Association of reduction in bone mineral density with mortality in male hemodialysis patients

Vitamin D Therapy in Adults With CKD: A Systematic Review and Meta-analysis

RATIONALE & OBJECTIVE

Vitamin D is widely used to manage chronic kidney disease-mineral and bone disorder (CKD-MBD). We evaluated the effects of vitamin D therapy on mortality, cardiovascular, bone, and kidney outcomes in adults with CKD.

STUDY DESIGN

Systematic review of randomized controlled trials (RCT) with highly sensitive searching of MEDLINE, Embase, and CENTRAL, through February 25, 2023.

SETTING & STUDY POPULATIONS

Adults with stage 3, 4, or 5 CKD, including kidney failure treated with dialysis. Recipients of a kidney transplant were excluded.

SELECTION CRITERIA FOR STUDIES

RCTs with≥3 months of follow-up evaluating a vitamin D compound.

DATA EXTRACTION

Data were extracted independently by three investigators.

ANALYTICAL APPROACH

Treatment estimates were summarized using random effects meta-analysis. Primary review endpoints were all-cause death, cardiovascular death, and fracture. Secondary outcomes were major adverse cardiovascular events, hospitalization, bone mineral density, parathyroidectomy, progression to kidney failure, proteinuria, estimated glomerular filtration rate, hypercalcemia, hyperphosphatemia, biochemical markers of CKD-MBD, and various intermediate outcome measures of cardiovascular disease. Risk of bias was assessed using the Cochrane Risk of Bias (RoB) 2 tool. Evidence certainty was adjudicated using GRADE.

RESULTS

Overall, 128 studies involving 11,270 participants were included. Compared with placebo, vitamin D therapy probably had no effect on all-cause death (relative risk [RR], 1.04; 95% CI, 0.84-1.24); and uncertain effects on fracture (RR, 0.68; 95% CI, 0.37-1.23) and cardiovascular death (RR, 0.73; 95% CI, 0.31-1.71). Compared with placebo, vitamin D therapy lowered serum parathyroid hormone and alkaline phosphatase, but increased serum calcium.

LIMITATIONS

Data were limited by trials with short-term follow-up periods, small sample size, and the suboptimal quality.

CONCLUSIONS

Vitamin D therapy did not reduce the risk of all-cause death in people with CKD. Effects on fracture and cardiovascular and kidney outcomes were uncertain.

TRIAL REGISTRATION

Registered at PROSPERO with study number CRD42017057691.

PLAIN-LANGUAGE SUMMARY

Chronic kidney disease (CKD) is associated with increased risk of death, cardiovascular disease, and fractures. This excess risk is thought to be related to changes in bone and mineral metabolism, leading to the development of CKD-mineral and bone disorder (CKD-MBD) which is characterized by vascular calcification and reduced bone quality. Vitamin D is commonly used in the treatment of this condition. We reviewed randomized controlled trials examining the effect of vitamin D therapy in CKD. We found that vitamin D therapy affects serum biomarkers, including an increase in serum calcium. However, it probably has no effect on risk of all-cause death in CKD, and the effects on other clinical bone, cardiovascular, and kidney outcomes are uncertain.

Bone Mineral Density Is Inversely Associated With Mortality in Chronic Kidney Disease Patients: A Meta-Analysis

