Evidence for protein leverage on total energy intake, but not body mass index, in a large cohort of older adults.

BACKGROUND: Protein leverage (PL) is the phenomenon of consuming food until absolute intake of protein approaches a 'target value', such that total energy intake (TEI) varies passively with the ratio of protein: non-protein energy (fat + carbohydrate) in the diet. The PL hypothesis (PLH) suggests that the dilution of protein in energy-dense foods, particularly those rich in carbohydrates and fats, combines with protein leverage to contribute to the global obesity epidemic. Evidence for PL has been reported in younger adults, children and adolescents. This study aimed to test for PL and the protein leverage hypothesis (PLH) in a cohort of older adults. METHODS: We conducted a retrospective analysis of dietary intake in a cohort of 1699 community-dwelling older adults aged 67-84 years from the NuAge cohort. We computed TEI and the energy contribution (EC) from each macronutrient. The strength of leverage of macronutrients was assessed through power functions ( TEI = µ * EC L ). Body mass index (BMI) was calculated, and mixture models were fitted to predict TEI and BMI from macronutrients' ECs. RESULTS: In this cohort of older adults, 53% of individuals had obesity and 1.5% had severe cases. The mean TEI was 7673 kJ and macronutrients' ECs were 50.4%, 33.2% and 16.4%, respectively for carbohydrates, fat, and protein. There was a strong negative association (L = -0.37; p < 0.001) between the protein EC and TEI. Each percent of energy intake from protein reduced TEI by 77 kJ on average, ceteris paribus. However, BMI was unassociated with TEI in this cohort. CONCLUSIONS: Findings indicate clear evidence for PL on TEI, but not on BMI, likely because of aging, body composition, sarcopenia, or protein wasting.

Systematic review of research barriers, facilitators, and stakeholders in long-term care and geriatric settings, and a conceptual mapping framework to build research capacity.

BACKGROUND: Older adults are underrepresented in research. Heterogeneity of research processes in this population, specifically in long-term care (LTC) and geriatric acute care (GAC), is not well described and may impede the design, planning, and conduct of research. In this study, we identified, quantified, and mapped stakeholders, research stages, and transversal themes of research processes, to develop a mapping framework to improve research capacity by better characterizing this heterogeneity. METHODS: Multicomponent mixed methods study. An environmental scan was used to initiate a preliminary framework. We conducted a systematic literature search on processes, barriers, and methods for clinical research in GAC and LTC to extract and update stakeholders, research stages, and themes. Importance and interactions of elements were synthesized via heatmaps by number of articles, mentions, and content intersections. RESULTS: For our initial framework and environmental scan, we surveyed 24 stakeholders. Of 9277 records, 68 articles were included in our systematic review and allowed us to identify 12 stakeholders, 13 research stages, 17 transversal themes (either barriers, facilitators, general themes, or recommendations), and 1868 intersections. Differences in relative importance between LTC and GAC emerged for stakeholders (staff, managers vs. caregivers, ethics committees), and for research stages (funding, facility recruitment vs. ethics, individual recruitment). Crucial themes according to specific stakeholders were collaboration for the research team; communication, trust, and human resources for managers; heterogeneity for patients and residents. A heatmap framework synthesizing vital stakeholders and themes per research stage was generated. CONCLUSIONS: We identified and quantified the interactions between stakeholders, stages, and themes to characterize heterogeneity in LTC and GAC research. Our framework may serve as a blueprint to co-construct and improve each stage of the research process.

Multidimensional associations between nutrient intake and healthy ageing in humans.

