The association of increased body mass index on cardiorespiratory fitness, physical activity, and cognition in adults with down syndrome.

BACKGROUND

Obesity is a significant risk factor for Alzheimer's disease; however, this association has not been explored in adults with Down syndrome.

OBJECTIVE

To examine the association of obesity, assessed by body mass index (BMI), with factors related to Alzheimer's disease risk including cardiorespiratory fitness, physical activity, and cognition in adults with Down syndrome.

METHODS

Adults with Down syndrome attended a laboratory visit where BMI, cardiorespiratory fitness (VO2 peak), and cognitive function (CANTAB® DS Battery) were obtained. Physical activity (accelerometer) was collected over the week following the laboratory visit. Wilcoxon rank sum tests were used to evaluate differences in cardiorespiratory fitness, sedentary time, moderate-to-vigorous physical activity (MVPA), and cognition between adults with obesity (BMI≥ 30 kg/m2) and those with healthy weight or overweight (BMI <30 kg/m2). Spearman correlations and linear regressions were used to measure the impact of BMI on cardiorespiratory fitness, MVPA, sedentary time, and cognition.

RESULTS

Data was collected for 79 adults with Down syndrome (26.7 ± 9.0 years of age, 54% female, 54% with obesity). VO2 peak was significantly lower in participants with obesity (18.4 ± 2.5 ml/kg/min) compared to those with healthy weight or overweight (22.9 ± 4.0 ml/kg/min, p < 0.001). BMI was negatively associated with cardiorespiratory fitness (rho = -0.614, p < 0.001). No associations were observed between BMI and physical activity or cognition.

CONCLUSIONS

Lower BMI was associated with improved cardiorespiratory fitness. However, no associations were observed between BMI and cognition or physical activity.

NCT REGISTRATION: NCT04048759.