Low bone mineral density (BMD) is suggested to be associated with increased mortality in the general health population, but the relationship in chronic kidney disease (CKD) patients is still unclear. We performed a meta-analysis to investigate the association of BMD in different sites with risk of all-cause mortality in CKD patients. We searched PubMed, EMBASE, and Web of Science to identify eligible cohort studies that evaluated the association between BMD at different sites and risk of all-cause mortality in CKD patients. Twelve cohort studies were identified, which included 2828 CKD patients and 1052 deaths. Compared with normal/high level of total body BMD, lower total body BMD was associated with 25% higher risk of all-cause mortality. The pooled relative risk (RR) was 1.25 (95% confidence interval [CI] 1.09, 1.42) with little heterogeneity across studies. Regarding BMD measured at different sites, the risk of all-cause mortality was highest for lower BMD at hip/femoral neck (pooled RR = 1.69; 95% CI 1.20, 2.40). The pooled RRs were 1.26 (95% CI 1.04, 1.53) and 1.17 (95% CI 1.00, 1.37) for lower BMD at arm and spine, respectively. Similarly, the risk of death for per SD decrease in BMD was also higher at hip/femoral neck (pooled RR = 1.43, 95% CI 1.15, 1.77) compared with arm (pooled RR = 1.03, 95% CI 1.00, 1.06) and spine (pooled RR = 1.17, 95% CI 0.98, 1.39). In conclusion, lower BMD values at hip, arm, spine, as well as the whole body are associated with increased risk of all-cause mortality in CKD patients. The excess risk is highest for patients with lower BMD at hip/femoral neck, suggesting BMD measured at hip region may be the best indicator of mortality risk in CKD patients. © 2022 American Society for Bone and Mineral Research (ASBMR).

Efficacy of romosozumab in patients with osteoporosis on maintenance hemodialysis in Japan; an observational study

INTRODUCTION

Romosozumab reportedly increases bone mineral density (BMD) potently but might adversely affect cardiovascular disease (CVD). We evaluated the efficacy of romosozumab in osteoporotic HD patients with a high risk of fracture.

MATERIALS AND METHODS

This was a single-center 1-year study in Japanese HD patients. Among 96 HD romosozumab-treated HD patients with high risk of fracture, 76 HD patients completed 1 year of subcutaneous administration of romosozumab (210 mg/4 weeks) for 1 year. Romosozumab-untreated HD patients (n = 55) were also included. Changes in BMD and serum markers, together with fracture occurrence, and CVD events, were monitored.

RESULTS

During romosozumab treatment of 76 HD patients, BMD time-dependently increased significantly by 15.3% ± 12.9% at the lumbar spine (L1-4), and 7.2% ± 8.3% at the femoral neck at 1 year. Serum BAP and total P1NP increased significantly and serum TRACP-5b decreased at 4 weeks. Fragility fractures occurred in three (3.8%) patients. Hypocalcemia occurred at 4-48 weeks despite the increased dosing of active vitamin-D derivatives, but without any symptom. New CVD events occurred in 5.2% of romosozumab-treated HD patients and10.9% in romosozumab-untreated HD patients.

CONCLUSIONS

BMD was increased significantly during romosozumab treatment at the lumbar spine, and the femoral neck, respectively, at 1 year in HD patients. Hypocalcemia occurred but without any intolerable event. There was no apparent increase in CVD events during 1 year of study, suggesting romosozumab as a promising agent for HD patients with severe osteoporosis.

Sparing effect of peritoneal dialysis vs hemodialysis on BMD changes and its impact on mortality

INTRODUCTION

Bone loss in end stage renal disease (ESRD) patients associates with fractures, vascular calcification, cardiovascular disease (CVD) and increased mortality. We investigated factors associated with changes of bone mineral density (ΔBMD) during the initial year on dialysis therapy and associations of ΔBMD with subsequent mortality in ESRD patients initiating dialysis.

MATERIALS AND METHODS

In 242 ESRD patients (median age 55 years, 61% men) starting dialysis with peritoneal dialysis (PD; n = 138) or hemodialysis (HD; n = 104), whole-body dual-energy X-ray absorptiometry (DXA), body composition, nutritional status and circulating biomarkers were assessed at baseline and 1 year after dialysis start. We used multivariate linear regression analysis to determine factors associated with ΔBMD, and fine and gray competing risk analysis to determine associations of ΔBMD with subsequent mortality risk.

