Antipituitary antibodies after traumatic brain injury: is head trauma-induced pituitary dysfunction associated with autoimmunity?

OBJECTIVE

Traumatic brain injury (TBI) is a devastating public health problem that may result in hypopituitarism. However, the mechanisms responsible for hypothalamic-pituitary dysfunction due to TBI are still unclear. Although the antibodies against neurons have been demonstrated in injured animal studies, investigations regarding the occurrence of antipituitary antibodies (APAs) in patients with TBI are lacking in the literature. In order to investigate whether autoimmune mechanisms could play a role in the pituitary dysfunction after TBI, we have planned this study aimed at investigating the presence of APA at the third year of TBI and association between the TBI-induced hypopituitarism and APA.

PATIENTS AND DESIGN

Twenty-nine (25 males and 4 females; age 36.5+/-2.3 years) patients who had completed a 3-year follow-up after TBI were included in the present study. APA and pituitary function were evaluated in all the patients 3 years after TBI; moreover, APAs were tested also in sera of 60 age-/sex-matched normal controls. The APAs were investigated by an indirect immunofluorescence method. Results APAs were detected in 13 out of the 29 TBI patients (44.8%), but in none of the normal controls. Pituitary dysfunction development ratio was significantly higher in APA-positive patients (46.2%) when compared with APA-negative ones (12.5%; P=0.04). There was a significant association between APA positivity and hypopituitarism due to TBI (odds ratio: 2.25, 95% confidence intervals 1.1-4.6). Moreover, there was a significant positive correlation (r=0.74, P=0.004) between APA titer ratio and peak GH response to GHRH+GH related peptide (GHRP)-6 test, suggesting that high APA titers were associated with low GH response to GHRH+GHRP-6 test.

CONCLUSIONS

This study shows for the first time the presence of the APA in TBI patients 3 years after head trauma. Moreover, present investigation indicates preliminary evidence that APA may be associated with the development of TBI-induced pituitary dysfunction, thus suggesting that autoimmunity may contribute in the development of TBI-induced hypopituitarism. The presence of the association between APA and TBI-induced hypopituitarism may provide a new point of view in this field and promote further clinical and experimental studies.

The need to revise the cut-off level for the diagnosis of GH deficiency in children

The diagnosis of GH deficiency (GHD) in children is based on clinical findings, auxology, hormonal results, brain magnetic resonance imaging (MRI), molecular analysis, and two separate GH provocative tests, for which a GH cut-off level of less than 10 ng/ml is the gold standard for defining GHD in children. However, great variability exists in the GH response to stimulation, due to provocative test type and variability of GH peak with age, sex, body composition and pubertal stage. Variability in GH measurements is attributed to GH assay type, GH molecule heterogeneity, GH-binding protein interference, GH calibrators, antibody recognition of different GH isoforms, and inconsistency of unit-conversion factors. Each parameter has a significant effect on GH measurement and consequently, on the diagnosis of GHD and the decision for GH therapy. Most routine laboratories have replaced the manual radioimmunoassay (RIA) with fully automated two-site sandwich immunoassays: the two are well-correlated but the latter provide significantly lower results than the former, which has enormous implications for interpretation of the GH provocative tests, the diagnosis of GHD, and the decision for GH therapy. Despite these lower values, the cut-off level for GHD diagnosis has not been revisited. Here, the reasons for the variability in GH measurements and the need to revisit GH cut-off values are discussed.

Growth hormone decreases visceral fat and improves cardiovascular risk markers in women with hypopituitarism: a randomized, placebo-controlled study

CONTEXT

Data regarding gender-specific efficacy of GH on critical endpoints are lacking. There are no randomized, placebo-controlled studies of physiological GH therapy solely in women.

OBJECTIVE

Our objective was to determine the effects of physiological GH replacement on cardiovascular risk markers and body composition in women with GH deficiency (GHD).

DESIGN

This was a 6-month, randomized, placebo-controlled, double-blind study.

SETTING

The study was conducted at the General Clinical Research Center.

STUDY PARTICIPANTS

43 women with GHD due to hypopituitarism were included in the study.

INTERVENTION

Study participants were randomized to receive GH (goal mid-normal serum IGF-1) or placebo.

MAIN OUTCOME MEASURES

Cardiovascular risk markers, including high-sensitivity C-reactive protein, tissue plasminogen activator, and body composition, including visceral adipose tissue by cross-sectional computed tomography, were measured.

RESULTS

Mean daily GH dose was 0.67 mg. The mean IGF-1 sd score increased from -2.5 +/- 0.3 to -1.4 +/- 0.9 (GH) (P < 0.0001 vs. placebo). High-sensitivity C-reactive protein decreased by 38.2 +/- 9.6% (GH) vs.18.2 +/- 6.0% (placebo) (P = 0.03). Tissue plasminogen activator and total cholesterol decreased, and high-density lipoprotein increased. Homeostasis model assessment-insulin resistance and other markers were unchanged. Body fat decreased [-5.1 +/- 2.0 (GH) vs. 1.9 +/- 1.0% (placebo); P = 0.002] as did visceral adipose tissue [-9.0 +/- 5.9 (GH) vs. 4.3 +/- 2.7% (placebo); P = 0.03]. Change in IGF-1 level was inversely associated with percent change in visceral adipose tissue (r = -0.61; P = 0.002), total body fat (r = -0.69; P < 0.0001), and high-sensitivity C-reactive protein (r = -0.51; P = 0.003).

CONCLUSIONS

Low-dose GH replacement in women with GHD decreased total and visceral adipose tissue and improved cardiovascular markers, with a relatively modest increase in IGF-1 levels and without worsening insulin resistance.

Serum nitric oxide levels and flow-mediated dilatation in patients with Sheehan syndrome and the effect of combination therapy consisting of L-thyroxine, prednisolone, and conjugated estrogen/medroxyprogesterone acetate

Baseline and stimulated nitric oxide (NO) levels were higher, whereas baseline arterial diameter, FMD-stimulated NO increment, and arterial dilatation ratio were lower in Sheehan syndrome (SS) patients than in control subjects. After combination therapy consisting of prednisolone, L-thyroxine, and conjugated estrogen, baseline and stimulated NO levels of SS remained as high, but FMD-stimulated NO, NO increment ratio, and arterial dilatation ratio increased with treatment.

Effects of GH treatment in GH-deficient adults on adiponectin, leptin and pregnancy-associated plasma protein-A

OBJECTIVE

GH deficiency (GHD) in adults is associated with adverse effects on metabolism and increased cardiovascular risk. Pregnancy-associated plasma protein-A (PAPP-A) is a protease that promotes IGF-I availability in vascular tissues. PAPP-A levels appear to correlate with carotid intima-media thickness and have been proposed as an early predictor of cardiac events. The aim of our study was to evaluate PAPP-A levels in GHD adults at baseline and after GH replacement and correlate them with changes in body composition, lipid profile, glucose homeostasis, inflammatory markers and in leptin and adiponectin.

