Introduction: Vitamin C is an essential nutrient. Sex differences in serum vitamin C concentrations have been observed but are not fully known. Investigation of levels of metabolites may help shed light on how dietary and other environmental exposures interact with molecular processes. O-methylascorbate and ascorbic acid 2-sulfate are two metabolites in the vitamin C metabolic pathway. Past research has found genetic factors that influence the levels of these two metabolites. Therefore, we investigated possible effect modification by sex of genetic variant-metabolite associations and characterized the biological function of these interactions. Methods: We included individuals of European descent from the Canadian Longitudinal Study on Aging with available genetic and metabolic data (n = 9004). We used linear mixed models to tests for genome-wide associations with O-methylascorbate and ascorbic acid 2-sulfate, with and without a sex interaction. We also investigated the biological function of the important genetic variant-sex interactions found for each metabolite. Results: Two genome-wide statistically significant (p value < 5 × 10-8) interaction effects and several suggestive (p value < 10-5) interaction effects were found. These suggestive interaction effects were mapped to several genes including HSD11B2, associated with sex hormones, and AGRP, associated with hunger drive. The genes mapped to O-methylascorbate were differently expressed in the testis tissues, and the genes mapped to ascorbic acid 2-sulfate were differently expressed in stomach tissues. Discussion: By understanding the genetic factors that impact metabolites associated with vitamin C, we can better understand its function in disease risk and the mechanisms behind sex differences in vitamin C concentrations.

Using data from the Canadian Longitudinal Study on Aging, in this study we provide an alternative explanation for the gap of life satisfaction between living-alone immigrants and Canadian-born older adults. Based on the Big-Five personality traits, we use the latent class analysis to generate two types of social dispositions, social independence and social dependence. With social dispositions taken into account, living alone contributes to life satisfaction in opposite ways for immigrant and Canadian-born older adults, by playing a negative role for the former group and a positive role for the latter. The trend of higher life satisfaction among the living-alone Canadian-born are mainly among the socially independent, whereas for immigrants, socially dependent older adults experience the lowest level of life satisfaction when living alone. Therefore, while socially independent Canadian-born older adults gain a \"living-alone premium\" in life satisfaction; their socially dependent immigrant counterparts experience a \"living-alone penalty\" in life satisfaction.

OBJECTIVE: To explore whether the association between physical activity (PA) and cognition is moderated by neighbourhood disadvantage, and whether this relationship varies with age.
METHODS: A longitudinal analysis of the Canadian Longitudinal Study on Aging, wherein we included participants (N = 41,599) from urban areas who did not change their residential postal code from baseline (2010-2015) to first follow-up (2015-2018).
METHODS: At baseline, we measured PA using the Physical Activity Scale for the Elderly, and neighbourhood disadvantage using the Material and Social Deprivation Indices.
RESULTS: Using latent change score regression models, we determined that higher PA at baseline was independently associated with greater maintenance in memory performance from baseline to first follow-up both for adults aged 45-64 (B = 0.04, SE = 0.01, p = 0.001) and for those aged 65+ years (B = 0.12, SE = 0.02, p < 0.001). For participants aged 45-64 years, greater material deprivation was independently associated with declines in memory performance (B = -0.10, SE = 0.03, p < 0.001). In addition, greater social deprivation was associated with a stronger effect of PA on changes in executive functions (B = 0.17, SE = 0.08, p = 0.025) for adults aged 45-64 years; greater material deprivation was associated with a stronger effect of PA on changes in memory performance (B = 0.07, SE = 0.03, p = 0.022). We failed to detect any interactions between PA and neighbourhood disadvantage among adults aged 65+ years (all p values >0.05).
CONCLUSIONS: For middle-aged adults, the benefits of PA on cognitive performance may be strongest among adults living with greater neighbourhood social and material disadvantages. For older adults, PA may be beneficial to cognitive performance irrespective of neighbourhood disadvantages.