RESULTS

BMD decreased significantly in HD patients (significant reductions of BMD_total and BMD_{leg, trunk, rib, pelvis and spine}) but not in PD patients. HD compared to PD therapy associated with negative changes in BMD_{total (β=- 0.15)}, BMD_{head (β=- 0.14)}, BMD_{leg (β=- 0.18)} and BMD_{trunk (β=- 0.16)}. Better preservation of BMD associated with significantly lower all-cause mortality for ΔBMD_total (sub-hazard ratio, sHR, 0.91), ΔBMD_head (sHR 0.91) and ΔBMD_leg (sHR 0.92), while only ΔBMD_head (sHR 0.92) had a beneficial effect on CVD-mortality.

CONCLUSIONS

PD had beneficial effect compared with HD on BMD changes during first year of dialysis therapy. Better preservation of BMD, especially in bone sites rich in cortical bone, associated with lower subsequent mortality. BMD in cortical bone may have stronger association with clinical outcome than BMD in trabecular bone.

Association and predictive value of geriatric nutritional risk index, body composition, or bone mineral density in haemodialysis patients

AIM

Assess the association and predictive value of geriatric nutritional risk index (GNRI), body composition, and bone mineral density (BMD) in haemodialysis (HD) patients.

METHODS

Laboratory data, body composition parameters measured via body composition monitor, and radius, lumbar spine, femoral neck BMD measured using dual energy X-ray absorptiometry were assessed in all subjects on HD or online haemodiafiltration (HDF) at baseline. Regression analysis for GNRI, Cox proportional hazard analyses and comparison of multiple receiver operating characteristic (ROC) curves were performed.

RESULTS

Among all 264 patients, age was 65 ± 12 years and dialysis vintage was 79 (39-144) months. GNRI tertile (T)1, T2, and T3 were 88 (85-91), 94 (93-95), and 98 (97-101), respectively. Patients in GNRI T1 had lower fat tissue index (FTI), lean tissue index, and femoral neck, lumbar spine, and distal mid-third radius BMD, but higher overhydration/extracellular fluid than patients in GNRI T2 or T3 (P < .05). GNRI was significantly associated with FTI, lean tissue index, and femoral neck, lumbar spine, and distal mid-third radius BMD (P < .01). GNRI was a significant predictor of 2-year all-cause mortality (HR 0.92, P < .05). Area under the ROC curve for all-cause mortality using traditional risk factors (age, sex, diabetes mellitus, cardiovascular disease, use of vasopressors for dialysis-related hypotension, and C-reactive protein) was 0.67 and changed by adding GNRI (0.78, P < .05), FTI (0.75), or femoral neck BMD (0.66), respectively.

CONCLUSION

Associations between GNRI, body composition, and BMD were confirmed in HD patients. Combining GNRI with traditional risk factors improved mortality prediction in HD patients.

Bone mineral density and mortality in end-stage renal disease patients

Osteoporosis characterized by low bone mineral density (BMD) as assessed by dual-energy X-ray absorptiometry (DXA) is common among end-stage renal disease (ESRD) patients and associates with high fracture incidence and high all-cause mortality. This is because chronic kidney disease-mineral bone disorders (CKD-MBDs) promote not only bone disease (osteoporosis and renal dystrophy) but also vascular calcification and cardiovascular disease. The disturbed bone metabolism in ESRD leads to 'loss of cortical bone' with increased cortical porosity and thinning of cortical bone rather than to loss of trabecular bone. Low BMD, especially at cortical-rich bone sites, is closely linked to CKD-MBD, vascular calcification and poor cardiovascular outcomes. These effects appear to be largely mediated by shared mechanistic pathways via the 'bone-vascular axis' through which impaired bone status associates with changes in the vascular wall. Thus, bone is more than just the scaffolding that holds the body together and protects organs from external forces but is-in addition to its physical supportive function-also an active endocrine organ that interacts with the vasculature by paracrine and endocrine factors through pathways including Wnt signalling, osteoprotegerin (OPG)/receptor activator of nuclear factor-κB (RANK)/RANK ligand system and the Galectin-3/receptor of advanced glycation end products axis. The insight that osteogenesis and vascular calcification share many similarities-and the knowledge that vascular calcification is a cell-mediated active rather than a passive mineralization process-suggest that low BMD and vascular calcification ('vascular ossification') to a large extent represent two sides of the same coin. Here, we briefly review changes of BMD in ESRD as observed using different DXA methods (central and whole-body DXA) at different bone sites for BMD measurements, and summarize recent knowledge regarding the relationships between 'low BMD' and 'fracture incidence, vascular calcification and increased mortality' in ESRD patients, as well as potential 'molecular mechanisms' underlying these associations.

