Previous fracture and subsequent fracture risk: a meta-analysis to update FRAX

A large international meta-analysis using primary data from 64 cohorts has quantified the increased risk of fracture associated with a previous history of fracture for future use in FRAX.

INTRODUCTION

The aim of this study was to quantify the fracture risk associated with a prior fracture on an international basis and to explore the relationship of this risk with age, sex, time since baseline and bone mineral density (BMD).

METHODS

We studied 665,971 men and 1,438,535 women from 64 cohorts in 32 countries followed for a total of 19.5 million person-years. The effect of a prior history of fracture on the risk of any clinical fracture, any osteoporotic fracture, major osteoporotic fracture, and hip fracture alone was examined using an extended Poisson model in each cohort. Covariates examined were age, sex, BMD, and duration of follow-up. The results of the different studies were merged by using the weighted β-coefficients.

RESULTS

A previous fracture history, compared with individuals without a prior fracture, was associated with a significantly increased risk of any clinical fracture (hazard ratio, HR = 1.88; 95% CI = 1.72-2.07). The risk ratio was similar for the outcome of osteoporotic fracture (HR = 1.87; 95% CI = 1.69-2.07), major osteoporotic fracture (HR = 1.83; 95% CI = 1.63-2.06), or for hip fracture (HR = 1.82; 95% CI = 1.62-2.06). There was no significant difference in risk ratio between men and women. Subsequent fracture risk was marginally downward adjusted when account was taken of BMD. Low BMD explained a minority of the risk for any clinical fracture (14%), osteoporotic fracture (17%), and for hip fracture (33%). The risk ratio for all fracture outcomes related to prior fracture decreased significantly with adjustment for age and time since baseline examination.

CONCLUSION

A previous history of fracture confers an increased risk of fracture of substantial importance beyond that explained by BMD. The effect is similar in men and women. Its quantitation on an international basis permits the more accurate use of this risk factor in case finding strategies.

Update of the fracture risk prediction tool FRAX: a systematic review of potential cohorts and analysis plan

We describe the collection of cohorts together with the analysis plan for an update of the fracture risk prediction tool FRAX with respect to current and novel risk factors. The resource comprises 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures.

INTRODUCTION

The availability of the fracture risk assessment tool FRAX® has substantially enhanced the targeting of treatment to those at high risk of fracture with FRAX now incorporated into more than 100 clinical osteoporosis guidelines worldwide. The aim of this study is to determine whether the current algorithms can be further optimised with respect to current and novel risk factors.

METHODS

A computerised literature search was performed in PubMed from inception until May 17, 2019, to identify eligible cohorts for updating the FRAX coefficients. Additionally, we searched the abstracts of conference proceedings of the American Society for Bone and Mineral Research, European Calcified Tissue Society and World Congress of Osteoporosis. Prospective cohort studies with data on baseline clinical risk factors and incident fractures were eligible.

RESULTS

Of the 836 records retrieved, 53 were selected for full-text assessment after screening on title and abstract. Twelve cohorts were deemed eligible and of these, 4 novel cohorts were identified. These cohorts, together with 60 previously identified cohorts, will provide the resource for constructing an updated version of FRAX comprising 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures. For each known and candidate risk factor, multivariate hazard functions for hip fracture, major osteoporotic fracture and death will be tested using extended Poisson regression. Sex- and/or ethnicity-specific differences in the weights of the risk factors will be investigated. After meta-analyses of the cohort-specific beta coefficients for each risk factor, models comprising 10-year probability of hip and major osteoporotic fracture, with or without femoral neck bone mineral density, will be computed.

CONCLUSIONS

These assembled cohorts and described models will provide the framework for an updated FRAX tool enabling enhanced assessment of fracture risk (PROSPERO (CRD42021227266)).

The association of coffee consumption with the risk of osteoporosis and fractures: a systematic review and meta-analysis

To elucidate the association of coffee and bone health would help fracture risk reduction via dietary intervention. Although those who had higher coffee consumption were less likely to have osteoporosis, the associations between coffee consumption and fracture risk need further investigations with better study designs.

INTRODUCTION

The associations between coffee consumption and the risk of osteoporosis and fracture remain inconclusive. We aimed to better quantify these associations by conducting meta-analyses of observational studies.

METHODS

Relevant studies were systematically searched on PubMed, Web of Science, Cochrane library, and Embase Database up to November 25, 2021. The odds ratio (OR) or relative risk (RR) with 95% confidence intervals (CI) was pooled and a dose-response analysis was performed.

RESULTS

Four studies with 7114 participants for osteoporosis and thirteen studies with 391,956 participants for fracture incidence were included in the meta-analyses. High versus low coffee consumption was associated with a lower risk of osteoporosis [pooled OR (95% CI): 0.79 (0.65-0.92)], while it was non-significantly associated with fracture incidence [pooled OR (95% CI): 0.86 (0.67-1.05) at hip and 0.89 (0.42-1.36) at non-hip]. A non-linear association between the level of coffee consumption and hip fracture incidence was shown (P = 0.004). The pooled RR (95% CI) of hip fracture risk in those who consumed 1, 2-3, 4, and ≥ 9 cups of coffee per day was 0.92 (0.87-0.97), 0.89 (0.83-0.95), 0.91 (0.85-0.98), and 1.10 (0.76-1.59), respectively. The significance in the association between coffee consumption and the hip fracture incidence decreased in those studies that had larger sample size, higher quality, and more adjustments.

CONCLUSIONS

A dose-dependent relationship may exist between coffee consumption and hip fracture incidence. The effect of high versus low coffee consumption was influenced by study designs. Further studies with dedicated designs are needed to confirm the independent effects of coffee consumption on bone health.

A bi-layered membrane with micro-nano bioactive glass for guided bone regeneration

Guided bone regeneration (GBR) is widely used to treat oral bone defects. However, the osteogenic effects are limited by the deficiency of the available barrier membranes. In this study, a novel bi-layer membrane was prepared by solvent casting and electrospinning. The barrier layer made of poly (lactic-co-glycolic acid) (PLGA) was smooth and compact, whereas the osteogenic layer consisting of micro-nano bioactive glass (MNBG) and PLGA was rough and porous. The mineralization evaluation confirmed that apatite formed on the membranes in simulated body fluid. Immersion in phosphate-buffered saline led to the degradation of the membranes with proper pH changes. Mechanical tests showed that the bi-layered membranes have stable mechanical properties under dry and wet conditions. The bi-layered membranes have good histocompatibility, and the MNBG/PLGA layer can enhance bone regeneration activity. This was confirmed by cell culture results, expression of osteogenic genes, and immunofluorescence staining of RUNX-related transcription factor 2 and osteopontin. Therefore, the bi-layered membranes could be a promising clinical strategy for GBR surgery.

Validation of the Construct of Intrinsic Capacity in a Longitudinal Chinese Cohort

OBJECTIVES

We examined the structure and predictive ability of intrinsic capacity in a cohort of Chinese older adults.

METHODS

We used data from the MrOS and MsOS (Hong Kong) study, which was designed to examine the determinants of osteoporotic fractures and health in older Chinese adults. We analysed baseline and the 7-year follow-up data using exploratory factor analysis, confirmatory factor analysis (CFA), and mediation analysis.

