Vitamin K status and inflammation are associated with cognition in older Irish adults.

Studies have shown associations between reduced vitamin K status and poor cognitive function. However, despite this apparent link, direct studies measuring cognitive function, vitamin K status and inflammation are lacking. In the current study, The ELDERMET cohort was investigated to identify associations between cognition, vitamin K status and inflammation. The primary aim of the ELDERMET study was to investigate the relationship between gut bacteria, diet, lifestyle and health in 500 older Irish adults. Significant differences in serum phylloquinone, dietary phylloquinone and inflammatory markers were found across varying levels of cognitive function, after controlling for sex, age, body mass index (BMI), triglycerides and blood pressure. In addition, significantly higher levels of dietary phylloquinone were found in those with better cognition compared to those with the poorest function. Higher levels of inflammatory were also associated with poor cognition. Furthermore, both dietary and serum phylloquinone were significant independent predictors of good cognitive function, after controlling for confounders. This study highlights the importance of dietary vitamin K as a potentially protective cognitive factor; it also provides evidence for the correlation between cognition and inflammation. Strategies should be devised by which elderly populations can access rich dietary sources of phylloquinone to maintain cognition.

The impact of recent advances in laboratory astrophysics on our understanding of the cosmos.

An emerging theme in modern astrophysics is the connection between astronomical observations and the underlying physical phenomena that drive our cosmos. Both the mechanisms responsible for the observed astrophysical phenomena and the tools used to probe such phenomena-the radiation and particle spectra we observe-have their roots in atomic, molecular, condensed matter, plasma, nuclear and particle physics. Chemistry is implicitly included in both molecular and condensed matter physics. This connection is the theme of the present report, which provides a broad, though non-exhaustive, overview of progress in our understanding of the cosmos resulting from recent theoretical and experimental advances in what is commonly called laboratory astrophysics. This work, carried out by a diverse community of laboratory astrophysicists, is increasingly important as astrophysics transitions into an era of precise measurement and high fidelity modeling.

Feasibility and preliminary efficacy of the LEAD trial: a cluster randomized controlled lifestyle intervention to improve hippocampal volume in older adults at-risk for dementia.

BACKGROUND: Healthy diet and exercise are associated with reduced risk of dementia in older adults. The impact of diet and exercise interventions on brain health is less consistent, especially with dietary interventions which rely on varying approaches. Our objective was to evaluate the feasibility and preliminary efficacy of a 6-month intervention combining exercise with a novel dietary counseling approach to improve hippocampal volume among older adults at-risk for dementia. METHODS: Participants with vascular risk factors and subjective cognitive decline or early mild cognitive impairment were cluster randomized in groups of 3-4 to the diet intervention (DIET) or control education (ED) group. All participants engaged in 1 h of supervised exercise per week and additional exercise at home. DIET involved 1 h per week of group-based dietary counseling comprising education, goal setting, and strategy training. ED involved 1 h per week of group-based brain health education classes. Our primary outcome was change in hippocampal volume from baseline to 6 months. Secondary outcomes included changes in cognitive function, blood biomarkers, diet, and fitness. Recruitment challenges and early discontinuation of the trial due to COVID-19 necessitated a revised focus on feasibility and preliminary efficacy. RESULTS: Of 190 older adults contacted, 14 (7%) were eligible and enrolled, constituting 21% of our recruitment target. All participants completed the intervention and attended 90% of exercise and DIET/ED sessions on average. All 6-month assessments prior to COVID-19 were completed but disruptions to in-person testing resulted in incomplete data collection. No serious adverse events occurred and all participants expressed positive feedback about the study. Preliminary findings did not identify any significant changes in hippocampal volume; however, substantial improvements in diet and HbA1c were observed with DIET compared to ED (d = 1.75 and 1.07, respectively). CONCLUSIONS: High adherence and retention rates were observed among participants and preliminary findings illustrate improvements in diet quality and HbA1c. These results indicate that a larger trial is feasible if difficulties surrounding recruitment can be mitigated. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03056508 .

