Inhibition of Heat Shock Factor 1 Enhances Repressive Molecular Mechanisms on the POMC Promoter.

BACKGROUND: Cushing's disease (CD) is caused by adrenocorticotropic hormone (ACTH)-secreting pituitary tumours. They express high levels of heat shock protein 90 and heat shock factor 1 (HSF1) in comparison to the normal tissue counterpart, indicating activated cellular stress. AIMS: Our objectives were: (1) to correlate HSF1 expression with clinical features and hormonal/radiological findings of CD, and (2) to investigate the effects of HSF1 inhibition as a target for CD treatment. PATIENTS/METHODS: We examined the expression of total and pSer326HSF1 (marker for its transcriptional activation) by Western blot on eight human CD tumours and compared to the HSF1 status of normal pituitary. We screened a cohort of 45 patients with CD for HSF1 by immunohistochemistry and correlated the HSF1 immunoreactivity score with the available clinical data. We evaluated the effects of HSF1 silencing with RNA interference and the HSF1 inhibitor KRIBB11 in AtT-20 cells and four primary cultures of human corticotroph tumours. RESULTS: We show that HSF1 protein is highly expressed and transcriptionally active in CD tumours in comparison to normal pituitary. The immunoreactivity score for HSF1 did not correlate with the typical clinical features of the disease. HSF1 inhibition reduced proopiomelanocortin (Pomc) transcription in AtT-20 cells. The HSF1 inhibitor KRIBB11 suppressed ACTH synthesis from 75% of human CD tumours in primary cell culture. This inhibitory action on Pomc transcription was mediated by increased glucocorticoid receptor and suppressed Nurr77/Nurr1 and AP-1 transcriptional activities. CONCLUSIONS: These data show that HSF1 regulates POMC transcription. Pharmacological targeting of HSF1 may be a promising treatment option for the control of excess ACTH secretion in CD.

The Development of Neuroendocrine Disturbances over Time: Longitudinal Findings in Patients after Traumatic Brain Injury and Subarachnoid Hemorrhage.

Previous reports suggest that neuroendocrine disturbances in patients with traumatic brain injury (TBI) or aneurysmal subarachnoid hemorrhage (SAH) may still develop or resolve months or even years after the trauma. We investigated a cohort of n = 168 patients (81 patients after TBI and 87 patients after SAH) in whom hormone levels had been determined at various time points to assess the course and pattern of hormonal insufficiencies. Data were analyzed using three different criteria: (1) patients with lowered basal laboratory values; (2) patients with lowered basal laboratory values or the need for hormone replacement therapy; (3) diagnosis of the treating physician. The first hormonal assessment after a median time of three months after the injury showed lowered hormone laboratory test results in 35% of cases. Lowered testosterone (23.1% of male patients), lowered estradiol (14.3% of female patients) and lowered insulin-like growth factor I (IGF-I) values (12.1%) were most common. Using Criterion 2, a higher prevalence rate of 55.6% of cases was determined, which correlated well with the prevalence rate of 54% of cases using the physicians' diagnosis as the criterion. Intraindividual changes (new onset insufficiency or recovery) were predominantly observed for the somatotropic axis (12.5%), the gonadotropic axis in women (11.1%) and the corticotropic axis (10.6%). Patients after TBI showed more often lowered IGF-I values at first testing, but normal values at follow-up (p < 0.0004). In general, most patients remained stable. Stable hormone results at follow-up were obtained in 78% (free thyroxine (fT4) values) to 94.6% (prolactin values).

[The androgenital syndrome: Don't just think about it in childhood!] / Das adrenogenitale Syndrom: Nicht nur im Kindesalter daran denken!

The androgenital syndrome: Don't just think about it in childhood!In adrenogenital syndrome, the body permanently produces too many male sex hormones. Rare, congenital metabolic diseases are usually discovered in infancy and can be treated at an early stage treated at an early stage, but sometimes they only become apparent in adolescence and adulthood.This article provides background knowledge for GPs.

[Pituitary insufficiency: basics in diagnosis and therapy]. / Hypophyseninsuffizienz ­ das Einmaleins in Diagnostik und Therapie.

