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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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.

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.

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.

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.