Cerebrovascular hemodynamic correlates of aging in the Lou/c rat: a model of healthy aging.

The LOU/c rat is an inbred strain considered a model of healthy aging. It exhibits a longer free disease lifespan and a low adiposity throughout life. While this animal model has been shown to maintain eating behavior and neuroendocrine, metabolic and cognitive functions with age, no study has yet investigated vascular correlates in this model of healthy aging. In the present work, multispectral optical imaging was used to investigate the hemodynamic response in the somatosensory cortex of LOU/c rats following forepaw stimulation in three age groups, 4, 24 and 40months. Results indicate reduced hemodynamic responses in the contralateral somatosensory cortex between young (4months) and older groups following stimulation. This decrease was associated with an increase in the spatial extent of activation. The ipsilateral response did not change with aging leading to decreased laterality. Estimations of the relative change in the local cerebral metabolic rate of oxygen during stimulation based on multimodal data showed no significant change with age. The exponent describing the relation between blood volume and blood flow changes, Grubb's parameter, did display a significant change with age which may suggest vessel compliance modifications. This work finds its relevance in recent findings underlying the importance of vascular changes with aging and its impact on neurodegenerative disease.

Biophysical model estimation of neurovascular parameters in a rat model of healthy aging.

Neuronal, vascular and metabolic factors result in a deterioration of the cerebral hemodynamic response with age. The interpretation of neuroimaging studies in the context of aging is rendered difficult due to the challenge in untangling the composite effect of these modifications. In this work we integrate multimodal optical imaging in biophysical models to investigate vascular and metabolic changes occurring in aging. Multispectral intrinsic optical imaging of an animal model of healthy aging, the LOU/c rat, is used in combination with somatosensory stimulation to study the modifications of the hemodynamic response with increasing age. Results are fitted with three macroscopic biophysical models to extract parameters, providing a phenomenological description of vascular and metabolic changes. Our results show that 1) biophysical parameters are estimable from multimodal data and 2) parameter estimates in this population change with aging.

The evolution of nutritional status of geriatric patients without cachexia is associated with food intake in sub-acute care.

OBJECTIVES: To determine if changes in patients' nutritional status during hospitalization are related to daily energy and protein intakes when cachectic/inflammatory conditions are controlled for. DESIGN: Prospective study. SUBJECTS: A total of 32 non-cachectic patients (21 women; 65-92 y). METHODS: Nutritional status was evaluated at admission and discharge using the Protein-Energy Malnutrition Index which includes BMI, %IBW, TS, MAC, albumin, hemoglobin and lymphocyte count. Food intake was assessed 3 meals/day every other day for an average of 46.2 +/- 14.6 meals/participant. RESULTS: In all, 47% of the study sample was malnourished at admission. Nutritional status improved in 73% of patients who had been identified as malnourished and in 30 % of non-malnourished patients at admission. Total energy intake correlated with improvements in BMI, %IBW and total lymphocyte count (all p < 0.04). Improvement in PEMI score for the whole group was associated with functional status (p < 0.05). Controlling for this variable, energy (kj/kg body weight) and protein (g/kg body weight) intakes correlated positively with improvements in BMI, %IBW and MAC (Energy: partial r = 0.644, 0.624, 0.466 respectively; Protein: partial r = 0.582, 0.554, 0.433 respectively; all p < 0.05). CONCLUSIONS: Results from this study offer strong evidence that when cachectic/inflammatory conditions are controlled for, standard nutrition care is compatible with the maintenance or improvement of nutritional status during the hospital stay.

Production of photoionized plasmas in the laboratory with x-ray line radiation.

In this paper we report the experimental implementation of a theoretically proposed technique for creating a photoionized plasma in the laboratory using x-ray line radiation. Using a Sn laser plasma to irradiate an Ar gas target, the photoionization parameter, ξ=4πF/N_{e}, reached values of order 50ergcms^{-1}, where F is the radiation flux in ergcm^{-2}s^{-1}. The significance of this is that this technique allows us to mimic effective spectral radiation temperatures in excess of 1 keV. We show that our plasma starts to be collisionally dominated before the peak of the x-ray drive. However, the technique is extendable to higher-energy laser systems to create plasmas with parameters relevant to benchmarking codes used to model astrophysical objects.

