Adrenal gland volume and dexamethasone-suppressed cortisol correlate with total daily salivary cortisol in African-American women

Association between contralateral adrenal and hypothalamus-pituitary-adrenal axis in benign adrenocortical tumors

Context

Adrenal incidentaloma (AI) is commonly discovered on cross-sectional imaging. Mild autonomous cortisol secretion is the most common functional disorder detected in AI.

Objective

To delineate the association between radiological characteristics of benign adrenocortical tumors and hypothalamus-pituitary-adrenal (HPA) axis.

Methods

In the study, 494 patients diagnosed with benign unilateral adrenocortical tumors were included. Mild autonomous cortisol secretion (MACS) was diagnosed when cortisol after 1mg-dexamethasone suppression test (1-mg DST) was in the range of 1.8-5ug/dl. Non-functional adrenocortical tumor (NFAT) was diagnosed as cortisol following 1-mg DST less than 1.8ug/dL. We performed Logistics regression and causal mediation analyses, looking for associations between radiological characteristics and the HPA axis.

Results

Of 494 patients, 352 (71.3%) with NFAT and 142 (28.7%) with MACS were included. Patients with MACS had a higher tumor diameter, thinner contralateral adrenal gland, and lower plasma ACTH and serum DHEAS than those with NFAT. ACTH (OR 0.978, 0.962-0.993) and tumor diameter (OR 1.857, 95%CI, 1.357-2.540) were independent factors associated with decreased serum DHEAS (all P<0.05). ACTH was also associated with decreased contralateral adrenal diameter significantly (OR 0.973, 95%CI, 0.957-0.988, P=0.001). Causal mediation analysis showed ACTH mediated the effect significantly for the association between 1-mg DST results and DHEAS level (Pmediation<0.001, proportion=22.3%). Meanwhile, we found ACTH mediated 39.7% of the effects of 1-mg DST on contralateral adrenal diameter (Pmediation=0.012).

Conclusions

Patients with MACS had thinner contralateral adrenal glands and disturbed HPA axes compared with NFAT. ACTH may partially be involved in mediating the mild autonomous cortisol secretion to DHEAS and the contralateral adrenal gland.

Cardiovascular risk in bipolar disorder - A case for the hypothalamus-pituitary-adrenal axis?

BACKGROUND

Unipolar major depressive disorder (MDD) and bipolar disorder (BD) are associated with elevated mortality risk secondary to natural causes. Cardiovascular disease (CVD) constitutes the most prevalent underlying condition. Patients with BD display higher CVD-associated excess mortality than MDD patients. Epicardial adipose tissue (EAT) volume, a known predictor of premature CV morbidity and adrenal gland (AG) volume, an indicator for chronic hypothalamus-pituitary-adrenal (HPA) axis activation, were compared in BD and MDD patients.

METHODS

Magnetic resonance imaging was performed to assess EAT and AG volume in age-, gender-, and body mass index (BMI)-matched MDD (N = 27) and BD (N = 27) patients. Ten-year CV mortality risk and diabetes risk were assessed by PROCAM, ESC-SCORE, and FINDRISK, respectively; metabolic syndrome (MetS) was determined following NCEP/ATP III criteria.

RESULTS

Cardiometabolic risk scores and frequency of MetS were comparable, and scores of cardiometabolic risk indices did not significantly differ in both groups. After adjustment for age, BMI, and physical activity, EAT and AG volumes were significantly higher in BD compared to MDD. Partial correlation analyses showed a significant positive association of EAT and AG volumes in BD but not in the MDD.

LIMITATIONS

The modest sample size warrants confirmation in a larger cohort and the cross-sectional design does not allow for temporal or causal inferences.

CONCLUSION

Our study indicates increased EAT accumulation in BD patients. This was associated with HPA axis dysregulation. Therapeutic lifestyle interventions that reduce EAT volume should be considered in clinical BD management.

