Exercise, Training May Improve Global Cognition in Older Patients With Mild Dementia

Progressive aerobic-resistance exercises and sequential cognitive training as a multidomain intervention may significantly improve cognitive impairment in older adults with mild cognitive impairment (MCI), according to the results of a study published in JAMA Network Open.

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“Both aerobic exercise and resistance training have been demonstrated to improve cognition in older adults, although the benefits of combining these 2 modalities are unclear,” the study authors wrote. “Computer-based cognitive training also improves cognition in older adults through the repeated engagement of cognitive processes using challenging and preferably adaptive tasks. Furthermore, vitamin D in addition to exercise and cognitive training has been argued to enhance cognition due to its neuroprotective attributes. Thus, providing these interventions together, as a multidomain treatment, has the potential to delay progression from MCI to dementia.”

The study found that vitamin D supplementation or exercise alone may not significantly improve global cognition.

“Our trial is to our knowledge the first to show a greater effect of a multidomain intervention over exercise alone,” the study authors wrote in the article.

Investigators conducted the SYNERGIC (multisite, double-masked, fractional factorial) study to evaluate a multidomain intervention of progressive exercise, cognitive training, and vitamin D supplementation for older adults with MCI, also called mild dementia.

The primary outcomes were change in score on the Alzheimer Disease Assessment Scale Cognitive 13 (ADAS-Cog-13) and ADAS-Cog-Plus variant scale at 6 months. ADAS-Cog-13 measures global cognition—including memory, attention, word recognition, and orientation—which is worse in patients with MCI.

The cohort included 175 Canadian adults with MCI, aged 65 to 84 years, who were divided into 1 of 5 arms:

• Arm 1: Multidomain intervention (aerobic-resistance exercise, cognitive training, and vitamin D).
• Arm 2: Aerobic-resistance exercise, cognitive training, and placebo vitamin D.
• Arm 3: Aerobic-resistance exercise, sham cognitive training, and vitamin D.
• Arm 4: Aerobic-resistance exercise, sham cognitive training, and placebo vitamin D.
• Arm 5: Control (balance and toning exercise, sham cognitive training, and placebo vitamin D).

At 6 months, all active arms (1 to 4) significantly improved scores according to ADAS-Cog-13, compared to the control (mean difference, −1.79 points; 95% CI, −3.27 to −0.31 points; P = .02; d = 0.64). Arm 1 improved their ADAS-Cog-13 score by 44%. ADAS-Cog-13 score increased 37% in arm 2, 14% in arm 3, 24% in arm 4, and 15% in arm 5.

Previous studies have identified resistance and aerobic training as independent factors that can improve cognitive function in older adults. Computerized cognitive training has proven benefits on cognition as well.Analysis at 12 months (post-intervention) revealed that aerobic-resistance training and cognitive training can provide not only safe, but lasting, benefits for older adults with MCI.

“[Patients in the multidomain intervention] did not revert to baseline scores, suggesting a lasting effect even without participants engaging in exercise regimes during the follow-up period,” the study authors wrote.

They added that this may suggest continuing exercise and cognitive training maintain positive cognitive improvements. The ADAS-Cog-Plus scale did not clinically improve following any intervention. In addition, exercise alone or vitamin D supplementation also did not improve scores on the ADAS-Cog-13, despite the latter being said to have neuroprotective properties that may improve cognition.

Dementia is an incurable disease that affects more than 50 million people worldwide. However, nonpharmacologic and lifestyle interventions can delay dementia onset, and interventions such as these may be most effective when administered during the MCI stage, the study authors concluded.

Reference

M Montero-Odasso, Zou G, Speechley M, et al. Effects of Exercise Alone or Combined With Cognitive Training and Vitamin D Supplementation to Improve Cognition in Adults With Mild Cognitive Impairment. JAMA Netw Open. 2023;6(7):e2324465. doi:10.1001/jamanetworkopen.2023.24465