Relationship between cortisol, Interleukin-6 and homocysteine in Alzheimer's disease

Neelam Yeram; Shubhangi Dalvi; Ranjit Mankeshwar; Vinayak Patil; Vinayak Kale; Kamlesh Jagiasi; Leela Abichandani

doi:10.5339/qmj.2021.33

Relationship between cortisol, Interleukin-6 and homocysteine in Alzheimer's disease

Qatar Med J. 2021 Sep 6;2021(33):1-10. doi: 10.5339/qmj.2021.33. eCollection 2021.

Authors

Neelam Yeram¹, Shubhangi Dalvi¹, Ranjit Mankeshwar^{2

3}, Vinayak Patil^{1

4}, Vinayak Kale⁵, Kamlesh Jagiasi⁶, Leela Abichandani¹

Affiliations

¹ Department of Biochemistry, Grant Government Medical College & Sir J. J. Group of Hospitals, Mumbai, India E-mail: shubhangigg03@gmail.com.
² Grant Government Medical College & Sir J. J. Group of Hospitals, Mumbai, India.
³ Department of Community Medicine, Grant Government Medical College & Sir J. J. Group of Hospitals, Mumbai, India.
⁴ Department of Biochemistry, Vedantaa Institute of Medical Sciences, Dahanu, India.
⁵ Department of Psychiatry, GGMC & Sir J. J. Group of Hospitals, Mumbai, India.
⁶ Department of Neurology, GGMC & Sir J. J. Group of Hospitals, Mumbai, India.

Abstract

Objective: Alzheimer's disease (AD) is characterised by progressive cognitive decline due to neurodegeneration. Over activation of the hypothalamic-pituitary-adrenal axis, oxidative stress and inflammation potentially damage the neuronal system, affecting cognition.

Aim: This study aimed to assess the relationship between serum cortisol, Interleukin-6 (IL-6) and homocysteine (Hcy) levels in AD.

Methods: Case-Control observational study consisting of 71 patients with AD and 70 healthy controls above 60 years of age. Serum samples were analysed for cortisol, IL-6 and Hcy levels using chemiluminescence immunoassay (Immulite 1000) technique. Cognitive functions were measured using the Mini-Mental State Examination (MMSE) Score. AD subjects were categorised based on the modified Kuppuswamy socioeconomic status scale. Statistical evaluation was conducted using SPSS Statistics software. Group data were analysed using a two-tailed Student's t-test, analysis of variance (ANOVA), the Mann-Whitney U test and Pearson's correlation test.

Results: Serum cortisol, IL-6 and Hcy levels were significantly increased (p < 0.01) in AD (cortisol: 19.69 ± 8.96 ug/dl; IL-6: 10.27 ± 2.76 pg/ml; Hcy: 23.29 ± 3.81 μmol/l), as compared with the controls (cortisol: 13.37 ± 5.59 ug/dl; IL-6: 3.37 ± 0.79 pg/ml; Hcy: 8.25 ± 2.36 μmol/l). MMSE scores in AD were negatively correlated with cortisol, IL-6 and Hcy levels.

Conclusions: Serum cortisol, IL-6 and Hcy levels are independent biomarkers for AD progression. Hypercortisolaemia, hyperhomocysteinemia and inflammation play important roles in AD-related cognitive dysfunction and are interlinked.

Keywords: Alzheimer's disease; Interleukin-6; cortisol; homocysteine.