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.