Differences in association of lower bone mineral density with higher coronary calcification in female and male end-stage renal disease patients

Background

Risk of cardiac events and cardiovascular disease (CVD) in end-stage renal disease (ESRD) patients are predicted by coronary artery calcification (CAC) independently. It is not clear to what extent low bone mineral density (BMD) is associated with higher risk of CAC and if sex interacts. We investigated the sex-specific associations of CAC score with total body BMD (tBMD) as well as with BMD of different skeletal sub-regions.

Methods

In 174 ESRD patients, median age 57 (10th–90th percentiles 29–75) years, 63% males, BMD (measured by dual-energy X-ray absorptiometry; DXA), CAC score (measured by cardiac CT) and circulating inflammatory biomarkers were analysed.

Results

A total of 104 (60%) patients with CAC > 100 AUs were older, had higher prevalence of both clinical CVD and diabetes, higher level of high sensitivity C-reactive protein, tumour necrosis factor, interleukin-6 and lower T-score of tBMD. Female patients had significantly lower tBMD and BMD of all skeletal sub-regions, except head, than male patients. Female patients with high CAC (> 100 AUs) had significantly decreased T-score of tBMD, and lower BMD of arms, legs than those low CAC (≤ 100 AUs); elevated CAC score were associated with tBMD, T-score, Z-score of tBMD and BMD of arms and legs, while no such differences was observed in males. Multivariate generalized linear model (GLM) analysis adjusted for age, diabetes and hsCRP showed that in females per SD higher CAC score (1057 AUs) was predicted by either per SD (0.13 g/cm²) lower tBMD or per SD (0.17 g/cm²) lower BMD at legs. No such associations were found in male ESRD patients.

Conclusions

In female, but not male, lower BMD, in particular sub-regions of legs, was associated with higher CAC score independently. Low BMD has the potential to identify increased risk for high CAC score in ESRD patients.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1235-z) contains supplementary material, which is available to authorized users.

Bone Mineral Density of the Radius Predicts All-Cause Mortality in Patients With Type 2 Diabetes: Diabetes Heart Study

This study aimed to determine the association between areal and volumetric bone mineral density (BMD) with all-cause mortality in patients with type 2 diabetes (T2D). Associations between BMD and all-cause mortality were examined in 576 women and 517 men with T2D in the Diabetes Heart Study. Volumetric BMD in the thoracic and lumbar spine was measured with quantitative computed tomography. Areal BMD (aBMD) in the lumbar spine, total hip, femoral neck, ultradistal radius, mid radius, and whole body was measured using dual X-ray absorptiometry. Association of BMD with all-cause mortality was determined using sequential models, stratified by sex: (1) unadjusted; (2) adjusted for age, race, smoking, alcohol, estrogen use; (3) model 2 plus history of cardiovascular disease, hypertension, and coronary artery calcification; (4) model 3 plus lean mass; and (5) model 3 plus fat mass. At baseline, mean age was 61.2 years for women and 62.7 years for men. At mean 11.0 ± 3.7 years' follow-up, 221 (36.4%) women and 238 (43.6%) men were deceased. In women, BMD at all skeletal sites (except spine aBMD and whole body aBMD) was inversely associated with all-cause mortality in the unadjusted model. These associations remained significant in the mid radius (hazard ratio per standard deviation  = 0.79; p = 0.0057) and distal radius (hazard ratio per standard deviation  = 0.76; p = 0.0056) after adjusting for all covariates, including lean mass. In men, volumetric BMD measurements but not aBMD were inversely associated with mortality and only in the unadjusted model. In this longitudinal study, lower baseline aBMD in the radius was associated with increased all-cause mortality in women with T2D, but not men, independent of other risk factors for death.

