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WEDNESDAY, July 11, 2018 (HealthDay News) — The endogenous circadian system, behavioral cycle, and circadian misalignment have distinct effects on insulin sensitivity and \u03b2-cell function, according to a study published online June 4 in Diabetes, Obesity and Metabolism<\/i>.<\/p>\n
Noting that shift workers, who experience circadian misalignment, have an increased risk of type 2 diabetes, Jingyi Qian, Ph.D., from Brigham and Women’s Hospital in Boston, and colleagues examined the separate and relative impacts of the circadian system, behavioral\/environmental cycles, and their interaction (circadian misalignment) on insulin sensitivity and \u03b2-cell function. The major determinants of glucose control were quantitatively assessed in 14 healthy adults using a randomized, crossover design with two eight-day laboratory protocols that involved three baseline inpatient days with habitual sleep\/wake cycles followed by four inpatient days with the same nocturnal bedtime or with 12-hour inverted behavioral\/environmental cycles.<\/p>\n
The researchers found that circadian phase and circadian misalignment impact glucose tolerance through different mechanisms. The circadian system mainly decreases both dynamic and static \u03b2-cell responsivity to reduce glucose tolerance in the biological evening versus the biological morning. In contrast, circadian misalignment did not affect \u03b2-cell function but reduced glucose tolerance mainly by lowering insulin sensitivity.<\/p>\n
“The results show separate effects of the endogenous circadian system, the behavioral cycle, and circadian misalignment on insulin sensitivity and \u03b2-cell responsivity with relevance for daily glucose regulation in diurnally active people as well as night-shift workers,” the authors write.<\/p>\n
Two authors disclosed financial ties to the pharmaceutical and nutrition industries.<\/p>\n