OBJECTIVE: Obstructive sleep apnea (OSA) is a common chronic condition that is often undiagnosed or diagnosed after many years of symptoms and has an impact on quality of life and several health factors. We estimated the Canadian national prevalence of OSA using a validated questionnaire and physical measurements in participants in the Canadian Longitudinal Study on Aging (CLSA).
METHODS: The method used individual risk estimation based upon the validated STOP-BANG scale developed for OSA. This stratified population sample spans Canada to provide regional estimates.
RESULTS: In this sample of adults aged 45 to 85 years old, the overall prevalence in 2015 of combined moderate and severe OSA in the 51,337 participants was 28.1% (95% confidence intervals, 27.8‒28.4). The regional prevalence varied statistically between Atlantic Canada and Western Canada (p < 0.001), although clinically the variations were limited. The provincial prevalence for moderate and severe OSA ranged from 27.5% (New Brunswick and British Columbia) to 29.1% (Manitoba). Body mass index (BMI) was the dominant determinant of the variance between provinces (β = 0.33, p < 0.001). Only 1.2% of participants had a clinical diagnosis of OSA.
CONCLUSIONS: The great majority (92.9%) of the participants at high risk of OSA were unrecognized and had no clinical diagnosis of OSA.
RéSUMé: OBJECTIFS: Le syndrome de l’apnée du sommeil (SAS) est une maladie chronique courante qui est souvent non diagnostiquée ou diagnostiquée plusieurs années après l’apparition de symptômes et qui a un impact sur la qualité de vie ainsi que plusieurs autres facteurs de santé. Nous avons estimé la prévalence nationale canadienne du SAS à l’aide d’un questionnaire validé et de mesures physiques chez les participants de l’Étude longitudinale canadienne sur le vieillissement (ÉLCV). MéTHODES: L’étude mesure l’estimation du risque individuel du SAS basée sur l’échelle validée STOP-BANG qui a été développée pour l’évaluation du SAS. Cet échantillon de population stratifié couvre tout le Canada et permet de fournir des estimations régionales. RéSULTATS: Dans cet échantillon d’adultes âgés de 45 à 85 ans, la prévalence globale du SAS modéré et sévère chez les 51 337 participants était de 28,1 % en 2015 (intervalles de confiance à 95 %: 27,8‒28,4). La prévalence régionale variait statistiquement entre le Canada atlantique et l’ouest du Canada (p < 0,001), bien que les variations cliniques soient limitées. La prévalence provinciale du SAS modéré et sévère variait entre 27,5 % (Nouveau-Brunswick et Colombie-Britannique) et 29,1 % (Manitoba). L’indice de masse corporelle représentait le facteur dominant de la variance entre les provinces (β = 0,33, p < 0,001). Seulement 1,2 % des participants avaient un diagnostic clinique du SAS. CONCLUSION: La grande majorité (92,9 %) des participants présentant un risque élevé du SAS n’étaient pas identifiés auparavant et n’avaient aucun diagnostic clinique du SAS.

UNASSIGNED: Falls, and more specifically, fall-related injuries, are costly to the healthcare system and can harm one\'s autonomy.
UNASSIGNED: To study the impact of sedentary behaviour associated with fall-related injuries and how a change in sedentary behaviour may impact the risk of a fall-related injury.
UNASSIGNED: From baseline to the first follow-up, cross-sectional and longitudinal data analysis from the Canadian Longitudinal Study of Aging (CLSA) cohort.
UNASSIGNED: CLSA data from 43,558 Canadians aged 45-85 were included in this study.
UNASSIGNED: At baseline and follow-up, sedentary behaviour time was categorized as low (<1,080 minutes/week), moderate (1,080-1,440), or high (>1,440). Sedentary behaviour was estimated via the Physical Activity Scale for the Elderly (PASE). At follow-up, participants were dichotomized as either increased or decreased/no change in sedentary behaviour according to their categorical change between time points.
UNASSIGNED: Sedentary behaviour was associated with fall-related injuries independently of age, sex, number of chronic conditions, and total physical activity levels OR (95%CI) 1.10 (1.05-1.15). In contrast, a change in sedentary behaviour was not associated with the risk of fall-related injury 1.00 (0.92-1.01).
UNASSIGNED: A higher level of sedentary behaviour is associated with injurious falls for people between 40 and 80 years old. However, a short-term change in sedentary behaviour does not influence the risk of injury-related falls. Despite the results, a more precise measure of sedentary behaviour is needed for epidemiology studies to capture changes over time better.

Frailty reflects age-related damage to multiple physiological systems. Executive dysfunction is often a presenting symptom of diseases characterized by cognitive impairment. A decline in cardiovascular health is associated with worse executive function. We tested the hypothesis that higher frailty would be associated with executive dysfunction and that cardiovascular health would mediate this relationship. Middle- and older-aged adults at baseline (n = 29,591 [51% female]) and 3-year follow-up (n = 25,488 [49% females]) from the Canadian Longitudinal Study on Aging (comprehensive cohort) were included. Frailty was determined at baseline from a 61-item index, a cumulative cardiovascular health score was calculated from 30 variables at baseline, and participants completed a word-color Stroop task as an assessment of executive function. Multiple linear regressions and mediation analyses of cardiovascular health were conducted between frailty, Stroop interference-condition reaction time, and cardiovascular health in groups stratified by both age and sex (middle-aged males [MM], middle-aged females [MF], older-aged males [OM], older-aged females [OF]). Frailty (MM, 0.15 ± 0.05; MF, 0.16 ± 0.06; OM, 0.21 ± 0.06; OF, 0.23 ± 0.06) was negatively associated with cardiovascular health (MM, 0.12 ± 0.08; MF, 0.11 ± 0.07; OM, 0.20 ± 0.10; OF, 0.18 ± 0.09; β > 0.037, p < 0.001), as well as the Stroop reaction time at 3-year follow-up (MM, 23.7 ± 7.9; MF, 23.1 ± 7.3; OM, 32.9 ± 13.1; OF, 30.9 ± 12.0; β > 2.57, p < 0.001) across all groups when adjusted for covariates. Cardiovascular health was a partial (~ 10%) mediator between frailty and reaction time, aside from MFs. In conclusion, higher frailty levels are associated with executive dysfunction, which was partially mediated by cardiovascular health. Strategies to improve frailty and better cardiovascular health may be useful for combatting the age-related decline in executive function.