BACKGROUND: Little is known about how normal variation in dietary patterns in humans affects the ageing process. To date, most analyses of the problem have used a unidimensional paradigm, being concerned with the effects of a single nutrient on a single outcome. Perhaps then, our ability to understand the problem has been complicated by the fact that both nutrition and the physiology of ageing are highly complex and multidimensional, involving a high number of functional interactions. Here we apply the multidimensional geometric framework for nutrition to data on biological ageing from 1560 older adults followed over four years to assess on a large-scale how nutrient intake associates with the ageing process. RESULTS: Ageing and age-related loss of homeostasis (physiological dysregulation) were quantified via the integration of blood biomarkers. The effects of diet were modelled using the geometric framework for nutrition, applied to macronutrients and 19 micronutrients/nutrient subclasses. We observed four broad patterns: (1) The optimal level of nutrient intake was dependent on the ageing metric used. Elevated protein intake improved/depressed some ageing parameters, whereas elevated carbohydrate levels improved/depressed others; (2) There were non-linearities where intermediate levels of nutrients performed well for many outcomes (i.e. arguing against a simple more/less is better perspective); (3) There is broad tolerance for nutrient intake patterns that don't deviate too much from norms ('homeostatic plateaus'). (4) Optimal levels of one nutrient often depend on levels of another (e.g. vitamin E and vitamin C). Simpler linear/univariate analytical approaches are insufficient to capture such associations. We present an interactive tool to explore the results in the high-dimensional nutritional space. CONCLUSION: Using multidimensional modelling techniques to test the effects of nutrient intake on physiological dysregulation in an aged population, we identified key patterns of specific nutrients associated with minimal biological ageing. Our approach presents a roadmap for future studies to explore the full complexity of the nutrition-ageing landscape.

Vitamin B-12 Intake from Dairy but Not Meat Is Associated with Decreased Risk of Low Vitamin B-12 Status and Deficiency in Older Adults from Quebec, Canada.

BACKGROUND: Vitamin B-12 deficiency can result in irreversible neurologic damages. It is most prevalent among older adults (∼5%-15%), mainly due to impaired absorption. Vitamin B-12 bioavailability varies between food sources, so their importance in preventing deficiency may also vary. OBJECTIVES: Using the NuAge Database and Biobank, we examined the associations between vitamin B-12 intake (total and by specific food groups) and low vitamin B-12 status and deficiency in older adults. METHODS: NuAge-the Quebec Longitudinal Study on Nutrition and Successful Aging-included 1753 adults aged 67-84 y who were followed 4 y. Analytic samples comprised 1230-1463 individuals. Dietary vitamin B-12 intake was assessed annually using three 24-h dietary recalls. Vitamin B-12 status was assessed annually as low serum vitamin B-12 (<221 pmol/L), elevated urinary methylmalonic acid (MMA)/creatinine ratio (>2 µmol/mmol), and a combination of both (deficiency). Vitamin B-12 supplement users were excluded. Multilevel logistic regressions, adjusted for relevant confounders, were used. RESULTS: Across all study years, 21.8%-32.5% of participants had low serum vitamin B-12, 12.5%-17.0% had elevated urine MMA/creatinine, and 10.1%-12.7% had deficiency. Median (IQR) total vitamin B-12 intake was 3.19 µg/d (2.31-4.37). Main sources were "dairy" and "meat, poultry, and organ meats." The ORs (95% CIs) in the fifth quintile compared with the first of total vitamin B-12 intake were as follows: for low serum vitamin B-12, 0.52 (0.37, 0.75; P-trend < 0.0001); for elevated urine MMA/creatinine, 0.63 (0.37, 1.08; P-trend = 0.091); and for vitamin B-12 deficiency, 0.38 (0.18, 0.79; P-trend = 0.006). Similarly, ORs (95% CIs) in the fourth quartile compared with the first of dairy-derived vitamin B-12 intake were 0.46 (0.32, 0.66; P-trend < 0.0001), 0.51 (0.30, 0.87; P-trend = 0.006), and 0.35 (0.17, 0.73; P-trend = 0.003), respectively. No associations were observed with vitamin B-12 from "meat, poultry, and organ meats." CONCLUSIONS: Higher dietary vitamin B-12 intake, especially from dairy, was associated with decreased risk of low vitamin B-12 status and deficiency in older adults. Food groups might contribute differently at reducing risk of deficiency in older populations.

Serum ω-3 Fatty Acids and Cognitive Domains in Community-Dwelling Older Adults from the NuAge Study: Exploring the Associations with Other Fatty Acids and Sex.

