Leptin, identified as an antiobesity hormone, also has important role in responses to stress and processing of memory. This study was designed to determine effects of academic examination stress-induced changes in serum leptin and its impact on academic performance. Eighty five healthy female students (age 19-21 years; BMI 21.9 ± 1.6) were recruited for the study. Serum leptin and cortisol were monitored at base line (beginning of academic session) and on the day of examination; using a standardized ELISA kit. Acute perception of academic examination stress was determined with the help of a questionnaire derived from Hamilton Anxiety Scale and self report of stress perception. Academic performance was evaluated by the percentage of marks obtained in the examination. Serum cortisol levels were positively correlated (p < 0.01) with the subjective perception of examination stress but not with academic performance. There was an inverted U-shape relationship between level of stress and academic performance. Leptin increased in all stress groups and correlated (p < 0.01) positively with academic performance. There was an inverted U-shape relationship between level of stress and circulating leptin. The findings suggest the peptide hormone, leptin, is a biomarker of stress perception and a mediator of facilitating effects of stress on cognition.
Keywords: Academic performance; Cortisol; Depression/anxiety; Leptin; Memory; Stress.