PATIENTS AND METHODS

Fourteen GHD adults were evaluated at baseline and after 1 year of GH therapy. All patients were compared at baseline with 28 age-, sex- and body mass index (BMI)-matched control subjects.

RESULTS

At baseline, GHD adults showed higher PAPP-A levels (P=0.03) and higher leptin (P=0.04), fibrinogen (P=0.002) and highly sensitive C-reactive protein (P=0.01) values than controls. Therapy with GH reduced PAPP-A (P=0.03) and fibrinogen levels (P=0.002) while increased BMI (P=0.01) and reduced waist-hip ratio (WHR; P=0.05) were observed. Insulin and homeostasis model assessment of insulin resistance index increased after treatment (P<0.004/P=0.007), without changes in leptin or adiponectin levels. PAPP-A values correlated positively with BMI and WHR and negatively with adiponectin before and after treatment, with no correlation with glucose homeostasis parameters, lipid profile or leptin.

CONCLUSIONS

Our study suggests that PAPP-A expression is increased in GHD adults, and that 1 year of GH replacement therapy is able to reduce PAPP-A levels in this population. However, further studies are required to determine whether this decrease correlates with an improvement in atherosclerosis.

Three years prospective investigation of anterior pituitary function after traumatic brain injury: a pilot study

OBJECTIVE

It has been recently demonstrated that traumatic brain injury (TBI)-mediated hypopituitarism could be more frequent than previously known. However, most of the previous data were obtained from retrospective studies, and the natural history of the hypopituitarism due to TBI is still unclear. So far no study has been reported in which the pituitary function of the same patients has been investigated more than 1 year after TBI. Therefore, we report the results of 3 years prospective follow-up of anterior pituitary function in patients with mild, moderate and severe TBI.

PATIENTS AND DESIGN

Thirty patients (25 males, 5 females; age 37.2 +/- 2.4 years) with TBI were included in the study. Pituitary function was evaluated at 1 and 3 years after TBI.

RESULTS

After individual evaluation of GH deficiency from 1 year to 3 years after TBI, 7 of 13 (53.8%) GH-deficient patients at 1st year recovered after 3 years of TBI, and GH deficiency detected at 3 years in one patient was new onset. Additionally, five of six (83.3%) ACTH-deficient patients at 1st year recovered after 3 years of TBI, and ACTH deficiency detected at 3 years in one patient was new onset.

CONCLUSIONS

GH deficiency is the most common pituitary deficit 1 and 3 years after TBI. In patients with mild and moderate TBI, pituitary function improves over time in a considerable number of patients, but it may also worsen rarely over the 3-year period. In patients with severe TBI, ACTH and GH deficiencies at 1st year evaluation persist at 3rd year.

Hypopituitarism in the elderly: multifaceted clinical and biochemical presentation

Hypopituitarism (HYPO) is a rare and under-investigated pathology in the elderly.

AIM

to review our case records of patients > or =65 yrs with first diagnosis of anterior global hypopituitarism, in order to evaluate presentation symptoms, etiology, biochemical and hormonal pictures, pituitary morphology, and efficacy of therapy.

PATIENTS

15 patients (65-82 yrs) were studied: in 11 (73%) HYPO was secondary to pituitary macroadenoma (non-secreting in 10 and GH-secreting in 1); in 3 it was associated to empty sella, and in 1 to pituitary hypoplasia.

RESULTS

major presenting symptoms were visual-field defects and asthenia (40%) but also memory and/or gait impairment and nausea (30%) and depression (20%) were significantly observed. Dyslipidemia (73%), anemia (20%) and severe hyponatremia (13%) were found. After starting substitutive therapy and clinical improvement, 10 patients with macroadenoma underwent uneventful neurosurgery, which improved visual alterations but not pituitary function. Immunohistochemistry showed positivity for FSH in one patient and for GH in one patient. Six out of the eight patients with a post-surgical tumor remnant required treatment (surgery/radiotherapy/somatostatin analogue treatment in the acromegalic patient).

CONCLUSIONS

The diagnosis of HYPO is often delayed in the elderly, since symptoms may be ascribed to aging and associated comorbidities. In our series, most of the aspecific symptoms were retrospectively addressed to HYPO since their resolution/improvement with replacement therapy. The prevalent cause of HYPO remains non-functioning pituitary macroadenomas. Hyponatremia can be a life-threatening presenting symptom. Symptoms considered apparently aspecific in the elderly should be investigated in order to possibly diagnose an important treatable disorder as HYPO.

Anti-hypothalamus and anti-pituitary antibodies may contribute to perpetuate the hypopituitarism in patients with Sheehan's syndrome

OBJECTIVE

While anti-pituitary antibodies (APAs) were detected in some patients with Sheehan's syndrome (SS) suggesting an autoimmune pituitary involvement in the development of their hypopituitarism, hypothalamic cell anti-hypothalamus antibodies (AHAs) have not been investigated so far.

DESIGN

The aim of this study was to evaluate the presence of AHA and APA in SS patients to verify whether an autoimmune hypothalamic-pituitary process can contribute to their late hypopituitarism.

METHODS

Twenty women with SS with a duration of disease ranging from 3 to 40 years (median 25.5 years) were enrolled into the study. Out of 20 patients, 12 (60%) had panhypopituitarism and the others had partial hypopituitarism well corrected with appropriate replacement therapy. None of them had clinical central diabetes insipidus. AHA and APA were investigated by immunofluorescence method in all patients. In addition, a four-layer immunofluorescence method was used to verify whether AHA immunostained vasopressin-secreting cells (AVP-c) or not.

RESULTS

AHAs were found in 8 out of 20 (40%) and APAs in 7 out of 20 (35%) patients with titers ranging from 1:32 to 1:128 and 1:16 to 1:32 respectively; however, in none of these positive patients AHA immunostained vasopressin cells. None of controls resulted positive for both antibodies.

CONCLUSIONS

Patients with SS, even many years after the onset of SS, can show antibodies to pituitary and/or hypothalamic but not AVP-secreting cells. Antibodies to unknown hypothalamic cells (releasing factor-secreting cells) other than APAs suggest that an autoimmune process involving both the hypothalamus and pituitary gland may contribute to late pituitary dysfunction in SS patients.