RESULTS

The study consisted of 3736 participants at baseline (mean 72.2 years), with 1475 in the 7-year follow-up. Bi-factor CFA revealed five sub-factors labelled as 'cognitive', 'locomotor', 'vitality', 'sensory', and 'psychological' and one general factor labelled as 'intrinsic capacity'. The model fits the data well, with Root Mean Square Error of Approximation (RMSEA)=0.055 (90% CI=0.053-0.058) for the 5-factor model and RMSEA=0.031 (90% CI=0.028-0.035) for the bi-factor model. Significantly lower intrinsic capacity scores were found in older age groups, women, as well as those who had lower levels of education, lower subjective social status, reported more chronic diseases, or a higher number of IADL limitations (All p<0.0001). Intrinsic capacity had a direct effect in predicting incident IADL limitations at the 7-year follow-up (β=-0.21, p<0.001). The effect was larger than the direct effect of the number of chronic diseases on incident IADL limitations (β=0.05, not significant).

CONCLUSIONS

This study supports the construct and predictive validity of the proposed capacity domains of intrinsic capacity. The findings could inform the development of an intrinsic capacity score that would facilitate implementation of the concept of intrinsic capacity in clinical practice.

Effectiveness of B Vitamins and Their Interactions with Aspirin in Improving Cognitive Functioning in Older People with Mild Cognitive Impairment: Pooled Post-Hoc Analyses of Two Randomized Trials

BACKGROUND AND OBJECTIVES

A randomized placebo-controlled trial found a significant negative interaction between aspirin and B vitamins in cognitive functioning in older people with mild cognitive impairment (MCI). To validate this finding, we pooled data of this trial with that of a similar B-vitamin trial (VITACOG) to examine the effectiveness of B vitamins and their interactions with aspirin in improving global cognitive functioning and slowing brain atrophy in older people with MCI.

DESIGN

Pooled post-hoc analyses of two randomized placebo-controlled trials.

PARTICIPANTS

In total, 545 older people with MCI were included in the study.

INTERVENTION

Placebo or B-vitamin supplements (vitamin B12, folic acid with or without vitamin B6) for 24 months.

MEASUREMENTS

The primary outcome was the Clinical Dementia Rating scale-global score (CDR-global). The secondary outcomes were CDR-sum of box score (CDR-SOB), memory Z-score, executive function Z-score, and whole brain atrophy rate.

RESULTS

71 (26.2%) and 83 (30.3%) subjects in the active and placebo group respectively were aspirin users. Overall, B vitamins reduced whole brain atrophy rate significantly (P = 0.003), but did not have significant effect on CDR-global, CDR-SOB, memory and executive function. Aspirin use had significant negative interaction effects on B vitamins in CDR-global and CDR-SOB (Beta = 0.993, P = 0.038, and Beta = 0.583, P = 0.009, respectively), but not in memory or executive function Z-scores. Among aspirin non-users, B-vitamin group subjects had more favourable changes in CDR-global and CDR-SOB (P = 0.019 and 0.057, respectively). B vitamins significantly slowed brain atrophy in aspirin non-users (P = 0.001), but not in aspirin users, though the interaction term was not significant (Beta = 0.192, P = 0.276).

CONCLUSION

In older people with MCI, B vitamins had significantly favourable effects on global cognitive functioning and whole brain atrophy rate in those who were not taking aspirin, but not in aspirin users.

Neighborhood Social Cohesion Associates with Loneliness Differently among Older People According to Subjective Social Status

OBJECTIVES

To examine whether neighborhood social cohesion can alleviate the negative impact of low subjective social status on feelings of loneliness.

DESIGN

Cross-sectional study.

SETTING

Community, Hong Kong.

PARTICIPANTS

Older people who participated in a cohort study on osteoporosis and general health in Hong Kong (MrOs study).

METHODS

Data were sourced from the 14-year follow-up data of the MrOs study. Loneliness was measured using the 6-item De Jong Gierveld Loneliness Scale. Neighborhood social cohesion was measured by the Hong Kong version of Neighborhood Cohesion Instrument. Linear regression models were used to examine the associations between neighborhood social cohesion and loneliness, controlled for age, sex, marital status, educational level, lifestyle, number of diseases, and maximum lifetime income. The analyses were stratified by subjective social status as measured by a 10-rung self-anchoring scale.

RESULTS

1,037 participants with a mean age of 83 years were included in the study, of whom 72%, 83%, and 64% were classified as at risk of overall loneliness, emotional loneliness, and social loneliness, respectively. Those who were classified as at risk of overall loneliness reported lower subjective social status and had lower levels of neighborhood social cohesion. Linear regression models showed that higher levels of neighborhood social cohesion were associated with lower levels of overall and social loneliness. Stratified analyses showed that the associations between neighborhood social cohesion and loneliness vary across subjective social status groups. Among those with low/middle social status ranking, higher levels of neighborhood social cohesion were associated with lower overall (low-ranking B=-0.111, p=0.001; middle-ranking B=-0.057, p=0.026) and social (low-ranking B=-0.093, p<0.001; middle-ranking B=-0.073, p<0.001) loneliness scores. Among those with high ranking, higher levels of neighborhood social cohesion were associated with lower overall (B=-0.099, p=0.041) and emotional (B=-0.056, p=0.017) loneliness scores, but the associations became insignificant when controlling for maximum lifetime income.

CONCLUSIONS AND IMPLICATIONS

Neighborhood social cohesion may operate differently in different social ranking groups. Interventions to alleviate feelings of loneliness should be subjective social status specific.

Prospective Analysis of Fruit and Vegetable Variety on Health Outcomes in Community-Dwelling Chinese Older Adults

OBJECTIVES

Evidence on the topic regarding fruit and vegetable (FV) variety and health outcomes among older adults is limited. This study explored the prospective association of fruit variety, vegetable variety and combined FV variety with the risk of sarcopenia, frailty, all-cause and cause-specific mortality in community-dwelling Chinese older adults.

DESIGN

Prospective cohort study.

SETTING

Community.

PARTICIPANTS

Community-dwelling Chinese older adults aged ≥65 years in Hong Kong.

MEASUREMENTS

Fruit variety, vegetable variety and combined FV variety at baseline were assessed using a validated food frequency questionnaire and the variety scores were stratified into tertiles. Sarcopenia (Asian Working Group for Sarcopenia 2019), frailty (Cardiovascular Health Study) and all-cause and cause-specific mortality (retrieved from an official database) were assessed at 14-year follow-up. Adjusted binary logistic regression or Cox proportional hazards model were performed to examine the association of fruit variety, vegetable variety and combined FV variety with each health outcome. Data are presented as hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Baseline dietary data of 3992 participants (median age: 72 years (interquartile range: 68-76), 49.9% women) was available. There were 436 and 371 participants who were newly identified as having sarcopenia and frailty respectively, and 1654 all-cause mortality, 367 cardiovascular diseases (CVD) mortality and 534 cancer mortality over 14-year. Tertiles of fruit variety, vegetable variety and combined FV variety were not associated with sarcopenia, frailty, CVD mortality and cancer mortality. Participants in the highest tertile of fruit variety (HR 0.81, 95% CI 0.70-0.95, p-trend 0.010), vegetable variety (HR 0.77, 95% CI 0.67-0.89, p-trend <0.001) and combined FV variety (HR 0.77, 95% CI 0.67-0.89. p-trend <0.001) showed lower risk of all-cause mortality compared with participants in the lowest tertile.

CONCLUSION

Among community-dwelling Chinese older adults, FV variety was not associated with sarcopenia, frailty, CVD mortality and cancer mortality over 14-year. Higher fruit variety, vegetable variety and combined FV variety were associated with a lower risk of all-cause mortality. Promoting a wide FV variety might be recommended to benefit the health and longevity of this population.

