Date of Completion


Embargo Period



Helen Swede, PhD; Pavlos Papasavas, MD; Valerie Duffy, PhD; Stacey Brown, PhD

Field of Study

Public Health


Master of Public Health

Open Access

Open Access


Background: Improving weight loss after bariatric surgery remains a clinical concern. An unstudied factor is the role of leptin, the appetite control hormone, as a pre-surgical predictor of weight loss. High serum levels, often seen in obesity, are an indicator of leptin resistance as the brain no longer responds to satiety signaling.

Methods: Leptin levels were ascertained in female bariatric patients (n=28) prior to surgery at a large tertiary care hospital. We calculated Pearson Correlation Coefficients (r) and unstandardized β coefficients using multivariate linear regression. Primary outcome: Percent Excess Weight Loss (%EWL) evaluated at 6- and 12-months post-surgery. Independent variables were: baseline leptin and, potential confounders, Healthy Eating Behavioral Index (HEBI) and age.

Results: Pearson correlation coefficients showed inverse associations baseline leptin with %EWL at 6-months (r=-.45, p,05). In Linear Regression, baseline leptin was inversely associated with %EWL at 6-months (adjusted β=-.12, p=.03) but the relationship was attenuated at 12-months (adjusted β=-.07. p=.47). HEBI was positively associated with %EWL at both 6-months (adjusted β=.19, p=.04) and 12-months (adjusted β=.26, p=.07).

Conclusion and Discussion: Findings suggest that higher baseline leptin might impede weight loss in the first 6 months after surgery possibly due to reduced appetite control, which held when controlling for age and healthy eating. The effect at 6-months (adjusted β = -.12) denotes that a 75 ng/mL increase in leptin might incur about 10 percentage points less EWL. Longitudinal investigations in larger studies containing an array of potential explanatory variables are recommended.

Major Advisor

Helen Swede, PhD

Available for download on Friday, May 07, 2021