Bone density and turnover in young adult patients with growth hormone deficiency after 2-year growth hormone replacement according with gender

GH deficiency (GHD) in adults is accompanied by reduced bone mass that may revert only after 2 yr of GH replacement. However, it is unclear whether the gender may modify bone responsiveness to GH replacement in adults. In this study we have evaluated whether bone mineral density (BMD) and turnover improve after GH replacement according to patients' gender. BMD at lumbar spine (LS) and femoral neck (FN), serum osteocalcin (OC), and urinary cross-linked N-telopeptides of type I collagen (Ntx) were assessed in 64 hypopituitaric patients (35 men, 30-50 yr) before and 2 yr after the beginning of GH replacement. Values of IGF-I and BMD at LS and at FN were expressed as Zscores. At study entry, IGF-I and BMD resulted similar among men and women with GHD. During GH replacement, IGF-I levels increased in both men and women without any difference in the percentage of IGF-I increase between the genders (p=0.47). In women receiving estrogen replacement, however, the percentage of IGF-I increase (p<0.05), and the Z IGF-I score (p<0.001) were significant lower than estrogen untreated women, although IGF-I levels were similar in the 2 groups (p=0.53). The GH dose adjusted for body weight required to restore normal age- and sex- matched IGF-I levels was lower in men than in women (p<0.001), and was higher in women receiving than in those not receiving estrogen replacement (p<0.05). In contrast, hypogonadal men treated with testosterone and eugonadal men received a similar GH dose (p=0.97). Also OC, Ntx levels, lumbar and femoral BMD improved (p<0.001) in all patients. Nevertheless, a greater increase in lumbar BMD increase was observed in men than in women (8.0+/-2.1 vs 2.6+/-0.4%; p<0.05). No significant difference was revealed in bone parameters in women treated or untreated with estrogen replacement and in men treated or not with testosterone replacement for concomitant hypogonadism. At the multiple correlation analysis, gender was a stronger predictor for the required GH dose than the age (p<0.001 and p=0.02, respectively). In conclusion, a 2-yr GH replacement normalizes IGF-I levels, increases bone mass and improves bone turnover both in men and in women with GHD without any difference between the 2 groups, provided that the dose of GH was modulated on the basis of IGF-I levels. Women receiving oral estrogens should receive a GH dose approximately doubled, as compared to men and women not receiving oral estrogens, to achieve similar effects on bone density and turnover. In particular, GH replacement dose, to be successful on bone mass and turnover, depends on gender in hypopituitary patients aged below 50 yr.

Predictors of anterior pituitary insufficiency after traumatic brain injury

BACKGROUND

Several studies have reported a high prevalence of hypopituitarism after traumatic brain injury (TBI). Risk stratification is a prerequisite for cost-effective hormonal screening of these patients. However, it is still unclear which risk factors predispose patients to develop anterior hypopituitarism after TBI.

OBJECTIVE

To assess clinical and radiological risk factors for post-traumatic hypopituitarism.

PATIENTS AND METHODS

Seventy-eight consecutive patients (52 men, 26 women; mean age 36.0 years, range 18-65 years) with mild, moderate or severe TBI were studied. Endocrine and clinical parameters were assessed 3 and 12 months after TBI.

RESULTS

We found diffuse axonal injury, basal skull fracture and older age to be major risk factors of post-traumatic hypopituitarism.

CONCLUSIONS

We have defined specific risk factors for the development of post-traumatic hypopituitarism that are consistent with pathophysiological considerations. These findings might help to identify at-risk patients.

Dehydroepiandrosterone sulfate in the assessment of the hypothalamic-pituitary-adrenal axis

CONTEXT

The role of dehydroepiandrosterone-sulfate (DHEA-S) in assessing the integrity of the hypothalamic-pituitary-adrenal (HPA) axis in patients with suspected insufficiency is uncertain.

OBJECTIVE

The objective of the study was to prospectively evaluate the diagnostic value of DHEA-S on HPA function in consecutive patients with suspected HPA insufficiency with and without pituitary lesions at a tertiary referral center.

DESIGN AND PATIENTS

In 70 consecutive patients, insulin tolerance test was accompanied by measurement of basal DHEA-S. Assessment of HPA axis was based on peak cortisol response in insulin tolerance test (normal > or = 550 nmol/liter). To account for the age and gender dependency of DHEA-S, a z-score was calculated using age- and gender-specific reference values of the assay.

RESULTS

Individuals with HPA insufficiency had significantly lower z-scores than those with normal HPA function (-1.66 vs. -0.62, P < 0.0001). In individuals up to 30 yr of age, a z-score of -2.0 had 100% sensitivity and specificity regarding HPA function [area under receiver operating characteristics (ROC) curve 1.00], whereas z-scores proved less useful in older individuals. In individuals with pituitary macroadenoma, a z-score below -2.0 had 100% specificity to predict HPA insufficiency (area under ROC curve 0.82). In the absence of a pituitary adenoma, the diagnostic value of the z-score was reduced (area under ROC curve 0.71).

CONCLUSIONS

Individuals with HPA insufficiency have lower z-scores for DHEA-S than those with normal HPA function. There is evidence that a z-score could be of diagnostic value in assessing HPA integrity, especially in younger patients and patients with pituitary macroadenoma, but further studies are needed to consolidate these findings.

Effect of gonadal status on bone mineral density and radiological spinal deformities in adult patients with growth hormone deficiency

Growth hormone deficiency (GHD) in adult patients is associated with marked decrease in bone turnover, low bone mass and high risk of clinical and subclinical fractures. We investigated whether the prevalence of spinal deformities in adults with GHD was related to the gonadal status of patients. A total of 89 adult hypopituitary patients with severe GHD were evaluated for bone mineral density (BMD) and vertebral deformities (quantitative morphometric analysis). At the study entry, 54 patients were eugonadic whereas 35 patients were hypogonadic without replacement treatment. Radiological spinal deformities were found in 55 patients (61.8%) with higher prevalence in untreated (56 cases) versus treated (33 cases) GHD patients. Eugonadic and hypogonadic patients showed no significant difference in spinal deformities although T-score was significantly lower in hypogonadic as compared with eugonadic patients. Gonadal function was not correlated with the occurrence of spinal deformities which was instead inversely correlated with rhGH treatment. In conclusion, gonadal status may influence BMD in adult patients with GHD without affecting the risk to develop vertebral deformities. Conversely, rhGH replacement treatment seems to be the only factor influencing the risk to develop vertebral deformities in adult GHD patients.

Impact of 5 years of growth hormone replacement therapy on cardiovascular risk factors in growth hormone-deficient adults

The benefits of long-term effects of growth hormone (GH) substitution on carbohydrate and lipid metabolism in GH-deficient (GHD) adults are still controversial. The purpose of this study was to evaluate the effects of 5 years of GH substitution on body composition, glucose and lipid metabolism, and carotid artery intima-media thickness (IMT) in GHD adults. Fourteen patients were clinically assessed every 3 months for 5 years. Serum insulin-like growth factor 1 levels, lipid profile, oral glucose tolerance test, and ultrasonography of the carotid arteries were performed at baseline, 6 months, and every year during replacement. Visceral fat was measured by computed tomographic scan at baseline and at 6, 12, 24, and 60 months. The waist circumference was reduced after 6 months but increased during the next months toward baseline values. Visceral fat decreased during the study. Fasting glucose and insulin levels did not change, as well as the homeostasis model assessment of insulin resistance index. Despite an initial increase in frequency of abnormal glucose tolerance, mean 2-hour oral glucose tolerance test glucose levels decreased during the last 2 years. There was an increase in apolipoprotein A-1 levels during the treatment. Apolipoprotein B levels were reduced after 6 months and remained stable thereafter. A reduction in carotid artery IMT was observed during replacement. We concluded that 5 years of GH replacement therapy promoted positive effects on visceral fat, lipid profile, and carotid artery IMT in GHD adults. Long-term therapy improves insulin sensitivity through a reduction in visceral fat, and continuing monitoring is mandatory in terms of glucose metabolism.