BACKGROUND: Omega-3 (n-3) PUFAs are suggested to play a role in the prevention of cognitive decline. The evidence may be inconsistent due to methodologic issues, including interrelations with other long-chain (14 or more carbons) fatty acids (LCFAs) and use of sex as a confounding factor rather than an effect modifier. OBJECTIVES: This study evaluated the association between serum n-3 PUFAs and performance across 4 cognitive domains, overall and by sex, while controlling for other LCFAs. METHODS: In total, 386 healthy older adults (aged 77.4 ± 3.8 y; 53% females) from the Quebec Longitudinal Study on Nutrition and Successful Aging underwent a cognitive evaluation and blood sampling. Verbal and nonverbal episodic memory, executive functioning, and processing speed were evaluated. Serum LCFA concentrations were measured by gas chromatography. LCFAs were grouped according to standard fatty acid classes and factor analysis using principal component analysis (FA-PCA). Multivariate linear regression models were performed, including unadjusted and adjusted models for other LCFAs. RESULTS: Higher n-3 PUFA concentrations were associated with better nonverbal memory and processing speed in fully adjusted models not including other LCFAs (ßs of 0.21 and 0.19, respectively). The magnitude of these associations varied when other LCFAs were entered in the model (ßs of 0.27 and 0.32, respectively) or when FA-PCA factors were considered (ßs of 0.27 and 0.21, respectively). Associations with verbal episodic memory were limited to higher concentrations of EPA, whereas there was no association between n-3 PUFAs and executive functioning. Higher n-3 PUFAs were associated with better verbal and nonverbal episodic memory in females and with better executive functioning and processing speed in males. CONCLUSIONS: These results suggest that other LCFAs should be considered when evaluating the association between n-3 PUFAs and cognitive performance in healthy older adults. Sex differences across cognitive domains warrant further investigation.

Protein intake, physical activity and grip strength in European and North American community-dwelling older adults: a pooled analysis of individual participant data from four longitudinal ageing cohorts.

INTRODUCTION: Higher dietary protein, alone or in combination with physical activity (PA), may slow the loss of age-related muscle strength in older adults. We investigated the longitudinal relationship between protein intake and grip strength, and the interaction between protein intake and PA, using four longitudinal ageing cohorts. METHODS: Individual participant data from 5584 older adults (52% women; median: 75, IQR: 71.6, 79.0 years) with up to 8.5 years (mean: 4.9, SD: 2.3 years) of follow-up from the Health ABC, NuAge, LASA and Newcastle 85+ cohorts were pooled. Baseline protein intake was assessed with food frequency questionnaires and 24h recalls and categorized into <0.8, 0.8-<1.0, 1.0-<1.2 and ≥1.2 g/kg adjusted body weight (aBW)/d. The prospective association between protein intake, its interaction with PA, and grip strength (sex- and cohort-specific) was determined using joint models (hierarchical linear mixed effects and a link function for Cox proportional hazards models). RESULTS: Grip strength declined on average by 0.018 SD (95%CI: -0.026, -0.006) every year. No associations were found between protein intake, measured at baseline, and grip strength, measured prospectively, or rate of decline of grip strength in models adjusted for sociodemographic, anthropometric, lifestyle and health variables (e.g., protein intake ≥1.2 vs <0.8 g/kg aBW/d: ß= -0.003, 95%CI: -0.014,0.005 SD per year). There also was no evidence of an interaction between protein intake and PA. CONCLUSIONS: We failed to find evidence in this study to support the hypothesis that higher protein intake, alone or in combination with higher PA, slowed the rate of grip strength decline in older adults.

Olfactory Dysfunction Associated with Cognitive Decline in an Elderly Population.

BACKGROUND: In many neurological disorders, including Alzheimer disease, early olfactory dysfunction is observed. OBJECTIVE: In order to determine if deficits in olfactory memory are present in the elderly and if olfactory dysfunction correlates with cognitive impairment in the aging population, olfactory testing has been done on seniors from the NuAge cohort accepting to participate in the Olfactory Response Cognition and Aging (ORCA) secondary sub-study. The t-Mini Mental Statement Examination and the Telephone Interview for Cognitive Status tests were done to assess cognition levels. RESULTS: Overall, 94% of the ORCA cohort displayed olfactory dysfunction. Deficits in olfactory memory were also present. A correlation was observed between olfactory function and cognitive test scores. Moreover, in women who smoked, there was an association between olfactory memory and cognitive scores. CONCLUSION: Our results suggest that olfactory dysfunction may predict impending cognitive decline and highlights the need for olfactory training in seniors to improve olfaction and overall well-being.

