Ratio of urine albumin to creatinine attenuates the association of dementia with hip fracture risk

CONTEXT

Microvascular disease is a leading cause of cognitive impairment. Approximately 50% of people with a hip fracture have cognitive impairment.

OBJECTIVE

We tested the hypothesis that microvascular diseases of the brain (lacunar infarcts and white matter disease [WMD]), kidney (albuminuria [≥ 30 mg/g creatinine] and albumin creatinine ratio [ACR]), and eye (retinal vascular disorders) attenuate the association of cognitive impairment with hip fracture risk.

SETTING

The Cardiovascular Health Cognition Study.

PATIENTS

Three thousand, one-hundred six participants (mean age, ∼ 79 y; 8.84 y median follow-up) with cognitive testing. Subsets received ACR testing (n=2389), brain magnetic resonance imaging scans (n = 2094), and retinal photography (n = 1098).

MAIN OUTCOME MEASURE

Incident hip fracture.

RESULTS

There were 488 participants (16%) with mild cognitive impairment (MCI) and 564 (18%) with dementia. There were 337 incident hip fractures, of which 19% occurred in participants with MCI and 26% in participants with dementia. Adjusted hazard ratios (HR) and 95% confidence interval for hip fracture in participants with MCI were 2.45 (1.67-3.61) and for dementia 2.35 (1.57-3.52). With doubling of ACR, the HR for fracture was attenuated in participants with dementia compared with participants with normal cognition [interaction HR 0.70 (0.55-0.91)]. No such effect was found in participants with MCI. Albuminuria, lacunar infarcts, WMD, and retinal vascular disease (RVD) did not modify the association of dementia or MCI with hip fracture risk.

CONCLUSIONS

ACR attenuates part of the risk of hip fracture in people with dementia, suggesting that these disorders share a common pathogenesis.

Current criteria for hip fracture risk assessment--are we missing something?

BACKGROUND

Hip fracture rates are increasing worldwide, and the risk for a second hip fracture is high. The decision to administer antiresorptive treatment is based mainly on bone mineral density and/or a history of previous osteoporotic fractures.

OBJECTIVES

To evaluate the contribution of BMD, previous fractures, clinical and laboratory parameters to hip fracture risk assessment.

METHODS

The study population included 113 consecutive hip fracture patients, aged 72.5 +/- 9.4 years, discharged from the orthopedic surgery department. BMD was assessed at the lumbar spine, femoral neck and total hip. The results were expressed in standard deviation scores as T-scores--compared to young adults and Z-scores--compared to age-matched controls. Plasma or serum levels of parathyroid hormone, 25-hydroxyvitamin 3 and urinary deoxypyridinoline cross-links were evaluated.

RESULTS

We observed T-scores < or = 2.5 in 43 patients (45.3%) at the lumbar spine, in 47 (52.2%) at the femoral neck and in 33 (38%) at the total hip. Twenty-eight patients (29.5%) had neither low BMD nor previous osteoporotic fractures. Using a T-score cutoff point of (-1.5) at any measurement site would put 25 (89%) of these patients into the high fracture risk group. Mean DPD level was 15.9 +/- 5.8 ng/mg (normal 4-7.3 ng/mg creatinine). Vitamin D inadequacy was observed in 99% of patients.

CONCLUSIONS

Using current criteria, about one-third of elderly hip fracture patients might not have been diagnosed as being at risk. Lowering the BMD cutoff point for patients with additional risk factors may improve risk prediction yield.

Biochemical bone markers are useful to monitor fracture repair

Biochemical bone markers reflect bone metabolism but little is known regarding their usefulness during fracture repair. Reduced bone mineral density may influence fracture healing. We hypothesized that low bone mineral density results in decreased levels of bone markers during the acute phase of fracture healing, especially in women who are postmenopausal. We also addressed the question of different fracture types and locations resulting in different levels of bone markers. Urinary levels of N-terminal cross-linked telopeptide, deoxypyridinoline, and pyridinoline were measured preoperatively and postoperatively in patients with hip fractures, distal forearm fractures, and in 25 control subjects. Bone mineral density was determined using quantitative computed tomography of the spine. Patients with low bone mineral density, especially women who were postmenopausal, had greater concentrations of N-terminal cross-linked telopeptide when compared with patients with normal bone mineral density or men. Patients with pertrochanteric fractures had greater concentrations than patients with femoral neck fractures, as did patients with hip fractures compared with patients with fractures of the distal forearm. These results suggest that levels of bone markers increase during fracture healing despite low bone mineral density and that different fracture types and locations result in different levels of bone markers.

LEVEL OF EVIDENCE

Prognostic study, Level I (high quality prospective study-all patients were enrolled at the same time with > or = 80% of followup of enrolled patients). See the Guidelines for Authors for a complete description of levels of evidence.