Circadian pattern of prolactin secretion in children with growth hormone deficiency and congenital organic lesions in the hypothalamic-pituitary region

OBJECTIVES

Prolactin (Prl) secretion in children manifests circadian rhythm. The aim of the study was to assess circadian Prl pattern in children with growth hormone deficiency (GHD) and congenital organic disorders in the hypothalamic-pituitary region (HPR).

MATERIAL AND METHODS

The analysis comprised 47 children (aged: 11.05+/-3.5 years) with GHD, divided (based on MRI) into subgroups: NORM (no disturbances in HPR); HP (pituitary hypoplasia) and PSIS (pituitary stalk interruption syndrome). The profile of circadian Prl secretion was determined, based on Prl measurements in serum every 3 hours during 24 hours. The macroscopic analysis of circadian Prl rhythm in particular groups was performed. The comparison group consists of 41 children (aged: 11.45+/-3.20 years) with idiopathic short stature (ISS).

RESULTS

In GHD-HP, diurnal and nocturnal Prl concentrations were low but with the dispersion between them and with normal rhythm in most of cases. In GHD-PSIS, diurnal and nocturnal Prl concentrations were on the same level and the rhythm was not observed in most of cases. No significant differences were found in Prl secretions and Prl rhythm between GHD-NORM and ISS. The rhythm of Prl secretion was disturbed in: 72.7% of children with GHD-PSIS, 23.5% - with GHD-HP, 10.5% with GHD-NORM and 7.3% with ISS, only.

CONCLUSIONS

Congenital organic lesions of HPR are associated with quantitative disorders and changes of the circadian pattern of Prl secretion. In children with GHD without organic lesions of HPR, the circadian rhythm of Prl secretion was not different from that with ISS.

Hypothyroid cardiomyopathy due to hypopituitarism: a diagnostic dilemma

A case of hypothyroid cardiomyopathy secondary to hypopituitarism posed a diagnostic challenge. This lesson describes the patient's presentation with simultaneous acute heart failure and neurological signs; the investigations and imaging findings which initially suggested myocardial infarction (MI) and/or infiltration; and the response to treatment, with biochemical, sonographic and clinical resolution of the cardiomyopathy following thyroxine replacement therapy. This lesson illustrates the cardiovascular sequelae of severe hypothyroidism, and physicians are reminded of the difficulties involved in investigating putative coronary events in hypothyroid patients, since hypothyroidism itself may mimic MI.

Acute and long-term pituitary insufficiency in traumatic brain injury: a prospective single-centre study

OBJECTIVE

To assess the prevalence of hypopituitarism following traumatic brain injury (TBI), describe the time-course and assess the association with trauma-related parameters and early post-traumatic hormone alterations.

DESIGN

A 12-month prospective study.

PATIENTS

Forty-six consecutive patients with TBI (mild: N = 22; moderate: N = 9; severe: N = 15).

MEASUREMENTS

Baseline and stimulated hormone concentrations were assessed in the early phase (0-12 days post-traumatically), and at 3, 6 and 12 months postinjury. Pituitary tests included the Synacthen-test (acute +6 months) and the insulin tolerance test (ITT) or the GHRH + arginine test if the ITT was contraindicated (3 + 12 months). Insufficiencies were confirmed by retesting.

RESULTS

Early post-traumatic hormone alterations mimicking central hypogonadism or hypothyroidism were present in 35 of the 46 (76%) patients. Three months post-traumatically, 6 of the 46 patients failed anterior pituitary testing. At 12 months, one patient had recovered, whereas none developed new insufficiencies. All insufficient patients had GH deficiency (5 out of 46), followed by ACTH- (3 out of 46), TSH- (1 out of 46), LH/FSH- (1 out of 46) and ADH deficiency (1 out of 46). Hypopituitary patients had more frequently been exposed to severe TBI (4 out of 15) than to mild or moderate TBI (1 out of 31) (P = 0.02). Early endocrine alterations including lowered thyroid and gonadal hormones, and increased total cortisol, free cortisol and copeptin were positively associated to TBI severity (P < 0.05), but not to long-term development of hypopituitarism (P > 0.1), although it was indicative in some.

CONCLUSION

Long-term hypopituitarism was frequent only in severe TBI. During the 3-12 months follow-up, recovery but no new insufficiencies were recorded, indicating manifest hypothalamic or pituitary damage already a few months postinjury. Very early hormone alterations were not associated to long-term post-traumatic hypopituitarism. Clinicians should, nonetheless, be aware of potential ACTH deficiency in the early post-traumatic period.

Growth hormone (GH) replacement decreases serum total and LDL-cholesterol in hypopituitary patients on maintenance HMG CoA reductase inhibitor (statin) therapy

OBJECTIVE

Adult onset GH deficiency (GHD) is characterized by abnormalities of serum lipoprotein profiles and GH replacement results in favourable alterations in serum total and low density lipoprotein (LDL)-cholesterol. Preliminary evidence has indicated that the effect of GH replacement in this respect may be additive to that of HMG CoA reductase inhibitor (statin) therapy. We have examined this possibility during prospective follow-up of adult onset hypopituitary patients enrolled in KIMS (Pfizer International Metabolic Database), a pharmacoepidemiological study of GH replacement in adult hypopituitary patients.

DESIGN

Lipoprotein profiles were measured centrally at baseline and after 12 months GH replacement therapy.

PATIENTS

Sixty-one hypopituitary patients (30 male, 31 female) on maintenance statin therapy (mean 2.5 +/- 2.7 SD years before GH) (statin group - SG) and 1247 (608 male, 639 female) patients not on hypolipidaemic therapy (nonstatin group - NSG) were studied. All patients were naïve or had not received GH replacement during the 6 months prior to study. Patients who developed diabetes mellitus during the first year of GH therapy or in the subsequent year and those with childhood onset GHD were excluded from this analysis. An established diagnosis of diabetes mellitus was present in 18% SG and 4.4% NSG at baseline.

MEASUREMENTS

Serum concentrations of total, high density lipoprotein (HDL)-cholesterol, triglycerides and IGF-I were measured centrally in all patients and LDL-cholesterol was estimated using Friedewald's formula.