The association between adrenal adenoma size, autonomous cortisol secretion and metabolic derangements

OBJECTIVE

Autonomous cortisol secretion (ACS) is common in patients with adrenal incidentalomas (AI). ACS is associated with increased cardiovascular morbidity and mortality. Data regarding the association between radiological characteristics of adrenal adenomas, their hormonal functionality and metabolic outcomes, are scarce and inconclusive. In this study, we aim to delineate the association between radiological characteristics of AI, ACS and metabolic status.

METHODS

A cross-sectional study of 77 patients with AI who underwent a comprehensive hormonal evaluation. Radiological assessments were performed by an independent radiologist blinded to the clinical and hormonal phenotype of each case. Linear regression models were used to evaluate the association between post dexamethasone suppression test (DST) cortisol levels, metabolic indices and radiological measurements.

RESULTS

Mean maximal adenoma diameter was greater in patients with versus without ACS (20.35 ± 6 vs. 27.09 ± 9.3 mm, respectively, p < .01). Maximal adenoma diameter was found to be positively and linearly correlated with post-DST morning cortisol levels across their entire range (R = .474, p < .01). Linear correlations between maximal adenoma diameter and indices of glycemic control showed a correlation coefficient (R) of .481 and .463 for fasting plasma glucose (FPG) and haemoglobin A1c (HbA1c), respectively, p < .01. When analysis included only patients with ACS, an R = .584 and R = .565 was observed for FPG and HbA1c, respectively (p < .01 for both). The association between maximal adenoma diameter and both FPG and post-DST morning cortisol intensified in patients with metabolic syndrome.

CONCLUSION

There is a quantitative positive mild correlation between AI size and both cortisol autonomy and metabolic parameters.

The effect of concurrent resistance-aerobic training on serum cortisol level, anxiety, and quality of life in pediatric type 1 diabetes

Background Given the importance of anxiety and quality of life for the mental health of children with type 1 diabetes (T1D), exercise prescription can be of crucial significance. The present study aims to explore the effect of concurrent resistance-aerobic training on serum cortisol level, anxiety, and quality of life among pediatric T1D. Methods Forty children (aged 8-14 years) were randomly assigned to experimental (n = 20) and control groups (n = 20) for 16 weeks. The exercise training program was composed of 16 weeks of interval concurrent resistance-aerobic training with a duration of 60 min performed three times a week. The subjects first performed the resistance training (20 min of Pilates exercises and 20 min of body weight-bearing exercises). Then, the aerobic exercises were performed with an intensity of 50-75% of maximum heart rate. Before and after the training, blood tests including cortisol were carried out on the subjects by RIA kit. Anxiety and quality of life were measured by the Revised Children's Manifest Anxiety Scale (RCMAS) and Pediatric Quality of Life (PedsQL), respectively. Body composition was measured by InBody. Data were analyzed by paired and independent t-test at p < 0.05 significance level. Results Sixteen weeks of concurrent resistance-aerobic exercise significantly reduced the anxiety index (p = 0.001) and increased the quality of life (p = 0.003). Although the cortisol index was increased, it did not reveal any significant differences between the experimental and control groups (p = 0.781). No significant differences were observed in the indices of quality of life, anxiety, and cortisol in the control group. Conclusions A 16-week program of concurrent resistance-aerobic training can improve the quality of life and anxiety among children suffering from T1D, but it may not influence the cortisol level (p > 0.05).

Hyperactivation of the hypothalamo-pituitary-adrenocortical axis in streptozotocin-diabetic gerbils (Gerbillus gerbillus)

