Impact of Competing Risk of Mortality on Association of Weight Loss With Risk of Central Body Fractures in Older Men: A Prospective Cohort Study

Repeat Bone Mineral Density Screening Measurement and Fracture Prediction in Older Men: A Prospective Cohort Study

CONTEXT

Whether repeated bone mineral density (BMD) screening improves fracture prediction in men is uncertain.

OBJECTIVE

We evaluated whether a second BMD 7 years after the initial BMD improves fracture prediction in older men.

METHODS

Among 3651 community-dwelling men (mean age 79.1 years) with total hip BMD at baseline and Year 7 (Y7), self-reported fractures after Y7 were confirmed by radiographic reports. Fracture prediction assessed using Cox proportional hazards regression and logistic regression with receiver operating characteristic curves for models based on initial BMD, BMD change, and the combination of initial BMD and BMD change (combination model).

RESULTS

During an average follow-up of 8.2 years after Y7, 793 men experienced ≥ 1 clinical fractures, including 426 men with major osteoporotic fractures (MOF) and 193 men with hip fractures. Both initial BMD and BMD change were associated with risk of fracture outcomes independent of each other, but the association was stronger for initial BMD. For example, the multivariable hazard ratio of MOF in the combination model per 1 SD decrement in BMD was 1.76 (95% CI 1.57-1.98) for initial BMD and 1.19 (95% CI 1.08-1.32) for BMD change. Discrimination of fracture outcomes with initial BMD models was somewhat better than with BMD change models and similar to combination models (AUC value for MOF 0.68 [95% CI 0.66-0.71] for initial BMD model, 0.63 [95% CI 0.61-0.66] for BMD change model, and 0.69 [95% CI 0.66-0.71] for combination model).

CONCLUSION

Repeating BMD after 7 years did not meaningfully improve fracture prediction at the population level in community-dwelling older men.

Age-Related Changes in Bone Density, Microarchitecture, and Strength in Postmenopausal Black and White Women: The SWAN Longitudinal HR-pQCT Study

Higher fracture risk in White versus Black women is partly explained by lower BMD and worse bone microarchitecture in White women. However, whether rates of decline in bone density, microarchitecture and strength differ between postmenopausal Black and White women is unknown. Further, factors that influence rates of age-related bone microarchitecture deterioration remain ill-defined. Thus, over 6.7 years, longitudinal changes were measured in peripheral volumetric bone mineral density (vBMD), microarchitecture, and strength at the distal radius and tibia using HR-pQCT in postmenopausal Black (n = 80) and White (n = 137) women participating in the Study of Women's Health Across the Nation. It was assessed whether age-related changes in vBMD and microarchitecture were influenced by body weight, body composition, and/or weight change. It was found that at the radius, where White women appeared to have slightly greater rates of loss in total vBMD, cortical bone volume, and porosity than Black women, those differences were attenuated after adjusting for clinical covariates. At the tibia, Black and White women had similar rates of bone loss. Independent of race and other clinical covariates, women with the lowest baseline body weight experienced the greatest decline in total and trabecular vBMD at the radius. Furthermore, women who lost weight over the follow-up period had higher rates of bone loss, particularly at the tibia, compared with those who maintained or gained weight. Higher baseline total body fat mass was also protective of bone loss at both the radius and tibia. In conclusion, these findings indicate that lower fracture risk among postmenopausal Black women is not caused by slower rates of bone deterioration, and highlight the importance for postmenopausal women to avoid lower body weight and excessive weight loss to avert rapid bone loss and subsequent fractures. © 2021 American Society for Bone and Mineral Research (ASBMR).

Growth differentiation factor-15 and incident chronic kidney disease: a population-based cohort study

Background

The relationship between growth differentiation factor 15 (GDF-15) and the development of chronic kidney disease (CKD) is still unclear. We sought to examine whether plasma GDF-15 was related to incident CKD and kidney function decline using a large prospective cohort study.