OBJECTIVE: To examine the impact of two key choices when conducting a network analysis (clustering methods and measure of association) on the number and type of multimorbidity clusters.
METHODS: Using cross-sectional self-reported data on 24 diseases from 30,097 community-living adults aged 45-85 from the Canadian Longitudinal Study on Aging, we conducted network analyses using 5 clustering methods and 11 association measures commonly used in multimorbidity studies. We compared the similarity among clusters using the adjusted Rand index (ARI); an ARI of 0 is equivalent to the diseases being randomly assigned to clusters, and 1 indicates perfect agreement. We compared the network analysis results to disease clusters independently identified by two clinicians.
RESULTS: Results differed greatly across combinations of association measures and cluster algorithms. The number of clusters identified ranged from 1 to 24, with a low similarity of conditions within clusters. Compared to clinician-derived clusters, ARIs ranged from -0.02 to 0.24, indicating little similarity.
CONCLUSIONS: These analyses demonstrate the need for a systematic evaluation of the performance of network analysis methods on binary clustered data like diseases. Moreover, in individual older adults, diseases may not cluster predictably, highlighting the need for a personalized approach to their care.

Purpose: To examine the social network factors associated with changes in nutrition risk scores, measured by SCREEN-8, over three years, in community-dwelling Canadians aged 45 years and older, using data from the Canadian Longitudinal Study on Aging (CLSA).Methods: Change in SCREEN-8 scores between the baseline and first follow-up waves of the CLSA was calculated by subtracting SCREEN-8 scores at follow-up from baseline scores. Multivariable linear regression was used to examine the factors associated with change in SCREEN-8 score.Results: The mean SCREEN-8 score at baseline was 38.7 (SD = 6.4), and the mean SCREEN-8 score at follow-up was 37.9 (SD = 6.6). The mean change in SCREEN-8 score was -0.90 (SD = 5.99). Higher levels of social participation (participation in community activities) were associated with increases in SCREEN-8 scores between baseline and follow-up, three years later.Conclusions: Dietitians should be aware that individuals with low levels of social participation may be at risk for having their nutritional status decrease over time and consideration should be given to screening them proactively for nutrition risk. Dietitians can develop and support programs aimed at combining food with social participation.

The COVID-19 pandemic has presented numerous challenges to older adults in Canada, including the ability to volunteer. The purpose of this study is to improve the understanding of the social context surrounding volunteering in Canada, by (a) determining changes in associations between human, social, and cultural capital and volunteering among older adults; and (b) examining the relationship between ethnic minority status and volunteering, using data from the Canadian Longitudinal Study on Aging (CLSA), collected prior to and during the pandemic. This study utilized data from 24,306 CLSA Baseline, Follow-up 1 (FUP1), and COVID-19 Baseline Survey participants (aged 55+). Results confirm a decrease in volunteering during the early stages of the pandemic. Compared to pre-pandemic associations, volunteers during the early stages of the pandemic were more likely to be young-old, male, employed, and not involved in religious activities. Findings provide evidence of pandemic effects on volunteering among older adults in Canada.

Memory plays a crucial role in cognitive health. Social isolation (SI) and loneliness (LON) are recognized risk factors for global cognition, although their combined effects on memory have been understudied in the literature. This study used three waves of data over six years from the Canadian Longitudinal Study on Aging to examine whether SI and LON are individually and jointly associated with memory in community-dwelling middle-aged and older adults (n = 14,208). LON was assessed with the question: \"In the last week, how often did you feel lonely?\". SI was measured using an index based on marital/cohabiting status, retirement status, social activity participation, and social network contacts. Memory was evaluated with combined z-scores from two administrations of the Rey Auditory Verbal Learning Test (immediate-recall, delayed-recall). We conducted our analyses using all available data across the three timepoints and retained participants with missing covariate data. Linear mixed models were used to regress combined memory scores onto SI and LON, adjusting for sociodemographic, health, functional ability, and lifestyle variables. Experiencing both SI and LON had the greatest inverse effect on memory (least-squares mean: -0.80 [95 % confidence-interval: -1.22, -0.39]), followed by LON alone (-0.73 [-1.13, -0.34]), then SI alone (-0.69 [-1.09, -0.29]), and lastly by being neither lonely nor isolated (-0.65 [-1.05, -0.25]). Sensitivity analyses confirmed this hierarchy of effects. Policies developed to enhance memory in middle-aged and older adults might achieve greater benefits when targeting the alleviation of both SI and LON rather than one or the other individually.