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.

Reduction in targeted potentially inappropriate medication use in elderly inpatients: a pragmatic randomized controlled trial.

PURPOSE: The use of potentially inappropriate medications (PIMs) in hospitalized older adults is a complex problem, but the use of computerized alert systems (CAS) has shown some potential. The study's objective is to assess the change in PIM use with a CAS-based pharmacist-physician intervention model compared to usual clinical care. METHODS: Pragmatic single-site randomized controlled trial was conducted at a university teaching hospital. Hospitalizations identified with selected Beers or STOPP criteria were randomized to usual clinical care or to the CAS-based pharmacist-physician intervention. The primary outcome was PIM drug cessation or dosage decrease. Clinical relevance of the CAS alerts was assessed. RESULTS: Analyses included 231 patients who had 128 and 126 hospitalizations in the control and intervention groups, respectively. Patients had a mean age of 81, and 60% were female. In the intervention compared to the control group, drug cessation or dosage decrease were more frequent at 48 h post-alert (45.8 vs 15.9%; absolute difference 30.0%; 95%CI 13.8 to 46.1%) and at discharge from the hospital (48.1 vs 27.3%; absolute difference 20.8%; 95%CI 4.6 to 37.0%). In a post hoc analysis of all alerts, regardless of their clinical relevance, the absolute difference in drug cessation or dosage decrease between the intervention and control groups was 16.2% (95%CI 2.9 to 29.6%) at 48 h and 8.0% (95%CI -4.0 to 20.0%) at discharge from the hospital. CONCLUSIONS: In hospitalized older adults, a CAS-based pharmacist-physician intervention, compared to usual clinical care, resulted in significant higher number of drug cessation and dosage reductions for targeted PIMs.

Comparison of Standardization Methods for the Harmonization of Phenotype Data: An Application to Cognitive Measures.

Standardization procedures are commonly used to combine phenotype data that were measured using different instruments, but there is little information on how the choice of standardization method influences pooled estimates and heterogeneity. Heterogeneity is of key importance in meta-analyses of observational studies because it affects the statistical models used and the decision of whether or not it is appropriate to calculate a pooled estimate of effect. Using 2-stage individual participant data analyses, we compared 2 common methods of standardization, T-scores and category-centered scores, to create combinable memory scores using cross-sectional data from 3 Canadian population-based studies (the Canadian Study on Health and Aging (1991-1992), the Canadian Community Health Survey on Healthy Aging (2008-2009), and the Quebec Longitudinal Study on Nutrition and Aging (2004-2005)). A simulation was then conducted to assess the influence of varying the following items across population-based studies: 1) effect size, 2) distribution of confounders, and 3) the relationship between confounders and the outcome. We found that pooled estimates based on the unadjusted category-centered scores tended to be larger than those based on the T-scores, although the differences were negligible when adjusted scores were used, and that most individual participant data meta-analyses identified significant heterogeneity. The results of the simulation suggested that in terms of heterogeneity, the method of standardization played a smaller role than did different effect sizes across populations and differential confounding of the outcome measure across studies. Although there was general consistency between the 2 types of standardization methods, the simulations identified a number of sources of heterogeneity, some of which are not the usual sources considered by researchers.

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.

Understanding the role of contrasting urban contexts in healthy aging: an international cohort study using wearable sensor devices (the CURHA study protocol).

BACKGROUND: Given the challenges of aging populations, calls have been issued for more sustainable urban re-development and implementation of local solutions to address global environmental and healthy aging issues. However, few studies have considered older adults' daily mobility to better understand how local built and social environments may contribute to healthy aging. Meanwhile, wearable sensors and interactive map-based applications offer novel means for gathering information on people's mobility, levels of physical activity, or social network structure. Combining such data with classical questionnaires on well-being, physical activity, perceived environments and qualitative assessment of experience of places opens new opportunities to assess the complex interplay between individuals and environments. In line with current gaps and novel analytical capabilities, this research proposes an international research agenda to collect and analyse detailed data on daily mobility, social networks and health outcomes among older adults using interactive web-based questionnaires and wearable sensors. METHODS/DESIGN: Our study resorts to a battery of innovative data collection methods including use of a novel multisensor device for collection of location and physical activity, interactive map-based questionnaires on regular destinations and social networks, and qualitative assessment of experience of places. This rich data will allow advanced quantitative and qualitative analyses in the aim to disentangle the complex people-environment interactions linking urban local contexts to healthy aging, with a focus on active living, social networks and participation, and well-being. DISCUSSION: This project will generate evidence about what characteristics of urban environments relate to active mobility, social participation, and well-being, three important dimensions of healthy aging. It also sets the basis for an international research agenda on built environment and healthy aging based on a shared and comprehensive data collection protocol.

