AUTHOR=Shaheen Nour , Shaheen Ahmed , Diab Rehab Adel , Saad Abdelrahman M. , Abdelwahab Omar Ahmed , Soliman Sama , Hefnawy Mahmoud Tarek , Ramadan Alaa , Meshref Mostafa , Nashwan Abdulqadir J. 

TITLE=Association of serum leptin and ghrelin levels with smoking status on body weight: a systematic review and meta-analysis

JOURNAL=Frontiers in Psychiatry

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2023.1296764

DOI=10.3389/fpsyt.2023.1296764

ISSN=1664-0640

ABSTRACT=<sec id="sec1"><title>Background and aims</title><p>Smoking cigarettes is a major global health problem that affects appetite and weight. The aim of this systematic review was to determine how smoking affected plasma leptin and ghrelin levels.</p></sec><sec id="sec2"><title>Methods</title><p>A comprehensive search of PubMed, Scopus, Web of Science, and Ovid was conducted using a well-established methodology to gather all related publications.</p></sec><sec id="sec3"><title>Results</title><p>A total of 40 studies were included in the analysis of 11,336 patients. The overall effect showed a with a mean difference (MD) of −1.92[95%CI; −2.63: −1.20] and <italic>p</italic> = 0.00001. Subgroup analysis by study design revealed significant differences as well, but with high heterogeneity within the subgroups (<italic>I</italic><sup>2</sup> of 82.3%). Subgroup by sex showed that there was a significant difference in mean difference between the smoking and non-smoking groups for males (MD = −5.75[95% CI; −8.73: −2.77], <italic>p</italic> = 0.0002) but not for females (MD = −3.04[95% CI; −6.6:0.54], <italic>p</italic> = 0.10). Healthy, pregnant, diabetic and CVD subgroups found significant differences in the healthy (MD = −1.74[95% CI; −03.13: −0.35], <italic>p</italic> = 0.01) and diabetic (MD = −7.69[95% CI, −1.64: −0.73], <italic>p</italic> = 0.03). subgroups, but not in the pregnant or cardiovascular disease subgroups. On the other hand, the meta-analysis found no statistically significant difference in Ghrelin serum concentration between smokers and non-smokers (MD = 0.52[95% CI, −0.60:1.63], <italic>p</italic> = 0.36) and observed heterogeneity in the studies (<italic>I</italic><sup>2</sup> = 68%).</p></sec><sec id="sec4"><title>Conclusion</title><p>This study demonstrates a correlation between smoking and serum leptin/ghrelin levels, which explains smoking’s effect on body weight.</p></sec><sec><title>Systematic review registration</title><p><ext-link xlink:href="https://www.crd.york.ac.uk/ prospero/display_record.php" ext-link-type="uri" xmlns:xlink="http://www.w3.org/1999/xlink">https://www.crd.york.ac.uk/ prospero/display_record.php</ext-link>, identifier (Record ID=326680).</p></sec>