Although neurocognitive dysfunction and physical performance are known to be impaired in patients with schizophrenia, evidence regarding the relationship between these two domains remains insufficient. Thus, we aimed to investigate the relationship between various physical performance domains and cognitive domains in individuals with schizophrenia, while considering other disorder-related clinical symptoms.

Sixty patients with schizophrenia participated in the study. Cardiorespiratory fitness and functional mobility were evaluated using the step test and supine-to-standing (STS) test, respectively. Executive function and working memory were assessed using the Stroop task and Sternberg working memory (SWM) task, respectively. Clinical symptoms were evaluated using the Brief Psychiatric Rating Scale, Beck Depression Inventory, and State-Trait Anxiety Inventory. Multivariate analyses were performed to adjust for relevant covariates and identify predictive factors associated with neurocognition.

Multiple regression analysis revealed that the step test index was most strongly associated with reaction time in the Stroop task (β = 0.434, p = 0.001) and SWM task (β = 0.331, p = 0.026), while STS test time was most strongly associated with accuracy on the Stoop task (β=−0.418, p = 0.001) and SWM task (β=−0.383, p = 0.007). Total cholesterol levels were positively associated with Stroop task accuracy (β=−0.307, p = 0.018) after controlling for other clinical correlates. However, clinical symptoms were not associated with any variables in Stroop or SWM task.

The present findings demonstrate the relationship between physical performance and neurocognition in patients with schizophrenia. Considering that these factors are modifiable, exercise intervention may help to improve cognitive symptoms in patients with schizophrenia, thereby leading to improvements in function and prognosis.

People with Alzheimer's disease (AD) experience, in addition to the progressive loss of cognitive functions, a decline in functional performance such as mobility impairment and disability in activities of daily living (ADL). Functional decline in dementia is mainly linked to the progressive brain pathology. Peripheral biomechanical changes by advanced glycation end-products (AGEs) have been suggested but have yet to be thoroughly studied.

A multi-center, longitudinal, one-year follow-up cohort study was conducted in 144 people with early stage AD or mixed Alzheimer's/Vascular dementia. Linear mixed model analyses was used to study associations between AGE-levels (AGE reader) and mobility (Timed Up and Go), and ADL (Groningen Activity Restriction Scale and Barthel index), respectively.

A significant association between AGE levels and mobility (β = 3.57, 95%CI: 1.43–5.73) was revealed; however, no significant association between AGE levels and ADL was found. Over a one-year time span, mean AGE levels significantly increased, and mobility and ADL performance decreased. Change in AGE levels was not significantly correlated with change in mobility.

This study indicates that high AGE levels could be a contributing factor to impaired mobility but lacks evidence for an association with ADL decline in people with early stage AD or mixed dementia. Future research is necessary on the reduction of functional decline in dementia regarding the effectiveness of interventions such as physical activity programs and dietary advice possibly in combination with pharmacologic strategies targeting AGE accumulation.