Endocrine and inflammatory profiles in type 2 diabetic patients with and without major depressive disorder
Authors: Alvarez Adriana , Faccioli Jose , Guinzbourg Mónica , Castex María M , Bayón Claudia , Masson Walter , Bluro Ignacio , Kozak Andrea , Sorroche Patricia , Capurro Lina , Grosembacher Luis , Proietti Adrián , Finkelsztein Carlos , Costa Lucas , Day Patricia Fainstein , Cagide Arturo , Litwak León E , Golden Sherita H 
Published: February 2013

Abstract

Background
There is a high prevalence of depression in individuals with type 2 diabetes mellitus. Depressive disorders are associated with increased medical morbidity and mortality in individuals with diabetes. It has been demonstrated that there is a higher prevalence of diabetic complications among individuals with diabetes and depression compared to those without depression. Several biological alterations have been reported in individuals with depressive disorders, particularly abnormal levels of endocrine-inflammatory markers.
This study aims to determine the prevalence of major depressive disorder (MDD) in type 2 diabetes patients, the prevalence of cardiovascular events in individuals with and without MDD and to compare the endocrine-inflammatory profile between groups.

Methods
The study was approved by the “Comité de Etica de Protocolos de Investigación del Departamento de Docencia e Investigación del Hospital Italiano de Buenos Aires” with the number “1262” and included only patients who provided written informed consent. The study was conducted in accordance with the Declaration of Helsinki and the Habeas Data law on protection of personal data (Law Nª 25326, Argentina).
Type 2 diabetes patients (n = 61) were included and they were classified as having MDD or not according to DSM-IV. Macrovascular disease was obtained from the medical history. Additionally, the intima-media thickness of the common carotid, carotid bifurcations and internal carotid arteries was measured non-invasively by two-dimensional ultrasound imaging. Fasting glucose, fasting lipid profile, inflammatory (CRP, TNF-α) and endocrine (urine free cortisol and saliva cortisol) markers. Student t tests were used to compare means for normally distributed variables and Mann-Whitney test for variables without normal distribution. Relative frequencies were calculated and a chi-square analysis was conducted. Data were expressed as mean ± standard deviation (SD) or median and interquartile range. Multivariable logistic regression was used to determine the relative odds of clinical cardiovascular disease in individuals with compared to those without depression. Differences were considered significant using a two-sided p < 0.05.

Results
21 patients (34%) had MDD and 40 patients (66%) didn’t have MDD. Diabetic patients with MDD had significantly higher CRP levels (4.1(1.9-7.6) vs 1.5(0.5-4.4) mg/l; p = 0.02) and 24-hour urine free cortisol (71.4 ± 21.3 vs 59.8 ± 29.3 ug/24 h; p = 0.03). The other metabolic and inflammatory parameters were not statistically different between groups. There was a significantly higher prevalence of cardiovascular events in individuals with MDD: 38% for the depressive group vs 15% for non-depressive group, p = 0.04). Patients with MDD had a 3.5-fold greater odd of having cardiovascular disease.

Conclusions
Diabetic patients with depression are more likely to have cardiovascular events, and different factors can determine this high association.