A study on the Relationship between morning cortisol levels and fasting blood glucose in shift workers exploring the hypothamic-pituitary-adrenal axis Dysregulation

Abstract

Background: Shift work is associated with disruption of circadian rhythms and
hypothalamic–pituitary–adrenal (HPA) axis dysregulation, potentially contributing to
metabolic abnormalities. Alterations in cortisol secretion patterns and glucose
metabolism among shift workers may increase the risk of early onset metabolic
syndrome and type 2 diabetes mellitus.
Objective: To assess the relationship between morning serum cortisol levels and
fasting blood glucose among shift workers, exploring the possible contribution of
HPA axis dysregulation to early metabolic derangements.
Materials and Methods: This prospective, observational study was conducted at
Katuri Medical College and Hospital over six months (October 2023 to March 2024).
A total of 100 participants were enrolled, including 70 shift workers and 30 daytime
controls. Morning serum cortisol levels and fasting blood glucose levels were
measured following overnight fasting. Statistical comparisons between groups were
made using the Independent Samples t-test, and the correlation between cortisol and
glucose was evaluated using Pearson's correlation coefficient. A p-value < 0.05 was
considered statistically significant.
Results: Shift workers exhibited significantly higher mean morning serum cortisol
levels (19.5 ± 4.2 µg/dL) compared to controls (15.8 ± 3.6 µg/dL; p = 0.001). Mean
fasting blood glucose levels were also elevated among shift workers (101.6 ± 12.5
mg/dL) relative to controls (91.2 ± 10.3 mg/dL; p = 0.002). A moderate positive
correlation was found between morning cortisol and fasting blood glucose levels
among shift workers (r = +0.41, p = 0.0008).
Conclusion: Morning cortisol levels and fasting blood glucose are significantly
elevated among shift workers, with a moderate positive correlation between the two
parameters. These findings highlight the early influence of HPA axis dysregulation
on glucose metabolism in shift workers and underscore the importance of early
screening and preventive strategies to mitigate long-term metabolic risks.