The Interrelationship between Insulin-Like Growth Factor 1, Apolipoprotein E ε4, Lifestyle Factors, and the Aging Body and Brain.

Aging is associated with a decrease in body and brain function and with a decline in insulin-like growth factor 1 levels. The observed associations between alterations in insulin-like growth factor 1 levels and cognitive functioning and Mild Cognitive Impairment suggest that altered insulin-like growth factor 1 signaling may accompany Alzheimer's disease or is involved in the pathogenesis of the disease. Recent animal research has suggested a possible association between insulin-like growth factor 1 levels and the Apolipoprotein E ε4 allele, a genetic predisposition to Alzheimer's disease. It is therefore hypothesized that a reduction in insulin-like growth factor 1 signaling may moderate the vulnerability to Alzheimer's disease of human Apolipoprotein E ε4 carriers. We address the impact of age-related decline of insulin-like growth factor 1 levels on physical and brain function in healthy aging and Alzheimer's disease and discuss the links between insulin-like growth factor 1 and the Apolipoprotein E ε4 polymorphism. Furthermore, we discuss lifestyle interventions that may increase insulin-like growth factor 1 serum levels, including physical activity and adherence to a protein rich diet and the possible benefits to the physical fitness and cognitive functioning of the aging population.

DNA methylation profiling in MEN1-related pancreatic neuroendocrine tumors reveals a potential epigenetic target for treatment.

OBJECTIVE: Epigenetic changes contribute to pancreatic neuroendocrine tumor (PanNET) development. Hypermethylation of promoter DNA as a cause of tumor suppressor gene silencing is a well-established oncogenic mechanism that is potentially reversible and therefore an interesting therapeutic target. Multiple endocrine neoplasia type 1 (MEN1) is the most frequent cause of inherited PanNETs. The aim of this study was to determine promoter methylation profiles in MEN1-related PanNETs. DESIGN AND METHODS: Methylation-specific multiplex ligation-dependent probe amplification was used to assess promoter methylation of 56 tumor suppressor genes in MEN1-related (n = 61) and sporadic (n = 34) PanNETs. Differences in cumulative methylation index (CMI), individual methylation percentages and frequency of promoter hypermethylation between subgroups were analyzed. RESULTS: We found promoter methylation of a large number of potential tumor suppressor genes. CMI (median CMI: 912 vs 876, P = 0.207) was the same in MEN1-related and sporadic PanNETs. We found higher methylation percentages of CASP8 in MEN1-related PanNETs (median: 59% vs 16.5%, P = 0.002). In MEN1-related non-functioning PanNETs, the CMI was higher in larger PanNETs (>2 cm) (median: 969.5 vs 838.5; P = 0.021) and in PanNETs with liver metastases (median: 1036 vs 869; P = 0.013). Hypermethylation of MGMT2 was more frequent in non-functioning PanNETs compared to insulinomas (median: 44.7% vs 8.3%; P = 0.022). Hypermethylation of the Von Hippel-Lindau gene promoter was observed in one MEN1-related PanNET and was associated with loss of protein expression. CONCLUSION: Promoter hypermethylation is a frequent event in MEN1-related and sporadic PanNETs. Targeting DNA methylation could be of therapeutic value in MEN1 patients with advanced PanNETs.

The relationship between serum IGF-1, handgrip strength, physical performance and falls in elderly men and women.

