independent risk factors for perimenopausal fractures are a low bone density, previous fracture history, nonuse of HRT, having had three or more chronic illnesses and smoking, the gradient of risk being similar for spinal and femoral neck BMD measurements in the perimenopausal population. The risk factors are slightly different for perimenopausal osteoporotic than for other types of fractures. Received: 6 April 1999 / Accepted: 18 August 1999     

Femoral Bone Mineral Density, Neck-Shaft Angle and Mean Femoral Neck Width as Predictors of Hip Fracture in Men and Women

The effect of femoral bone mineral density (BMD) and several parameters of femoral neck geometry (hip axis length, neck–shaft angle and mean femoral neck width) on hip fracture risk in a Spanish population was assessed in a cross-sectional study. All parameters were determined by dual-energy X-ray absorptiometry. There were 411 patients (116 men, 295 women; aged 60–90 years) with hip fractures in whom measurements were taken in the contralateral hip. Controls were 545 persons (235 men, 310 women; aged 60–90 years) who participated in a previous study on BMD in a healthy Spanish population. Femoral neck BMD was significantly lower, and neck–shaft angle and mean femoral neck width significantly higher, in fracture cases than in controls. The logistic regression analysis adjusted by age, height and weight showed that a decrease of 1 standard deviation (SD) in femoral neck BMD was associated with an odds ratio of hip fracture of 4.52 [95% confidence interval (CI) 2.93 to 6.96] in men and 4.45 (95% CI 3.11 to 6.36) in women; an increase of 1 SD in neck–shaft angle of 2.45 (95% CI 1.73 to 3.45) in men and 3.48 (95% CI 2.61 to 4.65) in women; and an increase of 1 SD in mean femoral neck width of 2.15 (95% CI 1.55 to 2.98) in men and 2.40 (95% CI 1.79 to 3.22) in women. The use of a combination of femoral BMD and geometric parameters of the femoral neck except for hip axis length may improve hip fracture risk prediction allowing a better therapeutic strategy for hip fracture prevention. Received: 16 September 1999 / Accepted: 22 February 2000     

Weight Variability, Weight Change and the Incidence of Hip Fracture: A Prospective Study of 39000 Middle-aged Norwegians

There is an increased risk of hip fracture and low bone mass in thin individuals. An association between weight loss and hip fracture has also been reported. In addition, it has been suggested that weight cycling might lead to bone loss. We studied weight variability and change in 19938 women and 19151 men who all attended three consecutive health examinations during an average period of 12 years, and assessed the effect of these on the incidence of hip fracture during a subsequent follow-up. Mean age at start of follow-up was 48.6 years in women and 48.5 years in men. For each subject weight variability and linear trend in weight change between the three examinations were assessed by linear regression of weight versus time. The cohort was followed on average 11.6 years from the third examination with respect to hip fracture. During follow-up, 148 hip fractures were identified in women and 59 in men. In both sexes, those with most weight variability had increased risk of fracture (relative risk (RR) = 2.07, 95% confidence interval (CI) 1.24–3.46 in women, and RR = 2.70, 95% CI 1.25–5.86 in men, high vs low quarter of weight variability). Overall, the effect of weight variability was not affected by adjustment for body mass index and linear trend in weight change. In men, there was also an association between weight loss and hip fracture. In summary, high weight variability defined a group with increased risk of hip fracture in this middle-aged cohort. The effect was independent of body mass index and linear trend in weight change. Whether weight variability leads to increased risk of fracture per se or whether it defines a group with otherwise increased risk of fracture is not known, and needs further investigation. Received: 14 October 1997 / Accepted: 8 January 1998     

Ultrasound Measurements for the Prediction of Osteoporotic Fractures in Elderly People

