Can an accelerometer-based monitor be used to accurately assess physical activity in a population of survivors of critical illness?

PURPOSE: To investigate the validity and reliability of the Activity Monitoring Pod (AMP331) to record gait parameters in  healthy young adults (YA) and intensive care unit inpatients (ICU). METHODS: Fifteen YA completed a series of over-ground walks. Another 15 YA completed a series of treadmill walks. The ICU group (N=20) completed a series of over-ground walks with repeat trials. Gait parameters were recorded simultaneously for each walk. RESULTS: For the YA over-ground condition, no significant differences were found between the measures recorded by the systems. For the YA treadmill condition, 43% of the measures differed (P < .05). For the ICU group, the AMP331 underestimated distance and speed by 3m and 25cm/s respectively. Reliability measures for distance (ICC 0.99, 95%CI 0.98 - 0.99) and step count (ICC 0.99, 95%CI 0.99 - 1.00) were excellent. CONCLUSIONS: The AMP 331 is a valid instrument for recording basic gait parameters for over-ground walking in healthy YA and ICU survivors.

A diet and exercise program to improve clinical outcomes in patients with obstructive sleep apnea--a feasibility study.

STUDY OBJECTIVES: To assess the feasibility and efficacy of a novel 16-week exercise and diet program for important clinical outcomes in obstructive sleep apnea (OSA). METHODS: Cohort study assessing sleep disordered breathing, cardiovascular risk factors, and neurobehavioral function prior to and following completion of the 16-week program. The program used a proprietary very low energy diet (Optifast, Novartis), and subjects participated in a supervised exercise schedule, which included both aerobic and resistance training. Follow-up contact was made at 12 months after program exit. Consecutive patients with newly diagnosed sleep apnea were approached who had an apnea-hypopnea index (AHI) of 10 to 50, a body mass index (BMI) of greater than 30 kg/m2, no significant comorbidities, and able to exercise. RESULTS: All data are presented as mean [SD]. Of 21 patients with OSA who were approached, 12 middle-aged (42.3 [10.4] years old), obese (BMI 36.1 [4.3] kg/m2), and predominantly female (75%) subjects with mild to moderate OSA were enrolled (AHI 24.6 [12.0]). Weight loss was significant (12.3 [9.6] kg, p <0.001), and 5 of the 10 who completed the program were able to independently maintain good weight loss at 12 months. At the 16-week assessment, there was a small nonsignificant fall in the AHI. Six of the 10 subjects had a reduction in sleep disordered breathing, and the AHI was less than 10 in 3 patients. There were significant improvements in neurobehavioral and cardiometabolic outcomes. Snoring improved in most subjects, but the improvement was clinically important (a score of < 2) in only 7. CONCLUSIONS: A supportive diet and exercise program may be of benefit to obese patients with mild to moderate sleep apnea. The results of this feasibility study showed significant weight loss and improvement in clinically important neurobehavioral and cardiometabolic outcomes but no significant change in sleep disordered breathing. These promising preliminary results need confirmation with a larger randomized trial.