Methods

4318 participants of the Malmö Diet and Cancer Study-Cardiovascular Cohort were examined in 1991-1994. Incidence of CKD was followed prospectively by linkage with national patient registers. Estimated glomerular filtration rate (eGFR) was available for all participants at baseline, and was re-measured in a subgroup of 2744 subjects after 16.6 ± 1.49 years. Incidence of CKD was examined in relation to GDF-15 using Cox regression analysis. Logistic regression was used to examine the association of GDF-15 with eGFR change and eGFR-based CKD. Models were carefully corrected for potential confounders including baseline eGFR, N-terminal pro-B-type natriuretic peptide, and competing risk from death.

Results

165 patients developed CKD after 19.2 ± 4.04 years of follow-up. The adjusted hazard ratio (95% confidence interval, CI) for CKD in 4th versus 1st quartile of GDF-15 was 2.37 (1.33, 4.24) (p for trend < 0.01). Each per 1 standard deviation increase in GDF-15 was associated with a decline in eGFR of − 0.97 mL/min/1.73 m² (95% CI, − 1.49 ~ − 0.45; p < 0.001). GDF-15 was also significantly associated eGFR-based CKD in 2713 subjects with baseline eGFR ≥60 mL/min/1.73 m².

Conclusions

GDF-15 predicted incidence of CKD and eGFR decline in the general population, independent of a wide range of potential risk factors and competing risk of death.

Exercise attenuates bone mineral density loss during diet-induced weight loss in adults with overweight and obesity: A systematic review and meta-analysis

BACKGROUND

Weight-loss-induced fat loss improves cardiometabolic health in individuals with overweight and obesity; however, weight loss can also result in bone loss and increased fracture risk. Weight-loss-induced bone loss may be attenuated with exercise. Our aim was to compare changes in bone mineral density (BMD) in adults with overweight and obesity who undertook diet-induced weight loss alone or in combination with exercise.

METHODS

We included randomized controlled trials (RCTs) in adults with overweight or obesity (aged ≥18 years; body mass index ≥25 kg/m²) that prescribed diet-induced weight loss alone or in combination with supervised exercise, and measured any bone structural parameters. Risk of bias was assessed using the Cochrane Risk of Bias tool. Random-effects meta-analyses determined mean changes and net mean differences (95% confidence intervals (95%CIs)) in the percentage of areal BMD (aBMD) change between groups.

RESULTS

We included 9 RCTs. Diet-induced weight loss led to significant losses in femoral neck aBMD (mean change: -1.73% (95%CI: -2.39% to -1.07%), p < 0.001) and total hip aBMD (-2.19% (95%CI: -3.84% to -0.54%), p = 0.009). Femoral neck aBMD losses were significantly greater in the diet-induced weight loss group compared to the exercise plus diet-induced weight loss group (net difference: -0.88% (95%CI: -1.73% to -0.03%)); however, there were no differences in aBMD changes at any other skeletal site: total hip (-1.96% (95%CI: -4.59% to 0.68%)) and lumbar spine (-0.48% (95%CI: -1.81% to 0.86%)). aBMD changes did not differ significantly according to exercise modality (resistance exercise, aerobic exercise, or a combination of the two) during diet-induced weight loss.

CONCLUSION

Diet-induced weight loss led to greater femoral neck bone loss compared to diet-induced weight loss plus exercise. Bone loss at the total hip and lumbar spine was not attenuated by exercise during diet-induced weight loss. The lack of consistent skeletal benefits may be due to the insufficient duration and/or training intensities of most exercise interventions. Additional RCTs with appropriate, targeted exercise interventions should be conducted.

