Associations between lipid profiles and late-life cognitive impairment among oldest-old and centenarian adults

Dyslipidemia and cognitive impairment are common among old adults and the occurrence of them rises exponentially with increasing age. Evidences of the relationships between serum lipids and cognitive impairment are inconsistent or equivocal among older adults. This study aimed to investigate the associations between lipid profiles and late-life cognitive impairment among oldest-old and centenarian adults. In this cross-sectional study, serum lipids were biochemically measured among 606 oldest-old adults and 653 centenarians, and cognitive function was evaluated using mini-mental state examination (MMSE). Multivariate linear and logistic regression analyses were performed to explore the associations between serum lipids and cognitive impairment. Results showed participants with cognitive impairment had lower total cholesterol (TC) levels compared with those without cognitive impairment (p < 0.05). TC levels were positively associated with MMSE (p < 0.05). Furthermore, a negative association was observed between TC levels and cognitive impairment (p for trend = 0.002). This negative association remained statistically significant after adjusting for confounders (p for trend = 0.028). These results suggested that older adults with higher TC levels were likely to have better cognitive function. Taking immoderate cholesterol-lowering drugs among older adults is questionable and requires investigation, and cognitive performance of old adults with lower TC levels deserves more attention.