Evidence from two cohorts for the frailty syndrome as an emergent state of parallel dysregulation in multiple physiological systems.

Frailty is a clinical syndrome often present in older adults and characterized by a heightened vulnerability to stressors. The biological antecedents and etiology of frailty are unclear despite decades of research: frailty is associated with dysregulation in a wide range of physiological systems, but no specific cause has been identified. Here, we test predictions stemming from the hypothesis that there is no specific cause: that frailty is an emergent property arising from the complex systems dynamics of the broad loss of organismal homeostasis. Specifically, we use dysregulation of six physiological systems using the Mahalanobis distance approach in two cohorts of older adults to test the breadth, diffuseness, and nonlinearity of associations between frailty and system-specific dysregulation. We find clear support for the breadth of associations between frailty and physiological dysregulation: positive associations of all systems with frailty in at least some analyses. We find partial support for diffuseness: the number of systems or total amount of dysregulation is more important than the identity of the systems dysregulated, but results only partially replicate across cohorts. We find partial support for nonlinearity: trends are exponential but not always significantly so, and power is limited for groups with very high levels of dysregulation. Overall, results are consistent with-but not definitive proof of-frailty as an emergent property of complex systems dynamics. Substantial work remains to understand how frailty relates to underlying physiological dynamics across systems.

Motoric cognitive risk syndrome and incident dementia in older adults from the Québec NuAge cohort.

BACKGROUND: The co-occurrence of slow walking speed and subjective cognitive complaint (SCC) in non-demented individuals defines motoric cognitive risk syndrome (MCR), which is a pre-dementia stage. There is no information on the association between MCR and incident dementia in Québec's older population. OBJECTIVE: The study aims to examine the association of MCR and its individual components (i.e. SCC and slow walking speed) with incident dementia in community-dwelling older adults living in the province of Québec (Canada). DESIGN: Québec older people population-based observational cohort study with 3 years of follow-up. SETTING: Community dwellings. SUBJECTS: A subset of participants (n = 1,098) in 'Nutrition as a determinant of successful aging: The Québec longitudinal study' (NuAge). METHODS: At baseline, participants with MCR were identified. Incident dementia was measured at annual follow-up visits using the Modified Mini-Mental State (≤79/100) test and Instrumental Activity Daily Living scale (≤6/8) score values. RESULTS: The prevalence of MCR was 4.2% at baseline and the overall incidence of dementia was 3.6%. MCR (Hazard Ratio (HR) = 5.18, with 95% confidence interval (CI) = [2.43-11.03] and P ≤ 0.001) and SCC alone (HR = 2.54, with 95% CI = [1.33-4.85] and P = 0.005) were associated with incident dementia, but slow walking speed was not (HR = 0.81, with 95%CI = [0.25-2.63] and P = 0.736). CONCLUSIONS: MCR and SCC are associated with incident dementia in NuAge study participants.

Effects of Sex and Physical Activity Level on Serum Biomarker-Based Physiological Dysregulation: The Impact to Predict Frailty and Mortality in the Quebec NuAge Cohort.

