Introduction: The prevalence of obesity and depression is increasing at an alarming rate. The state of obesity and perception of job stress is different in both genders. The circulating levels of stress related hormones cortisol, serotonin and leptin are attenuated in stress.
Objective: To investigate variations in the coding regions of leptin gene in relation to stress perception and other biochemical and physiological parameters of stress perception.
Method: With verbal and written consent, twenty working women were identified from 5 corporate sections of local banks in Karachi. Stress perception was measured by standardized questionnaire. Depending on stress scores the data were classified as no/minimal, mild, moderate and severe stress groups. Changes in appetite were determined by visual analogue scale for hunger and desire to eat during stress. The chemical analytes were measured by ELISA. Leptin gene was sequenced using 3130 Genetic Analyzer of (ABI) Applied Biosystems using BigDye Terminator 3.1 Sequencing Kit protocols at Centralized Science Laboratory University of Karachi. One way ANOVA was applied to analyze data. Result: The BMI and VAS for hunger and desire to eat increased significantly with the severity of stress (p<0.05). Although circulating levels of leptin and cortisol also increased with stress perception (p<0.05) but a decrease in cortisol levels was observed in the group with severe stress perception. Plasma serotonin decreased with increase in stress perception. A single nucleotide polymorphism was found in 5’ flanking region of exon 2 of leptin gene compared to the reference gene fragment retrieved from gene bank with no minimal perception of stress. The guanosine at position 15719 in the reference fragment was replaced by cytidine. No variation was found in the DNA sequences of exon 2 of women with mild, moderate or severe perception of stress. No variation was found in the segment of exon 3 of leptin gene. Conclusion: The consistent finding of a G15719C variant on the 5’ flanking region of exon 2 of LEP in the group of women who claimed no/minimal stress suggest a role of this gene in stress induced obesity and other physiological reactions to stress.