Dietary induced subclinical vitamin K deficiency in normal human subjects.

A subclinical vitamin K deficiency was induced in 32 healthy subjects (four groups of eight males and females) aged 20-40 and 60-80 yr residing in the Metabolic Research Unit of the Human Nutrition Research Center on Aging at Tufts University. Volunteers were initially fed (4 d) a baseline-period diet containing the recommended daily allowance for vitamin K which is equivalent to 80 micrograms/d of phylloquinone (vitamin K1). During the baseline period various parameters of vitamin K nutritional status were monitored. The baseline period was followed by a 13-d depletion period during which the subjects were fed a very low vitamin K1 diet (approximately 10 micrograms/d). After depletion, the subjects entered a 16-d repletion period (four stages lasting 4 d each) during which time they were repleted with 5, 15, 25, and 45 micrograms of vitamin K1 per day. Vitamin K1 depletion dramatically and significantly decreased plasma vitamin K1 levels (P < 0.0001) in both elderly and young groups to values 13-18% of day 1 (elderly 0.22 nM, young 0.14 nM). Repleting the subjects with up to 45 micrograms of vitamin K1 per day failed, in the case of the young subjects, to bring plasma vitamin K1 levels back into the normal range. Dietary vitamin K1 restriction induced different responses in the urinary excretion of gamma-carboxyglutamic acid between the young and the elderly subjects with values decreasing significantly (P < 0.03) in the young while remaining unchanged in the elderly. The vitamin K1 depletion period had no significant effect on either prothrombin and activated partial thromboplastin times, or Factor VII and protein C (as determined by antigenic and functional assays). By using a monoclonal antibody, decarboxy prothrombin was found to increase slightly but significantly in both groups (P < 0.05) as a consequence of the low vitamin K1 diet. This study clearly shows that a diet low in vitamin K1 can result in a functional subclinical deficiency of vitamin K (decreased urinary gamma-carboxyglutamic acid excretion) without affecting blood coagulation.

Nutritional implications of patient-provider interactions in hospital settings: evidence from a within-subject assessment of mealtime exchanges and food intake in elderly patients.

OBJECTIVE: To examine the nutritional implications of the interactions taking place between patients and care providers during mealtimes in hospital settings. Specifically, we tested research propositions that the amount and nature of interpersonal behaviours exchanged between patients and providers impact patients' food intake. These propositions were derived from prior evidence of social influences on eating behaviour and a well-established framework that identifies two fundamental modalities of human interaction: striving for mastery and power (agency) and efforts to promote union with others (communion). DESIGN: In a within-subject naturalistic study, participants were observed on multiple meals (n=1477, 46.2 meals/participant on average), during which participants' and providers' agency- and communion-related behaviours and patients' protein and energy intake were recorded. Meal-level frequency and complementarity of patients' and providers' behaviours were computed to test research propositions. SETTING: Dining room of a geriatric rehabilitation unit. SUBJECTS: Thirty-two elderly patients (21 females, mean age:78.8, 95% CI: 76.4, 81.1). RESULTS: Meal-level frequency of patient-provider exchanges (P=0.016) and patients' agency-related behaviours (P=0.029), as well as mutual reciprocation of patients' and providers' communion-related behaviours (P=0.015) on a given meal were positively linked to protein intake. Higher energy intake was found during meals where patients expressed more agency-related behaviours (P=0.029). CONCLUSION: Results present evidence that the amount and nature of patient-provider interpersonal exchanges on a given meal influence the nutritional quality of food intake in hospitalized elderly. They provide insights into how to improve the design and delivery of routine care to this malnutrition-prone population. SPONSORSHIP: This study was supported by the Canadian Institutes of Health Research (Operating grant to Laurette Dubé, Doctoral Fellowship to Catherine Paquet) the Fonds de la Recherche en santé du Québec and by the Danone Institute (Doctoral fellowship to Danielle St-Arnaud McKenzie).