Recovery Room Delirium Predicts Postoperative Delirium After Hip-Fracture Repair

In this study, we sought to determine the incidence of recovery room delirium in elderly patients having hip-fracture repair under general anesthesia and to discover whether recovery room delirium is associated with continuing postoperative delirium. In this prospective study, patients undergoing hip-fracture repair were anesthetized using a standardized protocol. In addition, postoperative pain management was standardized in both the postoperative anesthesia care unit and in the hospital ward. The presence of delirium was determined using the confusion assessment method (CAM) score. Recovery room delirium was assessed by obtaining a CAM score at 60 min after discontinuation of isoflurane. Postoperative delirium was assessed by obtaining a daily CAM score during the postoperative in-hospital recovery period. Fifty patients consented to the study and 47 patients were included in the analysis (surgery cancelled postinduction n = 1; nonadherence to protocol n = 2). Average patient age was 77 +/- 1 (mean +/- SE) yr (range, 56-98 yr). Seventy-seven percent of the study patients were ASA class III or more. The prevalence of recovery room delirium was 45%. The prevalence of postoperative delirium was 36%. Recovery room delirium predicted postoperative delirium (P < 0.001, Fisher's exact test) with a sensitivity of 100% and a specificity of 85%. Analgesic doses administered in the postoperative anesthesia care unit and ward were similar in patients with or without postoperative delirium. Results of this study show that recovery room delirium is a strong predictor of postoperative delirium.

IMPLICATIONS

In patients undergoing hip-fracture repair, recovery room delirium is a strong predictor of postoperative delirium when using a standardized protocol for general anesthesia and postoperative pain management.

Comparison of serum and urinary C-terminal telopeptide of type I collagen in aging, menopause and osteoporosis

BACKGROUND

Urinary C-terminal telopeptide of type I collagen (u-CTx) has been reported to be a sensitive biochemical marker of bone turnover. There have been two assays for urinary CTx, which are alpha-CTx and beta-CTx. A newly developed immunoassay for serum CTx (s-CTx) is now available for assessment of bone resorption. We evaluated the effects of aging, menopause, and osteoporosis on the measurements of serum CTx and compared them to urinary CTx assays.

METHODS

In 79 premenopausal healthy women, 80 postmenopausal healthy women, 61 osteoporotic patients with vertebral fractures and 34 osteoporotic patients with hip fractures, s-CTx and urinary beta-CTx (u-betaCTx) were measured by ELISAs, and urinary alpha-CTx (u-alphaCTx) was measured by an RIA.

RESULTS

In all subjects, s-CTx significantly correlated with both u-alphaCTx (r=0.54) and u-betaCTx (r=0.51). There was no significant difference among s-CTx, u-alphaCTx and u-betaCTx in the T-scores of the postmenopausal group over the premenopausal group. These findings indicate that the value of s-CTx, as well as urinary CTxs, reflected the increase of bone resorption associated with menopause with a high degree of sensitivity. Patients with vertebral fractures had moderately increased concentrations of bone resorption markers compared to age-matched healthy postmenopausal women (T-score; s-CTx: 0.8, u-alphaCTx: 0.9, u-betaCTx: 0.7), whereas bone resorption markers in hip fracture patients were greatly increased compared to healthy postmenopausal women (T-score; s-CTx: 1.1, u-alphaCTx: 1.3 u-betaCTx: 1.3). The T-scores of u-CTxs against the postmenopausal group in vertebral fracture group and in hip fracture group were not significantly different from those of s-CTx.

CONCLUSIONS

s-CTx, as well as urinary CTxs, reflects the increase of bone resorption in patients with vertebral fractures and hip fractures.

Serum and urine markers of bone metabolism during the year after hip fracture

OBJECTIVE

As part of a larger study to describe indices of recovery during the year after hip fracture, the current prospective study investigated longitudinal changes in serum and urine markers of bone metabolism for the year after hip fracture and related them to bone mineral density (BMD).

DESIGN

A representative subset of participants provided serum and urine samples and had bone density measured at 3, 10, 60, 180, and 365 days postfracture.

SETTING

Two Baltimore hospitals.

PARTICIPANTS

The subjects were 205 community-dwelling, white women age 65 and older with fresh proximal femur fractures.

MEASUREMENTS

Samples were assayed for specific bone-related proteins and bone turnover markers, including serum osteocalcin (OC), procollagen type 1 carboxy-terminal extension peptide (PICP), bone-specific alkaline phosphatase (BAP), and urinary deoxypyridinoline (DPD) cross-links. Selected hormonal regulators of bone metabolism, including parathyroid hormone (PTH), calcitonin (CT), 1,25-dihydroxy vitamin D(3) (1,25 (OH)(2)D), and estrone (E(1)) were measured from serum samples. Repeated measures analyses were used to evaluate postfracture changes in each of the markers.