This study was designed to investigate the HPA-axis impairment in the streptozotocin (STZ)-diabetic gerbils (Gerbillus gerbillus). Twenty-six male gerbils (body weight ~27 g) were divided into 3 groups: vehicle control (n = 10), 2 days of diabetes (n = 09) and 30 days of diabetes (n = 07). The latter 2 groups received an intraperitoneal injection of STZ (150 mg/kg of body weight). At 2 and 30 days of diabetes, streptozotocin-diabetic gerbils underwent a retro-orbital puncture for assessment of biochemical and hormonal parameters. Subsequently the animals were decapitated and the adrenal glands were removed, weighed and processed for light microscopy and stereology. Nondiabetic control gerbils that had been injected with citrate buffer were examined as a comparison. At 2 days of diabetes, STZ gerbils exhibited symptoms that are characteristic of human diabetes type 1. The adrenal gland showed significant increase in weight, associated with a larger cortex layer, hypertrophy of the fasciculate cells and a significant decrease in the nucleocytoplasmic index. These changes were associated with higher plasma ACTH and cortisol concentrations compared to nondiabetic controls. At 30 days postdiabetes, ACTH levels remained elevated, whereas cortisol levels decreased compared to the early stage of diabetes. Histological analysis revealed the existence of a band of connective tissue (collagen) that separates the cortical and medullary zones and is not present in humans or laboratory rodents, which represents a striking change seen throughout the disease. STZ-induced diabetes mellitus in Gerbillus gerbillus resulted in hyperactivation of the HPA axis in the early stages of diabetes mellitus which did not persist into the final stages of the disease, suggesting a possible reduction in adrenocortical sensitivity over time.

Pericardial adipose tissue and the metabolic syndrome is increased in patients with chronic major depressive disorder compared to acute depression and controls

OBJECTIVE

Major depressive disorder (MDD) is associated with an estimated fourfold risk for premature death, largely attributed to cardiovascular disorders. Pericardial adipose tissue (PAT), a fat compartment surrounding the heart, has been implicated in the development of coronary artery disease. An unanswered question is whether people with chronic MDD are more likely to have elevated PAT volumes versus acute MDD and controls (CTRL).

METHODS

The study group consists of sixteen patients with chronic MDD, thirty-four patients with acute MDD, and twenty-five CTRL. PAT and adrenal gland volume were measured by magnetic resonance tomography. Additional measures comprised factors of the metabolic syndrome, cortisol, relative insulin resistance, and pro-inflammatory cytokines (interleukin-6; IL-6 and tumor necrosis factor-α, TNF-α).

RESULTS

PAT volumes were significantly increased in patients with chronic MDD>patients with acute MDD>CTRL. Adrenal gland volume was slightly enlarged in patients with chronic MDD>acute MDD>CTRL, although this difference failed to reach significance. The PAT volume was correlated with adrenal gland volume, and cortisol concentrations were correlated with depression severity, measured by BDI-2 and MADRS. Group differences were found concerning the rate of the metabolic syndrome, being most frequent in chronic MDD>acute MDD>CTRL. Further findings comprised increased fasting cortisol, increased TNF-α concentration, and decreased physical activity level in MDD compared to CTRL.

CONCLUSION

Our results extend the existing literature in demonstrating that patients with chronic MDD have the highest risk for developing cardiovascular disorders, indicated by the highest PAT volume and prevalence of metabolic syndrome. The correlation of PAT with adrenal gland volume underscores the role of the hypothalamus-pituitary-adrenal system as mediator for body-composition changes. Metabolic monitoring, health advices and motivation for the improvement of physical fitness may be recommended in depressed patients, in particular in chronic depression.

The Adrenal Gland Volume Measurements in Manifestation of the Metabolic Status in Type-2 Diabetes Mellitus Patients

Objectives. The aim of our study was to investigate the differences in adrenal gland volume between nondiabetic controls and Type-2 diabetic patients and to examine the influence of glycemic control in diabetes mellitus on adrenal gland volume. Methods. From March 2 to November 25, 2015, 62 consecutive patients with Type-2 DM along with 62 nondiabetics matched by age, gender, and BMI were enrolled in this prospective study. Our diabetes patients were categorized into two groups, well-controlled and poorly controlled diabetes groups. Adrenal volumetric measurements were performed by two radiologists, prospectively and independently, with semiautomatic software. Interobserver reliability was studied using the interobserver correlation coefficient (ICC). Results. The total adrenal volume (TAV) was significantly higher in Type-2 diabetic patients when compared with nondiabetic patients (p < 0.05). When we investigated diabetic patients according to glycemic controls, the TAVs in controlled diabetic patients were significantly higher than in those of the poorly controlled or uncontrolled diabetic patients (p < 0.05). Nondiabetic control patients have significantly smaller TAVs when compared to controlled and poorly or noncontrolled diabetic patients (p < 0.05). Conclusion. Our study suggests that adrenal gland volume measurement may be used as an indirect marker of glycemic control in patients with diabetes.

