Daily activity patterns of 2316 men and women from five countries differing in socioeconomic development

Abstract

Daily rhythmicity in the locomotor activity of laboratory animals has been studied in great detail for many decades, but the daily pattern of locomotor activity has not received as much attention in humans. We collected waist-worn accelerometer data from more than 2,000 individuals from five countries differing in socioeconomic development and conducted a detailed analysis of human locomotor activity. Body mass index was computed from height and weight. Individual activity records lasting 7 days were subjected to cosinor analysis to determine the parameters of the daily activity rhythm: mesor (mean level), amplitude (half the range of excursion), acrophase (time of the peak), and robustness (rhythm strength). The activity records of all individual participants exhibited statistically significant 24-hour rhythmicity, with activity increasing noticeably a few hours after sunrise and dropping off around the time of sunset, with a peak at 1:42 pm on average. The acrophase of the daily rhythm was comparable in men and women in each country but varied by as much as 3 h from country to country. Quantification of the socioeconomic stages of the five countries yielded suggestive evidence that more developed countries have more obese residents, who are less active, and who are active later in the day than residents from less developed countries. These results provide a detailed characterization of the daily activity pattern of individual human beings and reveal similarities and differences among people from five countries differing in socioeconomic development.

Variability of behavioral chronotypes of 16 mammalian species under controlled conditions

“…In the absence of data, we assumed that the human acrophase occurs in the middle of the active phase of the daily activity-rest cycle (i.e., 8 hours after wake-up time, or 16:45 hours). The assumption of human acrophase occurring in the middle of the active phase is consistent with actigraphic data from a sample of 500 individuals in the United States [28]. From the latter study, we obtained also an estimate of rhythm robustness.…”

“…The horizontal dashed lines indicates the times of lights-on (07:00 hours) and lights-off (19:00 hours). Human data are from Roenneberg and colleagues [27] and Sani and colleagues [28]. The abscissas are in logarithmic scale.…”

Accelerometer-measured physical activity is not associated with two-year weight change in African-origin adults from five diverse populations

“…However, in order to reduce measurement errors, we provided the same brand/model of calibrated equipment items to all the research sites, and ensured their proper working order at all times. We also feel confident in the robustness of our data as a result of exploring potential seasonal/country differences and have found none to date (Sani et al, 2015). …”

Latitude affects Morningness-Eveningness: evidence for the environment hypothesis based on a systematic review

“…). A higher evening orientation was found with an increasing distance from the equator78911. Contradictory results have been found across the USA, where a higher morningness was related to higher latitudes10.…”

“…Other studies were based on much smaller samples and countries. For example, Sani et al 11. was based on 5 countries and Smith et al 17.…”