OBJECTIVE: Human aging is accompanied by a decrease in growth hormone secretion and serum insulin-like growth factor (IGF)-1 levels. Also, loss of muscle mass and strength and impairment of physical performance, ending in a state of frailty, are seen in elderly. We aimed to investigate whether handgrip strength, physical performance and recurrent falls are related to serum IGF-1 levels in community-dwelling elderly. DESIGN: Observational cohort study (cross-sectional and prospective). METHODS: We studied the association between IGF-1 and handgrip strength, physical performance and falls in participants of the Longitudinal Aging Study Amsterdam. A total of 1292 participants were included (633 men, 659 women). Serum IGF-1 levels were divided into quartiles (IGF-1-Q1 to IGF-1-Q4). Data on falls were collected prospectively for a period of 3 years. All analyses were stratified for age and physical activity and adjusted for relevant confounders. RESULTS: Men with a low physical activity score in IGF-1-Q1 and IGF-1-Q2 of the younger age group had a lower handgrip strength compared to IGF-1-Q4. In younger more active males in IGF-1-Q2 physical performance was worse. Recurrent fallers were less prevalent in older, low active males with low IGF-1 levels. In females, recurrent fallers were more prevalent in older, more active females in IGF-1-Q2. IGF-1 quartile may predict changes in handgrip strength and physical performance in men and women. CONCLUSIONS: Our results indicate that lower IGF-1 levels are associated with lower handgrip strength and worse physical performance, but less recurrent fallers especially in men. Associations were often more robust in IGF-1-Q2. Future studies on this topic are desirable.

Expression of p27Kip1 and p18Ink4c in human multiple endocrine neoplasia type 1-related pancreatic neuroendocrine tumors.

PURPOSE: Pancreatic neuroendocrine tumors are a major manifestation of multiple endocrine neoplasia type 1 (MEN1). This tumor syndrome is caused by germline mutations in MEN1, encoding menin. Insight into pathogenesis of these tumors might lead to new biomarkers and therapeutic targets for these patients. Several lines of evidence point towards a role for p27Kip1 and p18Ink4c in MEN1-related tumor development in animal models for MEN1, but their contribution to human MEN1-related pancreatic neuroendocrine tumor development is not known. METHODS: In this study, we characterized protein expression of p27Kip1 and p18Ink4c in human MEN1-related PanNETs by immunohistochemistry. From the nationwide DutchMEN1 Study Group database including > 90% of the Dutch MEN1 population, MEN1-patients, who underwent pancreatic surgery, were selected. A tissue micro-array was constructed with available paraffin tissue blocks, and PanNETs from 61 MEN1 patients were eligible for analysis. RESULTS: Expression of p27Kip1 was high in 57 (93%) PanNETs and 67% of the tumors showed low expression of p18Ink4c (67.3%). No association was found between expression of either p27Kip1 or p18Ink4c and clinic-pathological characteristics. CONCLUSIONS: These findings indicate that loss of p18Ink4c, but not p27Kip1, is a common event in the development of MEN1-related PanNETs. Restoration of p18Ink4c function through CDK4/6 inhibitors could be a therapeutic option for MEN1-related PanNETs.

Acute and short-term effects of caloric restriction on metabolic profile and brain activation in obese, postmenopausal women.

OBJECTIVE: Early anthropometric and metabolic changes during a caloric-restricted diet in obese postmenopausal women and correlations between these factors with activity in brain areas involved in processing of visual food related stimuli were investigated. SUBJECTS AND METHODS: An 8-week prospective intervention study of 18 healthy postmenopausal women, with a body mass index of 30-35 kg m-2. The first 2 weeks subjects were on an isocaloric diet and 4 weeks on a 1000 kcal restricted diet followed by 2 weeks on an isocaloric diet. Anthropometric and laboratory analyses were performed weekly during the isocaloric diet and three times a week during the caloric-restricted diet. Functional magnetic resonance imaging scans were obtained before and after the caloric restriction in four separate sessions (fasting or sated). Generalized Estimating Equations analysis was used for data analysis. RESULTS: A mean weight loss of 4.2±0.5 kg (4.8%) and a 4.2±0.4 cm decline in waist circumference were achieved. In the first week of caloric restriction, triglyceride, leptin, resistin and adiponectin levels as well as systolic blood pressure decreased and insulin-like growth factor-binding protein 1 levels increased. During and after weight loss, a significant increase in ghrelin levels was observed. Before weight loss, increased activation of the right amygdala was seen in response to food stimuli, and free fatty acids and glucose correlated with activity in various areas involved in food reward processing. After weight loss, fasting ghrelin and sated leptin levels correlated with activity in these areas. CONCLUSIONS: Already in the first week of caloric restriction in obese postmenopausal women, various favourable metabolic changes occur before clinically relevant weight loss is achieved. Activity in the amygdala region and correlations of metabolic factors with activity in brain areas involved in food reward processing differ substantially before and after weight loss.