Pituitary insufficiency is a partial or complete failure of secretion of one or more hormones from the pituitary gland. The pituitary gland is located in the hypophysial fossa of the sella turcica of the os sphenoidale and produces ACTH, LH, FSH, GH, TSH, and prolactin. Pituitary insufficiency can be caused by acute damage, such as secondary to traumatic brain injury. It can also be a result of chronic alterations, such as increasing tumor expansion.Pituitary insufficiency often presents with nonspecific symptoms (e.g. fatigue, listlessness, decreased performance, sleep disturbances, weight change) that leads to a challenging and sometimes delayed diagnosis. The symptoms correspond to the failure of the corresponding endorgans. Occasionally, symptoms such as a loss of libido, secondary amenorrhea or nausea in stressful situations are diagnostically indicative.Further clarification includes a clinical examination with endocrinological testing of the pituitary function. Alteration of pituitary hormone secretion can also occur physiologically as in pregnancy, depression or obesity. Substitution therapy of the failed corticotropic, thyrotropic and gonadotropic axis is corresponding to the therapy of a primary endorgan insufficiency. Adequate diagnosis and treatment of pituitary insufficiency is important, as this may prevent life-threatening crises such as an adrenal crisis.

Effects of growth hormone replacement within the KIMS survey on estimated cardiovascular risk and predictors of risk reduction in patients with growth hormone deficiency.

OBJECTIVE: There is growing evidence for an increased cardiovascular (CV) risk in untreated growth hormone deficiency of adults (GHD). We aimed at estimating CV risk with established algorithms before and during GH replacement in GHD and in healthy controls and at identifying predictors of risk reduction. DESIGN: A prospective, nested case-control study. PATIENTS: We included 344 patients (44·7 ± 14·9 years) from the German Pfizer (formerly Kabi) International Metabolic Database (KIMS) cohort and included a healthy sex- and age-matched control group from a primary care cohort. MEASUREMENTS: We calculated Framingham, Prospective Cardiovascular Münster Heart Study (PROCAM) and European Society of Cardiology (ESC) Score algorithms at all time points. In multivariate analyses, we analysed potential predictors of 2-year reduction in CV risk, defined as a higher than median reduction in risk. RESULTS: In KIMS, the estimated 10-year risks of CV events or CV mortality calculated with Framingham, PROCAM and ESC Score algorithms at baseline were 4·6%, 6·0% and 2·3%, respectively. These dropped to 2·4%, 4·8% and 0·8%, respectively, after 2 years of GH replacement (all P < 0·001 vs baseline) and returned to baseline levels after four years of GH replacement. In controls, the Framingham risk estimates were lower than in KIMS at baseline. All risk estimates increased during follow-up and were significantly higher than in KIMS after four years (all P < 0·01). In backward-selection models, high total cholesterol, low high-density lipoprotein (HDL) cholesterol and male sex were significant predictors of response in most scores. CONCLUSION: Two years of GH replacement decreased CV risk estimates approximately by half. Male sex, high total and low HDL cholesterol levels are potential predictors of good response.

[Transsexualism and transgender medicine - what every internal specialist should know about]. / Transsexualität und Transgender-Medizin ­ Was jeder Internist wissen sollte.

The authors present current findings on transsexualism and its treatment. According to the ICD-10, transsexualism is defined as the "desire to live and be accepted as a member of the opposite sex, usually accompanied by a sense of discomfort with, or inappropriateness of, one's anatomic sex, and a wish to have surgery and hormonal treatment to make one's body as congruent as possible with one's preferred sex." Synonyms of transsexualism are terms such as gender dysphoria reflecting the distress that persons feel due to a mismatch between their gender identity and their sex assigned at birth.The prevalence of transsexualism is estimated to be about 0,6 %. The diagnosis of transsexualism is made by psychiatrists, but at least five more medical specialties (endocrinologist, surgeon, ear, nose and throat specialist, speech therapist and dermatologist) are involved when treating transsexual persons. Hormonal therapy is a very important element of the treatment process; due to the complexity of transsexualism it should be undertaken by endocrinologists with experience and expertise in this field.

Prevalence of low male testosterone levels in primary care in Germany: cross-sectional results from the DETECT study.

