Authors' Response to Cao and Hu Re: “Metabolic Syndrome and Cognitive Performance Among Chinese ≥ 50 Years: A Cross-Sectional Study with 3988 Participants”

Dear Editor,

We thank Dr. Cao and Hu ¹ for discussing our published article and we would like to submit a response.

There were some other studies that also suggested that there was no association between metabolic syndrome (MetS) and cognitive impairment. ^{2 –4} A recent study conducted at 20 endocrinology clinics in top-ranked hospitals covering most of the major cities of China showed that the prevalence of dyslipidemia was 67.1% in patients with type 2 diabetes mellitus ⁵ ; so it is very common that the two factors of diabetes and dyslipidemia could be overlapped in the same observed human subjects. In our study, the sample size was large. The P value would be easy to reach near 0.05 for comparison of two groups even if there was no statistical difference. The body mass index (BMI) of the group with mild cognitive impairment (MCI) was 24.6 ± 3.2 and the BMI for the group without MCI was 24.5 ± 3.1 (P = 0.212). Even when we put the obesity status in the logistic regression for adjustment, the result was still the same as our conclusion that had been published.

We also recognized that the age was related with cognitive function in our study ⁶ and we had put the age as a confounding factor in the logistic regression for adjustment. There was another study that even showed that MetS may be associated with better cognitive function among the Chinese with age of >90 years. ⁷