How Dietary Patterns are Related to Inflammaging and Mortality in Community-Dwelling Older Chinese Adults in Hong Kong - A Prospective Analysis

INTRODUCTION

Studies examining dietary patterns and inflammageing in relation to mortality are limited.

OBJECTIVE

We examined the influence of various dietary patterns on all-cause and cardiovascular disease (CVD) mortality, taking into account demographics, lifestyle factors, and serum inflammatory markers.

METHODS

We conducted multivariate Cox regression analyses using data from a cohort of community-dwelling older Chinese adults (1,406 men, 1,396 women) in Hong Kong. Baseline interviewer administered questionnaires covered dietary intake estimation and dietary pattern generation from the food frequency questionnaire, demographic and lifestyle factors, cognitive function and depressive symptoms. Serum high-sensitivity C-reactive protein (hsCRP) and 25-hydroxyvitamin D (25OHD) were measured. All-cause and CVD mortality data at 14-year follow up were retrieved from an official database.

RESULTS

In men, higher hsCRP level was associated with lower Diet Quality Index-International (DQI-I) score, Mediterranean-DASH Intervention for Neurodegenerative Delay Diet (MIND) score, Okinawan diet score, "vegetables-fruits" pattern score and "snacks-drinks-milk" pattern score. Higher serum 25OHD level was associated with higher Mediterranean Diet Score (MDS) but lower "snacks-drinks-milk" pattern score. None of the dietary pattern scores was associated with all-cause or CVD mortality after adjusting for all covariates. In women, hsCRP level and serum 25OHD level were not associated with any dietary patterns. Higher DQI-I score (HR=0.77 (95% CIs: 0.59, 0.99) highest vs. lowest tertile, p-trend=0.038) and Okinawan diet score (HR=0.78 (95% CIs: 0.61, 1.00) highest vs lowest tertile, p-trend=0.046) was associated with a lower risk of all-cause mortality, whereas higher MIND score (HR=0.63 (95% CI: 0.36, 1.09) highest vs. lowest tertile, p-trend=0.045) was associated with a reduced risk of CVD morality in the multivariate adjusted model.

CONCLUSION

Higher DQI-I score and Okinawan diet score were associated with a lower risk of all-cause mortality, and higher adherence to the MIND diet was related to a reduced risk of CVD mortality in community-dwelling Chinese older women.

The role of previous falls in major osteoporotic fracture prediction in conjunction with FRAX in older Chinese men and women: the Mr. OS and Ms. OS cohort study in Hong Kong

Falls are a major concern in terms of fracture risk. Although awareness rising for the absence of falls in the FRAX algorithm, our study only identified the independent predictive role of previous recurrent falls and their better conjunction use with FRAX for major osteoporotic fracture prediction in older Chinese men.

The role of previous falls in major osteoporotic fracture prediction in conjunction with FRAX in older Chinese men and women: the Mr. OS and Ms. OS cohort study in Hong Kong

Falls are a major concern in terms of fracture risk. Although awareness rising for the absence of falls in the FRAX algorithm, our study only identified the independent predictive role of previous recurrent falls and their better conjunction use with FRAX for major osteoporotic fracture prediction in older Chinese men.

INTRODUCTION

Although the association of falls with fracture has been widely explored, the impact of previous falls is not included in the FRAX algorithm currently. Our aim was to examine the FRAX-independent associations between falls in the previous year and subsequent fracture risk, as well as the conjunctive use of falls and the FRAX score for major osteoporotic fracture (MOF) prediction in older Chinese people.

METHODS

Four thousand community older men and women aged 65 years or older were followed up for 9.9 ± 2.7 and 8.8 ± 1.5 years, respectively. The associations between falls in the previous 1 year and MOF risk by follow-up years were evaluated using the Fine and Gray model. New prediction scores were calculated by incorporating the falls and FRAX scores using the Fine and Gray model, or developed by adjusting the FRAX scores by 30% increased risk for each fall in the previous year. The predictive powers for MOF risk between the new scores and FRAX scores were evaluated by the area under the curve (AUC) and category-based net reclassification improvement index (NRI).

RESULTS

During the follow-up period, 139 (7.0%) men and 236 (11.8%) women had at least one incident MOF. One previous fall significantly predicted the first year incident MOF in men [hazard ratio (HR) (95%CI), 3.47 (1.02, 11.80)]. Previous recurrent falls significantly predicted a 10-year incident MOF in men [HR (95%CI), 2.42 (1.30, 4.51)]. In men, the fall-adjusting FRAX scores showed significant improvement on total net reclassification of fracture (3-6%). No improved predictive accuracy shown in women.

CONCLUSION

Falls in the previous year are likely to provide some predictive power to FRAX for MOF risk assessment in older Chinese men, but not women.

Decline and Peripheral Redistribution of Fat Mass in Old Age - A Four-Year Prospective Study in 3018 Older Community-Living Adults

BACKGROUND

It is widely recognized that fat will accumulate with ageing and is more prominent centrally. However, there were studies reported that fat might not gain either centrally or generally with ageing.

METHODS

The baseline, 2-year and 4-year total body fat mas, trunk fat mass and percentage fat mass, were measured by DXA in 3018 community-living Chinese older than 65 years. The respective 4-year trajectories of adiposity were analyzed by repeated measure ANOVA p-for-trend test.

RESULTS

There was a trend of increase in total body fat mass in men and a decreasing trend in women but neither reached statistical significance. However, there was a significant increase in percent fat mass in both genders. Fat mass was relatively stable in the 2 young-old groups but it declined in the oldest group, aged 75 years or above. (men, p=0.017; women, p<0.001). On the contrary, a corresponding rise of percent fat mass was observed, which was steeper in the 2 younger age groups but did not change in the oldest group. For trunk fat mass, there was a statistically significant decreasing trend in women (p < 0.001) but it remained static in men (p = 0.092). The fat mass in upper limbs of both genders did not change but for the lower limbs, there was a statistically significant increase in both men (p < 0.001) and women (p < 0.02).

CONCLUSION

Absolute total body fat mass does not accumulate in old age and in the contrary, in the oldest old group (75 years or above), it declined instead. With ageing, fat will redistribute from the central region to the lower limbs.

Added clinical use of trabecular bone score to BMD for major osteoporotic fracture prediction in older Chinese people: the Mr. OS and Ms. OS cohort study in Hong Kong

The thresholds of trabecular bone score (TBS) require validation for clinical application in older Chinese people. The lower threshold of TBS significantly improved the accuracy of prediction by bone mineral density-based osteoporosis status for major osteoporotic fracture in older Chinese men.

INTRODUCTION

Trabecular bone score (TBS) is a relatively new indicator of skeletal fragility. Its clinical application warrants further investigations. Our aim was to validate and recommend practical thresholds of TBS for fracture prediction in older Chinese people.

METHODS

Older men and women in Mr. and Ms. Os (Hong Kong) study were followed up for an average of 9.94 ± 2.77 and 8.82 ± 1.49 years, respectively. Major osteoporotic fracture (MOF) risks of TBS category in each BMD category (normal, osteopenia, or osteoporosis) were compared using Poisson regression model. The improved fracture risk prediction power was evaluated by the sensitivity, the specificity, the area under the receiver-operating characteristic curve (AUC), and the net reclassification improvement index (NRI).