OBJECTIVE: Low testosterone levels in men occur with increasing age and are associated with increased morbidity, particularly metabolic syndrome, and mortality. As the prevalence of hypogonadal testosterone levels has not been assessed in the primary care setting in Europe, we aimed to investigate the prevalence of low testosterone levels in this setting, and the patient characteristics and comorbidities associated with this finding. DESIGN: A cross-sectional, epidemiological study (the Diabetes Cardiovascular Risk-Evaluation: Targets and Essential Data for Commitment of Treatment (DETECT) study). PATIENTS: A total of 2719 male primary care patients (age 58.7 +/- 13.4 years) were included. MEASUREMENTS: Testosterone was measured in all patients. Information on diseases, risk conditions and treatments was documented by the primary care physicians. A large set of laboratory parameters was measured in a central laboratory. We calculated univariate and multivariate logistic regression models to assess the associations of low testosterone levels with different health and life style factors. RESULTS: A total of 19.3% of all men had hypogonadism as defined by testosterone levels < 3.0 ng/ml. Stepwise logistic regression analysis revealed that obesity, metabolic syndrome, cancer, intake of six or more drugs, acute inflammation and nonsmoking were associated with hypogonadal testosterone levels. Higher age, liver diseases, and cancer were associated with very low testosterone levels (< 1.0 ng/ml). CONCLUSIONS: Hypogonadal testosterone levels are common in primary care, particularly in patients with the above conditions.

Modulation of growth hormone and prolactin secretion in Trypanosoma cruzi-infected mammosomatotrophic cells.

OBJECTIVE: In a previous study, we reported an imbalance in the hypothalamus-pituitary-adrenal axis of mice acutely infected with the protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease. METHODS: Possible effects of this parasitic infection on the endocrine function of other pituitary cell types were studied, in particular regarding the production of prolactin (PRL) and growth hormone (GH). RESULTS: In the mammosomatotrophic cell line GH3, both GH and PRL secretion were decreased, reflecting the diminished PRL concentrations in the pituitary glands of infected mice. Additionally, expression of extracellular matrix proteins, e.g. laminin, was increased in T. cruzi-infected GH3 cells, which may be related to the diminished secretory function of these cells. Lastly, the expression of Pit-1, a major transcription factor for the PRL and GH genes, is also decreased in T. cruzi-infected cultures. CONCLUSION: T. cruzi infection downregulates PRL and GH production. Combined with our previous data showing increased glucocorticoid levels following T. cruzi infection, the immunosuppression induced by T. cruzi infection may be partially related to multiple endocrine changes involving the hypothalamus-pituitary axis and corresponding target endocrine glands.

Hypopituitarism.

Incidence and prevalence of hypopituitarism are estimated to be 4.2 per 100,000 per year and 45.5 per 100,000, respectively. Although the clinical symptoms of this disorder are usually unspecific, it can cause life-threatening events and lead to increased mortality. Current research has refined the diagnosis of hypopituitarism. Identification of growth hormone and corticotropin deficiency generally requires a stimulation test, whereas other deficiencies can be detected by basal hormones in combination with clinical judgment. Newly developed formulations of replacement hormones are convenient and physiological. Work has shown that many patients with brain damage--such as traumatic brain injury or aneurysmal subarachnoid haemorrhage--are at high risk of (sometimes unrecognised) hypopituitarism. Thus, a much increased true prevalence of this disorder needs to be assumed. As a result, hypopituitarism is not a rare disease and should be recognised by the general practitioner.

Insulin-like growth factor-1 in plasma and brain: regulation in health and disease.

IGF-1 was first described as a growth mediating factor regulated in the context of the somatotrophic axis. During the last decade, it has gained much attention for its role in the regulation of lifespan, brain function, cell growth, and metabolism. Associations of plasma IGF-1 levels in physiological and pathological conditions such as aging, cardiovascular disease, metabolic disorders, dementia, and neurodegenerative disorders, and its potential as a neurotrophic agent, have been intensively studied. Acromegaly due to jGH and IGF-1 excess and growth hormone deficiency with decreased GH and IGF-1 might serve as models to study IGF-1 function, but the effects of GH and IGF-1 in these conditions are often indistinguishable. Due to this overlap, this article will only briefly mention pathophysiological implications in acromegaly and growth hormone deficiency. It will focus on IGF-1 and give an overview of the vast literature on the role and regulation of IGF-1 in plasma and brain, its alteration in health and disease and its possible therapeutical applications.

Neuropsychiatric and metabolic aspects of dopaminergic therapy: perspectives from an endocrinologist and a psychiatrist.

