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=Volume 14 - 2023

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=Background and Aims: 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. Methods: A comprehensive search of PubMed, Scopus, Web of Science, and Ovid was conducted using a well-established methodology to gather all related publications. Results: A total of 40 studies were included in the analysis of 11336 patients. The overall effect showed a with a mean difference (MD) of -1.92 [95%CI; -2.63: -1.20] and P= 0.00001. Subgroup analysis by study design revealed significant differences as well, but with high heterogeneity within the subgroups (I² 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], P = 0.0002) but not for females (MD = -3.04[95% CI; -6.6:0.54], P = 0.10). Healthy, pregnant, diabetic and CVD subgroups found significant differences in the healthy (MD = -1.74[95% CI; -03.13: -0.35], P = 0.01) and diabetic (MD = -7.69[95% CI; -1.64: -0.73], P = 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], P = 0.36) and observed heterogeneity in the studies (I² = 68%). Conclusions:This study demonstrates a correlation between smoking and serum leptin/ghrelin levels, which explains smoking's effect on body weight.