Higher Expression of Denervation-responsive Genes is Negatively Associated with Muscle Volume and Performance Traits in the Study of Muscle, Mobility and Aging (SOMMA)

With aging skeletal muscle fibers undergo repeating cycles of denervation and reinnervation. In approximately the 8 th decade of life reinnervation no longer keeps pace, resulting in the accumulation of persistently denervated muscle fibers that in turn cause an acceleration of muscle dysfunction. The significance of denervation in important clinical outcomes with aging is poorly studied. The Study of Muscle, Mobility and Aging (SOMMA) is a large cohort study with the primary objective to assess how aging muscle biology impacts clinically important traits. Using transcriptomics data from vastus lateralis muscle biopsies in 575 participants we have selected 49 denervation-responsive genes to provide insights to the burden of denervation in SOMMA, to test the hypothesis that greater expression of denervation-responsive genes negatively associates with SOMMA participant traits that included time to walk 400 meters, fitness (VO 2peak ), maximal mitochondrial respiration, muscle mass and volume, and leg muscle strength and power. Consistent with our hypothesis, increased transcript levels of: a calcium-dependent intercellular adhesion glycoprotein (CDH15), acetylcholine receptor subunits (Chrna1, Chrnd, Chrne), a glycoprotein promoting reinnervation (NCAM1), a transcription factor regulating aspects of muscle organization (RUNX1), and a sodium channel (SCN5A) were each negatively associated with at least 3 of these traits. VO 2peak and maximal respiration had the strongest negative associations with 15 and 19 denervation-responsive genes, respectively. In conclusion, the abundance of denervation-responsive gene transcripts is a significant determinant of muscle and mobility outcomes in aging humans, supporting the imperative to identify new treatment strategies to restore innervation in advanced age.

Autophagy gene expression in skeletal muscle of older individuals is associated with physical performance, muscle volume and mitochondrial function in the Study of Muscle, Mobility and Aging (SOMMA)

Autophagy is an essential component of proteostasis and a key pathway in aging. Identifying associations between autophagy gene expression patterns in skeletal muscle and physical performance outcomes would further our knowledge of mechanisms related with proteostasis and healthy aging. Muscle biopsies were obtained from participants in the Study of Muscle, Mobility and Aging (SOMMA). For 575 participants, RNA was sequenced and expression of 281 genes related to autophagy regulation, mitophagy and mTOR/upstream pathways were determined. Associations between gene expression and outcomes including mitochondrial respiration in muscle fiber bundles (MAX OXPHOS), physical performance (VO2 peak, 400m walking speed, and leg power), and thigh muscle volume were determined using negative binomial regression models. For autophagy, key transcriptional regulators including TFE3 and NFKB-related genes (RELA, RELB, NFKB1) were negatively associated with outcomes. On the contrary, regulators of oxidative metabolism that also promote overall autophagy, mitophagy and pexophagy (PPARGC1A, PPARA, EPAS1) were positively associated with multiple outcomes. In line with this, several mitophagy, fusion and fission related genes (NIPSNAP2, DNM1L, OPA1) were also positively associated with outcomes. For mTOR pathway and related genes, expression of WDR59 and WDR24, both subunits of GATOR2 complex (an indirect inhibitor of mTORC1) and PRKAG3, which is a regulatory subunit of AMPK, were negatively correlated with multiple outcomes. Our study identifies autophagy and selective autophagy such as mitophagy gene expression patterns in human skeletal muscle related to physical performance, muscle volume and mitochondrial function in older persons which may lead to target identification to preserve mobility and independence.

Intensive Blood Pressure Management Preserves Functional Connectivity in Patients with Hypertension from the Systolic Blood Pressure Intervention Randomized Trial

BACKGROUND AND PURPOSE

The Systolic Blood Pressure Intervention (SPRINT) randomized trial demonstrated that intensive blood pressure management resulted in slower progression of cerebral white matter hyperintensities, compared with standard therapy. We assessed longitudinal changes in brain functional connectivity to determine whether intensive treatment results in less decline in functional connectivity and how changes in brain functional connectivity relate to changes in brain structure.

MATERIALS AND METHODS

Five hundred forty-eight participants completed longitudinal brain MR imaging, including resting-state fMRI, during a median follow-up of 3.84 years. Functional brain networks were identified using independent component analysis, and a mean connectivity score was calculated for each network. Longitudinal changes in mean connectivity score were compared between treatment groups using a 2-sample t test, followed by a voxelwise t test. In the full cohort, adjusted linear regression analysis was performed between changes in the mean connectivity score and changes in structural MR imaging metrics.

RESULTS

Four hundred six participants had longitudinal imaging that passed quality control. The auditory-salience-language network demonstrated a significantly larger decline in the mean connectivity score in the standard treatment group relative to the intensive treatment group (P = .014), with regions of significant difference between treatment groups in the cingulate and right temporal/insular regions. There was no treatment group difference in other networks. Longitudinal changes in mean connectivity score of the default mode network but not the auditory-salience-language network demonstrated a significant correlation with longitudinal changes in white matter hyperintensities (P = .013).

CONCLUSIONS

Intensive treatment was associated with preservation of functional connectivity of the auditory-salience-language network, while mean network connectivity in other networks was not significantly different between intensive and standard therapy. A longitudinal increase in the white matter hyperintensity burden is associated with a decline in mean connectivity of the default mode network.

Designing Drug Trials for Frailty: ICFSR Task Force 2018

To reduce disability and dependence in older adults, frailty may represent an appropriate target for intervention. While preventing frailty through lifestyle interventions may be the optimal public health approach for many population groups, pharmacological approaches will likely be needed for individuals who meet frailty criteria or who have comorbid conditions that contribute to and complicate the frailty syndrome, and for those who are not compliant with lifestyle interventions. Barriers to successful development of drug treatments for frailty include variability in how the frailty syndrome is defined, lack of agreement on the best diagnostic tools and outcome measures, and the paucity of sensitive, reliable, and validated biomarkers. The International Conference on Frailty and Sarcopenia Research Task Force met in Miami, Florida, on February 28, 2018, to consider the status of treatments under development for frailty and discuss potential strategies for advancing the field. They concluded that at the present time, there may be a more productive regulatory pathway for adjuvant treatments or trials targeting specific functional outcomes such as gait speed. They also expressed optimism that several studies currently underway may provide the insight needed to advance drug development for frailty.

International Clinical Practice Guidelines for Sarcopenia (ICFSR): Screening, Diagnosis and Management

OBJECTIVES

Sarcopenia, defined as an age-associated loss of skeletal muscle function and muscle mass, occurs in approximately 6 - 22 % of older adults. This paper presents evidence-based clinical practice guidelines for screening, diagnosis and management of sarcopenia from the task force of the International Conference on Sarcopenia and Frailty Research (ICSFR).

METHODS

To develop the guidelines, we drew upon the best available evidence from two systematic reviews paired with consensus statements by international working groups on sarcopenia. Eight topics were selected for the recommendations: (i) defining sarcopenia; (ii) screening and diagnosis; (iii) physical activity prescription; (iv) protein supplementation; (v) vitamin D supplementation; (vi) anabolic hormone prescription; (vii) medications under development; and (viii) research. The ICSFR task force evaluated the evidence behind each topic including the quality of evidence, the benefit-harm balance of treatment, patient preferences/values, and cost-effectiveness. Recommendations were graded as either strong or conditional (weak) as per the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. Consensus was achieved via one face-to-face workshop and a modified Delphi process.

RECOMMENDATIONS

We make a conditional recommendation for the use of an internationally accepted measurement tool for the diagnosis of sarcopenia including the EWGSOP and FNIH definitions, and advocate for rapid screening using gait speed or the SARC-F. To treat sarcopenia, we strongly recommend the prescription of resistance-based physical activity, and conditionally recommend protein supplementation/a protein-rich diet. No recommendation is given for Vitamin D supplementation or for anabolic hormone prescription. There is a lack of robust evidence to assess the strength of other treatment options.

Changes in bone mineral density over time by body mass index in the health ABC study

Obesity appears protective against osteoporosis in cross-sectional studies. However, results from this longitudinal study found that obesity was associated with bone loss over time. Findings underscore the importance of looking at the longitudinal relationship, particularly given the increasing prevalence and duration of obesity among older adults.

