Official Title
The Association Between Telomere Length in Peripheral Blood Leukocyte and Propofol Dose in Anesthesia-induction
Brief Title
The Association Between Telomere Length and Propofol Dose in Anesthesia-induction
Protocol ID
NCT03429309
Lead Sponsor
Guangzhou General Hospital of Guangzhou Military Command
Brief Summary
Telomeres are protein-bound DNA repeat structures at the end of eukaryotic chromosomes
that are made up of a simple repetitive sequence (in humans, TTAGGG) and regulate
cellular replicative capacity and cellular proliferation, protect chromosomes from fusing
together during mitosis and maintain genomic stability, and prevent the loss of genetic
data. Telomeres are specialized repetitive DNA sequences, typically ranging from 5,000 to
15,000 bp in humans, which are the critical chromosome capping DNA sequences. The loss of
telomere repeats diminishes telomeric functional capacity.Telomere length(TL) is
important in determining telomere function.This is known as the end replication problem
and results in a gradual decline in TL over time. Consequently,leukocyte TL shortens in a
predictable way with age by roughly 20-40 base pairs per year. Cellular senescence and
subsequent cell death often occur when the mean telomere length reaches a critical
value.Shortened telomeres and lower telomerase are linked to age-related risk factors and
disease.Peripheral blood leukocyte express telomerase at low levels, which can be
measured over a short duration (hours) to demonstrate immediate, short-term changes.
Shorter mean leukocyte telomere length has been shown to be associated with risk of
several age-related diseases.The dosage of propofol gradually reduced with the aging
process. However,it is not known whether the telomere length and variation of telomerase
in PBL relate to the dosage of propofol and time of consciousness disappearance in
anesthesia induction. In this exploratory study, the investigators examined that the
changes of peripheral blood leukocyte telomere length was associated with the dosage of
propofol and time of consciousness disappearance in anesthesia induction.
Given the importance of telomeres in nuclear and cellular function, the central role of
telomere length in determining telomere function,the investigator study that the changes
of telomere length in peripheral blood leukocyte of patients are associated with the
dosage of propofol in anesthesia induction.
Detailed Description
A hundred patients with the American Society of Anesthesiologists (ASA) physical status
I-II, aged from 18 to 80 years, gave an informed-written consent to participate.Testing
took place in the morning after an overnight fast. Patients were scheduled for elective
surgical procedures. After arrival to the operating theater, the peripheral venous line
for fluid and drug administration was inserted. The electrocardiogram, heart rate, a
noninvasive blood pressure, a pulse oximeter and bispectral (BIS) Index were monitored
continuously. 100% oxygen was given for 3 min by face mask. Anesthesia was induced by
intravenous infusion of propofol via the syringe pump at a rate of 30 mg/kg/h. Recordings
began before propofol induction started. After the start of the propofol infusion and BIS
Index at 80, patients were asked loudly "open eyes" and examined eyelash reflex at 15-s
intervals until loss of consciousness (unresponsiveness to the verbal command, no
spontaneous movements and loss of eyelash reflex); and recordings of the heart rate, a
noninvasive blood pressure and BIS Index were obtained during awake baseline and
unconsciousness induced by propofol. Propofol dosage and consciousness disappearance time
were recorded after propofol-induced loss of consciousness. The commands were spoken in a
loud voice by the investigator and were repeated up to three times, if the subject failed
to respond. A subject who obeyed command was considered conscious. The BIS index is
useful, and a reliable and sensitive indicator for assessing the level of consciousness
during sedation and hypnosis with propofol so that the investigators recorded BIS index
to evaluate level of consciousness. To minimize artifacts, patients were instructed not
to open their eyes, talk, or move during the heart rate, a noninvasive blood pressure and
BIS Index recordings before the propofol infusion and the sedation level was assessed
until the patient's unconsciousness.
Study Period
-
Enrollment Count
100 participants
Eligibility Criteria
Inclusion Criteria:
- Patients were scheduled for elective surgical procedures
Exclusion Criteria:
- patients with known cardiac, pulmonary, renal disease, hearing disorders or
neurological diseases, diabetes, and patients taking drugs affecting to the central
nervous system or consuming more than 20 g alcohol daily, a body mass index>30
Filters
General Anesthesia
NA
UNKNOWN
ADULT
OLDER_ADULT