RESULTS

The relative frequency of various statin use was simvastatin 52% (15.8 +/- 8.1 mg, mean +/- SD), atorvastatin 30% (14.4 +/- 7.8 mg), pravastatin 9.8% (31.6 mg +/- 13.9 mg), lovastatin 6.6% (17.5 +/- 5 mg) and fluvastatin 1.6% (40 mg). Baseline serum total and LDL-cholesterol (mean +/- SD) were 5.2 +/- 1.4 and 3.1 +/- 1.3 mmol/l in SG and 5.8 +/- 1.2 and 3.7 +/- 1.0 mmol/l in NSG, respectively (P < 0.0001, SG vs. NSG). After 12 months GH replacement (SG: 0.32 +/- 0.17 mg/day; NSG: 0.38 +/- 0.1 mg/day) serum total and LDL-cholesterol decreased by a mean (+/-SD) of 0.48 (+/- 1.25) mmol/l (P < 0.0004) and 0.53 (+/- 1.08) mmol/l (P < 0.0001) in SG and by 0.30 (+/- 0.89) mmol/l (P < 0.0001) and 0.28 (+/- 0.80) mmol/l (P < 0.0001) in NSG, respectively. There were no significant changes in HDL-cholesterol or triglycerides in either group (SG vs. NSG: NS). A relationship between LDL-cholesterol at baseline and the decrease in LDL-cholesterol after 12 months GH was evident in both groups (SG: R = -0.54, P < 0.001; NSG: R = -0.4, P < 0.001) and a similar relationship for cholesterol was observed.

CONCLUSIONS

These data indicate that GH replacement exerts additional beneficial effects on lipoprotein profiles in patients on maintenance statin therapy, confirming that the effects of these interventions are complementary rather than exclusive.

Severe hyponatremia due to hypopituitarism with adrenal insufficiency: a case report

OBJECTIVE

Adrenal insufficiency due to hypopituitarism can lead to severe hyponatremia with potentially fatal consequences. Prompt diagnosis and adequate hormonal replacement therapy are essential to block an otherwise unfavorable course and to re-establish a healthy life. Unfortunately, this condition is often misdiagnosed.

DESIGN

Case report.

SETTING

Intensive Care Unit of a teaching hospital.

PATIENT

A 76-yr-old man with refractory hypotension, acute myocardial infarction, and left ventricular dysfunction, secondary to severe chronic pan-hypopituitarism, associated with severe hyponatremia.

METHODS AND MAIN RESULTS

The patient underwent mechanical ventilation and continuous venous-venous hemodiafiltration, for severe respiratory and renal insufficiency. A hormonal replacement therapy with T4, hydrocortisone, and nandrolone was started and the patient was discharged to a rehabilitation facility after 31 days of hospitalization.

CONCLUSIONS

Hypopituitarism with secondary adrenal insufficiency is often misdiagnosed at an early stage and a high degree of suspicion is necessary for early diagnosis. Determination of plasma cortisol level in patients with hyponatremia not explained by other causes should always be obtained.

The Leu544Ile polymorphism of the growth hormone receptor gene affects the serum cholesterol levels during GH treatment in children with GH deficiency

OBJECTIVE

The cellular effects of growth hormone (GH) are mediated by the interaction between GH and the GH receptor (GHR). We investigated the association between polymorphisms in GHR and changes in height standard deviation scores (SDS), and lipid metabolism during GH treatment for GH-deficient children.

DESIGN

A 1-year study on growth rate and lipid metabolism under GH treatment.

PATIENTS

Eighty-three children (61 boys and 22 girls) with GH deficiency were treated with GH for 1 year after diagnosis.

INTERVENTION

The patients were treated with recombinant human GH (0.19 mg/kg/week) for at least 1 year after diagnosis. The growth rates and biochemical parameters for lipid metabolism were measured both before and during treatment. Four single nucleotide polymorphisms (SNPs) in the GHR gene, Cys440Phe, Pro495Thr, Leu544Ile and Pro579Thr, and exon 3 deletion polymorphisms were genotyped by direct sequencing and multiplex PCR.

RESULTS

We found no significant association between GHR polymorphisms and changes in height SDS during GH treatment. The total cholesterol levels of the GH-deficient boys with Ile/Ile at codon 544 showed significantly higher cholesterol levels before GH treatment and then maintained high levels during the GH treatment, compared to those with other genotypes. No other polymorphisms seemed to have any apparent effects on lipid metabolism.

CONCLUSION

The Leu544Ile polymorphism of the GHR gene is associated with cholesterol levels in boys with GH deficiency.

Small pituitary size in children with Fanconi anemia

BACKGROUND

Fanconi anemia (FA) is a genetic disorder associated with multiple congenital anomalies, bone marrow failure, and pituitary hypofunction including hypogonadism, thyroid dysfunction, and growth hormone (GH) deficiency.

PROCEDURE

Among 44 patients with FA referred to Cincinnati Children's Hospital Medical Center (CCHMC) between 1975 and 2005, 33 had neuroimaging studies, including 11 cranial magnetic resonance imaging (MRIs). Two separate measurements per patient from these MRIs were used to evaluate pituitary height compared to on-site control data of similar measurements of cranial MRIs on 22 age and gender-matched children without any pathology involving the hypothalamic-pituitary system. Growth pattern and endocrine studies were reviewed to assess potential correlation with pituitary size.

RESULTS

When compared to the age-gender matched on-site control sample, the mean pituitary height of FA patients was significantly smaller (P < 0.0001; mean +/- SE from mixed effects model with age and gender as covariates: 3.96 +/- 0.32 vs. 5.76 +/- 0.24). Upon further adjusting for the effect of the small head size by including bi-parietal diameter (BPD) as a covariate, the difference remained statistically significant (P = 0.0013). Findings on the growth pattern and endocrinological measurements are as follows: 50% of patients with small pituitary gland were short. GH and adrenal function tests were normal in all tested patients. Thyroid, pubertal status, and glucose regulation were abnormal in 30, 50, and 75% of patients tested.

CONCLUSIONS

Children with FA tend to have unsuspected small pituitary glands beyond what is expected from the effects of their stunted growth. Further studies are required to reveal the clinical implications of this finding.

Effects of testosterone therapy on cardiovascular risk markers in androgen-deficient women with hypopituitarism

CONTEXT

Low-dose testosterone replacement therapy in women with relative androgen deficiency has been shown to have beneficial effects on body composition, bone mass, and psychosexual function. However, the safety of chronic testosterone administration on cardiovascular risk and insulin resistance is unknown.

OBJECTIVE

The aim of the study was to determine the effects of physiological testosterone replacement on cardiovascular risk markers and insulin resistance in women.

DESIGN

A 12-month, randomized, placebo-controlled study was conducted.

SETTING

A General Clinical Research Center was the setting for the study.

STUDY PARTICIPANTS

A total of 51 women of reproductive age with androgen deficiency due to hypopituitarism participated.

INTERVENTION

Study participants were randomized to physiological testosterone administration, 300 mug daily, or placebo, by patch.

MAIN OUTCOME MEASURES

We measured fasting glucose, fasting insulin, insulin-resistance homeostasis model of assessment (IRHOMA), quantitative insulin sensitivity check index (QUICKI), high-sensitivity C-reactive protein, vascular cell adhesion molecule (VCAM), leptin, lipoprotein (a), apolipoprotein A1, and homocysteine.

RESULTS

At 12 months, fasting insulin and IRHOMA were significantly lower in the testosterone compared with the placebo group, and there was a trend toward a higher QUICKI level at 12 months in the testosterone compared with the placebo group. These differences were no longer significant after controlling for baseline levels. We observed no effect, either positive or negative, of testosterone administration on high-sensitivity C-reactive protein, VCAM leptin, lipoprotein (a), or apolipoprotein A1.