RESULTS

MOF incidence gradually increased with the increased risk categories of bone mineral density (BMD) and tertiles of TBS both in men and women. Compared with the lowest risk category, the rate ratios (RR, 95 % CI) of MOF for osteoporosis with the lowest TBS was 9.66 (4.19-22.26) and 6.24 (1.53-25.42) in men and women, respectively. The fracture risk for osteopenic men with the lowest TBS was significantly higher than that for normal men, with RR (95 % CI) of 4.68 (2.11-10.41). The predictive power of osteoporosis alone was significantly improved by TBS in men [mean AUC (95 % CI) rose from 0.604 (0.562-0.646) to 0.666 (0.623-0.710) and sensitivity rose from 32.5 to 64.3 %]. The improvement in predictive power was not significant in older women.

CONCLUSIONS

TBS in combination with BMD can predict MOF more reliably in older men than by BMD alone.

The added value of trabecular bone score to FRAX® to predict major osteoporotic fractures for clinical use in Chinese older people: the Mr. OS and Ms. OS cohort study in Hong Kong

The association of trabecular bone score (TBS) with fracture risk and its added predictive value to FRAX® for clinical use have never been independently evaluated in a Chinese population. TBS may improve the predictive power of FRAX® for clinical use in older Chinese men.

INTRODUCTION

Trabecular bone score (TBS) of lumbar spine on Dual X-ray densitometry provides information on bone architecture. We therefore examined the additive value of TBS to FRAX® in predicting major osteoporotic fractures (MOFs) in older Chinese people.

METHODS

Four thousand community-dwelling Chinese men and women aged ≥65 years were followed up for fracture incidence for an average period of 9.94 and 8.82 years, respectively. At baseline, areal BMD of hip and lumbar spine were measured by DXA, TBS was estimated for the lumbar spine, and FRAX® for 10-year risk of MOFs (hip, clinical spine, shoulder, and wrist) was estimated. Cox regression model was used to evaluate the associations between TBS and FRAX® with the MOFs risk. The area under receiver-operating characteristic curve (AUC), integrated discrimination improvement (IDI), and category-based net reclassification improvement (NRI) were applied to evaluate the improved prediction ability.

RESULTS

During the follow-up, 126 men and 215 women had at least one incident MOF. Each SD decrease in TBS was significantly associated with incident MOFs, with HR (95%CI) of 1.53 (1.30-1.80) and 1.40 (1.22-1.61) in men and women, respectively. TBS-adjusted FRAX® predicts better than FRAX® with a significantly increased AUC and IDI in men. Using specific intervention thresholds, TBS-adjusted FRAX® brings about 5 % overall correct reclassification for MOFs prediction than FRAX® in men. The increased correct MOFs risk classifications were not significant in older women.

CONCLUSIONS

TBS-adjusted FRAX® may improve the predictive power of FRAX® on MOFs for clinical use in older Chinese men.

High Serum Folate Is Associated with Brain Atrophy in Older Diabetic People with Vitamin B12 Deficiency

Previous studies have reported the adverse cognitive effects of high folate status in older individuals with vitamin B12 (VB12) deficiency. Thus, the aim of this study was to investigate how high serum folate and VB12 deficiency could collaboratively aggravate neuronal degeneration. In total, 146 older non-demented diabetic individuals with an average age of 75 ± 3.9 were recruited. VB12 deficiency and high folate status were based on high serum methylmalonic acid (MMA) concentrations (> 0.3 μmol/L) and the serum folate concentration being in the top tertile (> 31.4 nmol/L) respectively. Among these subjects, there were 20 with elevated MMA and high folate. The structural magnetic resonance imaging data of these subjects were analyzed by performing flexible factorial analysis with the "folate level" and "MMA level" added as main effects, and the interaction effect of folate and VB12 on brain volume was evaluated. The results showed significant gray matter atrophy of the right middle occipital gyrus and the opercular part of the inferior frontal gyrus in subjects with a simultaneous high folate status and VB12 deficiency. Together with previous observational studies on cognitive function, this study lends support to the notion that high serum folate concentrations in older people with VB12 deficiency may be associated with increased neurodegeneration.

Limits on Active to Sterile Neutrino Oscillations from Disappearance Searches in the MINOS, Daya Bay, and Bugey-3 Experiments

Searches for a light sterile neutrino have been performed independently by the MINOS and the Daya Bay experiments using the muon (anti)neutrino and electron antineutrino disappearance channels, respectively. In this Letter, results from both experiments are combined with those from the Bugey-3 reactor neutrino experiment to constrain oscillations into light sterile neutrinos. The three experiments are sensitive to complementary regions of parameter space, enabling the combined analysis to probe regions allowed by the Liquid Scintillator Neutrino Detector (LSND) and MiniBooNE experiments in a minimally extended four-neutrino flavor framework. Stringent limits on sin^{2}2θ_{μe} are set over 6 orders of magnitude in the sterile mass-squared splitting Δm_{41}^{2}. The sterile-neutrino mixing phase space allowed by the LSND and MiniBooNE experiments is excluded for Δm_{41}^{2}<0.8  eV^{2} at 95%  CL_{s}.

Improved Search for a Light Sterile Neutrino with the Full Configuration of the Daya Bay Experiment

This Letter reports an improved search for light sterile neutrino mixing in the electron antineutrino disappearance channel with the full configuration of the Daya Bay Reactor Neutrino Experiment. With an additional 404 days of data collected in eight antineutrino detectors, this search benefits from 3.6 times the statistics available to the previous publication, as well as from improvements in energy calibration and background reduction. A relative comparison of the rate and energy spectrum of reactor antineutrinos in the three experimental halls yields no evidence of sterile neutrino mixing in the 2×10^{-4}≲|Δm_{41}^{2}|≲0.3  eV^{2} mass range. The resulting limits on sin^{2}2θ_{14} are improved by approx imately a factor of 2 over previous results and constitute the most stringent constraints to date in the |Δm_{41}^{2}|≲0.2  eV^{2} region.

Evaluation of the effect of energy conservation techniques in the performance of activity of daily living tasks

Objective: To determine whether energy conservation techniques during common activity of daily living tasks actually result in lower energy expenditure, and to document subjective comments regarding any differences in the perceived level of effort.

Design: Descriptive study comparing energy expenditure in three tasks with and without energy conservation techniques, taking into account the effect of age.

Setting: Occupational therapy department of a rehabilitation hospital in Hong Kong.

Subjects: One hundred and eight subjects (30 < 60 years; 78 ≥ 60 years) were recruited from staff and members of an elderly social centre in the community.

Measurements: Energy expenditure was measured using a portable indirect calorimetry system for three tasks (shopping, washing clothes and hanging laundry) with and without energy conservation techniques. Dyspnoea, fatigue and perceived exertion were measured using visual analogue scales.

Results: Reduction in energy expenditure using energy conservation techniques for shopping and hanging laundry was documented in younger subjects only (O2 consumption fell from 13.89&plusmn;3.7 to 12.29&plusmn;3.8 mL/min per kg for shopping, P < 0.001 and 5.9&plusmn;1.2 to 5.0&plusmn;1.2 mL/min per kg, P < 0.001 for hanging laundry), although the older subjects experienced less perceived exertion with the energy conservation techniques. For washing clothes, no reduction in energy expenditure was observed in either age groups.

Conclusion: Measurable benefits were observed with use of labour-saving equipment and avoidance of overhead reaching in younger subjects only.