Bone mineral density of extremities is associated with coronary calcification and biopsy-verified vascular calcification in living-donor renal transplant recipients

Chronic kidney disease (CKD) mineral and bone disorders (CKD-MBD) may lead to low bone mineral density (BMD) and vascular calcification (VC), but links to the latter are unclear. Here we investigated associations between BMD, coronary artery calcium (CAC) scores, and histological signs of VC in end-stage renal disease (ESRD) patients undergoing living-donor kidney transplantation (LD-Rtx). In 66 ESRD patients (median age 45 years, 68% males), BMD (by dual-energy X-ray absorptiometry, DXA), CAC score (by computed tomography, CT; n = 54), and degree of VC score (graded by histological examination of epigastric artery specimens collected at LD-Rtx; n = 55) were assessed at the time of LD-Rtx. Of the patients, 26% had osteopenia and 7% had osteoporosis. Of those undergoing artery biopsy, 16% had extensive VC, and of those undergoing CT 28% had high CAC score (>100 Agatston units). CAC scores correlated with BMD of legs and pelvis. BMDs of leg and pelvic sub-regions were significantly lower in patients with extensive VC. In multivariate regression analysis adjusted for age and gender, lower BMD of leg sub-region was associated with CAC score >100 AUs and extensive VC, and patients with extensive VC had significantly higher CAC score. Both high CAC and extensive VC were independently predicted by low BMD of legs. Low BMD has the potential to identify ESRD patients at risk of vascular calcification.

Low hip bone mineral density predicts mortality in maintenance hemodialysis patients: a five-year follow-up study

BACKGROUND

Bone loss is common among hemodialysis patients and contributes to mortality. The association between bone loss and vascular calcification may explain the increased mortality risk. Studies on the association between decreased bone mass and mortality in maintenance hemodialysis patients are limited.

METHODS

Eighty-three hemodialysis patients underwent bone mineral density (BMD) and coronary artery calcification (CAC) measurements. The relationship between BMD and mortality was analyzed after a 5-year follow-up period.

RESULTS

Eighty percent of the patients had reduced hip BMD. In univariate Cox regression analyses, age, cardiovascular disease, dyslipidemia, increased CAC score, increased comorbidity score and decreased hip BMD were associated with mortality. Low hip BMD remained independently associated with mortality after adjustments for cardiovascular risk factors, comorbidity score and CAC score. Patients with BMD in the lowest tertile had the worst survival.

CONCLUSION

Low hip BMD predicted mortality in maintenance hemodialysis patients independent of CAC.

Increased active PTH(1-84) fraction as a predictor of poor mortality in male hemodialysis patients

We reported previously that serum parathyroid hormone [PTH(1-84)]/intact PTH[PTH(1-84) + PTH(7-84)] ratio provides the better marker for parathyroid function and bone turnover state than serum PTH level itself. The present study demonstrated that higher PTH(1-84)/intact PTH ratio, but not serum PTH(1-84) and intact PTH, predicted higher all-cause mortality in 177 male hemodialysis patients.

INTRODUCTION

We reported that PTH(1-84)/intact PTH ratio provides a clinically relevant marker for parathyroid function and the resultant bone turnover state. The purpose of our study was to investigate the association of PTH(1-84)/intact PTH ratio with all-cause mortality (ACM) in male hemodialysis patients.

METHODS

The study was performed for 70 months. Serum PTH in 177 male hemodialysis patients was measured with PTH(1-84)-specific whole PTH assay and intact PTH assay which cross-reacts with N-truncated PTH including PTH(7-84).