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.

Inflammation and Fat Mass as Determinants of Changes in Physical Capacity and Mobility in Older Adults Displaying A Large Variability in Body Composition: The NuAge Study.

Background/Study context: Determining whether C-reactive protein (CRP), blood lipids, total and trunk fat mass (FM), and waist circumference (WC) are associated with changes in physical capacity over 3 years (Δ) in elderly. METHODS: One hundred twenty-two men and women 68-83 years of age participated in a 3-year follow-up study. Physical capacity was measured using five objective tests: (1) Timed Up and Go (TUG), (2) chair stand (CS), (3) normal walking speed (NWS), (4) fast walking speed (FWS), and (5) one-leg stand (LS), along with physical performance score (PPS) at baseline (T1) and 3 years later (T4). Total and trunk FM, WC, blood lipids, and CRP measured at baseline, were considered as potential predictors. RESULTS: At baseline, CRP and total FM were significantly correlated with all physical capacity tests, whereas trunk FM was correlated with CS and LS, and blood lipids only with FSW. No significant correlation was observed for WC. Total and trunk FM measured at baseline were correlated with ΔTUG and ΔPPS, whereas trunk FM and WC measured at baseline were correlated with ΔNWS. CRP and blood lipids, measured at baseline, were not associated with any changes over 3 years. At the end, WC measured at baseline was the strongest independent predictor for all physical capacity measures at baseline (T1), and ΔPPS measured over 3 years could be predicted by baseline WC. CONCLUSION: FM distribution seems more useful to determine physical capacity than inflammation. Interestingly, over a short follow-up of 3 years, WC significantly predicted changes in a composite score of physical activity. More studies are needed to elucidate factors that may influence physical capacity decline over time.

Environmental Factors Associated With Social Participation of Older Adults Living in Metropolitan, Urban, and Rural Areas: The NuAge Study.

OBJECTIVES: We compared the social participation of older adults living in metropolitan, urban, and rural areas, and identified associated environmental factors. METHODS: From 2004 to 2006, we conducted a cross-sectional study using an age-, gender-, and area-stratified random sample of 1198 adults (aged 67-82 years). We collected data via interviewer-administered questionnaires and derived from Canadian censuses. RESULTS: Social participation did not differ across living areas (P = .09), but after controlling for potential confounding variables, we identified associated area-specific environmental variables. In metropolitan areas, higher social participation was associated with greater proximity to neighborhood resources, having a driver's license, transit use, and better quality social network (R(2) = 0.18). In urban areas, higher social participation was associated with greater proximity to neighborhood resources and having a driver's license (R(2) = 0.11). Finally, in rural areas, higher social participation was associated with greater accessibility to key resources, having a driver's license, children living in the neighborhood, and more years lived in the current dwelling (R(2) = 0.18). CONCLUSIONS: To enhance social participation of older adults, public health interventions need to address different environmental factors according to living areas.

Factors associated with nutritional decline in hospitalised medical and surgical patients admitted for 7 d or more: a prospective cohort study.

This prospective cohort study was conducted in eighteen Canadian hospitals with the aim of examining factors associated with nutritional decline in medical and surgical patients. Nutritional decline was defined based on subjective global assessment (SGA) performed at admission and discharge. Data were collected on demographics, medical information, food intake and patients' satisfaction with nutrition care and meals during hospitalisation; 424 long-stay (≥7 d) patients were included; 38% of them had surgery; 51% were malnourished at admission (SGA B or C); 37% had in-hospital changes in SGA; 19·6% deteriorated (14·6% from SGA A to B/C and 5% from SGA B to C); 17·4% improved (10·6% from SGA B to A, 6·8% from SGA C to B/A); and 63·0 % patients were stable (34·4% were SGA A, 21·3% SGA B, 7·3% SGA C). One SGA C patient had weight loss ≥5%, likely due to fluid loss and was designated as stable. A subset of 364 patients with admission SGA A and B was included in the multiple logistic regression models to determine factors associated with nutritional decline. After controlling for SGA at admission and the presence of a surgical procedure, lower admission BMI, cancer, two or more diagnostic categories, new in-hospital infection, reduced food intake, dissatisfaction with food quality and illness affecting food intake were factors significantly associated with nutritional decline in medical patients. For surgical patients, only male sex was associated with nutritional decline. Factors associated with nutritional decline are different in medical and surgical patients. Identifying these factors may assist nutritional care.