CONCLUSIONS

Our data suggest that physiological testosterone replacement in women with hypopituitarism for 12 months does not increase, and may improve, insulin resistance. Chronic low-dose testosterone administration does not increase markers of cardiovascular disease reflecting several different mechanistic pathways. Large, randomized, placebo-controlled, long-term prospective studies are needed to determine whether low-dose testosterone replacement affects cardiovascular risk and event rates in women.

Prolonged hypocortisolemia in hydrocortisone replacement regimens in adrenocorticotrophic hormone deficiency

OBJECTIVES

Studies of adults have shown that thrice-daily hydrocortisone dosing results in more physiologic cortisol profiles than twice-daily dosing. There are no data on thrice-daily dosing and only limited data on twice-daily dosing in children despite the possible adverse effects of glucocorticoid underreplacement or overreplacement.

METHODS

Using 24-hour cortisol and glucose profiles, along with computerized cognitive testing, our aim was to assess prescribed hydrocortisone regimens in children and adolescents with hypopituitarism.

RESULTS

Twenty patients with adrenocorticotrophic hormone deficiency participated. The hydrocortisone dosing regimen was thrice daily in 9 patients and twice daily in 11 patients (mean total daily dose: 8.3 +/- 2.6 and 7.6 +/- 2.1 mg/m2 per day, respectively). Those on twice-daily dosing had more waking hours (between 8:00 am and 8:00 pm) below the reference range than those on thrice-daily dosing (5.5 vs 2.1) and more daytime prolonged hypocortisolemia, defined as plasma cortisol level of < 50 nmol/L for > or = 4 hours (64% vs 0%). Morning doses > 4 mg/m2 caused larger postdose peaks than < 4 mg/m2 (151 vs 47 nmol/L, above the 97.5th percentile). However, there was no difference in the length of time taken to reach nadir below the 2.5th percentile (5.2 vs 4.8 hours). This was true for evening doses of > 2.5 mg/m2 and < 2.5 mg/m2. No hypoglycemia or hyperglycemia was detected in association with low or high cortisol levels. On predose and postdose cognitive testing (34 paired tests), no significant change in reaction speed was detected (453.3 vs 438.8 milliseconds) or in subgroup analysis of those who had symptoms of lethargy, predose cortisol levels of < 50 nmol/L, or prolonged hypocortisolemia.

CONCLUSIONS

Thrice-daily dosing resulted in less frequent and prolonged hypocortisolemia than twice-daily regimens, but we were unable to relate either regimen to acute clinical end points of glycemia, lethargy, or cognitive function.

Radiosurgery of growth hormone-producing pituitary adenomas: factors associated with biochemical remission

OBJECT

The authors reviewed outcomes after stereotactic radiosurgery for patients with acromegaly and analyzed factors associated with biochemical remission.

METHODS

Retrospective analysis was performed for 46 consecutive cases of growth hormone (GH)-producing pituitary adenomas treated by radiosurgery between 1991 and 2004. Biochemical remission was defined as a fasting GH less than 2 ng/ml and a normal age- and sex-adjusted insulin-like growth factor-I (IGF-I) level while patients were not receiving any pituitary suppressive medications. The median follow up after radiosurgery was 63 months (range 22-168 months). Twenty-three patients (50%) had biochemical remission documented at a median of 36 months (range 6-63 months) after one radiosurgical procedure. The actuarial rates of biochemical remission at 2 and 5 years after radiosurgery were 11 and 60%, respectively. Multivariate analysis showed that IGF-I levels less than 2.25 times the upper limit of normal (hazard ratio [HR] 2.9, 95% confidence interval [CI] 1.2-6.9, p = 0.02) and the absence of pituitary suppressive medications at the time of radiosurgery (HR 4.2, 95% CI 1.4-13.2, p = 0.01) correlated with biochemical remission. The incidence of new anterior pituitary deficits was 10% at 2 years and 33% at 5 years.

CONCLUSIONS

Discontinuation of pituitary suppressive medications at least 1 month before radiosurgery significantly improved endocrine outcomes for patients with acromegaly. Patients with GH-producing pituitary adenomas should not undergo further radiation therapy or surgery for at least 5 years after radiosurgery because GH and IGF-I levels continue to normalize over that interval.

[Paradoxal growth hormone and cortisol response to hypoglycemia caused by endogenous hyperinsulinemia: a case report]

Growth hormone (GH) together with cortisol are two important counter-regulatory hormones maintaining normal glycemia. Hyperinsulinemic hypoglycemia is a disorder of this counter-regulation described in neonates. We report here a rare case of reversible dissociated hypopituitarism secondary to an insulinoma in a 38-year-old man referred for investigation of hypoglycemic episodes. Hormonal investigations were in favour of dissociated anterior pituitary failure, with growth hormone and corticotroph deficiency. The hypothalamic-pituitary MRI was normal. The fasting test argued in favour of a hyperinsulinemic hypoglycemia. The abdominal scan and the endoscopic ultrasound showed a mass within the tail of the pancreas. Distal pancreatectomy was performed. Histology disclosed an insulinoma. On follow-up, no hypoglycemic episodes recurred and cortisol and GH response to induced hypoglycemia was normal. Our clinical case shows that hyperinsulinemia and hypoglycemia in patients with insulinoma can give rise to functional growth hormone and corticotrophin deficiency. The pathophysiological mechanism of this defective counter-regulation remains to be clarified; some studies suggest it could be related to hyperinsulinemia-induced decreased in CRF secretion and GHRH pulse.

Posterior pituitary function in Sheehan's syndrome

OBJECTIVE

We studied posterior pituitary function in 27 patients with Sheehan's syndrome and 14 controls.

DESIGN

All patients were investigated by water deprivation test and 26 of them by 5% hypertonic saline infusion test. None of the patients had symptoms of diabetes insipidus and all patients were on adequate glucocorticoid and thyroid hormone replacement therapy before testing.

RESULTS

According to dehydration test, 8 (29.6%) patients had partial diabetes insipidus (PDI group) and 19 (70.3%) had normal response (non-DI group). During the 5% hypertonic saline infusion test, the maximal plasma osmolality was higher in PDI (305 +/- 4.3) and non-DI (308 +/- 1.7) groups when compared with controls (298 +/- 1.7 mOsm/kg; P < 0.005), but the maximal urine osmolality was lower in PDI group (565 +/- 37) than in non-DI (708 +/- 45) and control (683 +/- 17 mOsm/kg) groups (P < 0.05). The osmotic threshold for thirst perception was higher in PDI (296 +/- 4.3) and non-DI (298 +/- 1.4) groups when compared with control group (287 +/- 1.5 mOsm/kg) (P < 0.005). Basal plasma osmolalities were also higher in PDI (294 +/- 1.0) and non-DI (297 +/- 1.1) groups than in controls (288 +/- 1.2 mOsm/kg; P < 0.001).