The dopaminergic treatment represents the primary treatment in prolactinomas, which are the most common pituitary adenomas and account for about 40% of all pituitary tumours with an annual incidence of six to ten cases per million population. The dopaminergic treatment includes ergot and non-ergot derivatives with high affinity for the dopamine receptors D1 or/and D2. Through the activation of the dopaminergic pathway on pituitary lactotrophs, the dopamine agonists inhibit the prolactin synthesis and secretion, therefore normalizing the prolactin levels and restoring eugonadism, but they also lead to tumour shrinkage. Treatment with dopamine agonists has been associated - apart from the common side effects such as gastrointestinal symptoms, dizziness and hypotension - with neuropsychiatric side effects such as impulse control disorders (e.g. pathological gambling, compulsive shopping, hypersexuality and binge eating) and also with behavioral changes from low mood, irritability and verbal aggressiveness up to psychotic and manic symptoms and paranoid delusions not only in patients with prolactinomas but also in patients with Parkinson's disease and restless leg syndrome. They usually have de novo onset after initiation of the dopaminergic treatment and have been mainly reported in patients with Parkinson's disease, who are being treated with higher doses of dopamine agonists. Moreover, dopamine and prolactin seem to play an essential role in the metabolic pathway. Patients with hyperprolactinemia tend to have increased body weight and an altered metabolic profile with hyperinsulinemia and increased prevalence of diabetes mellitus in comparison to healthy individuals and patients with non-functioning pituitary adenomas. Treatment with dopamine agonists in these patients in short-term studies seems to lead to weight loss and amelioration of the metabolic changes. Together these observations provide evidence that dopamine and prolactin have a crucial role both in the regard and metabolic system, findings that merit further investigation in long-term studies.

Hypothalamopituitary dysfunction following traumatic brain injury and aneurysmal subarachnoid hemorrhage: a systematic review.

CONTEXT: Neuroendocrine dysfunction following traumatic brain injury and aneurysmal subarachnoid hemorrhage may occur with a much higher prevalence than previously suspected. This sequela is a potentially serious but treatable complication of brain injury. OBJECTIVE: To review research on hypothalamopituitary dysfunction as an underdiagnosed consequence of traumatic brain injury and subarachnoid hemorrhage, the natural history of this complication, and the potential clinical and public health implications of posttraumatic hypopituitarism. EVIDENCE ACQUISITION: The MEDLINE database was searched for articles published between 2000 and 2007 using any combination of the terms traumatic brain injury or subarachnoid hemorrhage with pituitary, hypopituitarism, growth hormone deficiency, hypogonadism, hypocortisolism, hypothyroidism, or diabetes insipidus. The reference lists of articles identified by this search strategy were also searched. All articles reporting original data on endocrine outcomes after traumatic brain injury or aneurysmal subarachnoid hemorrhage in peer-reviewed journals with regard to prevalence, pathogenesis, risk factors, outcomes, and clinical course were selected. We pooled data and calculated prevalence rates and 95% confidence intervals (CIs). RESULTS: We identified 19 studies including 1137 patients. The pooled prevalences of hypopituitarism in the chronic phase after traumatic brain injury and aneurysmal subarachnoid hemorrhage were 27.5% (95% confidence interval [CI], 22.8%-28.9%) and 47% (95% CI, 37.4%-56.8%), respectively. The pooled prevalence of hypopituitarism was greater in patients with severe compared with those with mild or moderate traumatic brain injury. Early neuroendocrine abnormalities were transient in some patients while, less commonly, hypopituitarism evolved over time in others. Patients with posttraumatic hypopituitarism showed an impaired quality of life and an adverse metabolic profile. CONCLUSION: Hypopituitarism is a common complication of both traumatic brain injury and aneurysmal subarachnoid hemorrhage and might contribute to morbidity and poor recovery after brain injury.

Hypothalamus-pituitary-adrenal axis during Trypanosoma cruzi acute infection in mice.

