title: [Effect of chronic lead poisoning on the parameters of heart rate variability].
abstract: BACKGROUND
  The dysfunction of the autonomic nervous system is one of the effects of chronic exposure to lead. Heart rate variability (HRV) is a non-invasive method used to estimate the autonomic system. The aim of the study was to estimate HRV in people occupationally exposed to lead.
  
  
  METHODS
  The study group included 43 copper-smelters and 43 healthy subjects matched individually. A 24-hour ECG Holter monitoring was performed in all men.
  
  
  RESULTS
  The HRV time analysis in a 24-hour observation, as well as for daily activities (6:00-22:00) and nocturnal sleep (22:00-6:00) showed that pNN50 parameter, an estimator of the vagus nerve function, was significantly lower in copper-smelters than in healthy subjects (p < 0.05). The majority of time and spectral HRV parameters, estimated at 15-min intervals during day- and night-time in the group of lead exposed men, were lower than in the control group (p < 0.05).
  
  
  CONCLUSIONS
  In subjects occupationally exposed to lead, HRV is lower than in healthy men, which results rather from the decreased parasympathetic than from the increased sympathetic activity.
authors.affiliation: Kliniki Chorób Wewnetrznych, Zawodowych i Nadciśnienia Tetniczego, Akademii Medycznej we Wrocławiu.
authors.forename: Ryszard
authors.initials: R
authors.lastname: Andrzejak
authors.forename: Rafał
authors.initials: R
authors.lastname: Poreba
authors.forename: Arkadiusz
authors.initials: A
authors.lastname: Derkacz
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002908:Chronic Disease; D002940:Circadian Rhythm; D015716:Electrocardiography, Ambulatory / Q000379:methods; D006339:Heart Rate; D006801:Humans; D007855:Lead Poisoning / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D008669:Metallurgy; D008875:Middle Aged; D009784:Occupational Diseases / Q000139:chemically induced / Q000503:physiopathology*; D016273:Occupational Exposure / Q000009:adverse effects*; D011044:Poland; D012307:Risk Factors