CONCLUSIONS

Our findings demonstrated that patients with Sheehan's syndrome have an impairment of neurohypophyseal function. The thirst center may be affected by ischemic damage and the osmotic threshold for the onset of thirst in patients with Sheehan's syndrome is increased.

Elevation of E-selectin concentrations may correlate with potential endothelial dysfunction in individuals with hypopituitarism during therapy with growth hormone

Increased mortality due to cardiovascular disease has been described in adult patients with untreated growth hormone (GH) deficiency. GH replacement therapy has been demonstrate to improve vascular reactivity and reverses early atherosclerotic changes in GH deficient adults. The objective of this study was the assessment of fibrinolytic markers, soluble adhesion molecules, inflammatory cytokines and endothelial function in hypopituitary adults with GH deficiency and with GH replacement therapy. We studied 20 GH deficient patients, 10 men and 10 women (aged, 43.4 +/- 8.4 years) under GH replacement therapy compared with a control group matched for age and body mass index, 9 men and 16 women. All subjects, patients and controls, were life-long non-smokers, normotensive and non-diabetic. The following variables were recorded: anthropometrical and body composition variables, serum concentrations of glucose, insulin and C-peptide; thrombin anti-thrombin fragments and fibrin degradation product D-dimer that were determined by an enzyme-linked-immunosorbent assay (ELISA); IGF-I by radioimmunoassay; C-reactive protein by highly sensitive immunonephelometry; E-selectine, P-selectine, soluble intercellular cell adhesion molecule-1, soluble vascular cell adhesion molecule-1, interleukin-6 and monocyte chemoattractant protein-1 by ELISA. The assessment of endothelial function in vivo was measured by Doppler. Patients with GH deficiency had higher hip/waist ratio and C-peptide and triglycerides concentrations than controls. Our results demonstrated no difference in fibrinolytic markers among patients and controls. E-selectin concentrations were higher in patients than in controls, 22.5+/-11.4 vs. 10.7+/-6.2 microg/L, p = 0.0001. P-selectin, soluble intercellular cell adhesion molecule-1, soluble vascular cell adhesion molecule-1, interleukin-6, monocyte chemoattractant protein-1 and C-reactive protein were similar in the 2 groups. Vascular reactivity and carotid intima-media thickness were also similar in patients and controls. In this study we have demonstrated in adults with GH deficiency under GH substitution elevation of E-selectin concentrations that may correlate with potential endothelial dysfunction suggesting that the protective effect of GH in these patients may be enhancing other mechanisms.

GH response to ghrelin in subjects with congenital GH deficiency: evidence that ghrelin action requires hypothalamic-pituitary connections

OBJECTIVES

Evaluation of GH response to ghrelin in patients with GH deficiency (GHD) may help to elucidate the site and mechanism of action of ghrelin. We aimed to investigate the GH-releasing effect of ghrelin in children and young adults with childhood-onset GHD.

DESIGN

All subjects underwent ghrelin testing and neuro-imaging examination. Magnetic resonance imaging evidenced the presence of a vascular pituitary stalk (VPS) or its complete absence (PSA).

PATIENTS AND METHODS

Seventeen prepubertal children and nine adult patients with childhood-onset GHD were selected for the study. The children were enrolled at a median age of 5.8 years. The adult subjects were included at a median age of 23.3 years. The diagnosis of GHD in the adult patients had been established at a median age of 8.5 years. Ghrelin was administered at a dose of 1 microg/kg body weight, i.v. at time zero, and blood for GH determination was obtained at 0, 15, 30, 45, 60, 75, 90, 105 and 120 min.

RESULTS

Median GH response after ghrelin was similar between children and adults. Median peak GH response to ghrelin (7.45 microg/l, IQR: 3.9-11.3 microg/l) was significantly higher in patients with VPS (10.9 microg/l, IQR: 2.4-15.1 mcirog/l) than in those with PSA (IQR: 2.3-6.7 microg/l; P=0.001). It was significantly higher in subjects with isolated GHD (12.5 microg/l, IQR: 10.8-15.5 microg/l) than in those with multiple pituitary hormone deficiencies (5.15 microg/l, IQR: 2.4-9.0 microg/l; P=0.003). No correlation was found between the GH peak after ghrelin and body mass index.

CONCLUSION

The GH response to ghrelin in patients with congenital hypopituitarism depends on the degree of the anatomical abnormalities and lends further support to the assumption that the main action of the peptide is exerted at the hypothalamic level and requires the integrity of hypothalamic-pituitary connections.

Effect of weight loss on free insulin-like growth factor-I in obese women with hyposomatotropism

OBJECTIVE

It has been hypothesized that increased free insulin-like growth factor (IGF)-I levels generated from an increase in IGF-binding protein (IGFBP) protease activity could be the inhibitory mechanism for the decreased growth hormone (GH) secretion observed in obese subjects.

RESEARCH METHODS AND PROCEDURES

In this study, we determined basal and 24-hour levels of free IGF-I and -II, total IGF-I and -II, IGFBP-1, as well as basal IGFBP-2, -3, and -4, acid-labile subunit (ALS), IGFBP-1, -2, and -3 protease activity, and 24-hour GH release in obese women before and after a diet-induced weight loss. Sixteen obese women (age, 29.5+/-1.4 years) participated in a weight loss program and 16 age-matched non-obese women served as controls.

RESULTS

Circulating free IGF-I and 24-hour GH release were significantly decreased in obese women at before weight loss compared with non-obese women (1.29+/-0.12 vs. 0.60+/-0.09 microg/L; p<0.001 and 862+/-90 vs. 404+/-77 mU/24 hours; p<0.001, respectively). Free IGF-I and 24-hour GH release were not inversely correlated to each other. IGFBP-1 and -2 levels were decreased, whereas ALS, IGFBP-3 and -4, and IGFBP-1, -2, and -3 protease activity were similar in obese and non-obese women. Eight of the 16 obese women achieved an average weight loss of 30+/-5 kg during 26 to 60 weeks of dieting. After the considerable weight loss, significant differences in free IGF-I, GH release, and IGFBP-1 and -2 levels were no longer present between previously obese and non-obese women.

DISCUSSION

We showed that circulating free IGF-I is markedly decreased in severely obese women and does not per se mediate the concomitant hyposomatotropism. The decreased levels of free IGF-I seem to be transient and restored to normal levels after weight loss.

Defining Growth Hormone Status in Adults with Hypopituitarism

The identification of adults with severe growth hormone (GH) deficiency (GHD) is not straightforward. The insulin tolerance test remains the gold standard diagnostic test, although other stimuli such as GH-releasing hormone-arginine are gaining acceptance. Insulin-like growth factor-I has a poor diagnostic sensitivity in adult-onset GHD, but is more useful in the subgroup of adults with childhood-onset GHD. Therapeutic developments include increasing recognition of the need to continue GH therapy beyond final height in young adults with severe GHD on retesting. Consensus guidelines have provided a useful algorithm to identify individuals requiring retesting and the number of tests needed. The concept of partial GHD, recognized by paediatric endocrinologists for many years, is being examined in adults with hypothalamic-pituitary disease. Preliminary evidence suggests that this entity is associated with metabolic and anthropometric abnormalities intermediate between those in severe GHD and in healthy controls. It remains to be seen whether this subgroup will derive benefit from GH therapy. To date, therapeutic benefits of GH have been demonstrated only in adults with severe GHD. It is, therefore, imperative that these individuals are unequivocally identified; the diagnosis becomes more uncertain in the presence of obesity, increasing age, and in the absence of additional pituitary hormone deficits.

