Salivary Cortisol Levels and Body Composition in Mexican College Students

Abstract

Obesity is a serious public health problem worldwide, generating almos 82% of health care expenses in México. A growing young population is presenting overweight and excesive body fat mass wich in the long term evolves in metabolic syndrome. Cortisol plays a pivotal role in the generation of obestiy and inflammation, which leads to further endocrinological disorders as is insulin and leptin resistance. Therefore, it is imperative to study the association between body fat mass and cortisol levels, which can be studied in fasting saliva as a non‐invasive method.The aim of this study was to characterize body composition and fasting salival cortisol levels in a population of mexcian college students. This protocol was accepted by the Ethics Comittee of Nursing School of UASLP.150 female and 82 male college students aged 18–24 years were included in this study. Body composition was measured using a bioelectrical impedance scale (InBody, Korea), stadiometer and measuring rod as recomended by WHO procedures. Saliva samples were collected in a sterile plastic tube in fasting conditions, freezed and used for cortisol determination using a specific ELISA kit (Salimetrics, PA). For salivary cortisol studies, a cohort of 42 samples from women and 34 from men were selected representing all BMI categories. Psychological stress was measured in order to contol cortisol production due to anxiety.This population showed a lower percentage of obesity and overweight than that presented for this age group. BMI: 58.2% normal, 24.1% overweight, 12% obesity and 5.6 % low weight. Nevertheless, fat body mas was elevated in 63.8% of the population, concentrated mainly in the abdominal region (71.5% showed high degrees of abdominal fat mass, 25.4 % was normal and 3 % was low). Parameters for categorization of anthropometry were based on WHO standards. Skeletal muscle mass was normal in 53.4% of the population and low in 39.2% and basal metabolic rate was low for 64.2% . Regarding cortisol, a mean value of 0.40 ± 0.19 μg/dL was found for women and 0.41 ± 0.26 μg/dL for men. Higher levels of salivary cortisol were found in the high fat mass percentaje in the male population but not among BMI categories or in the female population. Psychological stress had no significant effect on cortisol levels in either population.We conclude that fat mass is altered earlier than BMI in this young population considered healthy. Morning cortisol levels are not significantly increased in women but are increased in men, and are neither affected by physchological stress.Support or Funding InformationCONACYT Scholarship 793437 to ERMUASLP Grant C17‐FAI‐06‐36.36 to PASThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.