RESULTS

BAP, OC, and PICP were most active during the early postfracture period (3-60 days). BAP and OC remained elevated at 365 days compared with 3 days. DPD rose 48% from 3 days to 60 days, but this difference was not statistically significant. PTH and 1,25 (OH)(2)D increased steadily and significantly from 3 to 365 days. E(1) was highest at baseline and decreased at each time point, whereas CT showed no significant changes. When subjects were stratified into high-, medium-, and low-BMD groups based on their measurement at 3 days, both osteoclastic and osteoblastic markers in the low-BMD group displayed exaggerated and different patterns over time compared with the other groups.

CONCLUSION

Currently, the standard treatment of care for hip fractures still results in high morbidity and mortality and failure to regain prefracture quality of life. Gaining an understanding of bone cell activity in these patients after hip fracture, derived by measuring markers longitudinally during recovery, provides a baseline by which to measure the effectiveness of new interventions to improve recovery from hip fracture.

Serum estradiol and sex hormone-binding globulin and the risk of hip fracture in elderly women: the EPIDOS study

It has been suggested that low serum 17beta-estradiol (E2) and sex hormone-binding globulin (SHBG) may predict hip fracture in postmenopausal women. We have investigated the predictive value of serum E2 and SHBG concentrations and urinary deoxypyridinoline (D-Pyr) and type I collagen breakdown products (CTX) in a large prospective cohort of 7,598 healthy elderly ambulatory women (EPIDOS study), aged 75 years or more. We performed a nested case control study, by matching 212 patients with incident hip fracture with 636 controls. Mean follow-up was 3.3 years (maximum, 4.9 years). Women having serum E2 below the limit of detection (3 pg/ml), that is, 2% of the population, were not at higher risk, with a relative hazard (RH) of 1.59 (95% CI = 0.45-5.55). Women having serum E2 below 5, 6, 7, or 8 pg/ml, in the lowest quartile, or below the median had no increased risk of hip fracture. In contrast, women having serum E2 in the highest quartile (i.e., > or = 10 pg/ml) were protected, with an RH of 0.66 (0.44-0.98) that did not remain significant after adjustment for weight (RH = 0.71 [0.47-1.06]). High serum SHBG values with different cut-offs tended to be associated with an increased risk of hip fracture. Women in the highest quartile had an RH of 2.5 (1.37-4.61), compared with those in the lowest quartile, that decreased markedly after adjustment for body weight (1.61 [0.99 -2.62]). The highest quartile of the ratio E2/SHBG, which is an index of free E2, was associated with a lower hip fracture risk (RH = 0.6 [0.4-0.91]) that was no longer significant after adjustment for weight. In contrast, urinary D-Pyr and CTX, when elevated above the upper limit of premenopausal values, were predictive of hip fracture, with an RH of 2.07 (1.49-2.9) and 1.67 (1.19-2.32), respectively, even after adjustment for body weight, serum E2, and SHBG. We conclude that in healthy elderly French women over 75 years of age, serum E2 and E2/SHBG in the highest quartile are associated with a lower risk of hip fracture and that this association is explained by a higher body weight. In addition, serum levels of E2 and SHBG do not account for the increased risk of hip fracture associated with high levels of bone resorption markers.

The relationships between the degree of beta-isomerization of type I collagen degradation products in the urine and aging, menopause and osteoporosis with fractures

We have evaluated the effect of aging, menopause and osteoporosis on the measurements of both nonisomerized type I collagen C-telopeptide breakdown products (alpha-CTx) by radioimmunoassay (RIA) and beta-isomerized type I collagen C-telopeptide breakdown products (beta-CTx) by enzyme-linked immunosorbent assay (ELISA). In 86 premenopausal healthy women (PRE), 144 postmenopausal healthy women (POST), 74 patients with vertebral fractures (VX) and 61 patients with hip fractures (HX), urinary CTx excretion was measured by both ELISA and RIA assays. Samples were collected more than 6 months after fracture in the VX group and within 48 h after fracture in the HX group. In all subjects a highly significant correlation was found between alpha-CTx and beta-CTx (r = 0.85). The values of beta-CTx in the POST group greatly increased compared with those in the PRE group (% mean increase: 82%), while the values of alpha-CTx in the POST group moderately increased compared with those in the PRE group (% mean increase: 47%). The values of both alpha-CTx and beta-CTx in the HX group were significantly higher than those in the other groups, but particularly the increase in mean alpha-CTx (211% for HX versus POST) was very high compared with the increase in mean beta-CTx (68% for HX versus POST). Moreover, the alpha-CTx/beta-CTx ratio in the HX group was significantly higher than in the other groups. These results suggest that both assays well reflect the increase in bone resorption associated with high bone turnover, especially, in osteoporotic patients with hip fracture. However, there was a difference between the urinary excretion of alpha-CTx and beta-CTx in patients with hip fracture, so the alpha-CTx/beta-CTx radio might be a good indicator reflecting the characteristics of bone metabolism for osteoporosis with hip fracture.