RESULTS

The patients (n = 177) were divided into higher and lower halves based on serum levels of PTH(1-84)/intact PTH ratio (cutoff value, 0.484), intact PTH (143.8 pg/mL), and PTH(1-84) (64.1 pg/mL). In Kaplan-Meier analysis, the higher group in whole PTH/intact PTH ratio had significantly higher ACM than the lower group (P = 0.020 by log-rank test), in contrast with the insignificant difference between the higher and lower groups in intact PTH and PTH(1-84). Multivariate Cox regression hazard analysis identified higher log [PTH(1-84)/intact PTH ratio], but not log intact PTH or log PTH(1-84) as a significant independent predictor [hazard ratio 14.428 (95% CI 2.486-83.728)] for ACM after adjustment for various factors including age, hemodialysis duration, presence/absence of diabetes mellitus, BMI, log C-reactive protein, serum albumin, calcium, and phosphate. The association existed between log [PTH(1-84)/intact PTH ratio] and ACM in those without vitamin D administration (n = 95).

CONCLUSION

Higher PTH(1-84)/intact PTH ratio, which provides a relevant marker for parathyroid function, may be a significant predictor of ACM in male hemodialysis patients.

Role of testosterone in the pathogenesis, progression, prognosis and comorbidity of men with chronic kidney disease

Testosterone deficiency and hypogonadism are common conditions in men with chronic kidney disease (CKD). A disturbed hypothalamic-pituitary-gonadal axis due to CKD is thought to contribute to androgen deficiency. Data from experimental studies support the hypothesis that exogenous administration of testosterone may induce the activation of the renin-angiotensin system (RAS), the production of endothelin and the regulation of anti- or/and proinflammatory cytokines involved in the pathogenesis of hypertension and kidney damage. On the other hand, low testosterone levels in male patients with CKD are paradoxically associated with a higher risk of morbidity and mortality, possibly explained by anemia, osteoporosis and cardiovascular disease. In this article, we present an overview of clinical and experimental studies of the impact of testosterone on the progression and prognosis of male patients with CKD; even today, this remains a controversial issue.

Impaired response of FGF-23 to oral phosphate in patients with type 2 diabetes: a possible mechanism of atherosclerosis

BACKGROUND

Fibroblast growth factor (FGF)-23, secreted from osteocytes/osteoblasts, plays major roles in phosphate (Pi)-mediated stimulation of PTH secretion and consequently in regulation of serum Pi. Osteocyte/osteoblast dysfunction develops in patients with type 2 diabetes mellitus (DM).

OBJECTIVE

Our objective was to examine whether increases in serum FGF-23 and PTH after oral Pi stimulation are impaired in type 2 DM.

DESIGN AND METHODS

The subjects were 10 DM and 10 non-DM patients without chronic kidney disease stage 3-5. Serum FGF-23, intact PTH (iPTH), and Pi were measured serially after oral Pi administration at a daily dose of 2.0 g.

RESULTS

Pi administration caused significant increases of FGF-23 by 2 h and iPTH by 4 h in non-DM patients. These increases were attenuated in DM patients. After 2 d of Pi stimulation, serum FGF-23 and iPTH remained elevated in non-DM patients but not in DM. In all subjects, initial changes of serum FGF-23 (0-2 h) and iPTH (0-4 h) were positively correlated (r = 0.528) and showed significant negative correlations with later changes in serum Pi (2-4 h) (r = -0.457 and r = -0.673, respectively). Serum Pi (2-4 h) significantly increased in DM patients, consistent with the lack of change in serum FGF-23 and iPTH, whereas serum Pi did not change significantly in non-DM patients.

CONCLUSION

These results show that increases of serum FGF-23 and PTH in response to Pi stimulation are impaired in type 2 DM and that serum Pi is significantly increased thereafter. This may be a mechanism underlying advanced atherosclerosis in type 2 DM.