Measurement of the Reactor Antineutrino Flux and Spectrum at Daya Bay

This Letter reports a measurement of the flux and energy spectrum of electron antineutrinos from six 2.9 GWth nuclear reactors with six detectors deployed in two near (effective baselines 512 and 561 m) and one far (1579 m) underground experimental halls in the Daya Bay experiment. Using 217 days of data, 296 721 and 41 589 inverse β decay (IBD) candidates were detected in the near and far halls, respectively. The measured IBD yield is (1.55±0.04) ×10(-18)  cm(2) GW(-1) day(-1) or (5.92±0.14) ×10(-43)  cm(2) fission(-1). This flux measurement is consistent with previous short-baseline reactor antineutrino experiments and is 0.946±0.022 (0.991±0.023) relative to the flux predicted with the Huber-Mueller (ILL-Vogel) fissile antineutrino model. The measured IBD positron energy spectrum deviates from both spectral predictions by more than 2σ over the full energy range with a local significance of up to ∼4σ between 4-6 MeV. A reactor antineutrino spectrum of IBD reactions is extracted from the measured positron energy spectrum for model-independent predictions.

New measurement of antineutrino oscillation with the full detector configuration at Daya Bay

We report a new measurement of electron antineutrino disappearance using the fully constructed Daya Bay Reactor Neutrino Experiment. The final two of eight antineutrino detectors were installed in the summer of 2012. Including the 404 days of data collected from October 2012 to November 2013 resulted in a total exposure of 6.9×10^{5} GW_{th}  ton days, a 3.6 times increase over our previous results. Improvements in energy calibration limited variations between detectors to 0.2%. Removal of six ^{241}Am-^{13}C radioactive calibration sources reduced the background by a factor of 2 for the detectors in the experimental hall furthest from the reactors. Direct prediction of the antineutrino signal in the far detectors based on the measurements in the near detectors explicitly minimized the dependence of the measurement on models of reactor antineutrino emission. The uncertainties in our estimates of sin^{2}2θ_{13} and |Δm_{ee}^{2}| were halved as a result of these improvements. An analysis of the relative antineutrino rates and energy spectra between detectors gave sin^{2}2θ_{13}=0.084±0.005 and |Δm_{ee}^{2}|=(2.42±0.11)×10^{-3}  eV^{2} in the three-neutrino framework.

Predictive ability of heel quantitative ultrasound for incident fractures: an individual-level meta-analysis

The relationship between bone quantitative ultrasound (QUS) and fracture risk was estimated in an individual level data meta-analysis of 9 prospective studies of 46,124 individuals and 3018 incident fractures. Low QUS is associated with an increase in fracture risk, including hip fracture. The association with osteoporotic fracture decreases with time.

INTRODUCTION

The aim of this meta-analysis was to investigate the association between parameters of QUS and risk of fracture.

METHODS

In an individual-level analysis, we studied participants in nine prospective cohorts from Asia, Europe and North America. Heel broadband ultrasonic attenuation (BUA dB/MHz) and speed of sound (SOS m/s) were measured at baseline. Fractures during follow-up were collected by self-report and in some cohorts confirmed by radiography. An extension of Poisson regression was used to examine the gradient of risk (GR, hazard ratio per 1 SD decrease) between QUS and fracture risk adjusted for age and time since baseline in each cohort. Interactions between QUS and age and time since baseline were explored.

RESULTS

Baseline measurements were available in 46,124 men and women, mean age 70 years (range 20-100). Three thousand and eighteen osteoporotic fractures (787 hip fractures) occurred during follow-up of 214,000 person-years. The summary GR for osteoporotic fracture was similar for both BUA (1.45, 95 % confidence intervals (CI) 1.40-1.51) and SOS (1.42, 95 % CI 1.36-1.47). For hip fracture, the respective GRs were 1.69 (95 % CI, 1.56-1.82) and 1.60 (95 % CI, 1.48-1.72). However, the GR was significantly higher for both fracture outcomes at lower baseline BUA and SOS (p < 0.001). The predictive value of QUS was the same for men and women and for all ages (p > 0.20), but the predictive value of both BUA and SOS for osteoporotic fracture decreased with time (p = 0.018 and p = 0.010, respectively). For example, the GR of BUA for osteoporotic fracture, adjusted for age, was 1.51 (95 % CI 1.42-1.61) at 1 year after baseline, but at 5 years, it was 1.36 (95 % CI 1.27-1.46).

CONCLUSIONS

Our results confirm that quantitative ultrasound is an independent predictor of fracture for men and women particularly at low QUS values.

Search for a light sterile neutrino at Daya Bay

A search for light sterile neutrino mixing was performed with the first 217 days of data from the Daya Bay Reactor Antineutrino Experiment. The experiment's unique configuration of multiple baselines from six 2.9 GW(th) nuclear reactors to six antineutrino detectors deployed in two near (effective baselines 512 m and 561 m) and one far (1579 m) underground experimental halls makes it possible to test for oscillations to a fourth (sterile) neutrino in the 10(-3) eV(2)<|Δm(41)(2) |< 0.3 eV(2) range. The relative spectral distortion due to the disappearance of electron antineutrinos was found to be consistent with that of the three-flavor oscillation model. The derived limits on sin(2) 2θ(14) cover the 10(-3) eV(2) ≲ |Δm(41)(2)| ≲ 0.1 eV(2) region, which was largely unexplored.

Spectral measurement of electron antineutrino oscillation amplitude and frequency at Daya Bay

A measurement of the energy dependence of antineutrino disappearance at the Daya Bay reactor neutrino experiment is reported. Electron antineutrinos (ν¯(e)) from six 2.9  GW(th) reactors were detected with six detectors deployed in two near (effective baselines 512 and 561 m) and one far (1579 m) underground experimental halls. Using 217 days of data, 41 589 (203 809 and 92 912) antineutrino candidates were detected in the far hall (near halls). An improved measurement of the oscillation amplitude sin(2)2θ(13)=0.090(-0.009)(+0.008) and the first direct measurement of the ν¯(e) mass-squared difference |Δm(ee)2|=(2.59(-0.20)(+0.19))×10(-3)  eV2 is obtained using the observed ν¯(e) rates and energy spectra in a three-neutrino framework. This value of |Δm(ee)2| is consistent with |Δm(μμ)2| measured by muon neutrino disappearance, supporting the three-flavor oscillation model.

The selection of a screening test for frailty identification in community-dwelling older adults

BACKGROUND

Frailty in older Chinese has been less often studied and the selection of one screening test feasible in primary care and population survey is needed. We attempted to examine the sensitivity and specificity of each of the five Fried's criteria as a single screening test in the identification of frailty.

METHODS

We recruited 4000 community-dwelling Chinese adults 65 years or older stratified by 3 age-stratum and identified frailty as having 3 or more of Fried's criteria: underweight(BMI<18.5), handgrip strength(

RESULTS

The proportion of frailty in the 3 age groups (65-69 years, 70-74 years, 75 years and above) were 2.3%, 3.4% and 11.9% respectively in men and 1.4%, 2.6% and 11.6% in women. Among the 5 criteria, walking speed, grip strength and physical activity (PASE score) divided at their respective lowest quintile values, achieved similar Area Under Curve in the Receiver Operating Characteristics analysis. For walking speed, the sensitivity and specificity were 82.7% and 83.1% in men and 91.9% and 84.5% in women respectively. For grip strength, the corresponding values were 89.5% and 80.6% in men; and 84.5% and 81.9% in women. For physical activity, they were 83.7% and 83.5% in men; and 82.8% and 84.7% in women.

