Identification of Neuroprotective Factors Associated with Successful Ageing and Risk of Cognitive Impairment among Malaysia Older Adults.

The increase of ageing population has raised public attention on the concept of successful ageing. Studies have shown that vitamin D, telomere length, and brain-derived neurotrophic factor (BDNF) have been associated with cognitive function. Therefore, this study aimed to identify neuroprotective factors for cognitive decline in different ageing groups. A total of 300 older adults aged 60 years and above were recruited in this population based cross-sectional study. Participants were categorized into three groups: mild cognitive impairment (MCI) (n = 100), usual ageing (UA) (n = 100), and successful ageing (SA) (n = 100). Dietary vitamin D intake was assessed through Diet History Questionnaire (DHQ). Out of the 300 participants, only 150 were subjected to fasting blood sample collection. These samples were used for serum vitamin D and plasma BDNF measurements. Whole blood telomere length was measured using RT-PCR method. The results show that the reduction of the risk of MCI was achieved by higher serum vitamin D level (OR: 0.96, 95% CI: 0.92-0.99, p < 0.05), higher plasma BDNF level (OR: 0.51, 95% CI: 0.30-0.88,  p < 0.05), and longer telomere (OR: 0.97, 95% CI: 0.95-0.99,  p < 0.001). In conclusion, participants with higher vitamin D level, higher BDNF level, and longer telomere length were more likely to age successfully.