Functional interactions between neuroendocrine and immune systems are mediated by similar ligands and receptors, which establish a bi-directional communication that is relevant for homeostasis. We investigated herein the hypothalamus-pituitary-adrenal (HPA) axis in mice acutely infected by Trypanosoma cruzi, the causative agent of Chagas' disease. Parasites were seen in the adrenal gland, whereas T. cruzi specific PCR gene amplification product was found in both adrenal and pituitary glands of infected mice. Histological and immunohistochemical analyses of pituitary and adrenal glands of infected animals revealed several alterations including vascular stasis, upregulation of the extracellular matrix proteins fibronectin and laminin, as well as T cell and macrophage infiltration. Functionally, we detected a decrease in CRH and an increase in corticosterone contents, in hypothalamus and serum respectively. In contrast, we did not find significant changes in the amounts of ACTH in sera of infected animals, whereas the serum levels of the glucocorticoid-stimulating cytokine, IL-6 (interleukin-6), were increased as compared to controls. When we analyzed the effects of T. cruzi in ACTH-producing AtT-20 cell line, infected cultures presented lower levels of ACTH and pro-opiomelanocortin production when compared to controls. In these cells we observed a strong phosphorylation of STAT-3, together with an increased synthesis of IL-6, suppressor of cytokine signaling 3 (SOCS-3) and inhibitor of activated STAT-3 (PIAS-3), which could explain the partial blockage of ACTH production. In conclusion, our data reveal that the HPA axis is altered during acute T. cruzi infection, suggesting direct and indirect influences of the parasite in the endocrine homeostasis.

Opposite associations of age-dependent insulin-like growth factor-I standard deviation scores with nutritional state in normal weight and obese subjects.

OBJECTIVE: Insulin-like growth factor-I (IGF-I) has been suggested to be a prognostic marker for the development of cancer and, more recently, cardiovascular disease. These diseases are closely linked to obesity, but reports of the association of IGF-I with measures of obesity are divergent. In this study, we assessed the association of age-dependent IGF-I standard deviation scores with body mass index (BMI) and intra-abdominal fat accumulation in a large population. DESIGN: A cross-sectional, epidemiological study. METHODS: IGF-I levels were measured with an automated chemiluminescence assay system in 6282 patients from the DETECT study. Weight, height, and waist and hip circumference were measured according to the written instructions. Standard deviation scores (SDS), correcting IGF-I levels for age, were calculated and were used for further analyses. RESULTS: An inverse U-shaped association of IGF-I SDS with BMI, waist circumference, and the ratio of waist circumference to height was found. BMI was positively associated with IGF-I SDS in normal weight subjects, and negatively associated in obese subjects. The highest mean IGF-I SDS were seen at a BMI of 22.5-25 kg/m2 in men (+0.08), and at a BMI of 27.5-30 kg/m2 in women (+0.21). Multiple linear regression models, controlling for different diseases, medications and risk conditions, revealed a significant negative association of BMI with IGF-I SDS. BMI contributed most to the additional explained variance to the other health conditions. CONCLUSIONS: IGF-I standard deviation scores are decreased in obesity and underweight subjects. These interactions should be taken into account when analyzing the association of IGF-I with diseases and risk conditions.

Neuroendocrine Disturbances One to Five or More Years after Traumatic Brain Injury and Aneurysmal Subarachnoid Hemorrhage: Data from the German Database on Hypopituitarism.

Neuroendocrine disturbances are common after traumatic brain injury (TBI) and aneurysmal subarachnoid hemorrhage (SAH), but only a few data exist on long-term anterior pituitary deficiencies after brain injury. We present data from the Structured Data Assessment of Hypopituitarism after TBI and SAH, a multi-center study including 1242 patients. We studied a subgroup of 351 patients, who had sustained a TBI (245) or SAH (106) at least 1 year before endocrine assessment (range 1-55 years) in a separate analysis. The highest prevalence of neuroendocrine disorders was observed 1-2 years post-injury, and it decreased over time only to show another maximum in the long-term phase in patients with brain injury occurring ≥5 years prior to assessment. Gonadotropic and somatotropic insufficiencies were most common. In the subgroup from 1 to 2 years after brain injury (n = 126), gonadotropic insufficiency was the most common hormonal disturbance (19%, 12/63 men) followed by somatotropic insufficiency (11.5%, 7/61), corticotropic insufficiency (9.2%, 11/119), and thyrotropic insufficiency (3.3%, 4/122). In patients observed ≥ 5 years after brain injury, the prevalence of somatotropic insufficiency increased over time to 24.1%, whereas corticotropic and thyrotrophic insufficiency became less frequent (2.5% and 0%, respectively). The prevalence differed regarding the diagnostic criteria (laboratory values vs. physician`s diagnosis vs. stimulation tests). Our data showed that neuroendocrine disturbances are frequent even years after TBI or SAH, in a cohort of patients who are still on medical treatment.

Night sleep EEG and daytime sleep propensity in adult hypopituitary patients with growth hormone deficiency before and after six months of growth hormone replacement.