BACKGROUND: Age-related changes in biological processes such as physiological dysregulation (the progressive loss of homeostatic capacity) vary considerably among older adults and may influence health profiles in late life. These differences could be related, at least in part, to the impact of intrinsic and extrinsic factors such as sex and physical activity level (PAL). OBJECTIVES: The objectives of this study were (1) to assess the magnitude and rate of changes in physiologi-cal dysregulation in men and women according to PAL and (2) to determine whether/how sex and PAL mediate the apparent influence of physiological dysregulation on health outcomes (frailty and mortality). METHODS: We used data on 1,754 community-dwelling older adults (age = 74.4 ± 4.2 years; women = 52.4%) of the Quebec NuAge cohort study. Physiological dysregulation was calculated based on Mahalanobis distance of 31 biomarkers regrouped into 5 systems: oxygen transport, liver/kidney function, leukopoiesis, micronutrients, and lipids. RESULTS: As expected, mean physiological dysregulation significantly increased with age while PAL decreased. For the same age and PAL, men showed higher levels of physiological dysregulation globally in 3 systems: oxygen transport, liver/kidney function, and leukopoiesis. Men also showed faster global physiological dysregulation in the liver/kidney and leukopoiesis systems. Overall, high PAL was associated with lower level and slower rate of change of physiological dysregulation. Finally, while mortality and frailty risk significantly increased with physiological dysregulation, there was no evidence for differences in these effects between sexes and PAL. CONCLUSION: Our results showed that both sex and PAL have a significant effect on physiological dysregulation levels and rates of change. Also, although a higher PAL was associated with lower level and slower rate of change of physiological dysregulation, there was no evidence that PAL attenuates the effect of physiological dysregulation on subsequent declines in health at the end of life. Substantial work remains to understand how modifiable behaviors impact the relationship between physiological dysregulation, frailty, and mortality in men and women.

Age-Related Increases in Marrow Fat Volumes have Regional Impacts on Bone Cell Numbers and Structure.

The increasing levels of bone marrow fat evident in aging and osteoporosis are associated with low bone mass and attributed to reduced osteoblastogenesis. Local lipotoxicity has been proposed as the primary mechanism driving this reduction in bone formation. However, no studies have examined the correlation between high levels of marrow fat volumes and changes in local cellularity. In this study, we hypothesize that areas of bone marrow with high fat volumes are associated with significant changes in cell number within a similar region of interest (ROI). Inbred albino Louvain (LOU) rats, originating from the Wistar strain, have been described as a model of healthy aging with the absence of obesity but expressing the typical features of age-related bone loss. We compared local changes in distal femur cellularity and structure in specific ROI of undecalcified bone sections from 4- and 20-month-old male and female LOU rats and Wistar controls. Our results confirmed that older LOU rats exhibited significantly higher fat volumes than Wistar rats (p < 0.001). These higher fat volume/total volume were associated with lower trabecular number (p < 0.05) and thickness (p < 0.05) and higher trabecular separation (p < 0.05). In addition, osteoblast and osteocyte numbers were reduced in the similar ROI containing high levels of adiposity, while osteoclast number was higher compared to control (p < 0.03). In summary, marrow ROIs with a high level of adiposity were associated with a lower bone mass and changes in cellularity explaining associated bone loss. Further studies assessing the levels of lipotoxicity in areas of high local marrow adiposity and identifying molecular actors involved in this phenomenon are still required.

Sex differences in the relationship between dietary pattern adherence and cognitive function among older adults: findings from the NuAge study.

BACKGROUND: Consumption of a prudent dietary pattern rich in healthy nutrients is associated with enhanced cognitive performance in older adulthood, while a Western dietary pattern low in healthy nutrients is associated with poor age-related cognitive function. Sex differences exist in dietary intake among older adults; however, there is a paucity of research examining the relationship between sex-specific dietary patterns and cognitive function in later life. METHODS: The current study aimed to investigate sex differences in the relationship between sex-specific dietary pattern adherence and global cognitive function at baseline and over a 3-year follow-up in 1268 community-dwelling older adults (Mage = 74 years, n = 664 women, n = 612 men) from the Quebec Longitudinal Study on Nutrition and Successful Aging (NuAge). A 78-item Food Frequency Questionnaire was used to estimate dietary intake over the previous year. Sex-specific dietary pattern scores were derived using principal component analysis. Global cognition was assessed using the Modified Mini-Mental State Examination (3MS). RESULTS: Adjusted linear mixed effects models indicated that a healthy, prudent dietary pattern was not associated with baseline cognitive performance in men or women. No relationship was found between Western dietary pattern adherence and baseline cognitive function in women. Among men, adherence to an unhealthy, Western dietary pattern was associated with poorer baseline cognitive function (ß = - 0.652, p = 0.02, 95% CI [- 1.22, - 0.65]). No association was found between prudent or Western dietary patterns and cognitive change over time in men or women. CONCLUSIONS: These findings highlight the importance of conducting sex-based analyses in aging research and suggest that the relationship between dietary pattern adherence and cognitive function in late life may be sex-dependent.