CONCLUSION

Either walking speed or grip strength measurement may be suitable for frailty screening in primary care or population health survey. A cut-off value of 0.9 m/s in walking speed and 28 kg in grip strength for older men; and a corresponding value of 0.8 m/s and 18 kg for older women is recommended for the screening of frailty in community-dwelling older Chinese adults.

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MESH Headings

• Aged
• Asian People
• Body Mass Index
• Fatigue
• Female
• Frail Elderly
• Geriatric Assessment/methods
• Hand Strength
• Humans
• Male
• Prospective Studies
• ROC Curve
• Socioeconomic Factors
• Thinness
• Walking

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Affiliation(s)

T W Auyeung Tung Wai Auyeung, The S. H. Ho Centre for Gerontology and Geriatrics, The Chinese University of Hong Kong, Department of Medicine and Geriatrics, Pok Oi Hospital, Au Tau, NT, Hong Kong, Email : , Telephone: 852 24868985, Fax: 852 24868976
J S W Lee
J Leung
T Kwok
J Woo

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Associations of dietary protein intake on subsequent decline in muscle mass and physical functions over four years in ambulant older Chinese people

OBJECTIVE

To examine the association of dietary protein intake with 4-year change in physical performance measures and muscle mass in Chinese community-dwelling older people aged 65 and older in Hong Kong.

DESIGN

Prospective cohort study design.

SETTING

Hong Kong, People's of Republic of China.

PARTICIPANTS

There were 2,726 (1411 male, 1315 female) community-dwelling older people aged 65 and older.

MEASUREMENTS

Baseline total, animal and vegetable protein intakes were collected using a validated food frequency questionnaire. Relative protein intake expressed as g/kg body weight was calculated and divided into quartiles for data analysis. Baseline and 4-year physical performance measures (normal and narrow 6-meters walking speed and step length in a 6-meters walk) were measured and 4-year change in appendicular skeletal muscle mass (ASM) from baseline was assessed by dual-energy X-ray absorptiometry. Univariate analysis identified age and sex as significant factors associated with change in physical performance measures or ASM, thus adjustments for these factors were made for subsequent analysis of covariance.

RESULTS

Median relative total protein intake was 1.3 g/kg body weight in men and 1.1 g/kg body weight in women. After adjustment for age and sex, relative total protein intake and animal protein intake were not associated with change in physical performance measures and ASM. In contrast, participants in the highest quartile (>0.72 g/kg body weight) of relative vegetable protein intake lost significantly less ASM over 4-year than those in the lowest quartile of relative vegetable protein intake (<=0.40 g/kg body weight) (adjusted mean ± SE: 0.270 ± 0.029 vs. 0.349 ± 0.030 kg, ptrend=0.025). There was no association between relative vegetable protein intake and change in physical performance measures.

CONCLUSIONS

Higher protein intake from vegetable source was associated with reduced muscle loss in Chinese community-dwelling older people in Hong Kong whereas no association between total and animal protein intake and subsequent decline in muscle mass or physical performance measures was observed in this sample.

Two rare cases of retinal vasculitis following vaccination

We write to report two rare cases of retinal vasculitis following administration of vaccinations. Both patients received recent vaccinations (within 4 weeks and 2 months respectively) and presented with unilateral visual loss due to retinal arteriolar vasculitis. Investigations did not reveal any other causes of vasculitis. The first patient's ocular inflammation settled following periocular steroid injection, whereas the second patient required the additional use of oral corticosteroid. Both patients had improved vision following treatment. Vaccinations can cause an autoimmune reaction. Systemic vasculitis has previously been described, whereas ocular vasculitic involvement is also possible but extremely rare. When seeing a patient with visual loss due to retinal vasculitis of unknown aetiology, a history of any recent vaccinations should be elicited.

Prevalence and risk factors of radiographic vertebral fractures in elderly Chinese men and women: results of Mr. OS (Hong Kong) and Ms. OS (Hong Kong) studies

This study investigated the prevalence of radiographic vertebral fractures using Genant's semiquantitative (SQ) scoring system in elderly Chinese men (n = 2,000; mean age, 72.4 years) and women (n = 2,000; mean age, 72.6 years). Vertebral deformities had similar prevalence in elderly men (14.9 %) and women (16.5 %). Majority of the deformities in men were mild (9.9 %, grade = 1). The prevalence of vertebral fractures (grade ≥ 2) was 5.0 % among men and 12.1 % among women.

INTRODUCTION

Vertebral fracture is a serious consequence of osteoporosis and is often under-diagnosed. Researches on different ethnicities and territories to estimate the prevalence of vertebral fractures and to identify the risk factors are necessary.

METHODS

Mr. OS (Hong Kong) and Ms. OS (Hong Kong) represent the first large-scale cohort studies ever conducted on bone health in elderly Chinese men (n = 2,000) and women (n = 2,000). The current study investigated the prevalence of radiographic vertebral fractures in these subjects using Genant's SQ scoring system and identified risk factors for vertebral fractures.

RESULTS

The radiographs of all men (mean age, 72.4 years) and women (mean age, 72.6 years) were obtained. Six hundred twenty-seven subjects (15.7 %) had at least one vertebral deformity (SQ grade ≥ 1), including 297 men (14.9 %) and 330 women (16.5 %, p = 0.151). Three hundred forty-two participants (8.6 %) were defined as having at least one vertebra fracture (SQ grade ≥ 2), consisted of 100 men (5.0 %) and 242 women (12.1 %, p < 0.001). Older age, lower bone mineral density, lower physical activity, lower grip strength, fracture history, and low back pain were significantly associated with higher vertebral fracture rate for both men and women.

CONCLUSION

Vertebral deformity had similar prevalence in older men and women, while vertebral fracture was more common in women. Majority of deformities in men was mild. The vertebral deformity prevalence of women from this study is similar to previous reports of other East Asian women and Latin American women.

Does the use of ACE inhibitors or angiotensin receptor blockers affect bone loss in older men?

In a prospective cohort study of 5,995 older American men (MrOS), users of angiotensin-converting enzyme (ACE) inhibitors had a small but significant increase in bone loss at the hip over 4 years after adjustment for confounders. Use of angiotensin II AT1 receptor blockers (ARB) was not significantly associated with bone loss.

INTRODUCTION

Experimental evidence suggests that angiotensin II promotes bone loss by its effects on osteoblasts. It is therefore plausible that ACE inhibitor and ARB may reduce rates of bone loss. The objective of this study is to examine the independent effects of ACE inhibitor and ARB on bone loss in older men.

METHODS

Out of 5,995 American men (87.2%) aged ≥65 years, 5,229 were followed up for an average of 4.6 years in a prospective six-center cohort study-The Osteoporotic Fractures in Men Study (MrOS). Bone mineral densities (BMD) at total hip, femoral neck, and trochanter were measured by Hologic densitometer (QDR 4500) at baseline and year 4.

RESULTS

Out of 3,494 eligible subjects with complete data, 1,166 and 433 subjects reported use of ACE inhibitors and ARBs, respectively. When compared with nonusers, continuous use of ACE inhibitors was associated with a small (0.004 g/cm(2)) but significant increase in the average rate of BMD loss at total hip and trochanter over 4 years after adjustment for confounders. Use of ARB was not significantly associated with bone loss.