INTRODUCTION

Cross-sectional studies have found a positive association between body mass index (BMI) and bone mineral density (BMD), but little is known about the longitudinal relationship in US older adults.

METHODS

We examined average annual rate of change in BMD by baseline BMI in the Health, Aging, and Body Composition Study. Repeated measurement of BMD was performed with dual-energy X-ray absorptiometry (DXA) at baseline and years 3, 5, 6, 8, and 10. Multivariate generalized estimating equations were used to predict mean BMD (femoral neck, total hip, and whole body) by baseline BMI (excluding underweight), adjusting for covariates.

RESULTS

In the sample (n = 2570), 43 % were overweight and 24 % were obese with a mean baseline femoral neck BMD of 0.743 g/cm(2), hip BMD of 0.888 g/cm(2), and whole-body BMD of 1.09 g/cm(2). Change in total hip or whole-body BMD over time did not vary by BMI groups. However, obese older adults lost 0.003 g/cm(2) of femoral neck BMD per year more compared with normal weight older adults (p < 0.001). Femoral neck BMD change over time did not differ between the overweight and normal weight BMI groups (p = 0.74). In year 10, adjusted femoral neck BMD ranged from 0.696 g/cm(2) among obese, 0.709 g/cm(2) among normal weight, and 0.719 g/cm(2) among overweight older adults.

CONCLUSIONS

Findings underscore the importance of looking at the longitudinal relationship between body composition and bone mineral density among older adults, indicating that high body mass may not be protective for bone loss over time.

Genetic Moderators of the Impact of Physical Activity on Depressive Symptoms

BACKGROUND

Converging evidence suggests that physical activity is an effective intervention for both clinical depression and sub-threshold depressive symptoms; however, findings are not always consistent. These mixed results might reflect heterogeneity in response to physical activity, with some subgroups of individuals responding positively, but not others.

OBJECTIVES

1) To examine the impact of genetic variation and sex on changes in depressive symptoms in older adults after a physical activity (PA) intervention, and 2) to determine if PA differentially improves particular symptom dimensions of depression.

DESIGN

Randomized controlled trial.

SETTING

Four field centers (Cooper Institute, Stanford University, University of Pittsburgh, and Wake Forest University).

PARTICIPANTS

396 community-dwelling adults aged 70-89 years who participated in the Lifestyle Interventions and Independence for Elders Pilot Study (LIFE-P).

INTERVENTION

12-month PA intervention compared to an education control.

MEASUREMENTS

Polymorphisms in the serotonin transporter (5-HTT), brain-derived neurotrophic factor (BDNF), and apolipoprotein E (APOE) genes; 12-month change in the Center for Epidemiologic Studies Depression Scale total score, as well as scores on the depressed affect, somatic symptoms, and lack of positive affect subscales.

RESULTS

Men randomized to the PA arm showed the greatest decreases in somatic symptoms, with a preferential benefit in male carriers of the BDNF Met allele. Symptoms of lack of positive affect decreased more in men compared to women, particularly in those possessing the 5-HTT L allele, but the effect did not differ by intervention arm. APOE status did not affect change in depressive symptoms.

CONCLUSIONS

Results of this study suggest that the impact of PA on depressive symptoms varies by genotype and sex, and that PA may mitigate somatic symptoms of depression more than other symptoms. The results suggest that a targeted approach to recommending PA therapy for treatment of depression is viable.

Arterialized venous bicarbonate is associated with lower bone mineral density and an increased rate of bone loss in older men and women

CONTEXT

Higher dietary net acid loads have been associated with increased bone resorption, reduced bone mineral density (BMD), and increased fracture risk.

OBJECTIVE

The objective was to compare bicarbonate (HCO3) measured in arterialized venous blood samples to skeletal outcomes.

DESIGN

Arterialized venous samples collected from participants in the Health, Aging and Body Composition (Health ABC) Study were compared to BMD and rate of bone loss.

SETTING

The setting was a community-based observational cohort.

PARTICIPANTS

A total of 2287 men and women age 74 ± 3 years participated.

INTERVENTION

Arterialized venous blood was obtained at the year 3 study visit and analyzed for pH and pCO2. HCO3 was determined using the Henderson-Hasselbalch equation.

MAIN OUTCOME MEASURE

BMD was measured at the hip by dual-energy x-ray absorptiometry at the year 1 (baseline) and year 3 study visits.

RESULTS

Plasma HCO3 was positively associated with BMD at both year 1 (P = .001) and year 3 (P = .001) in models adjusted for age, race, sex, clinic site, smoking, weight, and estimated glomerular filtration rate. Plasma HCO3 was inversely associated with rate of bone loss at the total hip over the 2.1 ± 0.3 (mean ± SD) years between the two bone density measurements (P < .001). Across quartiles of plasma HCO3, the rate of change in BMD over the 2.1 years ranged from a loss of 0.72%/y in the lowest quartile to a gain of 0.15%/y in the highest quartile of HCO3.

CONCLUSIONS

Arterialized plasma HCO3 was associated positively with cross-sectional BMD and inversely with the rate of bone loss, implying that systemic acid-base status is an important determinant of skeletal health during aging. Ongoing bone loss was linearly related to arterialized HCO3, even after adjustment for age and renal function. Further research in this area may have major public health implications because reducing dietary net acid load is possible through dietary intervention or through supplementation with alkaline potassium compounds.

The association between vitamin K status and knee osteoarthritis features in older adults: the Health, Aging and Body Composition Study

BACKGROUND

Vitamin K-dependent (VKD) proteins, including the mineralization inhibitor matrix-gla protein (MGP), are found in joint tissues including cartilage and bone. Previous studies suggest low vitamin K status is associated with higher osteoarthritis (OA) prevalence and incidence.

OBJECTIVE

To clarify what joint tissues vitamin K is relevant to in OA, we investigated the cross-sectional and longitudinal association between vitamin K status and knee OA structural features measured using magnetic resonance imaging (MRI).

METHODS

Plasma phylloquinone (PK, vitamin K1) and dephosphorylated-uncarboxylated MGP ((dp)ucMGP) were measured in 791 older community-dwelling adults who had bilateral knee MRIs (mean ± SD age = 74 ± 3 y; 67% female). The adjusted odds ratios (and 95% confidence intervals) [OR (95%CI)] for presence and progression of knee OA features according to vitamin K status were calculated using marginal models with generalized estimating equations (GEEs), adjusted for age, sex, body mass index (BMI), triglycerides and other pertinent confounders.

RESULTS

Longitudinally, participants with very low plasma PK (<0.2 nM) were more likely to have articular cartilage and meniscus damage progression after 3 years [OR (95% CIs): 1.7(1.0-3.0), 2.6(1.3-5.2) respectively] compared to sufficient PK (≥ 1.0 nM). Higher plasma (dp)ucMGP (reflective of lower vitamin K status) was associated with higher odds of meniscus damage, osteophytes, bone marrow lesions, and subarticular cysts cross-sectionally [ORs (95% CIs) comparing highest to lowest quartile: 1.6(1.1-2.3); 1.7(1.1-2.5); 1.9(1.3-2.8); 1.5(1.0-2.1), respectively].

CONCLUSION

Community-dwelling men and women with very low plasma PK were more likely to have progression of articular cartilage and meniscus damage. Plasma (dp)ucMGP was associated with presence of knee OA features but not progression. Future studies are needed to clarify mechanisms underlying vitamin Ks role in OA.

Association of hearing impairment and mortality in older adults

BACKGROUND

Hearing impairment (HI) is highly prevalent in older adults and is associated with social isolation, depression, and risk of dementia. Whether HI is associated with broader downstream outcomes is unclear. We undertook this study to determine whether audiometric HI is associated with mortality in older adults.

METHODS

Prospective observational data from 1,958 adults ≥70 years of age from the Health, Aging, and Body Composition Study were analyzed using Cox proportional hazards regression. Participants were followed for 8 years after audiometric examination. Mortality was adjudicated by obtaining death certificates. Hearing was defined as the pure-tone average of hearing thresholds in decibels re: hearing level (dB HL) at frequencies from 0.5 to 4kHz. HI was defined as pure-tone average >25 dB HL in the better ear.