Revisiting the hypothesis of syndromic frailty: a cross-sectional study of the structural validity of the frailty phenotype.

BACKGROUND: Fried's Phenotype Model of Frailty (PMF) postulates that frailty is a syndrome. Features of a syndrome are a heterogeneous population that can be split into at least two classes, those presenting and those not presenting the syndrome. Syndromes are characterized by a specific mixture of signs and symptoms which increase in prevalence, from less to more severe classes. So far, the null hypothesis of homogeneity - signs and symptoms of frailty cannot identify at least two classes - has been tested using Latent Class Analysis (LCA) on the five dichotomized components of PMF (unintentional weight loss, exhaustion, weakness, slowness, and low physical activity). The aim of this study is to investigate further the construct validity of frailty as a syndrome using the extension offered by Factor Mixture Models (FMM). METHODS: LCA on dichotomized scores and FMM on continuous scores were conducted to test homogeneity on the five PMF components in a sample of 1643 community-dwelling older adults living in Québec, Canada (FRéLE). RESULTS: With dichotomized LCA, three frailty classes were found: robust, prefrail and frail, and the hypothesis of homogeneity was rejected. However, in FMM, frailty was better represented as a continuous variable than as latent heterogeneous classes. Thus, the PMF measurement model of frailty did not meet the features of a syndrome in this study. CONCLUSION: Using the FRéLE cohort, the PMF measurement model validity is questioned. Valid measurement of a syndrome depends on an understanding of its etiological factors and pathophysiological processes, and on a modelling of how the measured components are linked to these processes. Without these features, assessing frailty in a clinical setting may not improve patient health. Research on frailty should address these issues before promoting its use in clinical settings.

Multi-block PLS discriminant analysis for the joint analysis of metabolomic and epidemiological data.

INTRODUCTION: Metabolomics is a powerful phenotyping tool in nutrition and health research, generating complex data that need dedicated treatments to enrich knowledge of biological systems. In particular, to investigate relations between environmental factors, phenotypes and metabolism, discriminant statistical analyses are generally performed separately on metabolomic datasets, complemented by associations with metadata. Another relevant strategy is to simultaneously analyse thematic data blocks by a multi-block partial least squares discriminant analysis (MBPLSDA) allowing determining the importance of variables and blocks in discriminating groups of subjects, taking into account data structure. OBJECTIVE: The present objective was to develop a full open-source standalone tool, allowing all steps of MBPLSDA for the joint analysis of metabolomic and epidemiological data. METHODS: This tool was based on the mbpls function of the ade4 R package, enriched with functionalities, including some dedicated to discriminant analysis. Provided indicators help to determine the optimal number of components, to check the MBPLSDA model validity, and to evaluate the variability of its parameters and predictions. RESULTS: To illustrate the potential of this tool, MBPLSDA was applied to a real case study involving metabolomics, nutritional and clinical data from a human cohort. The availability of different functionalities in a single R package allowed optimizing parameters for an efficient joint analysis of metabolomics and epidemiological data to obtain new insights into multidimensional phenotypes. CONCLUSION: In particular, we highlighted the impact of filtering the metabolomic variables beforehand, and the relevance of a MBPLSDA approach in comparison to a standard PLS discriminant analysis method.

Effect of a 12-week mixed power training on physical function in dynapenic-obese older men: does severity of dynapenia matter?

