ABSTRACT

This chapter addresses development of technical approaches for assessment of circadian rhythm, meal patterns, physical activity and sleep patterns in outpatient settings. The daily patterns of feeding, energy utilization, and energy storage across the 24-hour cycle are based on a neuro-endocrinological system. Physical activity interferes with circadian rhythm parameters. Circadian misalignment of sleep results in particular metabolic disturbances, including dysregulation in the hypothalamic–pituitary–adrenal (HPA) axis, increased cortisol secretion, higher fasting insulin concentrations, and a higher homeostasis model assessment of insulin resistance (HOMA-IR) index. In order to increase the reliability of circadian monitoring, integrated variables obtained from processing individual variables have been recently proposed. Measurement of circadianity is based on the responsiveness of the circadian pacemaker to light of the pineal melatonin rhythm. Synchronously with the onset of melatonin secretion, a fall in body temperature via cutaneous vasodilatation occurs in evening, and opposite occurs in morning. The rhythm of skin peripheral temperature has been proposed to measuring central temperature.