Correlation of lower 2 h C-peptide and elevated evening cortisol with high levels of depression in type 2 diabetes mellitus

Abstract

Background A number of studies have explored the association between depression and ghrelin, leptin, and cortisol; further, postprandial C-peptide levels have a therapeutic effect on type 2 diabetes mellitus (T2DM). However, the relationship between C-peptide and depression in patients with diabetes, remains unclear. The aim of this study was to explore the association between depression and ghrelin, leptin, cortisol, and C-peptide in patients with diabetes. Methods We enrolled 50 adults without T2DM, 77 non-depressed adults with T2DM (free of Axis-I psychiatric disorders as assessed using the Mental Illness Needs Index (MINI), Patient Health Questionnaire (PHQ-9 score ≤ 4)) and 59 patients with T2DM and depression (PHQ-9 ≥ 7 and positive by the Structured Clinical Interview for DSM-5). The age range of the participants was 45–59 years of age. We compared the above three groups and explored the association between ghrelin, leptin, cortisol, C-peptide, and depression in patients with diabetes. A post-hoc power-analysis was finished. Results Compared with the non-depression T2DM group, the depression T2DM group had significantly higher blood glucose fluctuations. Further, compared with the non-depression T2DM and non-diabetic groups, the depression T2DM group had significantly lower levels of post-meal 2-h C-peptide and elevated evening cortisol (p < 0.01). Regression analysis revealed a significant negative correlation between depression severity and 2-h postprandial C-peptide in patients with diabetes (p < 0.01) and a significant positive correlation with midnight cortisol levels (p < 0.01). A post hoc power analysis showed that we had an adequate sample size and met the minimum requirement to attain 80% power. A post hoc power calculation also demonstrated that this study basically achieved power of 80% at 5% alpha level. Conclusions Our findings indicate a correlation of low fasting levels of 2-h C-peptide as well as higher midnight cortisol levels with higher depression severity in middle-aged patients with T2DM.

The Effectiveness of a Self-Efficacy-Focused Structured Education Program (SSEP) in Improving Metabolic Control and Psychological Outcomes of Type 2 Diabetes Patients: A 12-Month Follow-Up of a Multicenter Randomized Controlled Trial

“…The intervention that is self-efficacy focused is capable of enhancing the self-efficacy of patients, and then further promoting patients to develop and maintain the DSM behaviors. Third, diabetes distress shows a close relation to cortisol or glycemic control, 26 , 27 so the decrease in diabetes distress may be conducive to the patients’ glycemic control by improving the secretion of cortisol. Moreover, the diabetes medications in the 12th month of the 12-month follow-up were also analyzed, and the non-significant difference was identified between the two groups.…”

Neurological and metabolic related pathophysiologies and treatment of comorbid diabetes with depression

“…The numerous articles exploring other mechanisms, such as the HPA axis and adipokine, suggest the diversity of mechanisms behind comorbidity. Higher depression severity was found to correlate positively with higher midnight cortisol levels 21 . Patients with diabetes presented the worst glycemia control, the most obese and the worst executive functions, and the reduction of executive functions resulted from depressive symptoms 22 .…”

“…The boost in serum corticosterone among diabetic patients and rats suggests that the HPA axis is too active 41–43 . Among patients with T2DM, there was an association between low fasting levels of 2‐h C‐peptide and higher levels of midnight cortisol and higher severity of depression 21 . Research revealed that stressor demands and stress perceptions were associated with depressive symptoms.…”

“… 41 , 42 , 43 Among patients with T2DM, there was an association between low fasting levels of 2‐h C‐peptide and higher levels of midnight cortisol and higher severity of depression. 21 Research revealed that stressor demands and stress perceptions were associated with depressive symptoms. According to the longitudinal pattern, hair cortisol responded to contextual features related to anticipation, novelty/familiarity, and social evaluative threat.…”

“…Higher depression severity was found to correlate positively with higher midnight cortisol levels. 21 Patients with diabetes presented the worst glycemia control, the most obese and the worst executive functions, and the reduction of executive functions resulted from depressive symptoms. 22 Also, the relationship between uncontrolled diabetes and depression had been possibly mediated by central adiposity.…”