In this prospective study we investigated the predictive value of quantitative ultrasound (QUS) measurements and other potential predictors of osteoporotic fractures in the elderly. During a 1-year period, 710 participants (132 men and 578 women), aged 70 years and older (mean age ± SD: 82.8 ± 5.9), were recruited from seven homes and apartment houses for the elderly. QUS measurements (broadband ultrasound attenuation (BUA) and speed of sound (SOS)) were assessed with a clinical bone densitometer. A structured questionnaire was used to collect information on other potential predictors. Follow-up of fractures was done each half year by telephone interviews. During the study period (median follow-up 2.8 years, maximum 3.7 years), 30 participants had a first hip fracture and 54 suffered from a first other nonspinal fracture. Cox regression analyses, adjusted for age and sex, showed that the relative risk (RR) of hip fracture for each standard deviation reduction was 2.3 (95% CI, 1.4–3.7) for BUA and 1.6 (95% CI, 1.1–2.3) for SOS. Slightly weaker relationships were found for any fracture (BUA: RR, 1.6; 95% CI, 1.2–2.1; SOS: RR, 1.3; 95% CI, 1.0–1.6). Multivariable analyses identified low BUA values and immobility as the strongest predictors for hip fractures and any fracture. Female gender proved to be the strongest predictor for other nonspinal fractures. It can be concluded that QUS measurements can predict the risk for hip fracture and any fracture in elderly people. Received: 23 July 1998 / Accepted: 19 November 1998     

Characteristics of Falls and Risk of Hip Fracture in Elderly Men

The steep rise in hip fracture incidence rates with age is not fully explained by an increase in the frequency of falls or by reduction in bone mineral density, suggesting that circumstances of falls may also affect the risk of hip fracture. Previous studies conducted mainly among women have identified the importance of the orientation of a fall in the etiology of hip fracture. In this case–control study among men of 45 years and older, we evaluated how the circumstances of falls affect the risk of hip fracture. We compared 214 cases with hip fracture due to a fall with 86 controls who had fallen within the past year but did not sustain a hip fracture. As expected, in multivariable age-adjusted analyses men who reported hitting the hip/thigh in a fall had a markedly elevated risk of hip fracture (OR = 97.8; 95% CI = 31.7–302). Hitting the knee in a fall was associated with reduced risk (OR = 0.24; 95% CI = 0.09–0.67). Other factors that were associated with reduced risk of hip fracture among men who fell were more hours of physical activity in the past year (OR = 0.84; 95% CI = 0.73–0.97, for each additional 4 h per week), a greater body mass index (OR = 0.60; 95% CI = 0.40–0.90, for each additional 4 kg/m²), and a history of a fracture when age 45 years or older (OR = 0.26; 95% CI = 0.10–0.69). Reported lower limb dysfunction was associated with increased risk of hip fracture (OR = 6.41; 95% CI = 2.09–19.6) among fallers. The increased risk associated with hitting the hip/thigh in a fall and the reduced risk associated with high body mass index suggest that preventive efforts for older men at high risk might include protective hip pads to reduce the force on the hip in a fall. Exercise and strength training programs may also reduce the risk of hip fracture among men who fall. Received: 12 May 1997 / Accepted: 14 October 1997     

Vertebral Fractures Predict Subsequent Fractures

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. Received: 2 September 1998 / Accepted: 9 February 1999     

Weight Loss from Maximum Body Weight among Middle-Aged and Older White Women and the Risk of Hip Fracture: The NHANES I Epidemiologic Follow-up Study

Although weight loss increases bone loss and hip fracture risk in older women, little is known about the relation between weight loss in middle-aged women and subsequent hip fracture risk. The objective of this study was to determine the association between weight loss from reported maximum body weight in middle-aged and older women and the risk of hip fracture. Data were from a nationally representative sample of 2180 community-dwelling white women aged 50–74 years from the Epidemiologic Follow-up Study of the first National Health and Nutrition Examination Survey (NHEFS). In this prospective cohort study, incident hip fracture was ascertained during 22 years of follow-up. The adjusted relative risks associated with weight loss of 10% or more from maximum body weight were elevated for both middle-aged (RR 2.54; 95% CI 1.10–5.86) and older women (RR 2.04; 95% CI 1.37–3.04). For both ages combined, women in the lowest tertile of body mass index at maximum who lost 10% or more of weight had the highest risk of hip fracture (RR 2.37; 95% CI 1.32–4.27). Weight loss from maximum reported body weight in women aged 50–64 years and 65–74 years increased their risk of hip fracture, especially among those who were relatively thin. Weight loss of 10% or more from maximum weight among both middle-aged and older women is an important indicator of hip fracture risk. Received: 13 August 1999 / Accepted: 26 April 2000     

Differences in Risk Factor Patterns Between Cervical and Trochanteric Hip Fractures

