Development, Validation and Field Evaluation of the Singapore Longitudinal Ageing Study (SLAS) Risk Index for Prediction of Mild Cognitive Impairment and Dementia.

BACKGROUND: Mild cognitive impairment (MCI) is a critical pre-dementia target for preventive interventions. There are few brief screening tools based on self-reported personal lifestyle and health-related information for predicting MCI that have been validated for their generalizability and utility in primary care and community settings. OBJECTIVE: To develop and validate a MCI risk prediction index, and evaluate its field application in a pilot community intervention trial project. DESIGN: Two independent population-based cohorts in the Singapore Longitudinal Ageing Study (SLAS). We used SLAS1 as a development cohort to construct the risk assessment instrument, and SLA2 as a validation cohort to verify its generalizability. SETTING: community-based screening and lifestyle intervention Participants: (1) SLAS1 cognitively normal (CN) aged ≥55 years with average 3 years (N=1601); (2) SLAS2 cohort (N=3051) with average 4 years of follow up. (3) 437 participants in a pilot community intervention project. MEASUREMENTS: The risk index indicators included age, female sex, years of schooling, hearing loss, depression, life satisfaction, number of cardio-metabolic risk factors (wide waist circumference, pre-diabetes or diabetes, hypertension, dyslipidemia). Weighted summed scores predicted probabilities of MCI or dementia. A self-administered questionnaire field version of the risk index was deployed in the pilot community project and evaluated using pre-intervention baseline cognitive function of participants. RESULTS: Risk scores were associated with increasing probabilities of progression to MCI-or-dementia in the development cohort (AUC=0.73) and with increased prevalence and incidence of MCI-or-dementia in the validation cohort (AUC=0.74). The field questionnaire risk index identified high risk individuals with strong correlation with RBANS cognitive scores in the community program (p<0.001). CONCLUSIONS: The SLAS risk index is accurate and replicable in predicting MCI, and is applicable in community interventions for dementia prevention.

Nutritional Status and Risks of Cognitive Decline and Incident Neurocognitive Disorders: Singapore Longitudinal Ageing Studies.

BACKGROUND: Studies suggest that nutritional interventions using the whole diet approach such as the Mediterranean diet may delay cognitive decline and dementia onset. However, substantial numbers of older adults are non-adherent to any ideally healthy dietary pattern and are at risk of malnutrition. OBJECTIVE: The present study investigated the relationship between global malnutrition risk and onsets of cognitive decline and neurocognitive disorders (NCD), including mild cognitive impairment (MCI) or dementia in community-dwelling older adults. METHODS: Participants aged ≥ 55 years in the Singapore Longitudinal Ageing Studies (SLAS) were assessed at baseline using the Elderly Nutritional Indicators for Geriatric Malnutrition Assessment (ENIGMA) and followed up 3-5 years subsequently on cognitive decline (MMSE drop ≥ 2) among 3128 dementia-free individuals, and incident neurocognitive disorders (NCD) among 2640 cognitive normal individuals. RESULTS: Individuals at high nutritional risk score (≥ 3) were more likely to develop cognitive decline (OR=1.42, 95%CI=1.01-1.99) and incident MCI-or-dementia (OR=1.64, 95%CI=1.03-2.59), controlling for age, sex, ethnicity, low education, APOE-e4, hearing loss, physical, social, and mental activities, depressive symptoms, smoking, alcohol, central obesity, hypertension, diabetes, low HDL, high triglyceride, cardiac disease, and stroke. Among ENIGMA component indicators, low albumin at baseline was associated with cognitive decline and incident NCD, and 5 or more drugs used, few fruits/vegetables/milk products daily, and low total cholesterol were associated with incident NCD. CONCLUSION: The ENIGMA measure of global malnutrition risk predicts cognitive decline and incident neurocognitive disorders, suggesting the feasibility of identifying vulnerable subpopulations of older adults for correction of malnutrition risk to prevent neurocognitive disorders.

Tea Consumption and Depression from Follow Up in the Singapore Longitudinal Ageing Study.