Fractures in pituitary adenoma patients from the Dutch National Registry of Growth Hormone Treatment in Adults.

PURPOSE: The effects of growth hormone (GH) replacement therapy on fracture risk in adult GH deficient (GHD) patients with different etiologies of pituitary GHD are not well known, due to limited data. The aim of this study was to investigate characteristics and fracture occurrence at start of (baseline) and during long-term GH replacement therapy in GHD adults previously treated for Cushing's disease (CD) or acromegaly, compared to patients with previous nonfunctioning pituitary adenoma (NFPA). METHODS: From the Dutch National Registry of Growth Hormone Treatment in Adults, a nationwide surveillance study in severe GHD adults, all patients using ≥30 days of GH replacement therapy with previous NFPA (n = 783), CD (n = 180) and acromegaly (n = 65) were selected. Patient characteristics, fractures and potential influencing factors were investigated. RESULTS: At baseline, patients with previous CD were younger, more often female and had more often a history of osteopenia or osteoporosis, whereas patients with previous acromegaly had more often received cranial radiotherapy and a longer duration between treatment of their pituitary tumor and start of adult GH replacement therapy. During follow-up, a fracture occurred in 3.8 % (n = 39) of all patients. Compared to patients with previous NFPA, only patients with previous acromegaly had an increased fracture risk after 6 years of GH replacement therapy. CONCLUSIONS: During GH replacement therapy, an increased fracture risk was observed in severe GHD adult patients previously treated for acromegaly, but not in those previously treated for CD, compared to severe GHD adult patients using GH replacement therapy because of previous NFPA. Further studies are needed to confirm these findings and to elucidate potential underlying mechanisms.

Oestrogens are Not Related to Emotional Processing: a Study of Regional Brain Activity in Female-to-Male Transsexuals Under Gonadal Suppression.

Although the prevailing opinion is that emotional processes are influenced by sex hormones, the literature is still inconclusive. The aim of the current study was to examine the effects of gonadal suppression on brain activity during affective picture processing. Twenty-one female-to-male (FtM) transsexuals and 19 control women were recruited and underwent functional magnetic resonance imaging scanning while rating emotional pictures adapted from the International Affective Picture System. The gonadal hormone production of the FtMs was suppressed for 8 weeks, the control group did not receive any treatment before scanning. Under gonadal suppression, FtMs showed less brain activation in the superior temporal lobe compared with female controls during perception of positive affective pictures. Regression analysis showed that during processing of positive affective images, brain activity within the right superior temporal lobe was not correlated with levels of estradiol, luteinizing hormone, and follicle-stimulating hormone. In the absence of associations with hormonal levels, the difference in activation in the superior temporal lobe during positive emotional stimuli between FtMs and control women may be attributed to a priori differences between the 2 groups. Future studies should clarify if these differences are a result of atypical sexual differentiation of the brain in FtMs.

Gender-Specific Associations of Serum Insulin-Like Growth Factor-1 With Bone Health and Fractures in Older Persons.