The two types of hip fracture – cervical and trochanteric femoral fractures – are generally considered together in etiologic studies. However, women with a trochanteric fracture may be more osteoporotic than those with cervical hip fractures, and have higher post-fracture mortality. To explore differences in risk factor patterns between the two types of hip fracture we used data from a large population-based case–control study in Swedish women, 50–81 years of age. Data were collected by questionnaire, to which more than 80% of subjects responded. Of the cases included, 811 had had a cervical fracture and 483 a trochanteric fracture during the study period; these cases were compared with 3312 randomly selected controls. Height and hormonal factors appeared to affect the risk of the two types of hip fracture differently. For every 5 cm of current height, women with a cervical fracture had an adjusted odds ratio (OR) of 1.23 (95% CI 1.15–1.32) compared with an OR of 1.06 (95% CI 0.97–1.15) for women with trochanteric fractures. Later menopausal age was protective for trochanteric fractures (OR 0.95, 95% CI 0.91–0.99 per 2 years) but no such association was found for cervical fractures. Compared with never smokers, current smokers had an OR of 1.48 (95% CI 1.12–1.95) for trochanteric fractures and 1.22 (95% CI 0.98–1.52) for cervical fractures. Current hormone replacement therapy was similarly protective for both fracture types, but former use substantially reduced risk only for trochanteric fractures: OR 0.55 (95% CI 0.33–0.92) compared with 1.00 (95% CI 0.71–1.39) for cervical fractures. These risk factor patterns suggest etiologic differences between the fracture types which have to be considered when planning preventive interventions. Received: 22 March 1999 / Accepted: 28 May 1999     

Factors Associated with Mortality after Hip Fracture

There is a well-known excess mortality subsequent to hip fracture, which is probably restricted to subgroups of hip fracture patients with reduced health status. We studied the association between risk factors and death in 248 hip fracture patients and 248 controls originally enrolled in a population-based case–control study. This cohort was followed for 3 1/2 years with respect to total mortality. A markedly increased mortality was found in hip fracture patients passing a mental status test at a low score [relative risk (RR) = 2.3, 95% confidence interval (CI) 1.4-3.7], in hip fracture patients reporting two or more selected chronic diseases (RR = 3.3, 95% CI 1.8–6.1), in hip fracture patients not walking outdoors before the fracture (RR = 3.2, 95% CI 2.0–5.1) and in hip fracture patients in the lower half of handgrip strength distribution (RR = 2.3, 95% CI 1.6–3.4), all compared with the control group. In contrast, hip fracture patients without these risk factors did not have increased mortality compared with the control group. This study suggests that otherwise healthy and fit patients do not have increased mortality subsequent to hip fracture. The excess mortality is restricted to persons with reduced mental status, reduced somatic health and low physical ability. Special attention should be paid to patients with such risk factors in the treatment and rehabilitation period. Received: 2 March 1999 / Accepted: 17 August 1999     

Maternal Height, Childhood Growth and Risk of Hip Fracture in Later Life: A Longitudinal Study

Although measures to enhance bone mineralization during childhood and adolescence are widely incorporated into preventive programmes against osteoporotic fracture, there are no published data directly linking growth rates in childhood with the risk of later hip fracture. We addressed this issue in a unique Finnish cohort in whom birth and childhood growth data were linked to later hospital discharge records. This permitted follow-up of 3639 men and 3447 women who were born in Helsinki University Central Hospital between 1924 and 1933, who went to school in Helsinki and still lived in Finland in 1971. Body size at birth was recorded and an average of 10 measurements were obtained of height and weight throughout childhood. We identified 112 subjects (55 men and 57 women) who sustained a hip fracture during 165 404 person-years of follow-up. After adjustment for age and sex in a proportional hazards model, we identified two major determinants of hip fracture risk: tall maternal height (p<0.001) and a low rate of childhood growth (height, p= 0.006; weight, p = 0.01). The hazard ratio for hip fracture was 2.1 (95% CI 1.2–3.5) among men and women born to mothers taller than 1.61 m, when compared with those whose mothers were shorter than 1.54 m. The ratio was 1.9 (95% CI 1.1–3.2) among those whose rate of childhood height gain was below the lowest quartile for the cohort, compared with those whose growth rate was above the highest quartile. The effects of maternal height and childhood growth rate were statistically independent of each other, and remained after adjusting for socioeconomic status. The patterns of childhood growth that predicted future hip fracture differed between boys and girls. In boys, there was a constant deficit in height and weight between ages 7 and 15 years among those later sustaining fractures; in girls, there was a progressively increasing deficit in weight but a delayed height gain among those later sustaining fractures. This epidemiologic study provides the first direct evidence that a low rate of childhood growth is a risk factor for later hip fracture. Whether reduced growth rate is a consequence of childhood lifestyle, genetic background or intrauterine hormonal programming, the data support measures to optimize childhood growth as part of preventive strategies against osteoporotic fracture in future generations. Received: May 2000 / Accepted: June 2001     

