Karl Obrant

Increasing age-adjusted risk of fragility fractures: a sign of increasing osteoporosis in successive generations?

The age-adjusted incidence of fragility fractures is increasing. This is the outcome of almost all epidemiologic studies that have been done throughout the world during the last 40 years. However, a few studies that have shown an unchanged incidence of hip fractures are as often cited in recent literature, which motivates a discussion of the issue. There are signs that favor the fact that the increasing incidence of fractures in the elderly is evidence of a deterioration of the skeleton in successive generations. Its possible reasons are discussed. The epidemiology of fractures has been studied more thoroughly in Malmr, Sweden than in any other place. The favorable conditions for such investigations in our city have been used in many studies since the beginning of this century [1, 2], up to the present, where all the fractures from those occurring at birth [3] to the fractures sustained by already hospitalized elderly [4] have been investigated. These investigations together with all other studies on fracture epidemiology (to our knowledge) are reviewed in the first part of this article. In the second, possible reasons for the increasing ageadjusted incidence of fragility fractures are discussed.

Biochemical Markers of Bone Metabolism and Prediction of Fracture in Elderly Women

We studied the ability of various markers of bone turnover to predict fracture in 1040 randomly recruited 75‐year‐old women. A total of 178 of the women sustained at least one fracture during follow‐up (mean, 4.6 years). In elderly women, TRACP5b and urinary fragments of osteocalcin are promising new markers for prediction of fracture, in particular, vertebral fracture.

Exercise during growth and bone mineral density and fractures in old age

If exercise is to be recommended during growth, benefits in bone mineral density (BMD) must be maintained in old age and shown to prevent fractures. Our cross-sectional study of soccer players suggests that a high BMD is no longer recorded after retirement and fracture frequency is no less than predicted in old age.

Pregnancy and Lactation Confer Reversible Bone Loss in Humans

Abstract: The influence of pregnancy on bone mineral density (BMD) was evaluated by dual-energy X-ray absorptiometry (DXA) in 73 women (mean age 29 years, range 20–44 years) postpartum. Fifty-five age-matched women served as controls. The influence of lactation was evaluated in 65 of the delivered women who were followed with repeated measurements, a mean of 4.5 ± 0.1 and 11.5 ± 0.1 months after the delivery. The influence of multiple pregnancies was evaluated in 39 premenopausal women (mean age 38 years, range 31–54 years) with a minimum of four pregnancies (range 4–7). Fifty-eight age-matched healthy premenopausal women with a maximum of two pregnancies (range 0–2) served as controls. Data are presented as mean ± SEM. BMD data are adjusted for differences in total fat mass and total lean mass. Lumbar spine BMD was 7.6 ± 0.1% and total body BMD 3.9 ± 0.1% lower in women postpartum compared with controls (both p<0.001). BMD did not decrease significantly in non-breastfeeding mothers. Mothers breastfeeding for 1–6 months decreased femoral neck BMD by 2.0 ± 1.0% during the first 5 months postpartum (p<0.001). No further BMD loss was seen between 5 and 12 months postpartum. Femoral neck BMD 12 months after delivery was 1.3 ± 0.8% lower than after delivery in mothers breastfeeding for 1–6 months (p= 0.05). Mothers breastfeeding for more than 6 months decreased Ward’s triangle BMD by 8.5 ± 1.0% and lumbar spine BMD by 4.1 ± 0.8% during the first 5 months postpartum (both p<0.05). No further BMD loss was seen between 5 and 12 months postpartum. Femoral neck BMD 12 months after delivery was 4.0 ± 1.1% lower and Ward’s triangle BMD 5.3 ± 1.9% lower than after delivery in mothers breastfeeding for more than 6 months (both p<0.05). BMD loss was higher during the first 5 months following delivery in the lactating women compared with the non-lactating women (p< 0.05 comparing lumbar spine BMD loss in lactating mothers versus non-lactating mothers). However, in women with a minimum of four pregnancies the BMD was no lower than in age-matched women with fewer pregnancies. Total duration of lactation was not correlated with the present BMD. In summary, pregnancy seem to confer a low BMD with additional BMD loss during 5 months of lactation. Even if complete restoration in BMD was not reached within 5 months of weaning, women with four pregnancies or more had a BMD no lower than women with two pregnancies or fewer. We conclude that neither an extended lactation period nor multiple pregnancies could be used as a risk factor when predicting women at risk for future osteoporosis.

Femoral neck geometry and radiographic signs of osteoporosis as predictors of hip fracture

A total of 125 consecutive hip fracture patients were investigated regarding hip geometry. There were 33 men of mean age 76 +/- 10 years, and 92 women of mean age 78 +/- 9 years. Patients with previous hip surgery were excluded. Hip geometry (hip-axis length, width of collum femoris, and femoral shaft and neck-shaft angle) were registered on both plain radiographs and DEXA scans performed within 2 weeks after fracture. On the radiographs, the calcar femorale, the Singh index, and the femoral neck index (FNI) were also calculated and compared with earlier published values of bone mineral density hip in the hip fracture patients. The fracture cases were compared with controls, 192 DEXA scans and 163 radiographs, in patients without hip surgery or known hip disease. As measured on the DEXA scans we found a wider collum femoris and a wider femoral shaft in both the male and female fracture cases, compared to controls. Also, the fracture cases showed signs of osteoporosis as measured by the calcar femorale, the Singh index, and the femoral neck index. These measurements showed good correlation with bone mineral density of the hip as measured by the DEXA scans.