Objective verification of dietary intake by measurement of urine osmolality.

A new method for assessing the accuracy of dietary nutrient intakes in metabolic studies is described. The theoretical basis of the method is the comparison of measurements of the urine osmole excretion rate (OER, the product of urine osmolality and urine weight) with values for OER predicted from dietary nitrogen, sodium, and potassium. The method was tested in 34 healthy male and female volunteers aged 18-78 y who made complete 24-h urine collections and consumed a diet over 6 d in metabolic-balance studies involving either overfeeding, weight maintenance, or weight loss. The coefficients of variation for equations relating measured OER to dietary nitrogen, sodium, and potassium intakes ranged from 14.1% for 1-d measurements to 6.94% for 6-d means. These results indicate that it should be possible to use measurements of the urine OER to identify dietary noncompliance in metabolic studies.

Effect of dietary restriction on lysosomal bodies and total protein synthesis in hepatocytes of aging rats.

The accumulation of lysosomal bodies has long been considered to be an important correlate of aging. However it is not well established whether these age related changes interfere with cellular function. In this study, an evaluation of lysosomes by ultrastructural analysis was performed in livers of 4-6 and 20-24-month-old Sprague-Dawley female rats, fed ad libitum (A) or a restricted diet (R). An attempt was made to relate this parameter to hepatic protein synthesis, a liver function known to decrease with age and increase with dietary restriction. Aging was accompanied in both A and R animals with higher number and size of secondary lysosomes (lipofuscin) and by a decrease in total protein synthesis in hepatocytes. When compared to age matched ad libitum fed animals, livers of food restricted rats contained higher number of secondary lysosomes, yet exhibited higher protein synthetic capacity. Thus in hepatocytes, lipofuscin accumulation does not seem to interfere with cellular function.

Characterization of liver lysosomal enzyme activity in hepatocytes, Kupffer and endothelial cells during aging: effect of dietary restriction.

The specific activity of 4 lysosomal enzymes was studied in homogenate, hepatocytes, Kupffer and endothelial cells isolated from the livers of female Sprague-Dawley rats aged 3.5, 12 and 24 months. Cells were obtained by enzymatic digestion and centrifugal elutriation. Cell viability was not affected by age or diet. In hepatocytes, the activities of all enzymes (acid phosphatase, beta-galactosidase, arylsulfatase B and cathepsin D) increased with age in rats fed ad libitum (A) but were not altered significantly by dietary restriction. The activities of all enzymes except acid phosphatase were systematically higher at 3.5 months of age in Kupffer and endothelial cells than in hepatocytes. Acid phosphatase, arylsulfatase B and cathepsin D activities increased with age in both Kupffer and endothelial cells. Beta galactosidase was decreased significantly with age in Kupffer cells but was elevated in endothelial cells. Rats exposed to dietary restriction (R) showed higher activities of beta-galactosidase, arylsulfatase B and cathepsin D when compared to corresponding A animals with the exception of the younger age group. No clear cut pattern was observed in acid phosphatase activity. Thus, the activities of liver lysosomal enzymes increase with age but the pattern of change differs with respect to enzyme and cell populations. The heightened enzyme activity in Kupffer and endothelial cells from R rats may reflect a more efficient phagocytic capacity in these animals.

The vitamin K-dependent proteins: an update.

Historically known for its role in blood coagulation, vitamin K also has been shown to be required for the physiologic activation of numerous proteins that are not involved in hemostasis. Over the last 20 years, vitamin K-dependent proteins have been isolated in bone, cartilage, kidney, atheromatous plaque, and numerous soft tissues. Although the precise mechanism of action of many of these proteins remains to be determined, their discovery has proven important from a physiologic point of view.

Dietary restriction influence bile formation in aging rats.

