The following is a summary of the “Obesity marker trajectories and cognitive impairment in older adults: a 10-year follow-up in Taichung community health study for elders” published in the November 2022 issue of Psychiatry by Li et al.

There is a correlation between age and the prevalence of both obesity and cognitive impairment. In addition, there is mounting evidence between fat and dementia in the elderly. However, linking the 2 is fraught with debate. The purpose of this research is to determine whether or if older persons living in the community who have been followed for 10 years are more likely to experience cognitive impairment or decline and to uncover trajectory patterns in obesity markers that indicate such an association. There were a total of 626 participants, all of whom were 65 and older, and each participant underwent at least 2 measurements (baseline and either 1 or 10 years afterwards).

The Mini-Mental-State-Examination was used to evaluate mental state. Body mass index, waist circumference, waist-to-hip ratio, fat mass, and abdominal fat were all used as indicators of obesity, as was dual-energy X-ray absorptiometry. The adjusted odds ratios (ORs) of cognitive impairment and cognitive decline for obesity marker trajectory patterns were estimated using multivariate logistic regression models, along with 95% CIs. A total of 168 older adults showed acute cognitive impairment after 10 years of follow-up, while 156 showed a rapid cognitive decline, or the top 25th percentile, based on their rate of decline. Obesity indicators were divided into 4 categories according to their predicted trajectories. Consistently high-level FM trajectory (ORs=0.41, 95% CI= 0.20-0.85), high-level U-shaped WHR trajectory (0.43, 0.22-0.84) groups, and median-level flat inverse U-shaped, consistently high-level. 

Low-level flat U-shaped AF trajectory groups had a low likelihood of cognitive impairment in multivariate logistic regression analyses (0.44, 0.26–0.77; 0.33, 0.18–0.61; 0.39, 0.18–0.82). Another finding from the WHR trajectory analysis showed that the low-level, slightly increasing trend group had a low risk of rapid decline (0.43, 0.22–0.85). In older persons, decreased chances of incident cognitive impairment are associated with FM and AF trajectories with consistently high levels and WHR trajectories with high levels and the U-shaped group. Similarly, a low but slowly growing WHR trajectory is linked to a reduced risk of cognitive deterioration.