Protein intake protects against weight loss in healthy community-dwelling older adults.

Weight loss is prevalent in the elderly population, with deleterious health consequences, notably loss of lean body mass and subsequent functional decline. Protein intake below the current RDA [0.8 g/(kg · d)] is also common in older adults; however, the link between the 2 has received little attention. Our objective was to assess the relation between protein intake and incident 1-y weight loss ≥5% in community-dwelling older adults. We conducted a nested, prospective, case-control study in 1793 community-living elderly participants of the Quebec Longitudinal Study of Nutrition as a Determinant of Successful Aging (NuAge). We studied 211 incident cases of 1-y weight loss (≥5%) and 211 weight-stable controls (±2%) matched by sex and age category (70 ± 2, 75 ± 2, and 80 ± 2 y). Diet was measured by 3 nonconsecutive 24-h recalls. ORs (95% CIs) for the association between protein intake and weight loss were computed by using conditional logistic regression. After adjustment for body mass index, energy intake, appetite, smoking status, physical activity level, physical function, chronic diseases and medications, depressive symptoms, and serum albumin and ultrasensitive C-reactive protein, the ORs of weight loss in participants with low protein intakes [<0.8 g/(kg · d)] were 2.56 (95% CI: 1.01, 6.50) compared with participants with very high protein intakes [≥1.2 g/(kg · d)]. Corresponding numbers were 2.15 (95% CI: 1.02, 4.56) in participants with moderate protein intakes [0.8-<1.0 g/(kg · d)] and 1.33 (95% CI: 0.77, 2.28) in participants with high protein intakes [1.0-1.2 g/(kg · d)]. Our results suggest that protein intakes >1.0 g/(kg · d) are protective against weight loss in healthy older adults. These findings add epidemiologic evidence in support of higher optimal protein intakes than the current guidelines for healthy older adults.

Relationship between diet quality and cognition depends on socioeconomic position in healthy older adults.

Both diet quality and socioeconomic position (SEP) have been linked to age-related cognitive changes, but there is little understanding of how the socioeconomic context of dietary intake may shape its cognitive impact. We examined whether equal adherence to "prudent" and "Western" dietary patterns, identified by principal components analysis, was associated with global cognitive function [Modified Mini-Mental State Examination (3MS)] in independently living older adults with different SEPs (aged 68-84 y; n = 1099). The interaction of dietary pattern adherence with household income, educational attainment, occupational prestige, and a composite indicator of SEP combining all 3 was examined in multiple-adjusted mixed models over 3 y of follow-up in participants of the NuAge study (Quebec Longitudinal Study on Nutrition and Successful Aging). Adherence to the prudent pattern (vegetables, fruits, fish, poultry, and lower-fat dairy products) was related to higher 3MS scores at recruitment only in the upper categories of income [parameter estimate (B): 0.56; 95% CI: 0.11, 1.01], education (B: 0.44; 95% CI: 0.080, 0.80), or composite SEP (B: 0.37; 95% CI: 0.045, 0.70). High prudent pattern adherence was associated with less cognitive decline only in those with low composite SEP (B: 0.25; 95% CI: 0.0094, 0.50). Conversely, adherence to the Western pattern (meats, potatoes, processed foods, and higher-fat dairy products) was associated with more cognitive decline (B: -0.23; 95% CI: -0.43, -0.032) only in those with low educational attainment. In summary, among individuals with equivalent diet quality, the magnitude and characteristics of the diet-cognition relationship depended on their socioeconomic circumstances. These results suggest that interventions promoting retention of cognitive function through improved diet quality would provide maximum benefit to those with relatively low SEP.

Comparison of two indices of availability of fruits/vegetable and fast food outlets.