Food restriction is one of the most effective interventions which increases the survival of rodents and influences a variety of physiologic and pathologic processes. Thus, we examined whether life-long caloric restriction would influence bile formation, one of the important hepatic functions. Female Sprague Dawley rats were subjected soon after weaning to a restricted diet (60% of the diet consumed by the rats fed ad libitum) and bile formation determined at 3.5, 12 and 24 months of age. Rats had their bile ducts cannulated under nembutal anesthesia and bile collected at 10 min. intervals. Bile flow rate decreased 35% between 3.5 and 24 months of age. This decrease was associated with a reduction of the bile acid dependent fraction of bile flow (BADF) up to 12 months of age, thereafter the bile acid independent fraction (BAIF) also decreased. Phospholipid and cholesterol secretion rates increased with age, but did not correlate with bile acid secretion. In rats fed the restricted diet, bile flow was about 20% higher at 3-5 months of age when compared with the ad libitum fed group. This bile flow rate remained constant until 24 months of age. The increased bile flow was attributed to higher BADF and BAIF. The phospholipid and cholesterol secretion followed that of bile acids. It thus appears that dietary restriction exerts a beneficial effect on the age related decline in bile formation.

Absence of nutritional or clinical consequences of decentralized bulk food portioning in elderly nursing home residents with dementia in Montreal.

OBJECTIVES: To evaluate the nutritional and clinical consequences of changing from a centralized food delivery system to decentralized bulk food portioning; a system in which meal portioning occurs on residents' floors of a nursing home. DESIGN: A pilot study with a pre-post design SUBJECTS/SETTING: The study took place on one floor of a home for elderly persons with dementia. Of the 34 residents, 22 (1 man) participated in this study. Average age was 82 years (range = 55 to 94 years). Nutritional status was verified before introduction of the bulk food portioning system by 3 nonconsecutive days of observed food intakes, anthropometric measurements (height, weight, triceps skinfold thickness, mid-upper-arm circumference), and biochemical parameters (albumin, lymphocytes, glucose, sodium, potassium, transferrin, vitamin B-12, folate, hemoglobin). Trained dietitians collected the dietary and anthropometric data and validated the food intake estimates and anthropometric measurements. Data were also collected 10 weeks after implementation of the new food distribution system. STATISTICAL ANALYSES PERFORMED: Paired t tests adjusted by a Bonferroni correction assessed differences between values measured before and after introduction of the new food distribution system. RESULTS: Average food consumption increased substantially and significantly after introduction of the bulk food portioning system. Mean energy intakes rose from 1,555 to 1,924 kcal/day and most other nutrients also increased, many significantly, but there were no changes in anthropometric values or biochemical parameters, except for albumin level which decreased to the lower normal limit. APPLICATIONS: Portioning of food in the residents' dining room simulates a homelike atmosphere thereby encouraging increased food consumption. With well-trained and enthusiastic staff, this system could contribute to improved nutritional status in the very elderly, even those who have dementia. Dietitians have a key role to play in overseeing residents' nutritional needs and in training, supervising, and motivating foodservice personnel.

Development of a diet low in vitamin K-1 (phylloquinone).

As part of a metabolic study aimed at inducing a subclinical vitamin K deficiency in healthy adults, we designed a diet containing less than 10 micrograms/day of vitamin K-1 (phylloquinone). Two-day menus were constructed from a vitamin K-1 food database developed in our laboratory. This diet offers palatability and provides nutrient adequacy; that is, it meets the Recommended Dietary Allowances for protein and all other vitamins and minerals. An interesting feature of the diet is that the vitamin K-1 level can be kept very low while still fulfilling a large range of energy needs (1,800 to 3,400 kcal/day). The diet proved useful in altering apparent nutritional status for vitamin K-1; after ingestion of the diet for 6 days, plasma concentrations of vitamin K-1 decreased by 80% and fell below the established normal range. Given the well documented drug-nutrient interaction between vitamin K and warfarin--a vitamin K antagonist routinely used in the management of thromboembolic diseases--the dietary information presented in this report may provide useful information for patients undergoing warfarin therapy.