INTRODUCTION: Mobility disability affects nearly 15% of people aged 65 or over worldwide. Excess weight or obesity (OB), along with an accentuated loss of muscle strength (dynapenia), is recognized to be one of the most common risk factors for mobility impairment among the elderly. OBJECTIVE: To investigate the effect of a 12-week mixed power training (MPT high-velocity resistance training mixed with functional exercises) on physical function in obese older men exhibiting different severities of dynapenia. METHODS: Community-dwelling older men (69 ± 6 years) were assigned to the study if they were considered obese (OB, fat mass ≥ 25% body weight, BW) and to one of the two groups according to severity of dynapenia [(handgrip strength-HS)/BW]: type 1(OB-DY1) or type 2(OB-DY2), < 1 or 2SD from a young reference group. Participants followed a 12-week MPT, three times/week, 75 min/session. Main outcomes included the performance on the 4-m and 6-min walking tests, Timed Up and Go, stair and balance tests. RESULTS AND DISCUSSION: At baseline, OB-DY1 performed better than OB-DY2 in all functional tests (p < 0.05). Following the intervention, medium-to-large training effect size (ES) were observed for fat (ES = 0.21) and lean (ES = 0.32, p < 0.001) masses, functional performance (ES 0.11-0.54, p < 0.05), HS (ES = 0.10, p < 0.05) and lower limb muscle strength (ES = 0.67, p < 0.001) and power (ES = 0.60, p < 0.05). Training-by-group interaction showed that OB-DY1 lost more FM (ES = 0.11, p = 0.03) and OB-DY2 improved more HS (ES = 0.19, p = 0.006) than their counterparts. CONCLUSIONS: Seniors with obesity and severe dynapenia have poorer physical function than those in the early stage of dynapenia. Both seem to benefit from a high-velocity resistance training mixed with functional exercises, although by slightly different pathways.

A prospective evaluation of the depression-nutrient intake reverse causality hypothesis in a cohort of community-dwelling older Canadians.

Studies have investigated the potential protective effects that diet may have on late-life depression incidence. This disorder can, however, affect the person's food intake, widely known as the reverse causality hypothesis of depression. To test this hypothesis, we compared mean nutrient intakes from three 24-h recalls during the year depression was detected (Geriatric Depression Scale ≥11 or antidepressant medication) with intakes from 1 year earlier among community-dwelling older adults (67-83 years) followed up annually in the 4-year Québec Longitudinal Study on Nutrition and Aging, who were free of depression and cognitive impairment at baseline. Participants (n 158, 64·4 % female) who became depressed and had data available for all follow-up years were matched by age group and sex with non-depressed participants. General linear mixed models were adjusted for percentage changes in physical activity, functional autonomy and stressful life events reported at the time of positive screening. A significant group effect for the dietary intake of all three B-vitamins was observed, as depression cases had consistently lower dietary intakes than controls (P<0·01). Over time, intakes of dietary vitamin B12 declined within depressed participants in bivariate analysis, but there was no time×group effect for any nutrient tested in the multivariate analyses. Intakes of energy, protein, saturated fat and total dietary fibre did not change in cases v. CONTROLS: Among community-dwelling older adults, declines in dietary vitamins B6, B12 and folate may precede depression incidence. To help preventative efforts by programmes and practitioners, longitudinal cohorts of longer duration should investigate the extent of the decline in dietary intakes relative to the time of depression.

Relationships between physical activity across lifetime and health outcomes in older adults: Results from the NuAge cohort.

This study aims to (1) describe participation in four physical activity (PA) domains across life and (2) examine the influence of PA during adolescence, early, middle, and later adulthood on health variables at older age. This observational study was conducted in 1378 generally healthy older adults (age 67-84 at baseline in 2003-2005; 52% women) in Quebec, Canada. Using a modified version of the interviewer-administered Lifetime Total Physical Activity Questionnaire (LTPAQ) and life events calendar to facilitate the recall, participants reported the frequency, duration, and intensity of occupational (OPA), commuting (CPA), household (HPA), and leisure time (LTPA) they participated in at age 15, 25, 45, and 65, and at the first follow-up (age 68-85 in 2005-2006). Fat mass, lean body mass, body mass index, waist-to-hip ratio, fasting glucose, systolic and diastolic blood pressures, self-reported chronic diseases, and socio-demographic data were assessed at baseline. Changes in PA over time differed by sex in each domain. However, there was a general decline in all PA domains in both sexes after age 65. In multiple regression analyses, LTPA at first-follow-up was associated with more favourable waist-to-hip ratio in both sexes, fat mass in women and fat mass percentage in men, whereas CPA, OPA, and HPA across life were not consistently associated with health variables. Older adults' LTPA at first follow-up was related to health variables, but PA recalled during adolescence, early adulthood, and mid-life was not. Results support the idea that current PA is positively related to better health outcomes.

Energy and protein intakes and their association with a decline in functional capacity among diabetic older adults from the NuAge cohort.