Height Loss in Old Age and Fracture Risk Among Men in Late Life: A Prospective Cohort Study

To assess the association of height loss in old age with subsequent risk of hip and any clinical fracture in men late in life while accounting for the competing risk of mortality, we used data from 3491 community-dwelling men (mean age 79.2 years). Height loss between baseline and follow-up (mean 7.0 years between examinations) was categorized as <1 cm (referent group), ≥1 to <2 cm, ≥2 to <3 cm, and ≥3 cm. Men were contacted every 4 months after the follow-up examination to ask about fractures (confirmed by radiographic reports) and ascertain vital status (deaths verified by death certificates). Competing risk methods were used to estimate absolute probabilities of fracture outcomes by height loss category and calculate adjusted risks of fracture outcomes by height loss. During an average of 7.8 years, 158 (4.5%) men experienced a hip fracture and 1414 (40.5%) died before experiencing this event. The absolute 10-year probability of fracture events accounting for the competing risk of death increased with greater height loss. For example, the hip fracture probability was 2.7% (95% confidence interval [CI] 1.9-3.8%) among men with height loss <1 cm increasing to 11.6% (95% CI 8.0-16.0%) among men with height loss ≥3 cm. After adjustment for demographics, fall history, multimorbidity, baseline height, weight change, and femoral neck bone mineral density and considering competing mortality risk, men with height loss ≥3 cm versus <1 cm had a nearly twofold (subdistribution hazard ratio [HR] = 1.94, 95% CI 1.06-3.55) higher risk of hip fracture and a 1.4-fold (subdistribution HR = 1.42, 95% CI 1.05-1.91) increased risk of any clinical fracture. Height loss ≥3 cm in men during old age was associated with higher subsequent risk of clinical fractures, especially hip fractures, even after accounting for the competing risk of death and traditional skeletal and non-skeletal risk factors. © 2021 American Society for Bone and Mineral Research (ASBMR).

Growth differentiation factor-15 is a biomarker for all-cause mortality but less evident for cardiovascular outcomes: A prospective study

BACKGROUND

Previous studies have proposed growth differentiation factor-15 (GDF-15) as a predictor of adverse cardiovascular outcomes and mortality. The present study aimed to determine if such associations remain after accounting for death as a competing risk, and if GDF-15 provides superior prediction performance than other biomarkers.

METHODS

Plasma GDF-15 levels and cardiovascular risk factors were measured in individuals without cardiovascular diseases (n = 4,143, aged 57.4 ± 5.96 years, 38.6 % men) from Malmö Diet and Cancer-Cardiovascular Cohort and were followed up for more than 20 years. Incidence of coronary events, ischemic stroke, cardiovascular mortality, and all-cause mortality was studied in relation to GDF-15 using Cox proportional hazards regression, with adjustment for potential confounders. Confounding from death as competing risk was carefully checked using the Fine and Gray subdistribution hazard model. Predictive capabilities were further evaluated using C-statistics, continuous net reclassification improvement, and integrated discrimination improvement.

RESULTS

During follow-up, 424 coronary events, 327 ischemic stroke, 368 cardiovascular deaths, and 1,308 all-cause deaths occurred. After controlling for death from other causes as competing events, only all-cause mortality remained significantly related to GDF-15. The addition of GDF-15 significantly improved prediction for all-cause mortality in addition to the traditional risk factors, high-sensitive C-reactive protein and N-terminal prohormone of brain natriuretic peptide. Only N-terminal prohormone of brain natriuretic peptide improved prediction for CVD mortality.

CONCLUSIONS

GDF-15 is a robust biomarker for all-cause mortality but less reliable for coronary event, ischemic stroke or cardiovascular mortality. Competing risk from death is an important consideration when interpreting the results.

Weight loss since early adulthood, later life risk of fracture hospitalizations, and bone mineral density: a prospective cohort study of 0.5 million Chinese adults

In a Chinese population from both urban and rural areas, weight loss of ≥ 5 kg from early adulthood to midlife was associated with a higher risk of hip fracture and lower BMD in later life.

INTRODUCTION

This study investigates the association of the long-term weight loss from young adulthood through the middle ages with the subsequent 10-year risk of hospitalized fracture and calcaneus bone mineral density (BMD).

METHODS

China Kadoorie Biobank (CKB) was established during 2004-2008 in ten areas across China. Weight at age 25 years was self-reported at baseline, and weight at baseline and resurvey was measured by the calibrated equipment. Outcomes were hospitalized fracture during follow-up and calcaneus BMD measured at resurvey. Analysis for fracture risk included 411,812 participants who were free of fracture in the last 5 years before baseline, cancer, or stroke at any time before baseline. Analysis for BMD included 21,453 participants who participated in the resurvey of 2013-2014 with the same exclusion criteria as above.

