Radial and spinal bone mineral density in a patient population

Abstract

Density of the radius (by single-photon absorptiometry) and the spine (by dual-photon absorptiometry) was measured in 281 normal young women and in a large heterogenous group of 1,622 consecutive female patients. Both spinal and radial density were useful measurements when performed on patients with medical indications; spine and radius densities in these patients averaged 1620% below those of age-matched controls. However, patients younger than 60 years of age had deficits of spine density that were twice as large as those in the radius, and twice as many of these patients had spinal osteopenia, compared with those with radial osteopenia. After age 70, loss of density in the radius approximated that in the spine and the prevalence of osteopenia was similar at both sites. The poorer sensitivity of the radius measurement reflected the fact that it did not predict spine density. The standard error of the estimate was 0.12 gm/cm2 in normal subjects and 0.15 gm/cm2 in patients. At any given radial density, the spinal density of patients averaged 0.18 gm/cm2 (15-20 % ) below that in normal subjects. Predictions of spinal density from body weight were as accurate as predictions from radial density. Preferential spinal osteopenia occurring without radial osteopenia precluded radial densitometry as a screening method for individuals with osteoporosis before age 60. However, measurement of the radius was more effective than body weight for defining groups at risk, even though the radius did not reliably predict individual spine density. A radius shaft density <0.55 gm/cm2 occurring with a body weight 6 5 kg was associated with a high prevalence of spinal osteopenia.Osteoporosis, or accentuated loss of bone in the axial skeleton, is a common disorder among the elderly that is manifested by fractures of the spine, proximal femur, and proximal humerus (1). Bone mineral content (BMC) is directly proportional to bone strength in these fracture regions (2,3). Bone loss at fracture sites, measured by dual-photon absorptiometry, is associated closely with increased fracture rates at these sites (43). A 10% decrease in bone mineral density (BMD) increases the risk of fracture 2-3-fold. Therefore, the 30-35% decrease in spine density and 45% decrease in femoral density, usually found in patients with fractures, implies a fracture risk that is 20-50 times greater than that in young normal women, and 10-20 times greater than that of age-matched controls.There is relatively poor diagnostic sensitivity for crush fracture using peripheral densitometry compared with axial densitometry (4,6). Pocock et a1 (7) showed that spinal or femoral osteopenia (>20% loss of BMD) could be detected with a sensitivity of 85% (1 5% undetected) from forearm densitometry only when the false-positive rate was higher than 60% (~4 0 % specificity). Presumably, this was due to the poor correlation between axial and appendicular bone

Prevalence of Low Forearm Bone Density in a Bulgarian Female Referral Population

“…The T-score decrease after age 50 years is very similar to that reported by Mazess et al [16] and Rey et al [26]. In the patient population of Mazess et al [16] osteopenic levels were reached at ages 52-55 years and osteoporosis at around age 75 years. At the distal forearm Rey et al [26] found a T-score reduction of -3.0 SD between 30 and 75 years of age.…”

“…In our total sample the prevalence of osteoporosis is 15.16% and in the age groups 50 years and over (6221 women) it is 20.45%. We compared our results with those of studies based on patient populations referred for forearm bone density testing [11,15,16]. In a sample of 1622 consecutive female patients Mazess et al [16] found osteoporosis defined as BMD values 430% lower than those of young healthy premenopausal females in 2-3% of all women aged 30-49 years, in 16% between 50 and 59 years, in 34% between 60 and 69 years, in 56% between 70 and 79 years, and in 62% between 80 and 89 years.…”

“…However, there is a limited number of studies based on bone densitometry data looking at the prevalence of osteoporosis in large populations [9][10][11]. Forearm BMD is used in a few studies including a general population sample [12][13][14] or a specific referral population [15][16][17]. There are still no convincing data available on osteoporosis prevalence in Bulgaria.…”

Estudo da densidade óssea na esclerodermia sistêmica

“…Além disso, as proporções entre osso cortical e trabecular sofrem variações significativas, dependendo do modo de aplicação das técnicas utilizadas, o que pode comprometer a precisão e a reprodutibilidade das medidas obtidas no rádio [13][14][15] . Outro aspecto a ser assinalado é o fato de diferentes autores [14][15][16] terem observado baixa correlação entre as densidades ósseas medidas no terço proximal e/ou distal do rádio com a coluna e a região proximal do fêmur. Da mesma forma, Aloia et al 16 , em 1990, ao estudarem mulheres saudáveis, também não encontraram correlação entre a densidade óssea do terço distal do rádio e o conteúdo do cálcio corporal total.…”

Comparative Assessment of Bone Mineral Measurements Using Dual X-ray Absorptiometry and Peripheral Quantitative Computed Tomography

“…A technique that measures information regarding both the mass and micro-architecture of bone should therefore provide the most accurate assessment of fracture risk. Currently, however, no such validated technique exists and a measurement of bone mass alone has been shown to be the single most important determinant of fracture risk [1][2][3][4].…”