Variation in the Efficacy of Hormone Replacement Therapy in the Prevention of Hip Fracture

Use of postmenopausal hormone replacement therapy (HRT) has been associated with a reduced risk of osteoporotic fractures. However, it is uncertain whether this risk reduction is modified by other risk factors for hip fracture. In a population-based case–control study in Sweden, we investigated the association between HRT and hip fracture risk within categories of age, body measures and lifestyle factors in postmenopausal women, 50–81 years of age. Mailed questionnaires and telephone interviews were used to collect data. Of those eligible, 1328 incident cases with hip fracture (82.5%) and 3312 randomly selected controls (81.6%) answered the questionnaire. Ever use of HRT in women less than 75 years old was associated with an odds ratio (OR) of 0.66 (95% confidence interval: 95% CI 0.50–0.87) for hip fracture compared with OR 0.40 (95% CI 0.21–0.77) in women 75 years or older. We found a significant interaction between HRT and both weight and physical activity (p<0.05). The protective effect of HRT was particularly pronounced in lean women: compared with never HRT users, ever users weighing under 60 kg had an OR of 0.44 (95% CI 0.30–0.66) whereas women weighing more than 70 kg had an OR of 0.91 (95% CI 0.53-1.-56). Women with low recent leisure physical activity (less than 1 h/week) similarly benefited more from HRT for hip fracture prevention than women with a higher degree of recreational physical activity. The observed interactions with weight and physical activity suggest that HRT has the best protective effect against hip fracture among high-risk women. Received: 7 October 1997 / Revised: 21 January 1998     

Predictors of Fractures in Elderly Women

In a prospective study of 348 apparently healthy women, aged 70 years and over (mean 80.3 years), we examined bone mineral density (BMD), biochemical markers of bone metabolism, and some easily measurable predictors in relation to hip and osteoporotic fractures. In addition, we constructed risk profiles for hip and osteoporotic fractures. At baseline, BMD at both hips, using dual-energy X-ray absorptiometry, body height and body weight were measured. At the same time, serum and urine samples were obtained for biochemical analysis. Serum samples were analyzed for vitamin D metabolites, sex hormone binding globulin, serum intact parathyroid hormone, osteocalcin, alkaline phosphatase, phosphate, albumin, calcium and creatinine. In 2 h fasting urine, hydroxyproline, type I collagen crosslinked N-telopeptide (NTx) and calcium excretion were measured. Furthermore, easily measurable predictors, such as previous fracture, body mass index (BMI) and mobility were assessed. During the follow-up period (mean duration 5.0 years), hip and any osteoporotic fracture (wrist, humerus or hip fracture) occurred in 16 and 33 participants, respectively. Data were analyzed using Cox regression analysis. BMD of the trochanter (per 1 SD decrease) and previous fracture were most strongly associated with hip fractures (adjusted relative risk (RR) = 3.0, 95% confidence interval (CI): 1.4–6.6; RR = 4.2, 95% CI: 1.5–11.6, respectively) and osteoporotic fractures (RR = 1.8, 95% CI: 1.1–2.8; RR = 2.9, 95% CI: 1.5–5.7, respectively). Previous fracture, BMI and mobility were identified as easily measurable predictors for hip fractures, whereas previous fracture, use of loop diuretics and age were predictors for osteoporotic fractures in the risk profile model. The risk of fractures can be predicted with three easily measurable predictors. This study confirms the importance of previous fracture as a predictor for hip fractures and other fractures. It also shows that the use of loop diuretics is a predictor for osteoporotic fractures. Received: 28 January 1999 / Accepted: 29 June 1999