MDCT Linear and Volumetric Analysis of Adrenal Glands: Normative Data and Multiparametric Assessment

OBJECTIVES

To study linear and volumetric adrenal measurements, their reproducibility, and correlations between total adrenal volume (TAV) and adrenal micronodularity, age, gender, body mass index (BMI), visceral (VAAT) and subcutaneous adipose tissue volume (SAAT), presence of diabetes, chronic alcoholic abuse and chronic inflammatory disease (CID).

METHODS

We included 154 patients (M/F, 65/89; mean age, 57 years) undergoing abdominal multidetector row computed tomography (MDCT). Two radiologists prospectively independently performed adrenal linear and volumetric measurements with semi-automatic software. Inter-observer reliability was studied using inter-observer correlation coefficient (ICC). Relationships between TAV and associated factors were studied using bivariate and multivariable analysis.

RESULTS

Mean TAV was 8.4 ± 2.7 cm(3) (3.3-18.7 cm(3)). ICC was excellent for TAV (0.97; 95 % CI: 0.96-0.98) and moderate to good for linear measurements. TAV was significantly greater in men (p < 0.0001), alcoholics (p = 0.04), diabetics (p = 0.0003) and those with micronodular glands (p = 0.001). TAV was lower in CID patients (p = 0.0001). TAV correlated positively with VAAT (r = 0.53, p < 0.0001), BMI (r = 0.42, p < 0.0001), SAAT (r = 0.29, p = 0.0003) and age (r = 0.23, p = 0.005). Multivariable analysis revealed gender, micronodularity, diabetes, age and BMI as independent factors influencing TAV.

CONCLUSIONS

Adrenal gland MDCT-based volumetric measurements are more reproducible than linear measurements. Gender, micronodularity, age, BMI and diabetes independently influence TAV.

KEY POINTS

• Volumetric measurements are more reproducible than linear measurements for adrenal glands. • Inter-observer reproducibility of adrenal gland volume is excellent using semiautomatic software. • Gender, age, BMI, and diabetes independently influence total adrenal gland volume. • Adrenal micronodularity is associated with increased total adrenal gland volume.

Adrenal gland volume, intra-abdominal and pericardial adipose tissue in major depressive disorder

Major depressive disorder (MDD) is associated with an increased risk for the development of cardio-metabolic diseases. Increased intra-abdominal (IAT) and pericardial adipose tissue (PAT) have been found in depression, and are discussed as potential mediating factors. IAT and PAT are thought to be the result of a dysregulation of the hypothalamus-pituitary-adrenal axis (HPAA) with subsequent hypercortisolism. Therefore we examined adrenal gland volume as proxy marker for HPAA activation, and IAT and PAT in depressed patients. Twenty-seven depressed patients and 19 comparison subjects were included in this case-control study. Adrenal gland volume, pericardial, intraabdominal and subcutaneous adipose tissue were measured by magnetic resonance imaging. Further parameters included factors of the metabolic syndrome, fasting cortisol, fasting insulin, and proinflammatory cytokines. Adrenal gland and pericardial adipose tissue volumes, serum concentrations of cortisol and insulin, and serum concentrations tumor-necrosis factor-α were increased in depressed patients. Adrenal gland volume was positively correlated with intra-abdominal and pericardial adipose tissue, but not with subcutaneous adipose tissue. Our findings point to the role of HPAA dysregulation and hypercortisolism as potential mediators of IAT and PAT enlargement. Further studies are warranted to examine whether certain subtypes of depression are more prone to cardio-metabolic diseases.