BACKGROUND: Hypopituitary patients with growth hormone deficiency (GHD) complain of reduced vitality, general fatigue, lack of concentration, irritability and reduced alertness during daytime. It is unclear whether these symptoms are primarily due to GH-deficiency and/or secondary to GHD related sleep impairments. Bi-directional interactions between the somatotropic system and human sleep patterns are well established. However, data on the effect of GH either in subjects without GHD or in patients with GHD under GH replacement therapy on the sleep electroencephalogram (EEG) are controversial. No reports exist about objective measures of daytime sleepiness in GH deficient patients before and during GH-therapy. OBJECTIVE: To assess the effects of GH on nocturnal and daytime sleep in adult patients with GHD before and during recombinant human GH (rhGH, Somatropin) replacement therapy. METHODS: Eighteen adult patients with GHD (4 women and 14 men) participated in the study. Mean age at the beginning of the study was 48.5 years (range 27-64 years). Ten patients were recruited from a double-blind, randomized placebo controlled trial over 6 months, followed by an open treatment period of 6 additional months (Group I). In all patients from this group, only the effects of the first 6 months of GH treatment were assessed. Eight additional patients were treated in an open study design for 6 months (Group II). Nocturnal sleep recordings and daytime sleep EEGs with a multiple sleep latency test were performed at baseline and after 6 months of additional GH replacement therapy. RESULTS: One patient dropped out due to side effects and was not included in sleep analysis. IGF-1 levels were increased in all patients, partially in a supraphysiologic range. Side effects were mainly mild but in one patient (from group II), general muscle pain led to interruption of the study. Therefore sleep analysis was only done in 17 patients. Sleep parameters were comparable to healthy control groups from the literature. GH substitution over 6 months did neither affect total sleep time nor times spent in different sleep stages. REM sleep density was also not changed. Daytime sleep propensity as measured by the multiple sleep latency test was not influenced by GH treatment. CONCLUSIONS: GH replacement does neither affect night sleep nor daytime sleep propensity in GH deficient hypopituitary adults. GH substitution has no sleep disturbing effect.

Anterior pituitary hormone abnormalities following traumatic brain injury.

Traumatic brain injury (TBI) leads to approximately 100 hospitalizations per 100,000/year. Whereas diabetes insipidus is a well-known complication of TBI, anterior hypopituitarism as a consequence of TBI has been regarded as rare. More recent studies, however, suggest a prevalence of at least 30% of anterior pituitary dysfunction after TBI. Clinical signs of anterior hypopituitarism are often subtle and may be masked by sequalae of TBI. Therefore, post-traumatic anterior pituitary dysfunction may remain undiagnosed and, possibly, aggravate symptoms of brain injury. Moreover it may, if undiagnosed, lead to potentially fatal endocrine crises. This review updates clinical researchers, physicians, and other healthcare providers on the relationship between TBI and subsequent anterior pituitary insufficiency.

IGF-I in major depression and antidepressant treatment response.

We analyzed insulin-like growth factor I (IGF-I) in serum of 78 inpatients with depression and 92 healthy controls. Patients were selected according to remission status after 6 weeks of antidepressant treatment with remission defined by Hamilton depression rating scale (HAM-D) 21-item score <10 (39 remitters and 39 non-remitters). IGF-I was analyzed in patients at admission and after 6 weeks of psychopharmacological treatment. IGF-I levels were compared between patients and controls and between remitters and non-remitters with general linear model using age, gender, and body mass index as covariates. In patients, IGF-I levels were significantly higher at admission (p=3.29E-04) and in week 6 (p=0.002) compared to controls. Furthermore, non-remitters showed significantly higher IGF-I levels at admission (p=0.046) and a trend for higher IGF-I levels in week 6 (p=0.11) compared to remitters. In remitters change in IGF-I levels during treatment was significantly correlated with change in cortisol levels (p=0.019). A genetic association analysis of polymorphisms in 10 genes contributing to the IGF-I system (IGF1, IGF1R, IGFBP1 to IGFBP7, and IGFBPL1) in the currently largest genetic databases for major depression (Psychiatric Genomics Consortium) revealed nominal associations with susceptibility for depression and treatment response, although results did not remain significant after multiple testing correction. In our study, elevated IGF-I levels were significantly associated with depression and impaired treatment response. Based on these findings IGF-I signaling could play a role in the pathophysiology of depression and could possibly influence the response to antidepressant treatment.