Citations

Abstract High caffeine consumption has been proposed as a risk factor for osteoporotic fracture, but the evidence associating high caffeine intake with low bone density is inconsistent. We therefore examined the influence of caffeine consumption on bone mineral at six skeletal sites in an age-stratified random sample of white women residing in Rochester, Minnesota. After age adjustment, there was no association between overall caffeine consumption and bone mineral at five of the six sites. In the femoral shaft, however, there was a statistically significant interaction between age and caffeine consumption so that high caffeine intake was associated with slight reductions in bone mineral among elderly subjects but with modestly increased bone mineral at younger ages. When caffeine intake was categorized by source, no consistent influence of coffee, tea, or other caffeinated beverage consumption could be detected on bone mineral. Caffeine intake was, however, positively associated with cigarette smoking and alcohol consumption. After adjusting for age, caffeine consumption was not correlated with biochemical indices of bone turnover, circulating concentrations of estradiol and estrone, or other dietary and musculoskeletal variables. These data suggest that caffeine intake in the range consumed by a representative sample of white women is not an important risk factor for osteoporosis. Among elderly women, however, in whom calcium balance performance is impaired, high caffeine intake may predispose to cortical bone loss from the proximal femur.

AbstractIn a population-based retrospective cohort study, Rochester women aged 35–69 years who were first diagnosed with one or more vertebral fractures in 1950–1979 were followed for the development of a subsequent hip fracture. The 336 women with no history of hip fracture at the time of their vertebral fracture experienced 52 proximal femur fractures in 4788 person-years of follow-up. The standardized morbidity ratio (SMR) of observed to expected hip fractures was 1.8 (95% CI, 1.3–2.4) and was higher for intertrochanteric than cervical femoral fractures (SMR, 2.3 versus 1.3; P = 0.07). Hip fracture risk among women with symptomatic vertebral fractures was slightly less than in those with asymptomatic vertebral fractures (SMR, 1.8 versus 2.3; not significant), and younger women had no higher risk of a subsequent hip fracture than women who were ≥60 years of age at the time of their vertebral fracture (SMR, 1.4 versus 1.8; not significant). Alternative explanations are possible, but these data are consistent with heterogeneity in the pathogenesis of different osteoporotic fractures.

Abstract To assess the influence on the risk of hip fractures in men of medical conditions associated with secondary osteoporosis or with an increased likelihood of falling, we conducted a population-based nested case-control study among the 232 Rochester, Minnesota, men with an initial hip fracture due to moderate trauma in 1965–1989 and an equal number of age-matched control men from the general population. Information on selected medical and surgical conditions and certain behavioral risk factors prior to fracture (or comparable index date for controls) was obtained from inpatient and outpatient medical records in the community that averaged over 36 years in duration. After adjusting for age, obesity, and inactivity, disorders linked with secondary osteoporosis were associated with a 2-fold increase in the risk of hip fracture in men (odds ratio [OR] 2.3; 95% confidence interval [CI] 1.3–4.3), while conditions linked with an increased risk of falling were associated with almost a 7-fold increase in risk (OR 6.9; 95% CI 3.3–14.8). These factors together appeared to account for about 72% of the hip fractures in men. Increased attention must be paid to these conditions which, in aggregate, are very common in elderly men and lead to a substantial increase in the risk of hip fracture with its devastating sequelae of death, disability, and cost.