OBJECTIVES: Experimental evidence suggest that tea polyphenols have anti-depressant effect and tea consumption may reduce the risk and severity of depression. We investigated whether tea consumption was associated with changes in depressive symptoms over time among Asian older adults. DESIGN: Population-based prospective cohort study with mean 4 years of follow up. SETTING: Singapore Longitudinal Ageing Study (SLAS) of community-living older persons. PARTICIPANTS: 3177 participants overall (mean age 67 years) and 3004 participants who were depression-free at baseline. MEASUREMENTS: Baseline tea consumption which include Chinese (black, oolong or green) tea or Western (mixed with milk) tea and change in Geriatric Depression Scale (GDS) measure of depression. Incident depression was defined by GDS≥5, and GDS depression improvement or deterioration by GDS change of ≥4 points. Estimated odds ratio and 95% confidence intervals (OR, 95%CI) were adjusted for baseline age, sex, ethnicity, education, housing type, single/divorced/widowed, living alone, physical and social activity, smoking, alcohol, number of comorbidities, MMSE, and baseline GDS level. RESULTS: Compared to non-tea drinkers, participants who consumed ≥3 cups of tea of all kinds were significantly less likely to have worsened GDS symptoms: OR=0.32, 95% CI=0.12, 0.84. Among baseline depression-free participants, the risk of incident GDS (≥5) depression was significantly lower (OR=0.34, 95%CI=0.13, 0.90) for daily consumption of all types of tea, and Chinese (black, oolong or green) tea (OR=0.46, 95%CI=0.21,0.99). CONCLUSION: This study suggests that tea may prevent the worsening of existing depressive symptoms and the reduce the likelihood of developing threshold depression.

Risk Factors of Progression to Frailty: Findings from the Singapore Longitudinal Ageing Study.

OBJECTIVES: To investigate risk factors of incident physical frailty. DESIGN: A population-based observational longitudinal study. SETTING: Community-dwelling elderly with age 55 years and above recruited from 2009 through 2011 in the second wave Singapore Longitudinal Ageing Study-2 (SLAS-2) were followed up 3-5 years later. PARTICIPANTS: A total of 1297 participants, mean age of 65.6 ±0.19, who were free of physical frailty. MEASUREMENTS: Incident frailty defined by three or more criteria of the physical phenotype used in the Cardiovascular Health Study was determined at follow-up. Potential risk factors assessed at baseline included demographic, socioeconomic, medical, psychological factors, and biochemical markers. RESULTS: A total of 204 (15.7%) participants, including 81 (10.87%) of the robust and 123 (22.28%) of the prefrail transited to frailty at follow-up. Age, no education, MMSE score, diabetes, prediabetes and diabetes, arthritis, ≥5 medications, fair and poor self-rated health, moderate to high nutritional risk (NSI ≥3), Hb (g/dL), CRP (mg/L), low B12, low folate, albumin (g/L), low total cholesterol, adjusted for sex, age and education, were significantly associated (p<0.05) with incident frailty. In stepwise selection models, age (year) (OR=1.07, 95%CI=1.03-1.10, p<0.001), albumin (g/L) (OR=0.85, 95%CI=0.77-0.94, p=0.002), MMSE score (OR=0.88, 95%CI=0.78-0.98, p=0.02), low folate (OR=3.72, 95%CI=1.17-11.86, p=0.03, and previous hospitalization (OR=2.26, 95%CI=1.01-5.04,p=0.05) were significantly associated with incident frailty. CONCLUSIONS: The study revealed multiple modifiable risk factors, especially related to poor nutrition, for which preventive measures and early management could potentially halt or delay the development of frailty.

Cognitive function and tea consumption in community dwelling older Chinese in Singapore.

OBJECTIVES: We aimed to examine the relationship between tea consumption and cognitive function in older adults. DESIGN: Cross-sectional study. SETTING: The Singapore Longitudinal Aging Studies (SLAS), a community-based study in urban Singapore. PARTICIPANTS: 716 Chinese adults aged > or = 55 years. MEASUREMENT: Self-reported current tea consumption habits (frequency and type). Cognitive performance was assessed by a battery of neuropsychological tests; composite domain scores on attention, memory, executive function, and information processing speed were computed using raw test scores. The Mini-Mental State Examination (MMSE) total score was used as a measure of global cognitive function. RESULTS: After adjusting for potential confounders, total tea consumption was independently associated with better performances on global cognition (B=0.055, SE=0.026, p=0.03), memory (B=0.031, SE=0.012, p=0.01), executive function (B=0.032, SE=0.012, p=0.009), and information processing speed (B=0.04, SE=0.014, p=0.001). Both black/oolong tea and green tea consumption were associated with better cognitive performance. There was no association between coffee consumption and cognitive function. CONCLUSIONS: Tea consumption was associated with better cognitive performance in community-living Chinese older adults. The protective effect of tea consumption on cognitive function was not limited to particular type of tea.