CONTEXT: IGF-1 plays a role in bone metabolism. Although IGF-1 and bone mass both decrease with advancing age, their relationship in older individuals remains to be elucidated. OBJECTIVE: The objective was to investigate associations of serum IGF-1 cross-sectionally with quantitative ultrasound and bone mineral density (BMD), and longitudinally with 3-year change in BMD and 10-year fracture risk in older individuals. DESIGN, SETTING, AND PATIENTS: The study included 627 men and 656 women aged ≥ 65 years from the Longitudinal Aging Study Amsterdam, an ongoing, population-based cohort study. MAIN OUTCOME MEASURES: Main outcome measures included baseline serum IGF-1 concentration; baseline quantitative ultrasound of the heel, including broadband ultrasound attenuation and speed of sound; BMD measured at several body sites at baseline and after 3 years; and prospective fracture incidence over 10 years. Associations were adjusted for relevant confounders. RESULTS: Women, but not men, in the lowest quintile of IGF-1 concentration had lower broadband ultrasound attenuation (B = -4.53; P = .03) and a greater 3-year decrease in total hip BMD (B = -0.02; P = .05), than women in the highest quintile of IGF-1. Moreover, compared to women in the highest quintile of IGF-1, women in the combined lowest four quintiles of IGF-1 had an increased 10-year fracture risk (hazard ratio = 1.98; P = .05). CONCLUSIONS: Associations of lower IGF-1 with lower BUA, greater 3-year decrease in BMD, and increased 10-year fracture risk were only observed in women, not in men. These results support previous findings of gender differences in the relationship between IGF-1 and bone in older individuals.

Tumor Recurrence or Regrowth in Adults With Nonfunctioning Pituitary Adenomas Using GH Replacement Therapy.

CONTEXT: GH replacement therapy (GH-RT) is a widely accepted treatment in GH-deficient adults with nonfunctioning pituitary adenoma (NFPAs). However, some concerns have been raised about the safety of GH-RT because of its potentially stimulating effect on tumor growth. OBJECTIVE: The aim of this study was to evaluate tumor progression in NFPA patients using GH-RT. DESIGN, SETTING, AND PATIENTS: From the Dutch National Registry of Growth Hormone Treatment in Adults, a nationwide surveillance study in severely GH-deficient adults (1998-2009), all NFPA patients with ≥ 30 days of GH-RT were selected (n = 783). Data were retrospectively collected from the start of GH-RT in adulthood (baseline). MAIN OUTCOME MEASURE: Tumor progression, including tumor recurrence after complete remission at baseline and regrowth of residual tumor. RESULTS: Tumor progression developed in 12.1% of the patients after a median (range) time of 2.2 (0.1-14.9) years. Prior radiotherapy decreased tumor progression risk compared to no radiotherapy (hazard ratio = 0.16; 95% confidence interval, 0.09-0.26). Analysis in 577 patients with available baseline imaging data showed that residual tumor at baseline increased tumor progression risk compared to no residual tumor (hazard ratio = 4.5; 95% confidence interval, 2.4-8.2). CONCLUSIONS: The findings in this large study were in line with those reported in literature and provide further evidence that GH-RT does not appear to increase tumor progression risk in NFPA patients. Although only long-term randomized controlled trials will be able to draw firm conclusions, our data support the current view that GH-RT is safe in NFPA patients.

Serum insulin-like growth factor 1 and late-life depression: a population-based study.