RESULTS

Of the 1,146 participants with HI, 492 (42.9%) died compared with 255 (31.4%) of the 812 with normal hearing (odds ratio = 1.64, 95% CI: 1.36-1.98). After adjustment for demographics and cardiovascular risk factors, HI was associated with a 20% increased mortality risk compared with normal hearing (hazard ratio = 1.20, 95% CI: 1.03-1.41). Confirmatory analyses treating HI as a continuous predictor yielded similar results, demonstrating a nonlinear increase in mortality risk with increasing HI (hazard ratio = 1.14, 95% CI: 1.00-1.29 per 10 dB of threshold elevation up to 35 dB HL).

CONCLUSIONS

HI in older adults is associated with increased mortality, independent of demographics and cardiovascular risk factors. Further research is necessary to understand the basis of this association and whether these pathways might be amenable to hearing rehabilitation.

Associations between vitamin K status and haemostatic and inflammatory biomarkers in community-dwelling adults. The Multi-Ethnic Study of Atherosclerosis

Vitamin K is integral to haemostatic function, and in vitro and animal experiments suggest that vitamin K can suppress production of inflammatory cytokines. To test the hypothesis that higher vitamin K status is associated with lower haemostatic activation and inflammation in community-dwelling adults, we analysed the cross-sectional association between serum phylloquinone (vitamin K1) with haemostatic and inflammatory biomarkers in 662 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) [mean (SD) age=62 (10) years; 46% female; 37% Caucasian, 25% African-American, 25% Hispanic, 13% Chinese-American]. Following adjustment for demographic and lifestyle characteristics, medication use, triglycerides and body mass index, those in the highest quartile of serum phylloquinone had significantly lower circulating interleukin-6 [adjusted mean (SEM) pmol/l: quartile 4 (Q4)=1.22 (0.07), quartile 1 (Q1)=1.45 (0.07); p-trend<0.01], C-reactive protein [adjusted mean (SEM) mg/dl: Q4=1.57 (0.11), Q1=2.08 (0.18); p-trend=0.02], soluble intercellular adhesion molecule-1 [adjusted mean (SEM) ng/ml: Q4=247 (11), Q1=288 (11); p-trend=0.02], and plasmin-antiplasmin complex [adjusted mean (SEM) nmol/l: Q4=4.02 (0.1), Q1=4.31 (0.1), p-trend=0.04]. We detected an interaction between age and serum phylloquinone with respect to factor VIII and D-dimer (interaction p-values=0.03 and 0.09, respectively). Among participants ≥70 years, serum phylloquinone was inversely associated with factor VIII activity (p-trend=0.06) and positively associated with D-dimer (p-trend=0.01), but was not associated with either marker among participants <70 years (both p≥0.38). In contrast, dietary phylloquinone intake was not associated with any inflammatory or haemostatic biomarker evaluated (all p-trend>0.11). These findings are consistent with laboratory-based studies that suggest a possible anti-inflammatory role for vitamin K. Whether or not these associations predict clinical outcomes linked to elevated inflammation or haemostatic activation remains to be determined.

Periaortic fat and cardiovascular risk: a comparison of high-risk older adults and age-matched healthy controls

Objective

Fat accumulation around the heart and aorta may impact cardiovascular (CV) health. The purpose of this study was to conduct a systematic investigation to examine potential associations of these fat depots with risk factors for CV events, which has not been done before.

Methods

Pericardial fat, periaortic fat around the ascending aorta (AA), descending aorta (DA) and aortic arch, and abdominal subcutaneous and visceral fat were measured by MRI in older adults with (n=385, 69±8 years, 52% female) and without (n=50, 69±8 years, 58% female) risk factors for a CV event.

Results

Individuals with CV risk factors exhibited greater fat volumes across all fat depots compared to those without risk factors. In analysis of covariance accounting for age, gender, race/ethnicity, diabetes, hypertension, coronary artery disease, smoking, and BMI, individuals with risk factors possessed higher epicardial, pericardial, AA, DA, and abdominal visceral fat (p<0.05). When matched one-to-one on age, gender, race/ethnicity, and BMI, AA and DA fat were higher in those with versus without CV risk factors (p<0.01).

Conclusions

Older adults with a high risk for CV events have greater periaortic fat than low-risk adults, even after accounting for BMI. More studies are needed to determine whether greater periaortic fat predicts future CV events.

The impact of sarcopenia on a physical activity intervention: the Lifestyle Interventions and Independence for Elders Pilot Study (LIFE-P)

OBJECTIVE

To determine if sarcopenia modulates the response to a physical activity intervention in functionally limited older adults.

DESIGN

Secondary analysis of a randomized controlled trial.

SETTING

Three academic centers.

PARTICIPANTS

Elders aged 70 to 89 years at risk for mobility disability who underwent dual-energy x-ray absorptiometry (DXA) for body composition at enrollment and follow-up at twelve months (N = 177).

INTERVENTION

Subjects participated in a physical activity program (PA) featuring aerobic, strength, balance, and flexibility training, or a successful aging (SA) educational program about healthy aging.

MEASUREMENTS

Sarcopenia as determined by measuring appendicular lean mass and adjusting for height and total body fat mass (residuals method), Short Physical Performance Battery score (SPPB), and gait speed determined on 400 meter course.

RESULTS

At twelve months, sarcopenic and non-sarcopenic subjects in PA tended to have higher mean SPPB scores (8.7±0.5 and 8.7±0.2 points) compared to sarcopenic and non-sarcopenic subjects in SA (8.3±0.5 and 8.4±0.2 points, p = 0.24 and 0.10), although the differences were not statistically significant. At twelve months, faster mean gait speeds were observed in PA: 0.93±0.4 and 0.95±0.03 meters/second in sarcopenic and non-sarcopenic PA subjects, and 0.89±0.4 and 0.91±0.03 meters/second in sarcopenic and non-sarcopenic SA subjects (p = 0.98 and 0.26), although not statistically significant. There was no difference between the sarcopenic and non-sarcopenic groups in intervention adherence or number of adverse events.

CONCLUSION

These data suggest that older adults with sarcopenia, who represent a vulnerable segment of the elder population, are capable of improvements in physical performance after a physical activity intervention.

Dietary antioxidants and forced expiratory volume in 1 s decline: the Health, Aging and Body Composition study

Increased antioxidant defences are hypothesised to decrease age- and smoking-related decline in lung function. The relationship between dietary antioxidants, smoking and forced expiratory volume in 1 s (FEV(1)) was investigated in community-dwelling older adults in the Health, Aging and Body Composition study. 1,443 participants completed a food frequency questionnaire, self-reported smoking history and had measurements taken of FEV(1) at both baseline and after 4 yrs of follow-up. The association of dietary intake of nutrients and foods with antioxidant properties and rate of FEV(1) decline was investigated using hierarchical linear regression models. In continuing smokers (current smokers at both time-points), higher vitamin C intake and higher intake of fruit and vegetables were associated with an 18 and 24 mL · yr(-1) slower rate of FEV(1) decline compared with a lower intake (p < 0.0001 and p = 0.003, respectively). In quitters (a current smoker at study baseline who had quit during follow-up), higher intake was associated with an attenuated rate of decline for each nutrient studied (p ≤ 0.003 for all models). In nonsmoking participants, there was little or no association of diet and rate of decline in FEV(1). The intake of nutrients with antioxidant properties may modulate lung function decline in older adults exposed to cigarette smoke.

Dietary fat and cholesterol and risk of cardiovascular disease in older adults: the Health ABC Study

BACKGROUND AND AIMS

Although dietary fats and cholesterol have previously been associated with risk of cardiovascular disease (CVD) in middle-aged populations, less is known among older adults. The purpose of this study was to determine the association between dietary fats, cholesterol, and eggs and CVD risk among community-dwelling adults aged 70-79 in the Health, Aging and Body Composition Study.

METHODS AND RESULTS

Diet was assessed using an interviewer-administered 108-item food frequency questionnaire (n=1941). CVD events were defined as a confirmed myocardial infarction, coronary death, or stroke. Relative rates of CVD over 9 years of follow-up were estimated using Cox proportional hazards models. During follow-up, there were 203 incident cases of CVD. There were no significant associations between dietary fats and CVD risk. Dietary cholesterol (HR (95% CI): 1.47 (0.93, 2.32) for the upper vs. lower tertile; P for trend, 0.10) and egg consumption (HR (95% CI): 1.68 (1.12, 2.51) for 3+/week vs. <1/week; P for trend, 0.01) were associated with increased CVD risk. However, in sub-group analyses, dietary cholesterol and egg consumption were associated with increased CVD risk only among older adults with type 2 diabetes (HR (95% CI): 3.66 (1.09, 12.29) and 5.02 (1.63, 15.52), respectively, for the upper vs. lower tertile/group).