PURPOSE: Diabetic older adults (OA) are at greater risk of muscle strength (MS) loss and functional capacity (FC) decline than non-diabetics. Protein and energy intakes are important determinants of muscle mass and MS maintenance and indirectly affect FC. The study sought to determine whether low protein and energy intakes were associated with FC decline and whether this association was mediated by MS in diabetic OA over a 3-year follow-up, in secondary analyses of the Quebec Longitudinal Study on Nutrition and Successful Aging. METHODS: In 172 diabetic OA (62 % men, mean age = 75 years), FC decline was defined as the change between SMAF (Système de Mesure de l'Autonomie Fonctionnelle) scores at baseline (T1) and 3 years later (T4). Baseline adequate protein and energy intakes were set at ≥1 g/kg BW and ≥30 kcal/kg BW, respectively. Sex-stratified linear regressions were controlled for confounding variables. RESULTS: Mean body weight (BW) was 85.42 ± 13.8 in men and 79.7 ± 11.5 in women (p ≤ .001). Adequate protein intake in women was associated with lesser FC decline (mean ± SE) (2.11 ± 0.81 vs. 4.91 ± 0.72; p = .029), while adequate energy intake was not associated with FC decline either in men or in women. In women, 1 g protein/kg BW helped maintain MS, hence minimizing FC decline. CONCLUSIONS: These results demonstrate that protein intake is important in maintaining FC in diabetic OA, albeit with sex differences. This study provides further evidence that protein requirements may be greater than the 0.8 g/kg BW currently recommended for OA. Future research in larger samples over longer follow-up is needed to confirm these results.

Individual and collective factors predicting change in diet quality over 3 years in a subset of older men and women from the NuAge cohort.

PURPOSE: This study examined individual and collective factors as predictors of change in global diet quality (DQ). METHODS: Subjects were 373 older adults (57 % female) aged 68-82 years at recruitment (T1) into the NuAge Cohort Study, and followed for three years. Data were collected by questionnaires, physical performance tests and anthropometric measurements. Diet was assessed at T1 and T4 using three non-consecutive 24-h diet recalls (24HR) and DQ (Canadian Healthy Eating Index), and was computed on the means of the 24HR. DQ change over three years was determined as "DQT4-DQT1". Baseline (T1) measures significantly correlated with DQ at T1 were entered into backward stepwise linear regression analyses along with selected theoretical constructs and controlled for baseline DQ to determine predictors of change in DQ over 3 years. RESULTS: Among men, education (p = .009) and sensations of hunger (p = .01) were positive predictors of DQ change over time, while DQ at T1 (p < .0001), cognition (p = .003) and social network (p = .019) were negative predictors (adjusted R (2) = 30.4 %). Finally, among women, diet knowledge (p = .044) was a positive predictor of DQ change, while DQ at T1 (p < .0001) and social network (p = .033) were negative predictors of DQ change over 3 years (adjusted R (2) = 24.1 %). CONCLUSIONS: These results can inform dietary intervention programmes targeting gender-specific determinants of diet quality in older adults.

A scoping review of anorexia of aging correlates and their relevance to population health interventions.

Anorexia of aging (AA, i.e., loss of appetite and/or reduction of food intake with aging) is an important public health issue. It leads to unintentional weight loss, which is an independent risk factor for morbidity and mortality among seniors. AA has mainly been studied from a biological perspective and regarded as a normal physiological consequence of aging, rather than a negative health outcome with underlying determinants. Some potentially modifiable correlates have however been found to be associated with this geriatric condition. Here, we conducted a scoping review of the literature to: 1) identify AA correlates, and 2) discuss their relevance to population health interventions. Our results indicate two main categories of AA correlates, namely, physiopathological and non-physiopathological. The first category relates to physiological dysfunctions, pathologies involving (or culminating in) biomarker dysregulation, and polypharmacy. These correlates are difficult to modify, especially through population health interventions. The second category, which contains fewer correlates, includes potentially modifiable public health targets, such as food-related properties, psychological, sociocultural, and environmental issues. We conclude that there are several AA correlates. Some of them are modifiable and could be targeted for development and implementation as appropriate population health interventions to prevent appetite loss and promote maintenance of adequate food intake in aging.