Assessment of Fitbit Charge 4 for sleep stage and heart rate monitoring against polysomnography and during home monitoring in Huntington's disease.

Study Objectives: Wearable devices that monitor sleep stages and heart rate offer the potential for longitudinal sleep monitoring in patients with neurodegenerative diseases. Sleep quality reduces with disease progression in Huntington's disease (HD). However, the involuntary movements characteristic of HD may affect the accuracy of wrist-worn devices.

Effect of 2000 IU compared with 800 IU vitamin D on cognitive performance among adults age 60 years and older: a randomized controlled trial.

Background: Findings on the effects of vitamin D on cognitive performance have been inconsistent and no clinical trials with detailed cognitive testing in healthy older adults have been reported.

Objectives: We tested whether 2000 IU is superior to 800 IU vitamin D3/d for cognitive performance among relatively healthy older adults.

Design: We analyzed data on cognitive performance as the secondary outcome of a 2-y double-blind randomized controlled trial that originally investigated the effect of vitamin D3 on knee function and pain in seniors with osteoarthritis.