CONCLUSIONS

Dietary cholesterol and egg consumption were associated with increased CVD risk among older, community-dwelling adults with type 2 diabetes. Further research on the biological mechanism(s) for the increased CVD risk with higher dietary cholesterol and frequent egg consumption among older adults with diabetes is warranted.

The association of cataract with leukocyte telomere length in older adults: defining a new marker of aging

Lens transparency, or the magnitude of cataract severity, is a potential in vivo marker of aging distinguishable from diagnosed cataract. To explore lens transparency as a marker of aging, we determined its association with leukocyte telomere length (LTL) measured with quantitative polymerase chain reaction. Cataract severity was directly measured in 259 participants, and prevalent cataract and incident cataract surgery were ascertained in 2,750 participants of the Health, Aging, and Body Composition Study. LTL was unassociated with clinical cataract outcomes. Six of 259 had successfully aged lenses and a mean LTL of 5,700 bp, whereas 253/259 with poorly aged lenses had a mean LTL of 4,770 bp. Participants with a 1,000 bp greater mean LTL had nearly half the odds of any cataract (odds ratio = 0.47, 95% confidence interval 0.22-1.02) after adjustment. Lens transparency might be associated with longer LTL in community-dwelling older adults and should be investigated further as a possible biomarker of aging.

Dietary factors in relation to daily activity energy expenditure and mortality among older adults

OBJECTIVES

To examine the association between dietary factors to daily activity energy expenditure (DAEE) and mortality among older adults.

DESIGN AND SETTING

A sub-study of Health, Aging, and Body Composition study.

PARTICIPANTS

298 older participants (aged 70-82 years) in the Health, Aging, and Body Composition Energy Expenditure sub-study.

MEASUREMENTS

Dietary factors, DAEE, and all-cause mortality were measured in 298 older participants. Dietary factors include dietary intake assessed by the Block Food Frequency Questionnaire (FFQ), Healthy Eating Index (HEI), and self-reported appetite and enjoyment of eating. DAEE was assessed using doubly labeled water. All-cause mortality was evaluated over a 9 year period.

RESULTS

Participants in the highest tertile of DAEE were more likely to be men and to report having a 'good' appetite; BMI among men, proportion married, IL-6 and CRP levels and energy intake were also higher. Fewer black participants were in the 'good' HEI category. Participants in the 'good' HEI category had higher cognitive scores and a higher education level. Participants who reported improvement in their appetite as well as participants who reported a 'good' appetite were at lower risk for mortality (HR (95% CI): 0.42 (0.24-0.74) and 0.50 (0.26-0.88), respectively) even after adjusting for DAEE, demographic, nutritional and health indices.

CONCLUSIONS

We showed an association between DAEE and appetite and mortality among well-functioning, community-dwelling older adults. These findings may have some practical use for the health providers. Inclusion of a question regarding appetite of an elderly patient may provide important information regarding risk for health deterioration and mortality.

Effects of dietary protein on the composition of weight loss in post-menopausal women

OBJECTIVES

To determine whether a hypocaloric diet higher in protein can prevent the loss of lean mass that is commonly associated with weight loss.

DESIGN

An intervention study comparing a hypocaloric diet moderately high in protein to one lower in protein.

SETTING

Study measurements were taken at the Wake Forest University General Clinical Research Center (GCRC) and Geriatric Research Center (GRC).

PARTICIPANTS

Twenty-four post-menopausal, obese women (mean age = 58 +/- 6.6 yrs; mean BMI = 33.0 +/- 3.6 kg/m2).

INTERVENTION

Two 20-week hypocaloric diets (both reduced by 2800 kcal/wk) were compared: one maintaining dietary protein intake at 30% of total energy intake (1.2-1.5 g/kg/d; HI PROT), and the other maintaining dietary protein intake at 15% of total energy (0.5-0.7 g/kg/d; LO PROT). The GCRC metabolic kitchen provided lunch and dinner meals which the women picked up 3 days per week and ate outside of the clinic.

MEASUREMENTS

Body composition, including total body mass, total lean mass, total fat mass, and appendicular lean mass, assessed by dual energy x-ray absorptiometry, was measured before and after the diet interventions.

RESULTS

The HI PROT group lost 8.4 +/- 4.5 kg and the LO PROT group lost 11.4 +/- 3.8 kg of body weight (p = 0.11). The mean percentage of total mass lost as lean mass was 17.3% +/- 27.8% and 37.5% +/- 14.6%, respectively (p = 0.03).

CONCLUSION

Maintaining adequate protein intake may reduce lean mass losses associated with voluntary weight loss in older women.

The I.A.N.A Task Force on frailty assessment of older people in clinical practice

Frailty is a commonly used term indicating older persons at increased risk for adverse outcomes such as onset of disability, morbidity, institutionalisation or mortality or who experience a failure to integrate adequate responses in the face of stress. Although most physicians caring for older people recognize the importance of frailty, there is still a lack of both consensus definition and consensual clinical assessment tools. The aim of the present manuscript was to perform a comprehensive review of the definitions and assessment tools on frailty in clinical practice and research, combining evidence derived from a systematic review of literature along with an expert opinion of a European, Canadian and American Geriatric Advisory Panel (GAP). There was no consensus on a definition of frailty but there was agreement to consider frailty as a pre-disability stage. Being disability a consequence rather than the cause of frailty, frail older people do not necessary need to be disabled. The GAP considered that disability (as a consequence of frailty) should not be included in frailty definitions and assessment tools. Although no consensual assessment tool could be proposed, gait speed could represent the most suitable instrument to be implemented both in research and clinical evaluation of older people, as assessment of gait speed at usual pace is a quick, inexpensive and highly reliable measure of frailty.

The association between weight history and physical performance in the Health, Aging and Body Composition study

OBJECTIVE

Although the association between current obesity and physical disability is well known, the cumulative effect of obesity is unknown. Using data from the Health, Aging and Body Composition study, we examined the association between weight history in young and middle adulthood and weight status in late adulthood with physical performance in late adulthood.

DESIGN

Longitudinal cohort study.

SUBJECTS

White and black men and women aged 70-79 years at study baseline (n=2803).

MEASURES

Body mass index (BMI; kg/m(2)) was calculated using recalled height at age 25 and weight at age 25 and 50 and measured height and weight at ages 70-79. Physical performance at ages 70-79 was assessed using a short physical performance battery (SPPB) and a 400-m walk test.

RESULTS

In this well-functioning cohort, approximately 24% of men and 8% of women reported being overweight or obese (BMI > or =25 kg/m(2)) at age 25, 51% of men and 37% of women reported being overweight or obese at age 50, and 69% of men and 66% of women were overweight or obese at ages 70-79. Men and women who were obese (BMI > or =30 kg/m(2)) at ages 25, 50 and 70-79 had significantly worse SPPB scores and 400-m walk times than those who were normal weight. Women who were overweight (BMI 25-29.9 kg/m(2)) at ages 25, 50 and 70-79 also had significantly worse physical performance. Furthermore, men and women who had a history of being overweight or obese at ages 25 or 50 had worse physical performance compared to those who were normal weight throughout or who were overweight or obese at ages 70-79 but not in midlife or earlier.

CONCLUSIONS

Maintaining a healthy body weight throughout adulthood may play a role in preventing or delaying the onset of physical disability.