The degree of osteoporosis in patients with vertebral fracture and patients with hip fracture: relationship to incidence of vertebral fracture

The most typical fracture that occurs in osteoporotic patients is a vertebral fracture, whereas hip fractures are thought to occur in the most severe osteoporotic patients. The purpose of this study was to compare the degree of osteoporosis between patients with vertebral fractures and patients with hip fracture by examining bone mineral density, biochemical markers of bone metabolism, and the incidence of vertebral fractures. Subjects were 50 female patients with vertebral fractures (VX) and 60 female patients with hip fracture (HX). Bone mineral densities (BMD) of the lumbar spine, femoral neck (Neck), and one-third of the radius were determined by DXA. Total and bone alkaline phosphatase, osteocalcin, N-MID osteocalcin, PICP, free deoxypyridinoline, and CTx were measured. All z-scores of BMD in the three areas of VX and HX patients were negative, meaning those BMDs were lower in VX and HX than a decade-matched normal reference. The z-score of Neck BMD was significantly lower in HX than in VX. Deoxypyridinoline and CTx were significantly higher in HX than in VX. N-MID osteocalcin was significantly lower in HX than in VX. VX and HX patients were divided into four subgroups according to the number of their vertebral fractures: VX, with a single fracture; VX, with multiple fractures; HX, without vertebral fractures: and HX, with vertebral fractures. VX with multiple fractures and HX with vertebral fractures had lower z-scores at all skeletal sites. HX with vertebral fractures had the lowest median z-score at spine and Neck, whereas HX without vertebral fractures had a low z-score only at Neck compared to VX with a single fracture. There was no significant difference in markers among the subgroups. The number of vertebral fractures was negatively correlated with z-scores of BMD at all three sites. We concluded that uncoupling between bone formation and resorption is greater in hip fractures than in vertebral fractures. Vertebral fractures are associated with general osteopenia of the total skeleton. We suggest that there are two types of osteoporosis in patients with hip fractures: one is that the bone mass of the femoral neck is specifically reduced, and the other is a terminal stage of osteoporosis which follows osteoporosis with vertebral fractures.

Urinary excretion of type I collagen degradation products in healthy women and osteoporotic patients with vertebral and hip fractures

We have evaluated both the effect of normal aging and menopause on urinary CrossLapstrade mark (u-CTx) excretion and the bone resorption status by u-CTx in patients with vertebral fracture and hip fracture. In 246 healthy women, 76 patients with vertebral fracture, and 63 patients with hip fracture, u-CTx excretion was measured by ELISA. The age-related changes of u-CTx in healthy females reflected the marked increase of bone resorption associated with modeling at childhood. The values in the subgroups of postmenopausal women 1-3 years since menopause and </=10 years since menopause were significantly higher than those in the subgroups of premenopausal adult women. The values in the vertebral fracture group were significantly higher than those in the premenopause group, but not those in the postmenopause groups. The values in the hip fracture group were significantly higher than those in the other groups. Of the 70 postmenopausal subjects aged 45-64 years, 43% had u-CTx values more than 2 SD above premenopausal mean. The corresponding values in the patients with vertebral fracture and those with hip fracture were 58% and 64%, respectively. This marker reflects well the increase of bone resorption associated with bone modeling at childhood and with high bone turnover after menopause. The excretions in the patients with hip fracture were much higher than those in the age-matched subjects and also higher than those in the patients with vertebral fracture. These findings indicate that the abnormality of bone resorption in the patients with hip fracture is more severe than in the patients with vertebral fracture.

The effect of short-term calcitonin administration on biochemical bone markers in patients with acute immobilization following hip fracture

The effect of salmon calcitonin on changes in mineral metabolism was studied in 40 elderly patients with recent hip fracture. All patients underwent surgery (internal fixation) 1 week after admission and were randomly divided into two equal groups: group A, which received no treatment, and group B, which received 100 IU/day salmon calcitonin intramuscularly for 2 weeks starting on admission. Blood and 24-h urine parameters of mineral metabolism were measured on admission and at the end of weeks 1 and 2. No intra- or intergroup changes in serum calcium, phosphorus or alkaline phosphatase were observed. At the end of week 2 biochemical markers of bone resorption (urinary calcium and hydroxyproline) had significantly increased in group A and significantly decreased in group B, indicating a reduction in bone resorption in group B. Urinary phosphorus had also increased in group B, possibly due to the phosphaturic effect of calcitonin. It is concluded that immobilization resulting from a hip fracture, and possibly surgery itself, causes significant changes in biochemical markers of bone resorption. Calcitonin successfully reverses these changes and may also be effective in preventing subsequent bone loss, particularly in patients who cannot be remobilized immediately.