title: Time Delays in Transdermal Alcohol Concentrations Relative to Breath Alcohol Concentrations.
abstract: OBJECTIVE
  Monitors of transdermal alcohol concentration (TAC) provide an objective measurement of alcohol consumption that is less invasive than measurements in blood, breath or urine; however, there is a substantial time delay in the onset of TAC compared to blood or breath alcohol concentrations (BrACs). The current study examined the characteristics of the delay between peak TAC and peak BrAC.
  
  
  METHODS
  Data was aggregated from three experimental laboratory studies (N = 61; 32 men, 29 women) in which participants wore a TAC monitor and BrAC was monitored while drinking one, two, three, four and five beers in the laboratory. Analyses examined the sex- and dose-related differences in peak BrAC and TAC, the time-to-peak BrAC and TAC, and time lag between the peak BrAC and TAC values.
  
  
  RESULTS
  The times-to-peak were an increasing function of the number of beers consumed. At each level of beer consumption the peak TAC averaged lower than peak BrAC and times-to-peak TAC were longer than for BrAC. The time-to-peak BrAC and TAC was longer for women than men. The congruence between peak TAC and BrAC increased as a function of the beers consumed. No sex difference in the time lag between peak BrAC and TAC was detected.
  
  
  CONCLUSIONS
  The congruence between TAC and BrAC and time lags between TAC and BrAC are related to the number of beers consumed. Peak values of TAC and BrAC became more congruent with higher doses but the time lag increased as a function of the amount of alcohol consumed.
  
  
  OBJECTIVE
  The time delay (or lag) and congruence between transdermal vs. BrACs increases as the number of beers increases. Though sex differences are evident in peak transdermal and BrACs, no sex differences were evident in the time lag and the congruence between transdermal and breath alcohol concentrations.
authors: Department of Psychiatry, The University of Texas Health Science Center at San Antonio, NRLC MC 7793, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA.
authors: Tara E
authors: TE
authors: Karns-Wright
authors: Department of Psychiatry, The University of Texas Health Science Center at San Antonio, NRLC MC 7793, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA.
authors: John D
authors: JD
authors: Roache
authors: Department of Psychiatry, The University of Texas Health Science Center at San Antonio, NRLC MC 7793, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA.
authors: Nathalie
authors: N
authors: Hill-Kapturczak
authors: Department of Epidemiology and Biostatistics, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
authors: Yuanyuan
authors: Y
authors: Liang
authors: Department of Psychiatry, The University of Texas Health Science Center at San Antonio, NRLC MC 7793, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA.
authors: Jillian
authors: J
authors: Mullen
authors: Department of Psychiatry, The University of Texas Health Science Center at San Antonio, NRLC MC 7793, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA DoughertyD@uthscsa.edu.
authors: Donald M
authors: DM
authors: Dougherty
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000378:metabolism*; D001515:Beer / Q000032:analysis*; D001944:Breath Tests / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012727:Sex Characteristics; D012869:Skin Absorption / Q000187:drug effects / Q000502:physiology*; D015813:Substance Abuse Detection / Q000379:methods*; D013997:Time Factors; D055815:Young Adult