[Sleep-wake cycle regularity and cardiometabolic indicators]

To evaluate the association between sleep-wake rhythm and cardiometabolic parameters.

103 participants, aged 25-64 years, underwent actigraphy study with Actigraph Actilife GT3X + device (USA) for 7 days. We assessed actigraphy indicators (physical activity and sleep data), anthropometric indicators, blood pressure and laboratory parameters. Actigraphy data was processed using the nparACT package in the R program with the calculation of nonparametric indicators: intraday variability, interday stability, the average level of lowest activity for five hours (L5) and ten hours with the highest activity (M10), relative amplitude is the ratio of M10/L5.

The nonparametric analysis showed an association of the higher night activity with sleep effectiveness, wake after sleep onset, indicators of physical activity. A more stable sleep pattern is associated with more steps, less weight and waist circumference, lower levels of diastolic blood pressure, creatinine and insulin. Increased fragmentation of sleep patterns is associated with increased CRP and increased sedentary time. Participants with higher activity contrast have less waist circumference, hips and body mass index, lower levels of CRP and insulin.

Rhythm and quality of sleep are important parameters associated with cardiometabolic indicators. Stable sleep patterns, higher activity during the day and lower night activity are associated with a more favorable condition of cardiovascular system.