Bone mineral density in weight lifters

SummaryThe effect of intense physical training on the bone mineral content (BMC) and soft tissue composition, and the development of these values after cessation of the active career, was studied in 40 nationally or internationally ranked male weight lifters. Nineteen were active and 21 had retired from competition sports. Fifty-two age- and sexmatched nonweight lifters served as controls. The bone mineral density (BMD) in total body, spine, hip, and proximal tibial metaphysis was measured with a Lunar Dual-energy X-ray absorptiometry (DXA) apparatus and the BMD of the distal forearm was measured with single photon absorptiometry (SPA). Seventeen of the lifters had been measured earlier with SPA in the forearm and 23 in the tibial condyle during their active career in 1975. The BMD was significantly higher in the weight lifters compared with the controls (10% in the total body P<0.001, 12% in the trochanteric region P<0.001, and 13% in the lumbar spine P<0.001). All measured regions except the head showed significant higher bone mass in the weight lifters compared with the controls. In older lifters, the difference from the controls seemed to increase in total body and lumbar vertebrae (BMD), but remained unchanged in the hip. Significant correlation was found between the SPA measurements in 1975 and the corresponding measurements 15 years later in both the forearm (r=0.51, P<0.05 at the 1-cm level and r=0.87, P<0.001 at the 6-cm level) and in the tibial condyle (r=0.61, P<0.01). There was no difference in BMD for any region between active and retired weight lifters that was not explained by difference in age. The weight lifters were on average 5 cm shorter but of the same weight as the controls. In the weight lifters, the body mass index (BMI) was increased as was the lean body mass, but not the fat content.

Age and sex patterns of hip fracture-changes in 30 years

The age- and sex-specific incidence of hip fractures was studied over a period of 30 years. There was a continuous increase in incidence over the years. The trend was most obvious in the oldest age groups and in men.

Is bone mineral density advantage maintained long-term in previous weight lifters?

This cross-sectional study was done in order to ascertain whether there is a lifelong beneficial effect on bone mineral density (BMD) of early, long-lasting, and intense physical exercise. Forty-eight male ex-weight lifters, mean age 64 years (range 50–79) participated. They had followed a training program of an average of 10 hours/week (range 4–20) for an average of 13 years (range 1–34). They had all retired from competitive sport an average of 30 years (range 7–50) ago. Sixty-six age-matched volunteers served as controls. The bone mineral density (BMD, areal density, g/cm2) in the total body, spine, and hips and the fat content and lean body mass were measured with the LUNAR DPX bone mass scanner. In ex-weight lifters 50–64 years of age, the BMD was greater than in controls. After 65 years, no difference was found between the former weight lifters and their controls.

Associations Between Homocysteine, Bone Turnover, BMD, Mortality, and Fracture Risk in Elderly Women†

Homocysteine has been suggested to be a risk factor for fracture, but the causal relationship is not clear. In 996 women from the OPRA study, high homocysteine level was associated with high bone marker levels and low BMD at baseline. During a mean 7‐year follow‐up, high homocysteine level was associated with mortality, but no clear association to fracture risk existed.

Changes of bone mineral mass and soft tissue composition after hip fracture

The aim of this prospective longitudinal study was to measure prospectively the bone mineral density (BMD) and anthropometric variables after a hip fracture. In particular, we studied changes in the BMD in both the injured and uninjured hips, and examined if the postoperative mortality rate and complications, including pseudarthrosis of the fracture and late segmental collapse of the head of the femur, could be predicted by early bone mass measurements. The bone mineral density and the body composition were measured with dual energy X-ray absorptiometry in 102 consecutive hip fracture patients, 31 men and 71 women, with a mean age of 74 and 79 years, respectively. All cases were operated on within 3 days. The measurements were undertaken within 10 days after the fracture, after 4 and after 12 months. The BMD of the hip fracture cases decreased, especially in the lower extremities where the patients lost 7%, during the first year after the fracture. The patients also lost lean body mass (5%) but gained fat (11%) during the same period. They lost significantly more bone mass in the fractured hip than in the uninjured hip (p < 0.05). No difference was found between those patients who survived and those who died within 2 years after their hip fracture in neither the initial measurement nor in the follow-up measurements. Also, we found no difference between those patients whose hip fracture healed and those who developed late segmental collapse or pseudarthrosis. In conclusion, osteoporotic hip fracture cases lose bone mass at an increased rate, especially in the fractured hip. Also, their soft tissue composition changes, gaining fat while losing muscle mass. Furthermore, it seems that early bone mineral measurements cannot predict postoperative failures or postoperative mortality.