Cognitive impairment among elderly individuals in Shanghai suburb, China: association of C-reactive protein and its interactions with other relevant factors.

ABSTRACT

OBJECTIVES: To investigate the association between serum C-reactive protein (CRP) concentration and cognitive impairment as well as interactions between CRP and other relevant factors. METHODS: Patients with cognitive impairment and 1 to 2 age- and sex-matched controls nested from a population-based study among residents aged 60 years and older in Shanghai suburb. The associations of serum CRP concentration and other relevant factors were examined with logistic regression analysis. RESULTS: The mean CRP in patients with cognitive impairment was higher than that in controls (P < .001). The highest quartile of CRP (>4.77 mg/L), abdomen obesity, hypertriglyceridemia, and hyperglycemia was associated with cognitive impairment. Significant interactions were found between increased CRP and hypertriglyceridemia as well as between increased CRP and hyperglycemia on cognitive impairment; and the attributable proportion due to interaction was 82% (P < .0001) and 37% (P = .007), respectively. CONCLUSIONS: Increased CRP was associated with cognitive impairment, and additive effects of increased CRP with hypertriglyceridemia and hyperglycemia on cognitive impairment were observed among elderly individuals.