OBJECTIVE: Serum insulin-like growth factor 1 (IGF-1) concentration decreases, while the prevalence of depressive symptoms increases with advancing age. Although basic research indicates a link between low IGF-1 concentration and depression, this has scarcely been investigated in humans. This study investigates whether lower IGF-1 concentrations are associated with prevalent and incident late-life depression over a 3-year period. METHODS: The study included 1188 participants, aged ≥ 65 years, from the Longitudinal Aging Study Amsterdam (LASA), an ongoing, population-based cohort study. Depression was assessed at baseline and after three years using the Center for Epidemiological Studies-Depression Scale (CES-D) and the Diagnostic Interview Schedule (DIS), and categorized into minor depression and major depression (MDD). Serum IGF-1 concentration was determined at baseline. Associations were adjusted for relevant confounders. RESULTS: Serum IGF-1 concentrations were within the normal range (mean 13.9 nmol/l, standard deviation 5.3 nmol/l). At baseline, in men, as compared to high concentrations, mid concentrations decreased the probability of prevalent minor depression (odds ratio [OR] = 0.35, 95% confidence interval [CI] = 0.15-0.82). In women, as compared to high concentrations, low concentrations tended to increase the probability of prevalent MDD (OR = 2.66, 95% CI = 0.89-7.89). At three-year follow-up, in men, no significant prospective associations were detected. In women, as compared to high concentrations, mid concentrations decreased the probability of incident minor depression (OR = 0.43, 95% CI = 0.19-0.95). CONCLUSIONS: Several associations, which differed across the genders, were observed between IGF-1 and depression. Cross-sectional findings were not supported by longitudinal findings, which suggest that IGF-1 may not play an important predictive role in the development of depression in older persons over time. However, a more acute role of IGF-1 in current depression, as indicated by the cross-sectional results, may be possible. Further studies are needed to elucidate the complex relation between IGF-1 and late-life depression.

Cerebrovascular events, secondary intracranial tumors, and mortality after radiotherapy for nonfunctioning pituitary adenomas: a subanalysis from the Dutch National Registry of Growth Hormone Treatment in Adults.

CONTEXT: Radiotherapy is frequently administered as adjuvant treatment in patients with clinically nonfunctioning pituitary adenomas (NFPAs). However, concerns have been raised about potential long-term side effects, including cerebrovascular events (CVEs) and secondary intracranial tumors. OBJECTIVE: The aim of this study was to analyze the risk of CVEs, secondary intracranial tumors, and mortality in irradiated (IRR) NFPA patients, compared with NFPA patients who were not irradiated (non-IRR). DESIGN, SETTING, AND PATIENTS: The study cohort included 806 patients with a NFPA from the Dutch National Registry of Growth Hormone Treatment in Adults, a nationwide long-term surveillance study in severe GH-deficient adult patients. IRR patients (n = 456) were compared with non-IRR patients (n = 350). MAIN OUTCOME MEASURES: CVEs, secondary intracranial tumors, and mortality were measured. RESULTS: Sixty-nine subjects developed a CVE. In men, but not in women, the incidence of a CVE was significantly higher in IRR patients than in non-IRR patients (hazard ratio 2.99, 95% confidence interval 1.31-6.79). A secondary intracranial tumor developed in five IRR patients and two non-IRR patients. After adjustment for age, radiotherapy was not associated with mortality. CONCLUSIONS: The incidence of secondary intracranial tumors and mortality did not differ between IRR and non-IRR patients. However, a CVE was found significantly more frequently in IRR men but not in women. Further research into the long-term effects of cranial radiotherapy seems mandatory. The potential risks of radiotherapy have to be taken into account when radiotherapy is considered in NFPA patients, and long-term follow-up is recommended.

Reduced growth hormone secretion after cranial irradiation contributes to neurocognitive dysfunction.

The objective of this study was to investigate the relation between growth hormone (GH) and attentional electro-cortical responses to task-relevant stimuli (N2b), target detections, speed of responding, P300 latencies, and performance on neuropsychological tests in 19 patients who received external beam radiation therapy for brain tumors in adulthood. In addition, we studied the association between IGF-I and activation of the motor cortex responses (lateralized readiness potential, LRP). Brain function was assessed using event-related potentials (ERPs) during a go/no go selective-attention task, including N2b, P300 and selective motor preparation as reflected in the LRP. Correlations were calculated between peak GH levels after a standardized growth hormone-releasing hormone (GHRH)-arginine test, plasma IGF-I, and cognitive functions. We separately studied four patients who were diagnosed with GHD according to the GHRH-arginine test. Performance on WAIS digit span backward and the Rey-Osterrieth complex figure test correlated positively with GH peak. GHD patients performed worse than non-GHD patients on Stroop interference, trail making B/A attentional shifting and Rey-Osterrieth complex figure test. At trend-level significance, trails A performance was better in patients with lower GH levels and higher radiation doses, and GHD participants detected fewer targets in the go/no go selective attention task. N2b was not significantly altered by GH status. Furthermore, plasma IGF-I was positively correlated with the sum of digit span forward and backward. No relations with P300 were observed. In this study only 21% (4/19) of the patients who received fractionated radiotherapy for a non-endocrine brain tumor were diagnosed with GHD. GHD in these patients was associated with impaired interference control, attentional shifting, and visual long-term memory. The results for interference control and attentional shifting suggest an additional effect of the radiation history.