Studies of food environment often examine single dimensions of areas that may not account for complexity of exposure to all food sources. With respect to the deprivation amplification hypothesis, particular needs are to assess whether relative or absolute measures of the food environment are related to characteristics of social environment. The objective of this study was to compare absolute availability (AA) of fast food outlets (FFO) and stores selling fresh fruits and vegetables (FVS) with the relative availability (RA) of the same food sources in relation to area-level poverty and ethnic diversity in 248 selected census tracts (CT) in Montreal, Canada. AA of FFO and FVS were expressed as areal densities of food sources within CTs. RA indices were calculated as the proportion of FVSs relative to total food stores and the proportion of FFOs relative to all restaurants within CTs, respectively. Whereas the AA of FFO was positively associated with area-level poverty and ethnic diversity, the RA of FFO was inversely associated with area-level poverty and not associated with ethnic diversity. Both measures of FVS were positively associated with area-level poverty and ethnic diversity. These findings do not support a model of deprivation amplification. Furthermore, results of FFO suggest that the alternate measure of RA can complement information based on AA indicators of the food environment, with potential utility in predicting eating practices.

A single measurement of serum phylloquinone is an adequate indicator of long-term phylloquinone exposure in healthy older adults.

Assessment of long-term phylloquinone exposure is challenging in studies investigating vitamin K in health. Data are equivocal as to whether a single measurement of circulating phylloquinone would be adequate. The primary purpose of the present study was to validate the use of a single measurement of serum phylloquinone as a surrogate for long-term phylloquinone exposure in healthy older adults. Using data from the Québec Longitudinal Study on Nutrition and Successful Aging, the objectives were to: 1) determine the reproducibility of circulating phylloquinone over 2 y (n = 234); 2) calculate how a single measurement would rank or classify individuals and attenuate the regression coefficient between circulating phylloquinone and a health outcome; and 3) investigate the association of a single measurement of serum phylloquinone with long-term phylloquinone intakes assessed over the year prior to the blood draw (n = 228). The variance analysis based on 2 blood samples showed a fair to good reproducibility for serum phylloquinone (intra-class correlation = 0.49). The correlation coefficient between the ranking of individuals based on a single measurement of circulating phylloquinone and the "true" ranking would be 0.70. The multiple regression analysis showed that long-term phylloquinone intake was the strongest predictor of serum phylloquinone (t = 4.94; P < 0.001). The partial correlation coefficient (r = 0.32) was comparable with those reported in studies where blood sampling and diet recording were juxtaposed and/or multiple blood samples were used. The present study provides evidence that the use of a single measurement of circulating phylloquinone is adequate for assessing long-term phylloquinone exposure in healthy older adults.

Associations between residential food environment and dietary patterns in urban-dwelling older adults: results from the VoisiNuAge study.

OBJECTIVE: To examine associations between the availability of residential-area food sources and dietary patterns among seniors. DESIGN: Cross-sectional analyses. Individual-level data from the NuAge study on nutrition and healthy ageing were merged with geographic information system data on food store availability and area-level social composition. Two dietary patterns reflecting lower- and higher-quality diets (respectively designated 'western' and 'prudent') were identified from FFQ data. Two food source relative availability measures were calculated for a 500 m road-network buffer around participants' homes: (i) proportion of fast-food outlets (%FFO) relative to all restaurants and (ii) proportion of stores potentially selling healthful foods (%HFS, healthful food stores) relative to all food stores. Associations between dietary patterns and food source exposure were tested in linear regression models accounting for individual (health and sociodemographic) and area-level (socio-economic and ethnicity) covariates. SETTING: Montréal metropolitan area, Canada. SUBJECTS: Urban-dwelling older adults (n 751), aged 68 to 84 years. RESULTS: %FFO was inversely associated with prudent diet (ß = -0·105; P < 0·05) and this association remained statistically significant in models accounting for %HFS. %HFS was inversely associated with lower western diet scores (ß = -0·124; P < 0·01). This latter association no longer reached significance once models were adjusted for area-level covariates. CONCLUSIONS: In Montréal, the food environment is related to the diet of older adults but these links are more complex than straightforward. The absence of significant relationships between healthful food stores and prudent diets, and between fast-food outlets and western diets, deserves further investigation.