Abstract Increasing body weight is associated both with higher bone mass and with lower rates of bone loss. Whether the effects of body weight are mediated by lean body mass (LBM) or fat body mass (FBM) is, however, uncertain because different studies have used different measures of bone mass and arrived at contradictory conclusions. The parameter actually measured is bone mineral content (BMC). Bone mineral density (BMD), bone mineral apparent density (BMAD), and the BMD/height attempt to “correct” BMC for differences in bone or body size, but these corrections may bias the analysis of the effects of body composition on the skeleton. To resolve this issue, we measured BMC at the total body, lumbar spine, proximal femur, and forearm using dual energy X-ray absorptiometry (DXA) in a population-based sample including 138 premenopausal women (age range 21–54 years, mean 35 years) and 213 postmenopausal women (age range 34–94 years, mean 68 years). BMD, BMAD, and BMD/ height were also calculated for each site. LBM and FBM were determined from the DXA whole body scan. In a multivariate analysis that included age and height, both LBM and FBM predicted total body BMC in pre- and postmenopausal women (p < 0.002 for LBM and FBM in both groups). LBM had a dominant effect on spine and forearm BMC in both groups (p < 0.004) and hip BMC in premenopausal women (p < 0.001), whereas both LBM and FBM predicted hip BMC in postmenopausal women (p < 0.001). However, as BMC was adjusted for bone or body size using BMD, BMAD, or BMD/height, FBM tended to become more important than LBM in the analysis. This was, in part, due to the fact that each of the correction factors in the BMD and BMAD calculations, as well as height, were highly correlated with LBM (r = 0.57 and 0.52 for height versus LBM in pre- and postmenopausal women, respectively [p < 0.001]), and weakly or not at all with FBM (r = 0.08 and 0.11, respectively). Therefore, dividing BMC by these correction factors tended to bias the analysis against potential effects of LBM on bone mass. Thus, the relationship between body composition and bone mass is critically dependent on which bone mass parameter is used in the analysis. Both LBM and FBM have important effects on bone mass, depending on the bone mass parameter used, the skeletal site measured, and menopausal status.

Abstract 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.

Abstract Bone mineral density (BMD) was measured at the lumbar spine and cervical and intertrochanteric regions of the proximal femur by dual-photon absorptiometry and bone mineral content was assessed at the distal and midradius by single-photon absorptiometry in an age-stratified random sample of 304 Rochester, Minnesota women aged 30–94 years. Over follow-up extending to 10 years (median 8.3 years), 93 women experienced 163 new fractures. After adjusting for age, these bone mineral measurements predicted the likelihood of any incident fracture due to moderate trauma, with relative hazards varying from 1.4 to 1.6 per SD decrease in baseline bone mineral. A 1 SD decrease in lumbar spine BMD increased the risk of a new vertebral fracture comparably to a 17 year increase in age; a 1 SD decrease in femoral BMD was comparable to a 13–14 year increase in age on the risk of a hip fracture. We conclude that bone mineral measurements made at a variety of skeletal sites can predict the occurrence for at least 8–10 years of moderate trauma fractures of the sort that might be related to osteoporosis.

Object Juxtafacet cysts (JFCs) in usual locations have recently been shown to have joint connections. The pathogenesis of JFCs in unusual locations has remained obscure. The authors hypothesize that all JFCs, including atypical ones, are joint derived. Methods In this study the authors sought to explain the occurrence and formation of clinical outliers of spinal JFCs. In Part I, they performed an extensive literature search to identify case reports of spinal intraneural cysts that have been unappreciated despite the fact that they should occur. In Part II, they studied far-lateral (extraforaminal) cysts treated at their institution and reported in the literature. The presence of a joint connection was specifically looked for since this finding has not been widely appreciated. Results In Part I, 3 isolated case reports of spinal intraneural JFCs without reported joint connections were identified: 2 involving L-5 and 1, C-8. In Part II, 6 cases involving patients with far-lateral JFCs treated at the authors' institution were reviewed and all 6 had joint connections. Two of these cases had been previously published, although their joint connections were not appreciated. In 2 of the newly reported cases, arthrography confirmed a communication between the facet and the cyst. Only 1 of 5 cases in the literature had a recognized joint connection. Conclusions The authors believe that all JFCs are joint derived. This explanation for intraneural and extraneural JFCs in typical locations would be consistent with the unified articular (synovial) theory and the pathogenesis for intraneural and extraneural ganglion cyst formation in the limbs. Facet joints appear no different from other synovial joints occurring elsewhere. Understanding the pathogenesis of these cysts will help target treatment to the joint, improve surgical outcomes, and decrease recurrences.

Dr Brazis has written a review of the literature on the clinical manifestations of idiopathic intracranial hypertension, possible associated venous hypertension and intracranial dural venous sinus abnormalities, and a brief discussion of medical and surgical therapies. The preferred terminology for this condition is idiopathic intracranial hypertension, but pseudotumour cerebri is so engrained in the literature that it stubbornly remains (1). The manuscript covers the literature well, and the information reviewed serves as an excellent reference source for interested readers. Unfortunately, Dr Brazis has noted the conflicting expert opinions regarding success, failure and complications for each of the surgical procedures, and, as a result, his summary discussion is barren of any algorithm of management, or even recommendations in approaching these difficult patients.