Polymorphisms of angiotensinogen and angiotensin-converting enzyme associated with lower extremity arterial disease in the Health, Aging and Body Composition study

The role of renin-angiotensin system (RAS) genes on the risk of lower extremity arterial disease (LEAD) in elderly people remains unclear. We assessed the relationship of genetic polymorphisms in RAS: G-6A, T174M and M235T of the angiotensinogen (AGT) gene, and the angiotensin-converting enzyme insertion/deletion (ACE_I/D) variant to the risk of LEAD in the Health, Aging and Body Composition (Health ABC) Study. This analysis included 1228 black and 1306 white men and women whose age ranged between 70 and 79 years at the study enrollment. LEAD was defined as ankle-arm index (AAI) <0.9. Genotype-phenotype associations were estimated by regression analyses with and without adjustment for established cardiovascular disease (CVD) risk factors. The proportion of LEAD was significantly higher in black (21.1%) than that in white elderly people (10.1%, P<0.0001). The distribution of AGT polymorphisms was also significantly different between black and white participants. There was no statistically significant association between the selected RAS genetic variants and LEAD after adjustment for age, antihypertensive medications, lipid-lowering medication, pack-year smoking, body mass index, low-density lipoprotein cholesterol, and prevalent diabetes and coronary heart disease. However, A-T haplotype of G-6A and M235T interacting with homozygous ACE_II (beta=-1.07, P=0.006) and with ACE inhibitors (beta=-1.03, P=0.01) significantly decreased the risk of LEAD in white but not in black participants after adjustment for the selected CVD risk factors. In conclusion, the study observed a gene-gene and gene-drug interaction for LEAD in the white elderly.

Cognitive ability is associated with suspected reporting errors on food frequency questionnaires

OBJECTIVE

To examine potential for bias in reported total energy intake on a Food Frequency Questionnaire (FFQ) among older adults.

DESIGN

Longitudinal cohort study.

SUBJECTS/SETTING

2,706 Community-dwelling Black and White older adults, aged 70-79 years, enrolled in the Health, Aging, and Body Composition study. Multivariate logistic regression analyses were conducted with potential errors on reported total energy intake on the Food Frequency Questionnaire (FFQ) as the outcome variable and with cognitive ability, measured by the Modified Mini Mental State Exam (3MS) as the primary independent variable. The regression model controlled for site, race, gender, age, body size, and physical activity. Separate models were fit using 3MS as a continuous variable and for multiple 3MS cutpoints. All models revealed similar findings.

RESULTS

Cognitive ability was inversely associated with potential errors in reporting total energy intake, whereby a five-point increase in 3MS scores was associated with a 14% decreased likelihood of reporting errors (Odds Ratio=0.86, 95% Confidence Interval: 0.77, 0.95). Additionally, compared to White women, White men were 2 times more likely, and Black women and Black men were 3 times more likely, to have errors in reporting total energy intake.

CONCLUSION

This study provides evidence that for older adults, lower cognition scores are associated with increased potential errors in reporting total energy intake.

APPLICATIONS

Dietary reporting from older adults may be inaccurate due to cognitive deficits. A brief assessment of cognitive function may assist clinicians in dietary evaluations and recommendation and may benefit studies using FFQ data where the measure of cognitive function could be utilized to stratify data analyses and conduct sensitivity analyses.

The loss of skeletal muscle strength, mass, and quality in older adults: the health, aging and body composition study

BACKGROUND

The loss of muscle mass is considered to be a major determinant of strength loss in aging. However, large-scale longitudinal studies examining the association between the loss of mass and strength in older adults are lacking.

METHODS

Three-year changes in muscle mass and strength were determined in 1880 older adults in the Health, Aging and Body Composition Study. Knee extensor strength was measured by isokinetic dynamometry. Whole body and appendicular lean and fat mass were assessed by dual-energy x-ray absorptiometry and computed tomography.

RESULTS

Both men and women lost strength, with men losing almost twice as much strength as women. Blacks lost about 28% more strength than did whites. Annualized rates of leg strength decline (3.4% in white men, 4.1% in black men, 2.6% in white women, and 3.0% in black women) were about three times greater than the rates of loss of leg lean mass ( approximately 1% per year). The loss of lean mass, as well as higher baseline strength, lower baseline leg lean mass, and older age, was independently associated with strength decline in both men and women. However, gain of lean mass was not accompanied by strength maintenance or gain (ss coefficients; men, -0.48 +/- 4.61, p =.92, women, -1.68 +/- 3.57, p =.64).

CONCLUSIONS

Although the loss of muscle mass is associated with the decline in strength in older adults, this strength decline is much more rapid than the concomitant loss of muscle mass, suggesting a decline in muscle quality. Moreover, maintaining or gaining muscle mass does not prevent aging-associated declines in muscle strength.

Inflammatory markers are associated with ventilatory limitation and muscle dysfunction in obstructive lung disease in well functioning elderly subjects

BACKGROUND

Inflammatory markers are increased in chronic obstructive pulmonary disease (COPD) and are hypothesised to play an important part in muscle dysfunction and exercise intolerance.

METHODS

The Health Aging and Body Composition (Health ABC) study is a prospective observational cohort of well functioning individuals aged 70-79 years. A cross sectional analysis of the baseline data was conducted to examine the association between inflammatory markers and ventilatory limitation, muscle strength, and exercise capacity. These associations were compared in participants with and without obstructive lung disease (OLD).

RESULTS

Of the 3075 participants enrolled in the Health ABC cohort, OLD was identified by spirometric testing in 268 participants and 2005 participants had normal spirometric results. Of the participants with OLD, 35%, 38%, and 27% participants had mild, moderate, and severe OLD, respectively. Participants with OLD had lower quadriceps strength (102.5 Nm v 108.9 Nm, p = 0.02), lower maximum inspiratory pressure (64.7 cm H(2)O v 74.2 cm H(2)O, p<0.0001), higher systemic interleukin (IL)-6 levels (2.6 pg/ml v 2.2 pg/ml, p<0.0001), and higher C-reactive protein (CRP) levels (3.5 mg/l v 2.5 mg/l, p<0.0001) than those with normal spirometry. In participants with OLD and those with normal spirometry, forced expiratory volume in 1 second (FEV(1)) was associated with IL-6 (adjusted regression coefficients (beta) = -5.3 (95% CI -9.1 to-1.5) and -3.1 (95% CI -4.3 to -1.9), respectively). IL-6 and TNF were also associated with quadriceps strength among participants with OLD and those with normal spirometry (beta = -6.4 (95% CI -12.8 to -0.03) and -3.4 (95% CI -5.4 to -1.3), respectively, for IL-6 and beta = -10.1 (95% CI -18.7 to -1.5) and -3.8 (95% CI -7 to -0.6), respectively, for TNF). IL-6, quadriceps strength, and maximum inspiratory pressures were independent predictors of reduced exercise capacity in both groups.

CONCLUSIONS

In well functioning elderly subjects with or without OLD, IL-6 is associated with reduced FEV(1), quadriceps strength, and exercise capacity.

Obesity, regional body fat distribution, and the metabolic syndrome in older men and women

BACKGROUND

The metabolic syndrome is a disorder that includes dyslipidemia, insulin resistance, and hypertension and is associated with an increased risk of diabetes and cardiovascular disease. We determined whether patterns of regional fat deposition are associated with metabolic syndrome in older adults.

METHODS

A cross-sectional study was performed that included a random, population-based, volunteer sample of Medicare-eligible adults within the general communities of Pittsburgh, Pa, and Memphis, Tenn. The subjects consisted of 3035 men and women aged 70 to 79 years, of whom 41.7% were black. Metabolic syndrome was defined by Adult Treatment Panel III criteria, including serum triglyceride level, high-density lipoprotein cholesterol level, glucose level, blood pressure, and waist circumference. Visceral, subcutaneous abdominal, intermuscular, and subcutaneous thigh adipose tissue was measured by computed tomography.

RESULTS

Visceral adipose tissue was associated with the metabolic syndrome in men who were of normal weight (odds ratio, 95% confidence interval: 2.1, 1.6-2.9), overweight (1.8, 1.5-2.1), and obese (1.2, 1.0-1.5), and in women who were of normal weight (3.3, 2.4-4.6), overweight (2.4, 2.0-3.0), and obese (1.7, 1.4-2.1), adjusting for race. Subcutaneous abdominal adipose tissue was associated with the metabolic syndrome only in normal-weight men (1.3, 1.1-1.7). Intermuscular adipose tissue was associated with the metabolic syndrome in normal-weight (2.3, 1.6-3.5) and overweight (1.2, 1.1-1.4) men. In contrast, subcutaneous thigh adipose tissue was inversely associated with the metabolic syndrome in obese men (0.9, 0.8-1.0) and women (0.9, 0.9-1.0).

CONCLUSION

In addition to general obesity, the distribution of body fat is independently associated with the metabolic syndrome in older men and women, particularly among those of normal body weight.