Incidence of venous thromboembolism in patients with Cushing's syndrome: a multicenter cohort study.

CONTEXT: Venous thrombosis has frequently been reported in patients with endogenous Cushing's syndrome (CS). OBJECTIVE: The aim of this study was to evaluate the incidence of venous thromboembolism (VTE) in patients with CS prior to treatment and after surgery. DESIGN AND SETTING: We conducted a multicenter cohort study at all university medical centers in The Netherlands. PATIENTS: Consecutive patients diagnosed with endogenous CS of benign origin between January 1990 and June 2010 were eligible for inclusion. Patients surgically treated for nonfunctioning pituitary adenoma served as controls for the incidence of postoperative VTE in ACTH-dependent CS. MAIN OUTCOME MEASURES: We documented all objectively confirmed VTE during 3 yr prior to, and 3 yr after treatment onset. The incidences of VTE were expressed as incidence rates. RESULTS: A total of 473 patients (mean age 42 yr, 363 women) were included (360 ACTH-dependent pituitary CS). The total number of person-years was 2526. Thirty-seven patients experienced VTE during the study period, resulting in an incidence rate of 14.6 [95% confidence interval (CI) 10.3-20.1] per 1000 person-years. The incidence rate for first-ever VTE prior to treatment was 12.9 (95% CI 7.5-12.6) per 1000 person-years (17 events). The risk of postoperative VTE, defined as risk within 3 months after surgery, was 0% for ACTH-independent and 3.4% (95% CI 2.0-5.9) for ACTH-dependent CS (12 events in 350 patients); most events occurred between 1 wk and 2 months after surgery. Compared with the controls, the risk of postoperative VTE in patients undergoing transsphenoidal surgery was significantly greater (P = 0.01). CONCLUSIONS: Patients with CS are at high risk of VTE, especially during active disease and after pituitary surgery. Guidelines on thromboprophylaxis are urgently needed.

The GH/IGF-I axis and pituitary function and size in adults with Prader-Willi syndrome.

BACKGROUND: In adults with Prader-Willi syndrome (PWS), limited information is available about pituitary function, more specifically the prevalence of growth hormone deficiency (GHD). The aim of this study was to gain more insight into endocrine function in PWS adults, with emphasis on GH secretion. METHODS: 15 randomly selected adult PWS individuals were included and 14 healthy brothers and sisters served as a control group. Main outcome measures were IGF-I, IGFBP-3 and peak GH level after a combined GHRH-arginine test. Other pituitary hormone deficits are diagnosed based on serum levels of the concerning hormones. The size of the pituitary gland was measured on MRI images. RESULTS: In PWS adults, IGF-I levels were low and IGFBP-3 levels normal when compared to healthy controls. GHD was diagnosed in 8-38% of the PWS patients, depending on the criteria used. Hypogonadism was present in 87% of the patients. Hypothyroidism and adrenal insufficiency could also be demonstrated. Anterior pituitary size was lower in PWS individuals when compared to healthy controls. CONCLUSION: In this study, pituitary hormone deficiencies are demonstrated in a considerable number of adults with PWS, hypogonadism and GHD being most prominent. Furthermore, the anterior pituitary is smaller in comparison with healthy controls.

