Four Days of Simulated Shift Work Reduces Insulin Sensitivity in Humans

The study with 17 healthy adults found that four days of simulated night shift work significantly decreased insulin sensitivity by 25% in the night shift group (N=8), with no changes observed in the day shift group (N=5). This reduction in insulin sensitivity was not due to changes in mitochondrial function or circadian rhythms and occurred despite no significant changes in sleep duration, diet, or circadian rhythm phase shifts. The night shift group also consumed less protein during the study. These results suggest that night shift work may increase the risk of developing type 2 diabetes by impairing glucose metabolism and insulin action.