Dietary resilience as described by older community-dwelling adults from the NuAge study "if there is a will -there is a way!".

Many older adults experience age-related changes that can have negative consequences for food intake. Some older adults continue to eat well despite these challenges showing dietary resilience. We aimed to describe the strategies used by older adults to overcome dietary obstacles and to explore the key themes of dietary resilience. The sample was drawn from the five-year Québec Longitudinal Study "NuAge". It included 30 participants (80% female) aged 73-87 years; 10 with decreased diet quality and 20 with steady or increased diet quality; all had faced key barriers to eating well. Semi-structured interviews explored how age-related changes affected participants' experiences with eating. Thematic analysis revealed strategies used to overcome eating, shopping, and meal preparation difficulties. Key themes of dietary resilience were: prioritizing eating well, doing whatever it takes to keep eating well, being able to do it yourself, getting help when you need it. Implications for health professionals are discussed.

A minimum of six days of diet recording is needed to assess usual vitamin K intake among older adults.

There is a growing interest in the role of vitamin K in health, especially in aging populations. Knowledge of inter- and intra-individual variability of dietary vitamin K intake could be useful to accurately assess usual intake and rank participants in epidemiological studies. Our objectives were to: 1) estimate the variance components of vitamin K intake; 2) investigate whether day of the week, season, and energy intake are factors related to intra-individual variance; and 3) calculate the requisite number of days to achieve desired degrees of accuracy for estimating individual vitamin K intake, ranking individuals and estimating regression coefficient. Vitamin K intake was assessed in 939 older adults (67-84 y) enrolled in the Québec Longitudinal Study on Nutrition and Successful Aging study using 2 sets of 3 nonconsecutive multiple-pass 24-h dietary recalls (24HR) collected 6 mo apart. Each set included 2 weekdays and one weekend day. Intra- to inter-individual variance ratios for vitamin K intake were 3.2 (95% CI = 2.6-3.9) overall, 2.6 (95% CI = 2.1-3.5) for men, and 3.7 (95% CI = 2.9-5.0) for women. Day of the week (weekdays) and season (May to October) were positively and significantly associated with vitamin K intake but explained a negligible part of intra-individual variation (<1%). Adjusting for energy intake explained <7% of variance and did not affect the variance ratio. Six to 13 24HR are required to properly rank individuals according to their usual vitamin K intake and limit attenuation of the regression coefficient. These results should be considered in studies planning to assess vitamin K intakes in older adults.

Longitudinal evidence on the association between interleukin-6 and C-reactive protein with the loss of total appendicular skeletal muscle in free-living older men and women.

BACKGROUND: there is no longitudinal evidence about the association between the loss of total appendicular skeletal muscle (TASM) and cytokines. OBJECTIVE: to investigate whether high levels of the inflammatory markers such as interleukin-6 (IL-6) and C-reactive protein (CRP) are associated with the loss of TASM in free-living non-sarcopenic older people. DESIGN: five-year prospective cohort study. SUBJECTS: one hundred and fifteen free-living non-sarcopenic older men and women aged 60-84 years at baseline and 5-year follow-up were included. METHODS: TASM was measured by dual-energy X-ray absorptiometry, and the relative change in TASM was calculated. The response variable was the loss of TASM defined as the lowest sex-specific 15th percentile of the cohort distribution of percentage of change in TASM. The exposure variables were the baseline serum IL-6 and CRP levels measured by ELISA. RESULTS: sixteen subjects were below the sex-specific 15th percentile of the cohort. The mean absolute loss of TASM in these men and women subjects was 1.9 and 1.3 kg, respectively. The risk of loss TASM was 1.29 times higher (95% confidence interval [CI], 1.01-1.64) (P = 0.03) per unit of increase in IL-6 (pg/ml) and 1.28 times higher (95% CI, 1.04-1.58) (P = 0.01) per unit of increase in CRP (mg/l). As a categorical variable, the risk of loss TASM was 4.85 times higher (95% CI, 1.24-18.97) among subjects with serum IL-6 >2.71 pg/ml and 3.97 times higher (CI 95%, 1.09-14.39) among subjects with serum CRP >3.74 mg/l. These findings remained after adjusting for age, sex and 5-year weight change. CONCLUSIONS: inflammation is associated with the loss of TASM in free-living non-sarcopenic older men and women.