Dutch National Registry of GH Treatment in Adults: patient characteristics and diagnostic test procedures.

OBJECTIVE: The Dutch National Registry of GH Treatment in Adults was established in 1998 as an initiative of the Ministry of Health. The main goals were to gain more insight into long-term efficacy, safety, and costs of GH therapy (GHT) in adult GH-deficient (GHD) patients in The Netherlands. METHODS: Baseline patient characteristics and diagnostic test procedures were evaluated. RESULTS: Until January 2009 in roughly 10 years, 2891 patients (1475 men and 1416 women, mean age 43.5±16.5 years) were registered. GHD was of childhood-onset (CO) in over 20% of the patients and of isolated in 11%. The most common causes of GHD were pituitary tumors and/or their treatment, craniopharyngiomas, and idiopathic GHD. In 85% of the patients, a GH stimulation test was performed, in the majority an insulin tolerance test (ITT) (49%) or a combined GHRH-arginine test (25%). In 12% of the patients, IGF1 levels were ≤-2 s.d. combined with two or more additional pituitary hormone deficits, and in 2%, it concerned patients with CO-GHD continuing GHT in adulthood. Over the years, the test of first choice shifted from ITT toward GHRH-arginine test. CONCLUSION: Nearly, 2900 patients were included in the nationwide surveillance database of the Dutch National Registry of GH Treatment in Adults until January 2009. Baseline patient characteristics are comparable to that reported previously. In 85% of these patients, the diagnosis of GHD was established by provocative testing, particularly an ITT or a combined GHRH-arginine test, with an evident increase in the percentage of GHRH-arginine tests being performed in the last years.

Self-reported loss of consciousness after head trauma does not predispose to hypopituitarism in an older population.

OBJECTIVE: This population study examines the prevalence of hypopituitarism and low bone mineral density (BMD) in older persons reporting loss of consciousness after head trauma (HT). METHODS: Data from the Longitudinal Aging Study Amsterdam were used pertaining to 630 women (53 HT) and 533 men (63 HT). Subjects were asked whether they had ever had an HT with loss of consciousness. Linear regression analysis (adjusted for age, body mass index, chronic diseases, smoking, alcohol use, and gender) was performed to examine the association between HT and serum anteriory pituitary hormone levels, BMD, and quantative ultrasound measurements. RESULTS: Serum follicle stimulating hormone was significantly higher in males in the HT group (P = .05) than in the non-HT group. This difference was not found in women (P = .25). No other differences were observed in serum hormone levels between subjects with and without HT (P > .30). Also, no significant differences between the HT and non-HT group were found in BMD and quantitative ultrasound measurements. CONCLUSION: A self-reported history of HT with loss of consciousness does not seem to increase the risk of hypopituitarism and lower BMD in an aging population.

The relationship between IGF-I concentration, cognitive function and quality of life in adults with Prader-Willi syndrome.

Mental retardation is one of the clinical characteristics of Prader-Willi syndrome (PWS) and in part of the patients growth hormone deficiency is demonstrable. Cognitive function seems to be influenced by insulin-like growth factor I (IGF-I); however, little is known about cognitive function in relation to IGF-I levels in PWS adults. The aim of the present study was to evaluate cognitive function in adult PWS patients in comparison to healthy siblings and to investigate whether there is a correlation between cognitive function and IGF-I levels. Anthropometric measurements, IGF-I levels, quality of life (QoL), Appetite Assessment Score, IQ (GIT and Raven) and cognitive function (by four subtests of the Cambridge Neuropsychological Automated Testing Battery, CANTAB) were evaluated in PWS patients and their healthy siblings served as control group. PWS patients had significantly lower IGF-I levels, IQ and QoL when compared to controls. Reaction times were longer and performance was worse on CANTAB subtests in PWS adults. IGF-I on one hand and IQ, Appetite Assessment Score and cognitive performance on the other hand seem to be correlated in PWS patients. In conclusion, IGF-I levels, IQ and QoL are significantly lower in PWS subjects when compared to healthy siblings. In PWS adults, temporal as well as prefrontal cognitive functions are impaired. Higher IGF-I levels appear to be related to better intellectual skills and faster temporal memory processing in PWS patients.

