TY - JOUR
T1 - Timing and intensity of light correlate with body weight in adults
AU - Reid, Kathryn J.
AU - Santostasi, Giovanni
AU - Baron, Kelly G.
AU - Wilson, John
AU - Kang, Joseph
AU - Zee, Phyllis C.
N1 - Funding Information:
The authors have read the journal’s policy and have the following to report, Dr. Reid reports receiving a grant from Philips. Dr. Santostasi, Mr. Wilson and Dr. Kang report no competing interest. Dr. Baron reports receiving grants from the National Institute of Health. Dr. Zee has served as a consultant to Purdue Pharma, Merck, Vanda, Jazz and Philips/Respironics, stock ownership in Teva, member of the Board of Directors of the Sleep Research Society. None of these potential competing interests relate to the work presented in this manuscript. This does not alter the authors’ adherence to all the PLOS ONE polices on sharing data and materials.
PY - 2014/4/2
Y1 - 2014/4/2
N2 - Light exposure can influence sleep and circadian timing, both of which have been shown to influence weight regulation. The goal of this study was to evaluate the relationship between ambient light, sleep and body mass index. Participants included 54 individuals (26 males, mean age 30.6, SD=11.7 years). Light levels, sleep midpoint and duration were measured with wrist actigraphy (Actiwatch-L) for 7 days. BMI was derived from self-reported height and weight. Caloric intake was determined from 7 days of food logs. For each participant, light and activity data were output in 2 minute epochs, smoothed using a 5 point (10 minute) moving average and then aggregated over 24 hours. The mean light timing above 500 lux (MLiT500) was defined as the average clock time of all aggregated data points above 500 lux. MLiT500 was positively correlated with BMI (r=0.51, p<0.001), and midpoint of sleep (r=0.47, p<0.01). In a multivariable linear regression model including MLiT 500 and midpoint of sleep, MLiT500 was a significant predictor of BMI (B=1.26 SE=0.34, β=0.53 p=0.001, r2 Δ=0.22). Adjusting for covariates, MLiT500 remained an independent predictor of BMI (B=1.28 SE=0.36, β=0.54, p=0.002, r 2Δ=0.20). The full model accounted for 34.7% of the variance in BMI (p=0.01). Exposure to moderate levels of light at biologically appropriate times can influence weight, independent of sleep timing and duration.
AB - Light exposure can influence sleep and circadian timing, both of which have been shown to influence weight regulation. The goal of this study was to evaluate the relationship between ambient light, sleep and body mass index. Participants included 54 individuals (26 males, mean age 30.6, SD=11.7 years). Light levels, sleep midpoint and duration were measured with wrist actigraphy (Actiwatch-L) for 7 days. BMI was derived from self-reported height and weight. Caloric intake was determined from 7 days of food logs. For each participant, light and activity data were output in 2 minute epochs, smoothed using a 5 point (10 minute) moving average and then aggregated over 24 hours. The mean light timing above 500 lux (MLiT500) was defined as the average clock time of all aggregated data points above 500 lux. MLiT500 was positively correlated with BMI (r=0.51, p<0.001), and midpoint of sleep (r=0.47, p<0.01). In a multivariable linear regression model including MLiT 500 and midpoint of sleep, MLiT500 was a significant predictor of BMI (B=1.26 SE=0.34, β=0.53 p=0.001, r2 Δ=0.22). Adjusting for covariates, MLiT500 remained an independent predictor of BMI (B=1.28 SE=0.36, β=0.54, p=0.002, r 2Δ=0.20). The full model accounted for 34.7% of the variance in BMI (p=0.01). Exposure to moderate levels of light at biologically appropriate times can influence weight, independent of sleep timing and duration.
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U2 - 10.1371/journal.pone.0092251
DO - 10.1371/journal.pone.0092251
M3 - Article
C2 - 24694994
AN - SCOPUS:84898792758
VL - 9
JO - PLoS One
JF - PLoS One
SN - 1932-6203
IS - 4
M1 - e92251
ER -