RESULTS

The mean age was 50.8 at baseline and 58.4 at resurvey. Median weight change from age 25 to baseline was 4.4 kg, with 20.7% losing weight and 58.5% gaining weight. During a median follow-up of 10.1 years, we documented 13,065 cases of first diagnosed fracture hospitalizations, including 1222 hip fracture. Compared with participants whose weight was stable (± 2.4 kg), the adjusted hazard ratios (95% CIs) for those with weight loss of ≥ 5.0 kg from age 25 to baseline was 1.39 (1.17 to 1.66) for hip fracture. Weight loss was not associated with fracture risk at other sites. Those with weight loss from age 25 to resurvey had the lowest BMD measures, with β (95% CIs) of - 4.52 (- 5.08 to - 3.96) for broadband ultrasound attenuation (BUA), - 4.83 (- 6.98, - 2.67) for speed of sound (SOS), and - 4.36 (- 5.22, - 3.49) for stiffness index (SI).

CONCLUSIONS

Weight loss from early adulthood to midlife was associated with a higher risk of hip fracture and lower BMD in later life.

Associations of Body Composition Trajectories with Bone Mineral Density, Muscle Function, Falls, and Fractures in Older Men: The Concord Health and Ageing in Men Project

Background

Weight loss increases fracture risk in older adults. We aimed to determine associations of 2-year body composition trajectories with subsequent falls and fractures in older men.

Methods

We measured appendicular lean mass (ALM) and total fat mass (FM) by dual-energy X-ray absorptiometry at baseline and Year 2 in 1,326 community-dwelling men aged ≥70 and older. Body composition trajectories were determined from residuals of a linear regression of change in ALM on change in FM (higher values indicate maintenance of ALM over FM), and a categorical variable for change in ALM and FM (did not lose [≥−5% change] versus lost [&lt;−5% change]). Bone mineral density (BMD), hand grip strength, and gait speed were assessed at Years 2 and 5. After Year 2, incident fractures (confirmed by radiographical reports) and falls were recorded for 6.8 years.

Results

Compared with men who did not lose ALM or FM, men who did not lose ALM but lost FM, and men who lost both ALM and FM, had reduced falls (−24% and −34%, respectively; both p &lt; .05). Men who lost ALM but did not lose FM had increased falls (incidence rate ratio = 1.73; 95% CI 1.37–2.18). ALM/FM change residuals were associated with improved lumbar spine BMD (B = 0.007; 95% CI 0.002–0.012 g/cm2 per SD increase) and gait speed (0.015; 0.001–0.029 m/s), and reduced hip fractures (hazard ratio = 0.68; 95% CI 0.47–0.99).

Conclusions

Fracture risk may be increased in older men who lose higher ALM relative to FM. Weight loss interventions for obese older men should target maintenance of lean mass.

Accelerated Bone Loss in Older Men: Effects on Bone Microarchitecture and Strength