Treating prolactinoma and psychosis: medication and cognitive behavioural therapy.

The patient in this case report had two severe medical conditions that require oppositional treatment: prolactinoma and psychosis. A prolactinoma is a benign tumour of the pituitary gland that produces prolactin. Dopamine agonist medication is the first-line treatment in patients with prolactinoma. The psychotic symptoms started after a dosage increase of a dopamine D2-receptor agonist. Several antipsychotic medications were tried with and without the dopamine D2-receptor agonist, but severe command hallucinations remained. Cognitive behavioural therapy (CBT) was added which reduced the impact of the hallucinations to a great extent, indicating that CBT can have an additional positive effect in prolactinoma patients with psychosis that shows incomplete recovery after antipsychotic medication. Future research should be aimed at the severe and prolonged side effects of dopamine agonists in the treatment of prolactinoma patients with multiple risk factors for a psychotic decompensation.

The impact of blood glucose levels on stimulated adrenocorticotropin hormone and growth hormone release in healthy subjects.

OBJECTIVE: In studies investigating the influence of glucose levels on the pituitary function the methods used have been variable and mainly focused on the change in function as a reaction to unphysiological low or high blood glucose levels. In the present study the impact of physiological and elevated blood glucose levels on adrenocorticotropin hormone (ACTH) and growth hormone release are investigated. DESIGN: The euglycaemic and hyperglycaemic clamp techniques were used to reach stable levels of 4, 8 and 12 mmol/l blood glucose levels. After a stabilization phase of 2 h, a corticotropin releasing hormone (CRH) or a growth hormone releasing hormone (GHRH) stimulation test was performed. SUBJECTS: Seven and eight healthy male volunteers, belonging to two groups, participated in this study. MEASUREMENTS: The area under the curve (AUC), peak values and time to peak of ACTH, cortisol and growth hormone were calculated to evaluate the response to the CRH and GHRH stimulation test. RESULTS: The peak values of ACTH, cortisol and growth hormone seemed to be the highest during the 4 mmol/l clamp sessions, compared with the 8 and 12 mmol/l clamps, although the differences were not statistically significant when analysed for every subject individually. The AUC and time to peak measurements were comparable during the three clamp procedures. CONCLUSION: The pituitary reaction on CRH and GHRH was not significantly changed by various blood glucose levels.

The role of leptin and ghrelin in the regulation of food intake and body weight in humans: a review.

Leptin and ghrelin are two hormones that have been recognized to have a major influence on energy balance. Leptin is a mediator of long-term regulation of energy balance, suppressing food intake and thereby inducing weight loss. Ghrelin on the other hand is a fast-acting hormone, seemingly playing a role in meal initiation. As a growing number of people suffer from obesity, understanding the mechanisms by which various hormones and neurotransmitters have influence on energy balance has been a subject of intensive research. In obese subjects the circulating level of the anorexigenic hormone leptin is increased, whereas surprisingly, the level of the orexigenic hormone ghrelin is decreased. It is now established that obese patients are leptin-resistant. However, the manner in which both the leptin and ghrelin systems contribute to the development or maintenance of obesity is as yet not clear. The purpose of this review is to provide background information on the leptin and ghrelin hormones, their role in food intake and body weight in humans, and their mechanism of action. Possible abnormalities in the leptin and ghrelin systems that may contribute to the development of obesity will be mentioned. In addition, the potentials of leptin and ghrelin as drug targets will be discussed. Finally, the influence of the diet on leptin and ghrelin secretion and functioning will be described.