Incidental adrenal enlargement: an overview from a retrospective study in a chinese population

Aim. To investigate incidental adrenal enlargement clinical characteristics and functional status and analyze functional lesion risk factors. Materials and Methods. This retrospective study included 578 patients with adrenal imaging features showing enlargement. Incidental adrenal enlargement cases (78) were considered eligible. Demographics, functional diagnosis, adrenal imaging features, and concomitant diseases were analyzed. Results. The number of adrenal enlargements and proportion of incidental adrenal enlargement increased each year. Mean patient age was 50.32 years. Thirty-nine cases had unilateral enlargement on the left side and 3 on the right side; 36 had bilateral enlargement. Routine medical checkup was found to have the greatest chance (43.59%) of revealing clinical onsets leading to discovery. Biochemical and functional evaluation revealed 54 (69.23%) cases of nonfunctional lesions, 12 (15.38%) of subclinical Cushing syndrome, 6 (7.69%) of primary hyperaldosteronism, 1 (1.28%) of metastasis, and 5 (6.41%) of unknown functional status. Nodular adrenal enlargement (OR, 7.306; 95% CI, 1.727-28.667; P = 0.006) was a risk factor for functional lesions. Age and lesion location were not significant factors. Conclusion. Incidental adrenal enlargement is a frequent radiographic finding and is accompanied by diverse clinical factors that require proper evaluation and management. Nodular adrenal enlargement was a risk factor.

HPA axis and aging in depression: systematic review and meta-analysis

One of the most consistent findings in the biology of depression is an altered activity of the hypothalamic-pituitary-adrenal (HPA) axis. However, data concerning this issue have never been examined with a focus on the older population. Here we present a systematic review and meta-analysis, based on studies investigating levels of cortisol, adrenocorticotropic hormone (ACTH) and corticotropin-releasing hormone (CRH) in depressed participants older than 60 and compared with healthy controls. We found 20 studies, for a total of 43 comparisons on different indices of HPA axis functioning. Depression had a significant effect (Hedges' g) on basal cortisol levels measured in the morning (0.89), afternoon (0.83) and night (1.39), but a smaller effect on cortisol measured continuously (0.51). The effect of depression was even higher on post-dexamethasone cortisol levels (3.22), whereas it was non-significant on morning ACTH and CRH levels. Subgroup analyses indicated that various methodological and clinical factors can influence the study results. Overall, older participants suffering from depression show a high degree of dysregulation of HPA axis activity, with differences compared with younger adults. This might depend on several mechanisms, including physical illnesses, alterations in the CNS and immune-endocrinological alterations. Further studies are needed to clarify the implications of altered HPA axis activity in older patients suffering from depression. Novel pharmacological approaches might be effective in targeting this pathophysiological feature, thus improving the clinical outcomes.

Assessment of the accuracy and reproducibility of adrenal volume measurements using MRI and its relationship with corticosteroid phenotype: a normal volunteer pilot study

OBJECTIVE

The significant role of corticosteroids in hypertension and cardiovascular disease highlights the importance of the adrenal gland in these disorders. The ability to correlate corticosteroid production with adrenal volume offers a novel research tool and intermediate phenotype in cardiovascular disease. The aim of this study was to develop and validate the use of magnetic resonance imaging (MRI) in adrenal volume assessment and investigate whether this associates with corticosteroid production.

DESIGN/METHODS

Twenty normotensive men underwent noncontrast 1·5T MRI scanning of adrenals, measurement of blood pressure and plasma corticosteroids. Left adrenal volume was calculated twice using standard segmentation software by four independent observers with differing levels of clinical expertise and segmentation experience. To optimize this process, adrenal 'phantoms' with known fixed volumes underwent MRI scanning and analysis by two observers.