CONCLUSION

Use of ACE inhibitors but not ARB may marginally increase bone loss in older men.

Sex steroids and bone health in older Chinese men

This study examines the association between sex steroids, bone mineral density (BMD), and incident fractures in 1,489 community-living Chinese men aged 65 and over. Chinese men with low serum estradiol levels display elevated bone loss and increased risk of fractures similar to findings in Caucasians.

INTRODUCTION

This study examines the association between serum total testosterone (TT), free testosterone (free T), estradiol (E(2)), bioavailable estradiol (bioE(2)), sex hormone binding globulin (SHBG), BMD, and incident fractures.

METHODS

This is a cohort study with 4-year follow-up in the community in Hong Kong SAR, China. One thousand four hundred eighty-nine community-living Chinese men aged 65 and over participated. Sex steroid levels and BMD were measured at baseline; BMD was repeated after 4 years of follow-up, and fracture incidence from ascertainment from hospital databases was determined over 4 years of follow-up.

RESULTS

The strongest age-adjusted positive association with total hip and femoral neck BMD was with bioE(2), followed by E(2). Greater bone loss occurred in the lowest quartile of E(2) and bioE(2). The lowest quartile of free T and bioE(2) and the two highest quartile of SHBG were associated with the highest percentage of participants with incident fractures. Those in the lowest quartile of E(2) and bioE(2) had approximately a 50% increased risk of incident fractures compared with the other three quartiles. This relationship remains significant for nonvertebral incident fractures (hip, radius, pelvis, and humerus) for E(2) only, but not bioE(2). Compared with the group with the three highest quartiles of TT and E(2), the group with the lowest quartile of both had approximately twice the risk of nonvertebral osteoporosis-related incident fractures.

CONCLUSION

Chinese men with low serum estradiol levels display elevated bone loss and increased risk of fractures similar to findings in Caucasians.

Observation of electron-antineutrino disappearance at Daya Bay

The Daya Bay Reactor Neutrino Experiment has measured a nonzero value for the neutrino mixing angle θ(13) with a significance of 5.2 standard deviations. Antineutrinos from six 2.9 GWth reactors were detected in six antineutrino detectors deployed in two near (flux-weighted baseline 470 m and 576 m) and one far (1648 m) underground experimental halls. With a 43,000 ton-GWth-day live-time exposure in 55 days, 10,416 (80,376) electron-antineutrino candidates were detected at the far hall (near halls). The ratio of the observed to expected number of antineutrinos at the far hall is R=0.940±0.011(stat.)±0.004(syst.). A rate-only analysis finds sin(2)2θ(13)=0.092±0.016(stat.)±0.005(syst.) in a three-neutrino framework.

Predictive values of calcaneal quantitative ultrasound and dual energy X ray absorptiometry for non-vertebral fracture in older men: results from the MrOS study (Hong Kong)

Calcaneal QUS is comparable to DXA in predicting non-vertebral fractures in older Chinese men.

INTRODUCTION

The predictive values of calcaneal quantitative ultrasound (QUS) and dual-energy X-ray absorptiometry (DXA) for non-vertebral fractures in older Chinese men were examined.

METHODS

One thousand nine hundred twenty-one Chinese men aged 65-92 years had calcaneal QUS and axial DXA bone mineral density (BMD) measurements. The incidence of non-vertebral fractures was documented. Cox regression and receiver operating curve (ROC) analysis were used to examine the associations of QUS parameters and BMD with the incidence of non-vertebral fractures.

RESULTS

The duration of follow-up was (mean ± SD) 6.5 ± 1.7 years. One hundred thirty-one non-vertebral fractures were recorded, 71 of which were major fragility fractures. Broadband ultrasound attenuation (BUA) and quantitative ultrasound index (QUI) were significantly associated with non-vertebral fractures and major fragility fractures, with age and fracture history-adjusted hazard ratio (95% CI) of 1.23 (1.03, 1.47) and 1.32 (1.10, 1.59) per standard deviation reduction, respectively, for non-vertebral fractures; 1.32 (1.04, 1.68) and 1.43 (1.11, 1.84), respectively, for major fragility fractures. Age and fracture history-adjusted areas under ROC curves of hip or spine BMDs were significantly greater than that of BUA or QUI in predicting major fragility fractures, but not in predicting all non-vertebral fractures. The addition of BUA or QUI had no effect on AUCs of total hip BMD alone.

CONCLUSIONS

The ability of calcaneal QUS to predict non-vertebral fractures was comparable to that of axial BMD by DXA, but was inferior to BMD in predicting major fragility fractures in older Chinese men.

The Alu polymorphism of angiotensin I converting enzyme (ACE) and atherosclerosis, incident chronic diseases and mortality in an elderly Chinese population

OBJECTIVE

We examined the contribution of ACE I/D polymorphism in a large Chinese population to four year change in ankle-brachial index (ABI), development of cardiovascular diseases and mortality in a prospective study adjusting for many confounding factors.

METHOD

Data are drawn from a longitudinal study of 4000 community-living men and women aged 65 years and over, for which detailed information regarding lifestyle, chronic diseases, body mass index (BMI), ABI measurements and ACE polymorphisms were documented at baseline. During the fifth year of follow up, incident cardiovascular diseases, ABI, and mortality were documented, and related to ACE genotype adjusting for age, smoking, alcohol, dietary intake, physical activity, body mass index, and use of ACE inhibitors.

RESULTS

Women with the D/D genotype had the greatest reduction in mean ABI after adjusting for confounding factors. D/D genotype was also more common among women who developed hypertension or myocardial infarction. However D/D genotype was associated with mortality only in men.

CONCLUSION

In a Chinese elderly population, ACE polymorphism may be considered "deleterious" to longevity, the D/D genotype being associated with mortality, the atherosclerotic process, hypertension and myocardial infarction. There are gender differences in the relationship between D/D genotype and cardiovascular diseases and mortality may not be mediated by the atherosclerotic process alone.

Vitamin B-12 supplementation improves arterial function in vegetarians with subnormal vitamin B-12 status

OBJECTIVE

Vegetarians are more vascular-healthy but those with subnormal vitamin B-12 status have impaired arterial endothelial function and increased intima-media thickness. We aimed to study the impact of vitamin B-12 supplementation on these markers, in the vegetarians.

DESIGN

Double-blind, placebo controlled, randomised crossover study.

SETTING

Community dwelling vegetarians.

PARTICIPANTS

Fifty healthy vegetarians (vegetarian diet for at least 6 years) were recruited.

INTERVENTION

Vitamin B-12 (500 µg/day) or identical placebo were given for 12 weeks with 10 weeks of placebo-washout before crossover (n=43), and then open label vitamin B-12 for additional 24 weeks (n=41).

MEASUREMENT

Flow-mediated dilation of brachial artery (FMD) and intima-media thickness (IMT) of carotid artery were measured by ultrasound.

RESULTS

The mean age of the subjects was 45±9 years and 22 (44%) were male. Thirty-five subjects (70%) had serum B-12 levels <150 pmol/l. Vitamin B-12 supplementation significantly increased serum vitamin B-12 levels (p<0.0001) and lowered plasma homocysteine (p<0.05). After vitamin B-12 supplementation but not placebo, significant improvement of brachial FMD (6.3±1.8% to 6.9±1.9%; p<0.0001) and in carotid IMT (0.69±0.09 mm to 0.67±0.09 mm, p<0.05) were found, with further improvement in FMD (to 7.4±1.7%; p<0.0001) and IMT (to 0.65±0.09 mm; p<0.001) after 24 weeks open label vitamin B-12. There were no significant changes in blood pressures or lipid profiles. On multivariate analysis, changes in B-12 (β=0.25; p=0.02) but not homocysteine were related to changes in FMD, (R=0.32; F value=3.19; p=0.028).