Low subcutaneous thigh fat is a risk factor for unfavourable glucose and lipid levels, independently of high abdominal fat. The Health ABC Study

AIMS

We investigated whether low subcutaneous thigh fat is an independent risk factor for unfavourable glucose and lipid levels, and whether these associations differ between sexes, and between white and black adults. Our secondary aim was to investigate which body composition characteristics (lean tissue, fat tissue) are reflected by anthropometric measures (waist and thigh circumference).

METHODS

Anthropometric measurements and computed tomography of the abdomen and of the thigh were performed for all participants of the Health, Aging and Body Composition Study, who were aged 70-79 years. Fasting glucose, triglycerides and HDL-cholesterol, and 2-h postload glucose were determined.

RESULTS

After excluding those already diagnosed with diabetes or dyslipidaemia, we analysed data from 2,106 participants. After adjustment for abdominal subcutaneous and visceral fat, and intermuscular thigh fat, larger thigh subcutaneous fat area was statistically significantly associated with lower ln-transformed triglycerides [standardised beta (95% CI) -0.12 (-0.20 to -0.04) in men and -0.13 (-0.21 to -0.05) in women] and higher ln-HDL-cholesterol [0.10 (0.02 to 0.19) and 0.09 (0.01 to 0.18), respectively]. The associations with lower glucose levels were strong in men [-0.11 (-0.20 to -0.02) for fasting and -0.14 (-0.23 to -0.05) for postload glucose], but not statistically significant in women [-0.02 (-0.10 to 0.07) and -0.04 (-0.13 to 0.05), respectively]. There were no differences in the associations between white and black persons. Waist circumference was more strongly associated with abdominal subcutaneous fat, and this association became stronger with increasing BMI, whereas the association with visceral fat became weaker. Thigh circumference was equally dependent on thigh fat and thigh muscle in men, whereas in women the fat component was the main contributor.

CONCLUSION

Larger subcutaneous thigh fat is independently associated with more favourable glucose (in men) and lipid levels (in both sexes) after accounting for abdominal fat depots, which are associated with unfavourable glucose and lipid levels. Anthropometric measures reflect different fat depots at different levels of BMI at the abdomen, and reflect both fat and lean tissue at the thigh. These results emphasise the importance of accurate measures of regional body composition when investigating potential health risks.

Association between Physical and Cognitive Function in Healthy Elderly: The Health, Aging and Body Composition Study

Performance measures of physical function (gait speed, chair stands, standing balance) and cognitive function [Teng-modified Mini-Mental Status Exam (3MS) and digit symbol substitution test (DSST)] were assessed at baseline in 3,075 participants in the Health, Aging and Body Composition Study. Each physical function measure was examined for the strength and magnitude of association with cognitive function. All physical function measures were associated with both the 3MS and DSST scores (p < 0.001), and in multivariate analysis each relationship was independent of demographic characteristics, weight, physical activity and comorbid health conditions of participants. The association of motor performance was consistently greater for the DSST than the 3MS and, among the motor tests, gait speed retained a significant association with both cognitive measures independent of demographic, weight, physical activity and comorbid health conditions. In this large cohort of high-functioning older adults, the correlation between physical and cognitive function was not entirely explained by demographics. Longitudinal studies are needed to determine the direction of causality in this relationship.

Urinary incontinence in elderly women: findings from the Health, Aging, and Body Composition Study

OBJECTIVE

To estimate the prevalence of and risk factors for stress and urge incontinence in a biracial sample of well-functioning older women.

METHODS

We performed a cross-sectional analysis of 1,584 white and black women, aged 70-79 years, enrolled in a longitudinal cohort study. Participants were asked about incontinence, medical problems, and demographic and reproductive characteristics and underwent physical measurements. Using multivariable logistic regression, we compared women reporting at least weekly incontinence with those without incontinence.

RESULTS

Overall, 21% reported incontinence at least weekly. Of these, 42% reported predominantly urge incontinence, and 40% reported stress. Nearly twice as many white women as black women reported weekly incontinence (27% versus 14%, P <.001). Factors associated with urge incontinence included white race (odds ratio [OR] 3.1, 95% confidence interval [CI] 2.0-4.8), diabetes treated with insulin (OR 3.5, 95% CI 1.6-7.9), depressive symptoms (OR 2.7, 95% CI 1.4-5.3), current oral estrogen use (OR 1.7, 95% CI 1.1-2.6), arthritis (OR 1.7, 95% CI 1.1-2.6), and decreased physical performance (OR 1.6 per point on 0-4 scale, 95% CI 1.1-2.3). Factors associated with stress incontinence were chronic obstructive pulmonary disease (OR 5.6, 95% CI 1.3-23.2), white race (OR 4.1, 95% CI 2.5-6.7), current oral estrogen use (OR 2.0, 95% CI 1.3-3.1), arthritis (OR 1.6, 95% CI 1.0-2.4), and high body mass index (OR 1.3 per 5 kg/m2, 95% CI 1.1-1.6).

CONCLUSION

Urinary incontinence is highly prevalent, even in well-functioning older women, whites in particular. Many risk factors differ for stress and urge incontinence, suggesting differing etiologies and prevention strategies.

Macronutrient intakes of elderly in the Lipid Research Clinics Program Prevalence Study

As part of the Lipid Research Clinics (LRC) Program Prevalence Study of coronary heart disease risk factors, nutrient intakes of two US populations over 59 years of age were determined by 24-hour recalls in the 1970s. Characteristics of the populations were (1) California: suburban, upper-middle class, 95% high school graduates, 10% blue collar occupations; (2) Oklahoma: rural lower-middle class, 75% high school graduates, and 40% blue-collar occupations. Macronutrients consumed by both populations were similar, except for alcohol. For both men and women, energy intake was approximately 25 kcal/kg/day (body weight) sources of energy were approximately 40% from carbohydrate, 16% from protein, 37% from fat, and 4% from alcohol. The Oklahoma population, however, consumed significantly less alcohol than did Californians. Percentages of calories from fatty acids were approximately 14% from saturated and 6% from polyunsaturated, which yielded a polyunsaturated: saturated ratio of 0.48. The intake of cholesterol for women was 190 mg/1000 kcal and for men, 210 mg/1000 kcal. Between the ages of 60 and 69, the Oklahoma men consumed more energy than did the California men. Both sexes demonstrated lower energy intakes with advancing age and with increasing body mass index. The higher energy intake of the Oklahoma cohort aged 60-69 was attributed to the greater physical demands of their occupations, but this difference disappeared after age 70. The California and Oklahoma women had similar caloric intakes beyond age 60. In summary, the LRC findings suggest that geographically diverse American populations consumed in the late 1970s remarkably similar intakes of macronutients and cholesterol, with the only major exception being energy from alcoholic beverages.

Association between the inception of a SAFE KIDS Coalition and changes in pediatric unintentional injury rates

OBJECTIVE

To assess the relationship between the implementation of a SAFE KIDS Coalition and pediatric unintentional injury rates.

SETTING

Shelby County, Tennessee.

DESIGN

Retrospective observational analysis.

PATIENTS

County residents nine years of age or younger presenting to the children's medical center, its emergency department, or its outpatient clinics from 1990-97.

INTERVENTION

Implementation of a SAFE KIDS Coalition.

MAIN OUTCOME MEASURES

Rates of unintentional injuries targeted by the SAFE KIDS Coalition that resulted in hospitalization or in death. Rates of motor vehicle occupant injuries that resulted in hospitalization or in death. Rates of non-targeted unintentional injuries, namely injuries secondary to animals and by exposure to toxic plants. Rates of severe injuries (defined as those targeted injuries that required hospitalization or resulted in death), and specifically, severe motor vehicle occupant injuries were compared before and after the inception of the coalition using Poisson regression analysis.

RESULTS

The relative risk of targeted severe injury rates decreased after implementation of the coalition even after controlling for changes in hospital admission rates. Specifically, severe motor vehicle occupant injury rates decreased 30% (relative risk 0.70; 95% confidence interval 0.54 to 0.89) after initiation of the coalition.

CONCLUSIONS

The implementation of a SAFE KIDS Coalition was associated with a decrease in severe targeted injuries, most notably, severe motor vehicle occupant injuries. Although causality cannot be determined, these data suggest that the presence of a coalition may be associated with decreased severe unintentional injury rates.