Accelerated bone loss (ABL) shown on routine dual-energy X-ray absorptiometry (DXA) may be accompanied by microarchitectural changes, increased cortical porosity, and lower bone strength. To test this hypothesis, we performed a cross-sectional study and used high-resolution peripheral quantitative computed tomography (HR-pQCT) scans (Scanco Medical AG, Brüttisellen, Switzerland) to measure estimated bone strength and microarchitecture in the distal radius and distal and diaphyseal tibia. We studied 1628 men who attended the year 14 exam of the Osteoporotic Fractures in Men (MrOS) study. We retrospectively characterized areal bone mineral density (aBMD) change from the year 7 to year 14 exam in three categories: "accelerated" loss, ≥10% loss at either the total hip or femoral neck (n = 299, 18.4%); "expected" loss, <10% (n = 1061, 65.2%), and "maintained" BMD, ≥0% (n = 268, 16.5%). The ABL cut-off was a safety alert established for MrOS. We used regression models to calculate adjusted mean HR-pQCT parameters in men with ABL, expected loss, or maintained BMD. Men who experienced ABL were older and had a lower body mass index and aBMD and experienced greater weight loss compared with other men. Total volumetric BMD and trabecular and cortical volumetric BMD were lower in men with ABL compared with the expected or maintained group. Men with ABL had significantly lower trabecular bone volume fraction (BV/TV), fewer trabeculae, and greater trabecular separation at both the distal radius and tibia than men with expected loss or who maintained aBMD, all p trend <0.001. Men with ABL had lower cortical thickness and lower estimated bone strength, but there was no difference in cortical porosity except at the tibia diaphyseal site. In summary, men with ABL have lower estimated bone strength, poorer trabecular microarchitecture, and thinner cortices than men without ABL but have similar cortical porosity. These impairments may lead to an increased risk of fracture. © 2018 American Society for Bone and Mineral Research.

Differential Mortality and the Excess Rates of Hip Fracture Associated With Type 2 Diabetes: Accounting for Competing Risks in Fracture Prediction Matters

Type 2 diabetes (T2DM) is associated with a reduced life expectancy. The latest published evidence suggests an increased risk of fractures among T2DM patients. We conducted a population-based cohort study to determine the impact of mortality as a competing risk in the study of the association between T2DM and hip fracture rates. Participants were all diagnosed T2DM patients registered in the Sistema de Información para el Desarrollo de la Investigación en Atención Primaria (SIDIAP) database aged 65 years and older; up to two non-T2DM were matched by age, sex, and primary care facility. We used Cox regression models to estimate cause-specific hazard ratio (HR) of death or hip fracture according to T2DM status. Fine and Gray models were then fitted to estimate the subhazard ratio (SHR) of hip fracture while accounting for competing risk with death and to estimate the probability of hip fracture within 5 years. A total of 55,891 T2DM and 103,093 matched non-T2DM patients were observed for a median of 8 years. Mortality was 48.8 per 1000 person years (py) in T2DM, and 33.8 per 1000 py in non-T2DM; hip fracture rates were 6.0 per 1000 py and 4.9 per 1000 py, respectively. Cox models confirmed a significant association for death and hip fracture: HR 1.51 (95% CI, 1.48 to 1.55), and HR 1.32 (95% CI, 1.24 to 1.40), respectively. Accounting for death as a competing event (Fine-Gray models), the association between T2DM and hip fracture risk remained statistically significant (SHR 1.15; 95% CI, 1.09 to 1.21) and the probability of a hip fracture within 5 years was 2.3% for TD2M and 1.9% for non-TD2M patients compared to 2.6% and 2.1% respectively using Kaplan-Meier (KM) estimates. T2DM patients have a 50% increased mortality and, after adjusting for differential survival at 5 years, a 21% increased incidence of hip fracture when compared to matched non-T2DM. Failing to account for differential mortality leads to an overestimation of fracture risk. © 2018 American Society for Bone and Mineral Research.

Weight loss in men in late life and bone strength and microarchitecture: a prospective study

Weight loss in men in late life was associated with lower bone strength. In contrast, weight gain was not associated with a commensurate increase in bone strength. Future studies should measure concurrent changes in weight and parameters of bone strength and microarchitecture and evaluate potential causal pathways underlying these associations.

INTRODUCTION

Our aim was to determine associations of weight loss with bone strength and microarchitecture.

METHODS

We used data from 1723 community-dwelling men (mean age 84.5 years) who attended the MrOS study Year (Y) 14 exam and had high-resolution peripheral quantitative computed tomography (HR-pQCT) scans at ≥ 1 skeletal sites (distal tibia, distal radius, or diaphyseal tibia). Weight change from Y7 to Y14 exams (mean 7.3 years between exams) was classified as moderate weight loss (loss ≥ 10%), mild weight loss (loss 5 to < 10%), stable weight (< 5% change), or weight gain (gain ≥ 5%). Mean HR-pQCT parameters (95%CI) were calculated by weight change category using linear regression models adjusted for age, race, site, health status, body mass index, limb length, and physical activity. The primary outcome measure was estimated failure load.