RESULTS

Intra-observer coefficients of repeatability (CoRs) in phantoms ranged from 0·23 to 0·43 ml (interobserver CoR 0·48 ml). In the subject group, mean adrenal volumes were 3·99-5·82 ml with intra-observer CoRs 0·27-1·94 ml. Interobserver variability was 2·73 ml. Segmentation expertise was the main factor affecting variability, with experienced observers having the lowest CoRs; clinical knowledge was a factor when combined with segmentation experience. Mean adrenal volume correlated with plasma glucocorticoids (r = 0·523, P < 0·05) and aldosterone (r = 0·515, P < 0·05) for the most experienced observer only.

CONCLUSIONS

Measurement of adrenal volume using MRI is challenging; most accurate volumes are achieved using a single observer with both segmentation experience and anatomical knowledge. The data also provide novel preliminary evidence that adrenal gland volume may be associated with plasma corticosteroid concentrations supporting further study of adrenal volume and steroid production across a range of blood pressures.

Comparative study on the effects of type 1 and type 2 diabetes on structural changes and hormonal output of the adrenal cortex in male Wistar rats

INTRODUCTION

Diabetes is one of the most common endocrine disorders characterized by hyperglycemia due to defects in insulin secretion, insulin function, or both. Causing dysfunction in the body general metabolism, diabetes-induced chronic hyperglycemia leads to alterations in those endocrine glands involved in regulating the body metabolism. In this line, the present study has been conducted to investigate the effects of type 1 and type 2 diabetes on the structural changes and hormonal output of the adrenal cortex in male Wistar rat.

METHODS

Eighteen male Wistar rats were divided into three groups including control, experimental type 1 diabetes (subcutaneous injection of 135 mg/kg alloxan) and experimental type 2 diabetes (8 weeks treatment with drinking water containing 10% fructose). Two months after the induction of both types of diabetes, the level of blood biochemical factors (glucose, insulin, cortisol, triglycerides, cholesterol, LDL, and HDL) were measured. Structural changes of the adrenal cortex were then evaluated, using stereological techniques.

RESULTS

Serum biochemical analysis showed significant difference in the levels of glucose, triglycerides, insulin and cortisol in experimental groups, compared to the control. The results of structural alterations were also indicative of increase in adrenal cortex volume in both types of diabetes.

CONCLUSION

Probably through increasing HPA axis activity, type1 diabetes-induced hyperglycemia leads to adrenal hypertrophy and increase the hormonal output of adrenal gland.

The clinical spectrum of adrenocortical hyperplasia

PURPOSE OF REVIEW

To describe the significance of a common adrenal radiological finding on computed tomography or MRI.

RECENT FINDINGS

Bilateral adrenocortical hyperplasia is the common expression of a variety of adrenal disorders, and its cause needs to be properly assessed in order to institute appropriate management.

SUMMARY

Behind the radiological finding of bilateral adrenal enlargement, there is a spectrum of diseases that require diagnostic evaluation and management. Many cases are benign and not associated with abnormalities of endocrine function. However, these abnormalities may develop years after the initial diagnosis has been made.

Evaluation of salivary cortisol measurements for the diagnosis of subclinical Cushing's syndrome

Late-night salivary cortisol (NSC) has been recognized as a sensitive and easy-to-perform screening test for the diagnosis of overt Cushing's syndrome (CS). However, there have been few reports on the diagnostic utility of salivary cortisol (SC) measurement in the diagnosis of subclinical Cushing's syndrome (SCS). Therefore, the present study was designed to evaluate the usefulness of SC measurements at late-night and after overnight 1 mg dexamethasone suppression test (DST) for the diagnosis of SCS in 42 patients with adrenal incidentaloma. We evaluated 16 patients with SCS, 12 with nonfunctioning adenoma (NFA), 8 with primary aldosteronism (PA), and 6 with pheochromocytoma (Pheo). NSC levels in SCS patients (0.238 ± 0.106 µg/dL) were significantly (P < 0.05) higher than those in NFA patients (0.154 ± 0.104 µg/dL); the cutoff value (0.11 µg/dL) by ROC analysis gave high sensitivity (100%) with low specificity (50%). Post DST SC levels in SCS patients (0.238 ± 0.116 µg/dL) were significantly (P = 0.0081) higher than those in NFA patients (0.136 ± 0.110 µg/dL); the cutoff value (0.12 µg/dL) by ROC analysis gave high sensitivity (93.8%) with somewhat improved specificity (58.3%). Both NSC and post DST SC levels were comparable between NFA, PA, and Pheo patients. In conclusion, our study revealed that measurements of NSC and/or post DST SC among patients with adrenal incidentaloma prove to have high sensitivities, but low specificities for the diagnosis of SCS from NFA, suggesting its possible alternative option before the screening tests for SCS currently employed in Japan.

