Correlates of serum leptin and insulin-like growth factor-I concentrations in normal weight and overweight/obese Iranian women

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

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 11,336 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%).

Conclusion

This study demonstrates a correlation between smoking and serum leptin/ghrelin levels, which explains smoking's effect on body weight.

Systematic review registration

https://www.crd.york.ac.uk/ prospero/display_record.php, identifier (Record ID=326680).

Body weight gain and serum leptin levels of non-overweight and overweight/obese pregnant women

Background

Our objective was to evaluate changes in serum leptin levels during pregnancy in overweight/obese and non-obese women and to assess total and percent weight gain during pregnancy as possible factors that influence leptin levels.

Material/Methods

In a prospective study of 42 low-risk pregnant women receiving prenatal care, we assessed serum leptin levels at gestational weeks 9–12, 25–28, and 34–37. Based on their pre-pregnancy body mass indices (BMIs), the cohort was divided into: non-overweight (BMI <25 kg/m²) and overweight/obese (BMI ≥25 kg/m²) subjects.

Results

We found a progressive increase in maternal weight gain during pregnancy in both groups. There was also a progressive increase in leptin levels in the 2 strata; however, the increase was significantly higher in the non-overweight patient group. We found that non-overweight pregnant women had a noticeably larger total weight gain. When analyzing the percent weight gain during pregnancy compared to the pre-pregnancy weight, the non-overweight group had a significantly greater percent weight gain than the overweight/obese group.

Conclusions

Our results suggest that the greater increase in leptin levels in non-overweight pregnant women can be explained by the higher percent weight gain in this group compared to overweight/obese women. These findings suggest that controlling the percent weight gain may be an important preventive measure when controlling leptin levels during pregnancy and subsequent medical complications.