RESULTS

There was a nonlinear association of weight change with failure load at each skeletal site with different associations for weight loss vs. weight gain (p < 0.03). Failure load and total bone mineral density (BMD) at distal sites were lower with greater weight loss with 7.0-7.6% lower failure loads and 4.3-5.8% lower BMDs among men with moderate weight loss compared to those with stable weight (p < 0.01, both comparisons). Cortical, but not trabecular, BMDs at distal sites were lower with greater weight loss. Greater weight loss was associated with lower cortical thickness at all three skeletal sites.

CONCLUSION

Weight loss in men in late life is associated with lower peripheral bone strength and total BMD with global measures reflecting cortical but not trabecular parameters.

Hydroxyapatite from Fish for Bone Tissue Engineering: A Promising Approach

Natural or synthetic hydroxyapatite (HA) has been frequently used as implant materials for orthopaedic and dental applications, showing excellent bioactivity, adequate mechanical rigidity and structure, osteoconductivity and angiogenic properties, no toxicity, and absence of inflammatory or antigenic reactions. HA can be easily synthesized or extracted from natural sources, such as bovine bone. However, the manufacturing costs to obtain HA are high, restricting the therapy. Herein, much effort has been paid for obtaning alternative natural sources for HA. The potential of HA extracted from skeleton of animals has been investigated. The aim of this review is to exploit the potential of HA derived from fish to fulfill biological activities for bone tissue engineering. In particular, HA from fish is easy to be manufactured regarding the majority of protocols that are based on the calcination method. Furthermore, the composition and structure of HA from fish were evaluated; the biomaterial showed good biocompatibility as a result of non-cytotoxicity and handling properties, demonstrating advantages in comparison with synthetic ones. Interestingly, another huge benefit brought by HA from bone fish is its positive effect for environment since this technique considerably reduces waste. Certainly, the process of transforming fish into HA is an environmentally friendly process and stands as a good chance for reducing costs of treatment in bone repair or replacement with little impact into the environment.

Frailty as a Risk Factor for Cardiovascular Versus Noncardiovascular Mortality in Older Men: Results From the MrOS Sleep (Outcomes of Sleep Disorders in Older Men) Study

Background

Frailty is associated with greater mortality; however, whether frail patients primarily die of cardiovascular disease (CVD) or non‐CVD causes is unknown.

Methods and Results

We assessed the cause of death in relation to frailty status, measured at baseline, among 3135 community‐dwelling older men in the MrOS Sleep (Outcomes of Sleep Disorders in Older Men) study. Absolute probability and risk of CVD mortality associated with frailty status were estimated with traditional methods that used censoring and newer methods that considered non‐CVD mortality as a competing risk. Of the 3135 men (mean age: 76.4±5.6 years), 475 (15.2%) were frail. During an average follow‐up of 9.2 years, 1275 (40.7%) men died, including 445 (34.9%) from CVD and 828 (64.9%) from non‐CVD causes (2 deaths unadjudicated). Both CVD and non‐CVD mortality risk increased with frailty. Cumulative absolute probability of CVD death at 10 years among frail men was 23.8% (20.2–27.6%) using the competing risk method versus 32.5% (27.3–37.8%) using the traditional Kaplan–Meier method (41.5% [95% confidence interval, 36.9–45.9%] and 48.6% [95% confidence interval, 43.6–53.4%], respectively, for non‐CVD mortality). The multivariable‐adjusted risk of CVD death among frail versus robust men was 1.38 (95% confidence interval, 0.99–1.92) using the competing risk method versus 1.84 (95% confidence interval, 1.35–2.51) using the traditional Cox proportional hazards method.

Conclusions

Among community‐dwelling older men, ≈35% of the deaths were due to CVD. Frail men were at increased risk of CVD death, but ignoring the competing risk of non‐CVD mortality overestimated their long‐term probability and relative risk of CVD death.