Measuring higher level physical function in well-functioning older adults: expanding familiar approaches in the Health ABC study

BACKGROUND

To evaluate development and progression of functional limitation and retain comparability with established approaches, we raised the measurement ceiling of commonly used self-report and performance-based measures of function. This study evaluated the utility and concurrent validity of these expanded measures.

METHODS

The study population consisted of 3075 black and white men and women aged 70 to 79 years, with no reported mobility limitations or disability, participating in the Health, Aging, and Body Composition, or Health ABC study. Self-report measures were expanded by ascertaining ease of performance and including more demanding levels of some tasks. A single foot stand and narrow walk supplemented an established performance battery. For walking endurance, we developed the Long Distance Corridor Walk (LDCW), which includes distance covered in 2 minutes and the time to walk 400 m.

RESULTS

The expanded self-report items identified one half of the men and one third of the women as exceptionally well functioning and 10% to 13% of men and 21% to 36% of women with lower capacity. The supplemented and rescored performance battery discriminated function over the full range. The LDCW further differentiated walking capacity at the high end and also identified a subgroup with limitations. The self-report and performance measures were significantly, but weakly, correlated (0.13-0.35) and were independent predictors of walking endurance.

CONCLUSIONS

Well-functioning persons in their 70s exhibit a broad range of functional capacity readily ascertained by expanded self-report and performance tests. Significant associations among these measures support their concurrent validity, but generally weak correlations indicate they tap different, but important, dimensions of physical function.

Airflow limitation is underrecognized in well-functioning older people

OBJECTIVES

Dyspnea is a common symptom in older people. A reduced forced expiratory volume in 1 second (FEV1) is associated with a higher mortality rate from cardiovascular and respiratory disease, and increased admissions to hospitals. Underrecognized or undertreated airflow limitation may exacerbate the problem. The purpose of this study was to assess the prevalence and treatment of airflow limitation in a cohort of well-functioning older people.

DESIGN

Cross-sectional study.

SETTING

Baseline of a clinical-epidemiological study of incident functional limitation.

PARTICIPANTS

Participants attended the baseline examination of the Health, Aging, and Body Composition study, a prospective cohort study of 3,075 well-functioning subjects age 70 to 79.

MEASUREMENTS

Demographic and clinical data were collected by interview. Spirometry was performed unless contraindicated and repeated until three acceptable sets of flow-volume loops were obtained. Patients on bronchodilator medications had spirometry performed posttherapy. Blinded readers assessed the flow-volume loops, and inadequate tests were omitted from analysis. Airflow limitation was defined as a reduced forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC) as determined by age-, sex-, and race-normalized values. Severity of airflow limitation was defined by American Thoracic Society criteria.

RESULTS

Two thousand four hundred eighty-five subjects (80.8%) had assessable spirometry and data on treatment and diagnosis (1,265 men, 1,220 women). The mean age was 73.6 years. Two hundred sixty-two subjects (10.5%) had airflow limitation; 43 (16.4%) of these never smoked. Only 37.4% of participants with airflow limitation and 55.6% of participants with severe airflow limitation reported a diagnosis of lung disease. Only 20.5% of subjects with at least moderate airflow limitation had used a bronchodilator in the previous 2 weeks.

CONCLUSION

Despite their good functional status, airflow limitation was present, and underrecognized, in a considerable proportion of our older population. The low bronchodilator use suggests a significant reservoir of untreated disease. Physicians caring for older people need to be more vigilant for both the presence, and the need for treatment, of airflow limitation.

Reliability assessment of a rod photoreceptor outer segment grading system

The purpose of this study was to assess the reliability of a rod photoreceptor outer segment (PR-OS) grading system based on the analysis of 1 microm thick retinal sections obtained from Xenopus laevis whole-eye organ cultures. Digitally captured images, representative of the entire spectrum of rod PR-OS organization levels, were selected and coded numerically. A total of 102 individual rod PR-OS profiles were graded according to a six-step classification scheme based on the percentage of rod PR-OS membrane organization. Unweighted (exact agreement) and weighted kappa (kappa) coefficients (for use with ordered categorical rating scales) were calculated. Differences between kappa coefficients were tested for by chi-square analysis. To investigate the intra- and inter-rater variability and the possible presence of an interaction of the measurements with time, a repeated-measures analysis of variance was performed. The overall unweighted and weighted intra-rater kappa coefficients were 0.78 and 0.92, respectively. The overall unweighted and weighted inter-rater kappa coefficients were 0.73 and 0.90, respectively. There was no significant difference between raters or between first and second reading, nor was interaction between raters and time of rating documented. Individual kappa coefficients were equivalent both between raters and between sessions. Intra- and inter-rater agreement was within one step in 100% of cases. The estimated values of the kappa coefficients are consistent with a good to excellent degree of reliability and reproducibility of this rod PR-OS grading system. This system will be useful in the assessment of rod PR-OS morphology in studies of photoreceptor physiology and pathology.

Comparison of clinical indicators for performance measurement of health care quality: a cautionary note

The use of clinical performance data is increasing rapidly. Yet, substantial variation exists across indicators designed to measure the same clinical event. We compared indicators from several indicator measurement systems to determine the consistency of results. Five measurement systems with well-defined indicators were selected. They were applied to 24 hospitals. Indicators for mortality from coronary artery bypass graft surgery and mortality in the perioperative period were chosen from these measurement systems. Analyses results and concludes that it is faulty to assume that clinical indicators derived from different measurement systems will give the same rank order. Widespread demand for external release of outcome data from hospitals must be balanced by an educational effort about the factors that influence and potentially confound reported rates.

Impact of hospital care on incidence of bloodstream infection: the evaluation of processes and indicators in infection control study

The Evaluation of Processes and Indicators in Infection Control (EPIC) study assesses the relationship between hospital care and rates of central venous catheter-associated primary bacteremia in 54 intensive-care units (ICUs) in the United States and 14 other countries. Using ICU rather than the patient as the primary unit of statistical analysis permits evaluation of factors that vary at the ICU level. The design of EPIC can serve as a template for studies investigating the relationship between process and event rates across health-care institutions.

Serum carotenoids and markers of inflammation in nonsmokers

One explanation for discrepant results between epidemiologic studies and randomized trials of beta-carotene and cardiovascular disease may be a failure to consider inflammation as a confounder. To evaluate the potential for such confounding, the authors relate the serum concentrations of five carotenoids (alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, and lutein/zeaxanthin) to levels of three inflammatory markers (C-reactive protein, fibrinogen, and white blood cell count) measured during the Third National Health and Nutrition Survey, 1988-1994. The analysis included 4,557 nonsmoking participants aged 25-55 years. Adjusted concentrations of all five carotenoids were significantly lower in those with C-reactive protein levels above 0.88 mg/dl (p = 0.001). There was a trend toward lower adjusted beta-cryptoxanthin concentrations with increasing level of fibrinogen (p value test for trend = 0.01), but other carotenoids were not related. Many of the carotenoid concentrations were lower among participants with high white blood cell counts. After log transformation, only adjusted mean beta-carotene levels were significantly lower in those with white blood cell counts above 7.85 x 10(9)/liter (p < 0.01). These cross-sectional data do not clarify the biologic relation between carotenoids and C-reactive protein but, to the extent that the carotenoids are associated with C-reactive protein levels, a carotenoid-heart disease association may be, in part, an inflammation-heart disease association.

Egg consumption and coronary heart disease: an epidemiologic overview

Serum cholesterol has been established as a modifiable risk factor for coronary heart disease. Experimental feeding studies show that saturated fat and cholesterol increase serum cholesterol levels; thus, dietary recommendations for lowering the risk of heart disease proscribe the intake of both substances. Recommendations have also included limits on the intake of eggs because of their high cholesterol content. In free-living populations, diet reflects a pattern of associated choices. Increases in one food may lead to changes in the consumption of other foods that may modulate disease risk. Epidemiologic data are helpful in assessing the importance of foods and nutrients in the context in which they are actually consumed. We review epidemiologic data relating dietary cholesterol and eggs to coronary disease risk. Cholesterol intake was associated with a modest increase in the risk of coronary events. The true magnitude of the association is difficult to estimate because most studies fail to account for potential confounding by other features of the diet. When a full-range of confounding factors was considered, the association between cholesterol intake and heart disease risk was small (6% increase in risk for 200mg/1,000kcal/day difference in cholesterol intake). Several studies have examined egg intake and its relationship with coronary outcomes. All but one failed to consider the role of other potentially confounding dietary factors. When dietary confounders were considered, no association was seen between egg consumption at levels up to 1 + egg per day and the risk of coronary heart disease in non-diabetic men and women.

