AT AAIC 2015
WASHINGTON (FRONTLINE MEDICAL NEWS) – A 3-month program of supervised aerobic exercise and strength training led to modest but statistically significant improvement in cognition in a pilot, single-center study that enrolled 15 patients with mild cognitive impairment.
“Aerobic strength training is an effective strategy capable of slowing down or even reversing early phases of cognitive decline,” Dr. Barbara Ukropcova said at the Alzheimer’s Association International Conference 2015. The impact of training on improved cognition might be mediated through increased physical fitness, muscle mass, and strength and motor performance, as well as by improvements in specific metabolic parameters that the study results documented, said Dr. Ukropcova, a researcher at the Institute of Experimental Endocrinology of the Slovak Academy of Sciences in Bratislava, Slovakia.
Although the study involved just 15 patients with mild cognitive impairment, as well as 11 control participants with normal cognitive scores, Dr. Ukropcova said that she believes the impact of regular exercise on cognition is real, in part because the results showed a multifold change in some of the metabolic parameters that linked with improved cognitive function.
“We plan to enroll increased numbers of patients that will hopefully prove” the ability of exercise to improve impaired cognition, she said in an interview. Future studies also will look at metabolic parameters in greater detail with the aim of finding biomarkers that can better define the relationship between exercise and cognition.
Dr. Ukropcova stressed the importance of starting regular exercise during childhood and maintaining it throughout life to help preserve cognitive function instead of waiting to start to exercise once impairment has been diagnosed.
Her study had participants engage in one 45-minute session of aerobic-coordination training each week and two 60-minute sessions of supervised strength and aerobic exercise each week for 12 weeks. The researchers performed a detailed set of physical assessments, metabolic measures, and cognitive tests on each participant before they began the program and at the end of the 12-week training program.
The average age of the 15 people with mild cognitive impairment was 72 years, and the average body mass index was 27 kg/m2. Twelve were women. The average age of the 11 people in the control group was 65 years, and the average body mass index also was 27 kg/m2. Six were women.
During the 12 weeks of the study, the dropout rate was 10%, and participants completed an average of 80% of their scheduled training and exercise sessions, Dr. Ukropcova said.
At the end of the 12-week program, all participants showed statistically significant increases in aerobic fitness, measured by their maximal oxygen uptake (V02 max), muscle strength, speed during a 10-meter walk test, and speed during a chair-stand test. Metabolic measures showed a significantly decreased average serum level of lactate, “indicating improved metabolic capacity,” Dr. Ukropcova said, and a “substantial” increase in circulating levels of brain-derived neurotrophic factor, specifically in the participants with mild cognitive impairment.
Following the training period, the participants with mild cognitive impairment showed statistically significant improvements in their average scores on the Mini Mental State Examination, the Montreal Cognitive Assessment, and the Addenbrooke’s Cognitive Examination-Revised. For example, their average score on the Mini Mental State Examination rose from 26.5 before the exercise program began to 28 after 12 weeks. Control participants showed no statistically significant changes in any of these measures.
Analysis of data from all participants showed significant positive correlations between higher levels of physical activity, walking speed, and aerobic fitness and cognitive measures, as well as positive correlations between improved metabolic parameters and cognitive measures, Dr. Ukropcova reported.
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