CONCLUSIONS

Vitamin B-12 supplementation improved arterial function in vegetarians with subnormal vitamin B-12 levels, proposing a novel strategy for atherosclerosis prevention.

Physical frailty in older adults is associated with metabolic and atherosclerotic risk factors and cognitive impairment independent of muscle mass

OBJECTIVE

Metabolic and atherosclerotic diseases are known risk factors for disability in old age, and can result in sarcopenia as well as cognitive impairment, which are both components of frailty syndrome. As muscle loss increases with ageing, it is unclear whether muscle loss per se, or the diseases themselves, are the underlying cause of physical frailty in those suffering from these diseases. We tested the hypothesis that metabolic and atherosclerotic diseases and cognitive impairment are associated with physical frailty independent of muscle loss in old age, and further examined their impact on the relationship between physical frailty and mortality.

DESIGN

Prospective.

SETTING

Community.

PARTICIPANTS

4000 community dwelling Chinese elderly ≥65 years.

MEASUREMENTS

Diabetes, hypertension, stroke, heart disease, cognitive impairment, smoking, physical activity, waist hip ratio (WHR) and ankle-brachial index (ABI)) were recorded. Physical frailty measurements (grip-strength, chair-stands, stride length and 6-metre walks) were summarized into a composite frailty score (0-20), 0 being the most frail) according to quartiles of performance. Appendicular muscle mass (ASM) was measured using dual X-ray absorptiometry. Relationships between the score and covariates were analyzed. Cox regression was used to study the impact of metabolic and atnerosclerotic risk factors on the relationship between physical frailty and 6-year mortality.

RESULTS

After adjustment for ASM, all metabolic diseases and indexes, and cognitive impairment were significantly associated with the composite physical frailty score in univariate analysis. In multivariate analysis, cognitive impairment, high WHR, diabetes, stroke and heart disease were all independently associated with higher physical frailty with adjustment for age, physical activity level and ASM. Hypertension was associated with physical frailty in men but not in women. In Cox regression, increased physical frailty was associated with higher 6-year mortality. The impact of metabolic and atherosclerotic risk factors was however only modest after adjustment for age and cognitive function.

CONCLUSION

Metabolic and atherosclerotic diseases and high WHR, was associated with physical frailty, independent of their adverse effect on cognitive function and muscle mass.

Physical frailty predicts future cognitive decline - a four-year prospective study in 2737 cognitively normal older adults

OBJECTIVE

To examine the association between baseline frailty measurements and cognitive function 4 years later.

DESIGN

Prospective observational study.

SETTING

Community.

PARTICIPANTS

Two thousand seven hundred and thirty seven cognitively normal older adults.

MEASUREMENT

The appendicular muscle mass (ASM), hand grip strength, timed chair-stand test, walking speed and step length were measured at baseline. The Mini-mental state examination (MMSE) was administered at baseline and 4 years later.

RESULTS

In men, all baseline frailty measurements, namely, being underweight, lower ASM, weaker grip strength, slower chair-stand test, shorter step length, slower timed walk were significantly associated with a lower MMSE score 4 years afterwards. After adjustment for age, years of education and baseline MMSE score, ASM and timed walk became insignificant. In women, all frailty measurements except underweight and low ASM were significantly associated with MMSE score 4 years later. Moreover, only weaker grip strength persisted to be significant after adjustment for age, years of education and baseline MMSE score.

CONCLUSION

Physical frailty, as represented by being underweight, weaker grip strength, slower chair-stand test, shorter step-length in men and weaker grip strength in women, was associated with cognitive decline over a four year period.

The effect of diabetes mellitus on age-associated lean mass loss in 3153 older adults

AIMS

Diabetes mellitus may be associated with excessive lean mass loss. Other diabetes-related conditions may also play a role. We assessed body composition changes associated with diabetes in older adults with adjustment for diabetes-related co-morbidities.

METHODS

Three thousand, one hundred and fifty-three community-living adults aged ≥ 65 years were examined for lifestyle factors, diabetes-related medical conditions and body composition by dual energy X-ray absorptiometry at baseline and 4 years later. Body composition changes were compared between participants with diabetes and those without diabetes. Multivariate linear regression was used to examine the relationship between appendicular lean mass loss and confounders.

RESULTS

Appendicular lean mass loss in men with diabetes was two times that of men without diabetes (-1.5% in 'no diabetes' vs. -3.0% in 'diabetes') and in women with diabetes was 1.8 times that of those without diabetes (-1.9% in 'no diabetes' vs. -3.4% in 'diabetes') over 4 years. Men with diabetes also had higher total body mass loss and higher total body fat loss than men without diabetes. Women with diabetes had higher total body mass loss but total body fat loss was similar. After adjusting for age, body mass index, diabetes-related conditions, lifestyle factors and total body mass loss, diabetes remained an independent predictor of appendicular lean mass loss in both men and women.

CONCLUSION

Diabetes was associated with higher body mass loss and higher appendicular lean mass loss in older adults. In men, diabetes was also associated with total body fat loss.

A unified framework for chaotic neural-network approaches to combinatorial optimization

As an attempt to provide an organized way to study the chaotic structures and their effects in solving combinatorial optimization with chaotic neural networks (CNN's), a unifying framework is proposed to serve as a basis where the existing CNN models can be placed and compared. The key of this proposed framework is the introduction of an extra energy term into the computational energy of the Hopfield model, which takes on different forms for different CNN models, and modifies the original Hopfield energy landscape in various manners. Three CNN models, namely the Chen and Aihara model with self-feedback chaotic simulated annealing (CSA), the Wang and Smith model with timestep CSA, and the chaotic noise model, are chosen as examples to show how they can be classified and compared within the proposed framework.

ACE inhibitor use was associated with lower serum dehydroepiandrosterone concentrations in older men

CONTEXT

Angiotensin converting enzyme (ACE) activity may influence the production of adrenal androgen precursors and testosterone. Use of ACE inhibitors may therefore have an influence on serum sex hormone concentrations in older men.

DESIGN AND METHODS

1486 out of 2,000 community-dwelling Chinese men aged 65years who participated in a cohort study were randomly selected to have archived fasting morning serum analyzed for androgen precursors and sex hormones. DNA was extracted from whole blood and analyzed for ACE gene I/D polymorphism.

RESULTS

Subjects with the ACE gene D allele (higher ACE activity) had higher serum dehydroepiandrosterone (DHEA) sulphate and DHEA than those with I/I genotype (P=0.014 and 0.018 respectively, Mann Whitney test). These differences were not significant after Bonferroni correction. Among those with history of hypertension, but without diabetes mellitus or cardiac failure, users of ACE inhibitors had significantly lower serum DHEA (median 1.78 versus 1.49ng/ml in non-users, P=0.0074, Mann Whitney test) and also tended to have lower serum androstenedione and androst-5-ene-3beta,17beta-diol (0.68 versus 0.72ng/ml in non-users; 552.4 versus 624.1pg/ml respectively, both P values <0.05). Serum testosterone and estradiol were not significantly changed.

CONCLUSIONS

ACE inhibitor use was associated with lower serum DHEA in older men.