Jennifer M Cavallari1, Shona C Fang, Murray A Mittleman, David C Christiani. 1. Harvard School of Public Health, Department of Environmental Health, Environmental and Occupational Medicine and Epidemiology Program, 665 Huntington Ave, FXB-103, Boston, MA 02115, USA. jcavalla@hsph.harvard.edu
Abstract
OBJECTIVE: To compare the circadian variation of hourly heart rate variability (HRV) on work and non-workdays among boilermaker construction workers. METHOD: A panel study of 18 males monitored by 24-h ambulatory ECG over 44 observation-days on paired work and non-workdays was conducted. ECGs were analysed and the SD of normal-to-normal beats index (SDNN(i)) was calculated from 5-min data and summarised hourly. SDNN(i)s over work and non-workdays were compared using linear mixed-effects models to account for repeated measures and harmonic regression to account for circadian variation. RESULTS: Both work and non-work hourly HRV exhibited circadian variation with an increase in the evening and a decrease in the afternoon. SDNN(i) was lower on workdays as compared with non-workdays with the largest, statistically significant differences observed between 10:00 and 16:00, during active working. Lower SDNN(i), albeit smaller yet statistically significant differences, was also observed in the evening hours following work (17:00-21:00) and early morning (4:00). In regression models using all time periods, an average workday SDNN(i) was 8.1 ms (95% CI -9.8 to -6.3) lower than non-workday SDNN(i). The circadian pattern of HRV exhibited two peaks which differed on work and non-workdays. CONCLUSION: While workday and non-workday HRV followed a circadian pattern, decreased HRV and variation of the circadian pattern were observed on workdays. Declines and changes in the circadian pattern of HRV is a concern among this exposed population.
OBJECTIVE: To compare the circadian variation of hourly heart rate variability (HRV) on work and non-workdays among boilermaker construction workers. METHOD: A panel study of 18 males monitored by 24-h ambulatory ECG over 44 observation-days on paired work and non-workdays was conducted. ECGs were analysed and the SD of normal-to-normal beats index (SDNN(i)) was calculated from 5-min data and summarised hourly. SDNN(i)s over work and non-workdays were compared using linear mixed-effects models to account for repeated measures and harmonic regression to account for circadian variation. RESULTS: Both work and non-work hourly HRV exhibited circadian variation with an increase in the evening and a decrease in the afternoon. SDNN(i) was lower on workdays as compared with non-workdays with the largest, statistically significant differences observed between 10:00 and 16:00, during active working. Lower SDNN(i), albeit smaller yet statistically significant differences, was also observed in the evening hours following work (17:00-21:00) and early morning (4:00). In regression models using all time periods, an average workday SDNN(i) was 8.1 ms (95% CI -9.8 to -6.3) lower than non-workday SDNN(i). The circadian pattern of HRV exhibited two peaks which differed on work and non-workdays. CONCLUSION: While workday and non-workday HRV followed a circadian pattern, decreased HRV and variation of the circadian pattern were observed on workdays. Declines and changes in the circadian pattern of HRV is a concern among this exposed population.
Authors: Tami A Martino; Gavin Y Oudit; Andrew M Herzenberg; Nazneen Tata; Margaret M Koletar; Golam M Kabir; Denise D Belsham; Peter H Backx; Martin R Ralph; Michael J Sole Journal: Am J Physiol Regul Integr Comp Physiol Date: 2008-02-13 Impact factor: 3.619
Authors: Tami A Martino; Nazneen Tata; Denise D Belsham; Jennifer Chalmers; Marty Straume; Paul Lee; Horia Pribiag; Neelam Khaper; Peter P Liu; Fayez Dawood; Peter H Backx; Martin R Ralph; Michael J Sole Journal: Hypertension Date: 2007-03-05 Impact factor: 10.190
Authors: Ciprian B Anea; Maoxiang Zhang; David W Stepp; G Bryan Simkins; Guy Reed; David J Fulton; R Daniel Rudic Journal: Circulation Date: 2009-03-09 Impact factor: 29.690
Authors: I Kawachi; G A Colditz; M J Stampfer; W C Willett; J E Manson; F E Speizer; C H Hennekens Journal: Circulation Date: 1995-12-01 Impact factor: 29.690
Authors: Jennifer M Cavallari; Ellen A Eisen; Shona C Fang; Joel Schwartz; Russ Hauser; Robert F Herrick; David C Christiani Journal: Environ Health Date: 2008-07-09 Impact factor: 5.984
Authors: Jennifer L Garza; Jennifer M Cavallari; Belinda H W Eijckelhof; Maaike A Huysmans; Ornwipa Thamsuwan; Peter W Johnson; Allard J van der Beek; Jack T Dennerlein Journal: Int Arch Occup Environ Health Date: 2014-09-24 Impact factor: 3.015
Authors: Peter E Umukoro; Jason Y Y Wong; Jennifer M Cavallari; Shona C Fang; Chensheng Lu; Xihong Lin; Murray A Mittleman; Georg Schmidt; David C Christiani Journal: J Occup Environ Med Date: 2016-03 Impact factor: 2.162
Authors: Jinming Zhang; Jennifer M Cavallari; Shona C Fang; Marc G Weisskopf; Xihong Lin; Murray A Mittleman; David C Christiani Journal: Occup Environ Med Date: 2017-06-29 Impact factor: 4.402
Authors: Alex Wilhelmus Jacobus van Kraaij; Giuseppina Schiavone; Erika Lutin; Stephan Claes; Chris Van Hoof Journal: J Med Internet Res Date: 2020-09-09 Impact factor: 5.428
Authors: David Lucas; François Guerrero; Emmanuel Jouve; Sophie Hery; Pascale Capellmann; Jacques Mansourati Journal: Front Public Health Date: 2022-09-28
Authors: Jinming Zhang; Shona C Fang; Murray A Mittleman; David C Christiani; Jennifer M Cavallari Journal: Environ Health Date: 2013-10-02 Impact factor: 5.984
Authors: Peter E Umukoro; Jennifer M Cavallari; Shona C Fang; Chensheng Lu; Xihong Lin; Murray A Mittleman; David C Christiani Journal: Occup Environ Med Date: 2015-12-07 Impact factor: 4.402