Short Term Effect of Smoking Cessation on Human Metabolism
Conditions: Smoking Cessation, Metabolic Syndrome
Sponsor: Hebrew University of Jerusalem

 
Short term  effect of smoking cessation on human metabolism 
Authors: Inbal A Segev Milber, Anna Aronis and Robert D Hoffman  
Helsinki Committee approval number (Meuhedet HCO, Israel): 05-23-03-16 
Date of the approval: 14/4/2016. 
Date of beginning of recruitment: 18/4/2016 
 
 

METHODS 
The trial was designed as a two-arm study - prospective and retrospective. 
The study was approved by the Meuhedet HMO Ethics Committee according 
to the ethical guidelines of the Helsinki Committee. 
Prospective Arm 
Studied population 
The prospective arm included 108 participants aged 30-70 who were recruited 
from the smoking cessation workshops of the Meuhedet HMO (Israeli Health 
Services) during 2016-2017. Candidates with benign tumors, bariatric 
surgeries, and endoscopic bariatric procedures before or during the study 
period were excluded. 
Study design 
All subjects signed informed consent to participate, after receiving detailed 
information about the study objectives and procedure. The collected data 
included weight, BMI, waist circumference and Waist Hip Ratio (WHR) at 3 time 
points: a. the third weekly meeting of the cessation workshop, pre-cessation 
phase (baseline- phase 0), b. workshop's last meeting (the eighth weekly 
cessation meeting – phase 1) and 6 months after the cessation program 
(phase 2). The effects of smoking cessation support medicines was also 
examined. 
Anthropometric measurements 
 Weight was measured with participants standing up, wearing light clothes and 
without shoes, using a digital scale. Waist circumference was measured above 

the iliac crest. Hip circumference was taken at the maximum circumference 
between the groin and the iliac crest. Height data were based on participants' 
self-report. Participants were classified as smokers (S), quitters (Q) and re-
smokers "relapsers" (RS) based on self-reported data at each visit. Participants 
also completed a questionnaire regarding cigarette-smoking habits and health 
information. The numerical value of pack years was calculated based on that 
questionnaire (Pack years is a unit quantifying the lifetime exposure to smoking, 
calculated by multiplying the number of packs of cigarettes smoked per day by 
the number of years the person has smoked). 
Retrospective Arm 
Studied population 
The retrospective arm presented a file review of 200 patients between 25-70 
years of age, who participated in smoking cessation workshops of the 
Meuhedet HMO in 2014.  
Candidates with benign tumors, bariatric surgeries, and endoscopic bariatric 
procedures before or during the study period were excluded, as well as those 
who were unavailable for a phone conversation. 
Study design 
Two blood test results, as documented in medical files, were collected and 
analyzed. The first one during the year preceding the smoking cessation 
workshops (baseline- phase 0), and the second during the year after 
completing them. Smoking status was verified by a telephone call. Participants 
were classified as smokers (S) and quitters (Q). 

The effect of smoking cessation medications on metabolic profile was also 
examined.  
Metabolic measurements 
File recorded blood measurements were used for Fasting Glucose (BFG), Total 
Cholesterol (TC), HDL Cholesterol (HDL), LDL Cholesterol (LDL) and 
triglycerides (TG) as examined in HMO laboratories. Results were analyzed 
according to WHO criteria. 
STATISTICAL ANALYSIS 
Data was analyzed using JMP Pro 12 and R software.  Mean values and their 
standard error (SE) were used to summarize the distribution of continuous 
variables. To determine significant statistical differences between two sets of 
data with normal distribution we used Student's t-test/ ANOVA. For paired sets 
of data that may not be normally distributed we used the Wilcoxon signed rank 
test, and for unmatched sets-, the Mann Whitney's u-test was used. Each 
patient constituted his own control – each post workshop result was compared 
with the pre workshop result. 
Fisher's proportion test was used to determine significant statistical differences 
between proportions in a given compatible groups. P<0.05 was considered 
significant. All statistical tests were two tailed.