Effect of aging and dietary restriction on bile acid metabolism in rats.

The aim of the present study was to determine whether increased output of phospholipid in bile during aging may be due to alteration of bile acid composition and stimulated hydrophobic bile acid formation. In female Sprague-Dawley rats we examined the influence of aging and life long dietary restriction (60% of the ad libitum intake) on bile flow, total bile acid secretion, bile acid composition and conjugation pattern, as well as phospholipid output. Rats were cannulated at 3.5, 8-12 and 24-27 months of age and bile collected for analysis. With age, there was a significant reduction in bile flow and total bile acid secretion, however, phospholipid output increased. Restriction of dietary intake exerted a beneficial effect on the age-related decline in bile formation. Studies of bile composition indicated that 12 alpha-hydroxylated bile acids (cholic acid and deoxycholic acid) secretion decreased in aged rats compared to 3.5-month-old rats. This was associated with a corresponding increase in secretion of chenodeoxycholic acid and hyodeoxycholic-ursodeoxycholic acid. However, the magnitude of the change in secretion of these bile acids could not account for the increased output of phospholipid in bile.

Determinants of diet quality among Quebecers aged 55-74.

OBJECTIVES: Sociodemographic, lifestyle and dietary characteristics were studied to gain insights into determinants of total diet quality and diversity in a weighted sample of 460 participants aged 55-74 (53% female) from the 1990 Enqu te qu b coise sur la nutrition (EQN) dataset. METHODS: Dietary data consisted of an interviewer-administered 24-hour recall and food frequency questionnaire, and a self-administered questionnaire on dietary behaviours, attitudes and perceptions. 24-hour recall data were coded into food groups as described in Canada's Food Guide for Healthy Eating. Diet quality was scored using the categorical Dietary Diversity Score (DDS, range 0-4) and continuous Dietary Adequacy Score (DAS, range 0-18). A second nonconsecutive recall (10% of subjects) permitted correction of food group portions for intraindividual variability and subsequent calculation and validation of usual DDS and DAS. Relationships were examined between the scores and independent variables. Forward leastwise logistic regession (DDS) and stepwise multiple regression (DAS) analyses were conducted with independent variables showing significant bivariate relationships. RESULTS: Among men, breakfast consumption and eating commercially-prepared meals were positively associated with usual DDS, but poor social support and supplement use negatively predicted this score. Eating fewer than 3 meals daily, smoking, and dietary supplement use were negative predictors of usual DAS (r2=0.155). Among women, eating commercial foods was a negative predictor of usual DDS, as was preferring overweight to depriving themselves of favourite foods. Reporting that health concerns influenced food choices and disagreeing with the statement that effort is needed to have a nice body were positive determinants of usual DAS in women. On the other hand, eating fewer than 3 meals daily negatively predicted this dietary index (r2 = 0.162). CONCLUSIONS: Gender differences in predictors of diet quality suggest the need to target nutrition health promotion to the needs of older men and women to encourage optimal eating habits.

Employee reactions to the introduction of a bulk food distribution system in a nursing home.

Decentralized bulk food distribution was implemented in a nursing home. Employees working with elderly residents with dementia were asked their opinion of the impact of the new system on residents and workload. A convenience sample of 24 employees (57% of the staff) completed a 31-item, self-administered Likert-scale questionnaire that allowed open-ended comments. Responses were subjected to descriptive quantitative analysis, and a qualitative approach was used to explore themes that emerged in comments. Qualitative analysis indicated that 52% of responses were negative in tone, 30% were positive, and 18% were neutral. Initially, three categories of comments emerged, with specific multiple themes related to the residents (41%), the employees (37%), or the food-service system (22%). Most comments in the employee category were negative, and suggested that the decentralized food-service system caused hardship for the staff. This problem was resolved by adding one staff-hour at the midday meal. One year later, an abbreviated repeat survey of 29 employees revealed adaptation and general acceptance of the system. Because a motivated patient care staff is essential to the successful feeding of nursing home residents with dementia, employees' concerns must be considered when operational changes are planned.