A small, randomized, controlled crossover study demonstrates changes in a critical insulin-signaling pathway in peripheral tissue.

Small experimental studies have revealed adverse effects of reduced sleep duration on glucose tolerance and insulin sensitivity. To explore the effects of sleep restriction on metabolic activity in peripheral tissue, investigators randomized seven lean, healthy young adults (aged 18–30) to undergo 4 weeks each of normal and restricted sleep (8.5 and 4.5 hours, respectively), in random order and under controlled conditions, 4 weeks apart. The primary endpoint was change in levels of phosphorylated Akt — an important step in the insulin-signaling pathway — in abdominal subcutaneous adipocytes.

Phosphorylation of Akt was 30% lower after restricted sleep than after normal sleep (P=0.01). This reduction coincided with a 16% reduction in total-body insulin sensitivity, as measured by frequently sampled intravenous glucose tolerance tests.

Comment: We know that partial sleep restriction is associated with marked adverse changes in insulin sensitivity and glucose tolerance; now, this small study shows a correlation between sleep restriction and significant changes in molecular metabolic pathways in subcutaneous abdominal fat. I wonder if this line of research will lead us to recognize sleep deprivation as a precursor risk factor for metabolic abnormalities that lead to vascular disease — and whether we might eventually prescribe more sleep to our high-risk patients.

Source: Journal Watch Cardiology