Reliability of hypothalamic-pituitary-adrenal axis assessment methods for use in population-based studies

Population-based studies have been hampered in exploring hypothalamic-pituitary-adrenal axis (HPA) activity as a potential explanatory link between stress-related and metabolic disorders due to their lack of incorporation of reliable measures of chronic cortisol exposure. The purpose of this review is to summarize current literature on the reliability of HPA axis measures and to discuss the feasibility of performing them in population-based studies. We identified articles through PubMed using search terms related to cortisol, HPA axis, adrenal imaging, and reliability. The diurnal salivary cortisol curve (generated from multiple salivary samples from awakening to midnight) and 11 p.m. salivary cortisol had the highest between-visit reliabilities (r = 0.63-0.84 and 0.78, respectively). The cortisol awakening response and dexamethasone-suppressed cortisol had the next highest between-visit reliabilities (r = 0.33-0.67 and 0.42-0.66, respectively). Based on our own data, the inter-reader reliability (r(s)) of adrenal gland volume from non-contrast CT was 0.67-0.71 for the left and 0.47-0.70 for the right adrenal glands. While a single 8 a.m. salivary cortisol is one of the easiest measures to perform, it had the lowest between-visit reliability (R = 0.18-0.47). Based on the current literature, use of sampling multiple salivary cortisol measures across the diurnal curve (with awakening cortisol), dexamethasone-suppressed cortisol, and adrenal gland volume are measures of HPA axis tone with similar between-visit reliabilities which likely reflect chronic cortisol burden and are feasible to perform in population-based studies.

Volume of the adrenal and pituitary glands in depression

Numerous studies have shown that the hypothalamic-pituitary-adrenal (HPA) axis is hyperactive in some depressed patients. It is unclear whether such hyperactivity results in changed volumes of the adrenal glands, pituitary gland and hypothalamus. We systematically reviewed all controlled studies on the adrenal or pituitary glands or hypothalamus volume in unipolar depressive disorder published in PubMed 1966 to December 2009. We identified three studies that investigated the volume of the adrenal glands and eight studies that examined the volume of the pituitary gland, but no studies on hypothalamus were found. Two out of three studies found a statistically significant increase in adrenal volume in patients compared to controls. Four out of eight studies found a statistically significant increase in pituitary volume in patients compared to controls. Different methodological problems were identified such as small population samples, different subtypes of depression and insufficient matching of patients and controls. Due to large heterogeneity of study designs and data, it was futile to make a meta-analysis. It is concluded that it remains unclear whether hyperactivity of the HPA axis results in enlarged adrenal and pituitary glands and it is suggested that prospective studies should be conducted with scanning during successive depressive episodes and periods of remission.

Biological basis of depression in adults with diabetes

Diabetes and depression are common comorbid conditions. Although certain health behaviors and risk factors partially explain the association of depression and diabetes, other potential mechanisms have yet to be elucidated. Certain neuroendocrine alterations such as activation of the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS) may contribute to the association. Additionally, presence of a proinflammatory state shown in recent literature in both diabetes and depression may contribute to this as well. The objectives of this review are to summarize and review the recent evidence showing alterations of these three biological systems-HPA axis, SNS, and inflammatory cascade--in depression, diabetes, and diabetes-related risk factors.