Serum adiponectin and bone mineral density in male hemodialysis patients

SUMMARY

Bone mineral density of the 1/3 distal radius, ultra-distal radius, and lumbar spine correlated significantly and negatively with serum adiponectin. There was a significant positive correlation between serum adiponectin and serum NTX. Thus, adiponectin may play a role in mineral and bone disorder in chronic kidney disease stage 5 dialysis (CKD 5D) patients.

INTRODUCTION

Serum adiponectin, an adipocyte-produced hormone, has been reported to correlate negatively with bone mineral density (BMD) in the general population. However, little is known about the association between adiponectin and BMD in patients with CKD.

METHODS

BMD of the 1/3 distal and ultra-distal radius, which are enriched with cortical and cancellous bone, respectively, and the lumbar spine was measured by dual X-ray absorptiometry in 114 Japanese male hemodialysis patients (age 61.0 ± 11.1 years; hemodialysis duration 6.6 ± 3.0 years; 43.9% diabetics). Serum total adiponectin, bone formation marker (bone alkaline phosphatase, BAP), and bone resorption marker (cross-linked N-telopeptide of type I collagen (NTX)) were measured.

RESULTS

The BMD of the 1/3 distal radius, ultra-distal radius, and lumbar spine correlated significantly and negatively with serum adiponectin level (r = -0.229, p = 0.014; r = -0.286, p = 0.002; r = -0.227, p = 0.013, respectively). In multiple linear regression analyses, serum adiponectin was significantly and independently associated with the BMD of the 1/3 distal radius (R(2) = 0.173, p < 0.001) and ultra-distal radius (R(2) = 0.278, p < 0.001) after adjustment of age, hemodialysis duration, body weight, %fat mass, and log [intact PTH], although it was not with the BMD of the lumbar spine. There was a significant positive correlation between serum adiponectin and serum NTX (r = 0.321, p < 0.001), although there was no significant correlation between serum adiponectin and serum BAP.

CONCLUSION

Increased levels of serum adiponectin were associated with decrease in BMD in male hemodialysis patients. Adiponectin may play a role in mineral and bone disorder, possibly in bone resorption, of patients with CKD 5D.

Significant association of fracture of the lumbar spine with mortality in female hemodialysis patients: a prospective observational study

Prevalent fracture of the lumbar spine is established as a predictor of increased mortality in the general population. To examine whether this association is retained in hemodialysis patients, we conducted a single-center prospective observational study in 635 hemodialysis patients (60.3 + or - 12.0 years old, male/female 369/266). Patients were divided into two groups (with and without lumbar fracture, assessed by simple lateral radiograph), and survival was followed for an average of 53.8 months. Lumbar fracture was present in 62 patients (9.76%; male 9.76%, female 9.77%). During the follow-up period, there were 176 all-cause deaths (27.7%; male 27.6%, female 27.8%), of which 72 were from cardiovascular diseases. In Kaplan-Meier analysis, all-cause and noncardiovascular mortality rates, but not cardiovascular mortality, were significantly higher in patients with fracture than in those without (P < 0.0001). In multivariate Cox proportional hazard analysis, the presence of lumbar fracture was significantly associated with increased noncardiovascular mortality (HR = 2.035, 95% CI 1.135-3.652, P < 0.05) after adjustment for age, duration of hemodialysis, presence of diabetes, body mass index, and serum calcium, phosphate, and albumin. Significantly higher all-cause and noncardiovascular mortality rates were also evident for patients with fracture in separate analyses in males and females, but multivariate analysis showed a significant association of lumbar fracture with increased all-cause (HR = 2.151, 95% CI 1.033-4.478, P < 0.05) and noncardiovascular (HR = 2.637, 95% CI 1.014-6.858, P < 0.05) mortality rates only in females. In conclusion, lumbar fracture is significantly associated with all-cause mortality in female patients.