Reexamining the sarcopenia hypothesis. Muscle mass versus muscle strength. Health, Aging, and Body Composition Study Research Group

The association of muscle mass and muscle strength with lower-extremity performance, as measured by timed repeated chair stands, was investigated using preliminary data from 3,075 Black and White participants (70-79 years old) in the Health, Aging, and Body Composition Study. Leg muscle mass (LM) was measured by dual-energy X-ray absorptiometry (Hologic QDR 4500). The maximal isokinetic torque of the leg extensors (LS) was measured at 60 degrees/s using a Kin-Com isokinetic dynamometer. Men were stronger, had greater LM, and better performance than women. As expected, low LS was associated with poorer performance after adjusting for race, study site, and body fat. Low LM was associated with poorer performance in men and women, with a potential threshold effect in women only. When LS and LM were modeled simultaneously, only LS remained independently associated with performance. In conclusion, muscle strength, but not muscle mass, is independently associated with lower-extremity performance.

Definition and adjustment of Cesarean section rates and assessments of hospital performance

BACKGROUND

Demand is growing for comparative data such as Cesarean section rates, but little effort has been made to develop either standardized definitions or risk adjustment approaches.

OBJECTIVE

To determine to what extent a seemingly straightforward indicator like Cesarean section rate will vary when calculated according to differing definitions used by various performance measurement systems.

DESIGN

Retrospective data abstraction of 200 deliveries per hospital.

SETTING

Fifteen acute care hospitals including two from outside the USA.

MEASUREMENTS

Four widely-used performance measurement systems provided specifications for their Cesarean section indicators. Indicator specifications varied on inclusion criteria (whether the population was defined using Diagnostic Related Groups or ICD-9-CM procedure codes or ICD-9-CM diagnosis codes) and risk-adjustment methods and factors. Rates and rankings were compared across hospitals using different Cesarean section indicator definitions and indicators with and without risk adjustment.

RESULTS

Calculated Cesarean section rates changed substantially depending on how the numerator and denominator cases were identified. Relative performance based on Cesarean section rankings is affected less by differing indicator definitions than by whether and how risk adjustment is performed.

CONCLUSIONS

Judgments about organizational performance should only be made when the comparisons are based upon identical indicators. Research leading to a uniform indicator definition and standard risk adjustment methodology is needed.

Emerging noninvasive biochemical measures to predict cardiovascular risk

New predictors of cardiovascular events are needed to improve the accuracy of risk stratification. Such predictors should be easily measurable in the population and potentially modifiable. This review reports on new biomarkers that are closely linked to the pathogenic mechanisms underlying the progression of the atherosclerotic plaque leading to rupture and thrombosis that ultimately precipitate acute clinical events, such as stroke and myocardial infarction. These risk factors have been associated with subclinical or clinical cardiovascular disease in large populations and include markers of lipoprotein and lipid metabolism, vitamin B12 metabolism, fibrinolysis, coagulation, inflammation, infection, endothelial dysfunction, the angiotensin system, and oxidative stress. For other key processes of atherosclerosis and cardiac disease, such as apoptosis or programmed cell death, there are currently no markers that can be measured noninvasively. Atherosclerosis is a multifactorial condition and possibly only a subset of factors are the main determinants of disease in a given patient. A better definition of the cardiovascular risk profile will help to better target primary and secondary prevention. Further epidemiological studies are needed to characterize the actual predictive and clinical value of these new emerging cardiovascular biomarkers.

beta-Carotene, carotenoids and the prevention of coronary heart disease

The importance of low density lipoprotein (LDL) oxidation to the atherosclerotic process has led to the examination of beta-carotene as a possible preventive agent. Several epidemiologic studies show an inverse association between serum/adipose beta-carotene levels and coronary heart disease risk. Randomized clinical trials, however, have not shown any benefit, and perhaps even an adverse effect, of beta-carotene supplementation. A number of possible confounding factors may explain the inconsistency between the trials and epidemiologic evidence. Other carotenoids that are correlated with beta-carotene both in the diet and in the blood might be important factors, as might other plant-derived compounds. Alternatively, low serum carotenoid levels may reflect either increased lipoprotein density or the presence of inflammation, both factors emerging as important novel risk factors for coronary heart disease. Whereas the trial results support no preventive role for beta-carotene, the epidemiologic evidence does generally support the idea that a diet rich in high carotenoid foods is associated with a reduced risk of heart disease.

Provitamin A carotenoid intake and carotid artery plaques: the Atherosclerosis Risk in Communities Study

We examined the cross-sectional association between intake of carotenoids with provitamin A activity and carotid artery plaques in 12,773 participants of the Atherosclerosis Risk in Communities Study aged 45-64 y. Usual diet was assessed with a 66-item food-frequency questionnaire. Plaques were examined by B-mode ultrasound of multiple carotid artery segments. In both women and men, those in the highest quintile of carotenoid consumption had a lower prevalence of plaques (women, 25.4%; men, 36.0%) than those in the lowest quintile of carotenoid consumption (women, 29.3%; men, 39.8%). The prevalence odds ratios contrasting extreme intake quintiles were 0.82 (95% CI: 0.70, 0.97) in women and 0.85 (95% CI: 0.72, 1.01) in men. The associations diminished slightly after potential confounders were adjusted for. In women, the inverse association was particularly strong for current smokers (adjusted odds ratio contrasting extreme quintiles: 0.67; 95% CI: 0.45, 0.98). In men, no such effect modification by smoking was seen. The inverse association was somewhat stronger in men aged 55-64 y than in those aged 45-54 y, whereas age made little difference in women. These findings, together with previous findings that carotenoid intake was unrelated to average carotid artery wall thickness, suggest that carotenoids may exert their influence later rather than earlier in the atherosclerotic process, and support the hypothesis that carotenoids or other plant-derived compounds may play a role in preventing arterial plaque formation.

Silent aspiration after coronary artery bypass grafting

BACKGROUND

"Silent" aspiration was recognized to be a more frequent complication at this hospital in patients who have had coronary artery bypass grafting than in the general surgical population.

METHODS

A case-control retrospective study covering a 4.5-year period was conducted to determine risk factors for pharyngeal dysfunction resulting in silent aspiration.

RESULTS

Significant predictors of silent aspiration were age, history of cerebral vascular disease, insulin-dependent diabetes mellitus, myocardial infarction, and chronic obstructive pulmonary disease. Intraaortic balloon pump and number of units of fresh-frozen plasma were the only independent intraoperative factors associated with silent aspiration in a model using continuous variables directly. Cold fibrillation was used in 7 of 53 study cases but no control patients, so it could not be modeled. Postoperative complications occurring with greater frequency included neurologic complications, adverse pulmonary outcomes, repeat surgical interventions, infection, and death. Using an Aspiration Risk Profile developed from the retrospective study, in a detailed prospective study of 10 patients, 3 of 4 patients with postoperative dysphagia had objective evidence of stroke.

CONCLUSIONS

These findings suggest that postoperative coronary artery bypass graft dysphagia may be the result of intraoperative cerebral injury, and that careful postoperative clinical evaluation of coronary artery bypass graft patients with risk factors may result in early diagnosis of pharyngeal dysfunction with the goals of preventing silent aspiration and reducing morbidity, mortality, and hospital cost.

Increased recognition of IgA nephropathy in African-American children

Based upon the percentage of cases of IgA nephropathy (IgAN) in biopsy series, a lower prevalence has been assumed for African-Americans compared with Americans of European descent. This may be due to a racial difference in the basic underlying pathology of IgAN or to racial differences in patterns of referral and biopsy selection practices. Over the past decade (1985-1994), we have found similar incidences of IgAN in Caucasian and African-American children from Shelby County, Tennessee. The incidence was 3.0 cases per million per year for Caucasian and 5.7 cases per million per year for African-American children. IgAN may be more common in African-American children than previously appreciated. Population-based incidence studies will be necessary to determine whether or not our experience has become a more widespread phenomenon.