Kickboxing sport as a new cause of traumatic brain injury-mediated hypopituitarism

OBJECTIVE

Traumatic brain injury, which is a frequent and a worldwide important public health problem, may result in pituitary dysfunction. Concussion, a common type of lesion after traumatic brain injury, is an injury associated with sports including boxing and kickboxing. Kickboxing is one of the most popular martial arts and approximately 1-million people around the world participate in kickboxing sport. Head is the most common site of injury in amateur and professional kickboxers. Pituitary consequences of chronic repetitive head trauma in kickboxing have not been investigated until now. Therefore, the present study was designed to investigate the pituitary function in both retired and active amateur kickboxers.

PATIENTS AND DESIGN

Twenty-two amateur kickboxers who have boxed in national and international championships (16 men, 6 women) with a mean age of 27.3 +/- 7.1 years, and 22 age- and sex-matched healthy controls were included in the study. Basal hormone levels were obtained from the participants. To assess GH-IGF-I axis, GHRH + GHRP-6 test and glucagon stimulation tests were used. Hypothalamo-pituitary-adrenal axis was assessed by glucagon stimulation test.

RESULTS

When mean basal hormone levels were compared between kickboxers and the controls, IGF-I level was significantly lower in kickboxers (P < 0.05). Five (22.7%) and two (9.1%) of the 22 kickboxers had GH deficiency had ACTH deficiency, respectively. There were significant negative correlations between IGF-I levels and age, duration of sports and number of bouts (P < 0.05).

CONCLUSIONS

Present data clearly demonstrate for the first time that amateur kickboxing is a novel cause of hypopituitarism and kickboxers are at a risk for hypopituitarism especially isolated GH deficiency. Therefore, participants of the combative sports who were exposed to chronic repetitive head trauma need to be screened.

Growth hormone reverses nonalcoholic steatohepatitis in a patient with adult growth hormone deficiency

BACKGROUND AND AIMS

Nonalcoholic steatohepatitis (NASH) is an emerging progressive hepatic disease and demonstrates steatosis, inflammation, and fibrosis. Insulin resistance is a common feature in the development of NASH. Molecular pathogenesis of NASH consists of 2 steps: triglyceride accumulation in hepatocytes with insulin resistance and an enhanced oxidative stress caused by reactive oxygen species. Interestingly, NASH demonstrates a striking similarity to the pathologic conditions observed in adult growth hormone deficiency (AGHD). AGHD is characterized by decreased lean body mass, increased visceral adiposity, abnormal lipid profile, and insulin resistance. Moreover, liver dysfunctions with hyperlipidemia and nonalcoholic fatty liver disease (NAFLD) are frequently observed in patients with AGHD, and it is accompanied by metabolic syndrome.

METHODS

We studied a case diagnosed as NASH with hyperlipidemia in AGHD. The effect of GH-replacement therapy on the patient was analyzed.

RESULTS

Six months of GH-replacement therapy in the patient drastically ameliorated NASH and the abnormal lipid profile concomitant with a marked reduction in oxidative stress.

CONCLUSIONS

These results suggest that GH plays an essential role in the metabolic and redox regulation in the liver.

Atherogenic lipoprotein phenotype and low-density lipoprotein size and subclasses in patients with growth hormone deficiency before and after short-term replacement therapy

OBJECTIVE

Patients with growth hormone deficiency (GHD) have increased cardiovascular risk and may show elevated triglyceride and reduced high density lipoprotein (HDL) cholesterol concentrations, two lipid abnormalities usually accompanied by increased small dense LDL in the 'atherogenic lipoprotein phenotype' (ALP). In the present study, we directly investigated (1) whether hypopituitary patients with GHD have increased small dense LDL; (2) whether growth hormone replacement therapy (GHRT) beneficially impact on such particles; (3) the prevalence of ALP in GHD and GHRT patients.

DESIGN AND METHODS

In 14 hypopituitary patients with GHD (44 +/- 13 years, body mass index (BMI) 27 +/- 3) before and after 4 months of GHRT, and in 11 healthy age- and BMI-matched controls we measured plasma lipids and LDL size and subclasses by gradient gel electrophoresis.

RESULTS

Compared with controls, GHD showed increased triglycerides (P = 0.0024), similar total and LDL cholesterol levels and a tendency towards reduced HDL cholesterol concentrations (P = 0.0894). GHRT reduced total and LDL cholesterol levels (P = 0.0303 and 0.0120 respectively), but no effect was found on triglycerides and HDL cholesterol levels. LDL size was unchanged in GHD versus controls (269 +/- 9 vs 274 +/- 6 A, P = ns), but LDL subclass analysis revealed a shift towards more dense particles (P = 0.0046). GHRT had no significant impact on LDL size and subclasses. The prevalence of ALP was 14% in GHD and 7% in GHRT.

CONCLUSIONS

In GHD patients, individual features of ALP (including increased small dense LDL) may be common, but complete ALP is relatively uncommon. Short-term replacement therapy seems to be ineffective on such lipid alterations, but the effect of a longer GHRT remains to be assessed.

A single growth hormone determination 30 minutes after the administration of the GHRH plus GHRP-6 test is sufficient for the diagnosis of somatotrope dysfunction in patients who have suffered traumatic brain injury

As hypopituitarism is frequent in patients who have suffered a traumatic brain injury (TBI) a hormonal check-up is necessary. However, the prevalence of TBI is so large that the number of potential candidates to be tested is difficult to manage, in particular for GH deficiency diagnosis that requires cumbersome and expensive dynamic tests. GHRH plus GH-releasing hexapeptide (GHRP-6) is a safe and effective test capable of segregating normal subjects from GH deficient patients. As the GHRH+GHRP-6 test induces GH peaks consistently in the first 30 min, the working hypothesis assessed in this study was whether a single determination of GH 30 min after stimulus could provide the same biochemical classification as the whole secretory curve. A total of 83 subjects who suffered TBI at least one year before the study were administered GHRH 1 mug/kg iv plus GHRP-6 1 mug/kg iv at 0 min, and blood samples were obtained at regular intervals. GH was determined in all samples. An excellent correlation was observed between GH values at 30 min and GH peaks (r=0.972, p<0.0001). When comparing the 30-min GH values against the peaks, the biochemical classification changed only in 5 out of 83 subjects from normal GH secretion to uncertain.

CONCLUSIONS

The GHRH+GHRP-6 test is convenient, safe and in patients with TBI can be reduced to a single fixed GH determination 30 min after stimulus without losing diagnostic power.

An Unusual Cause of Severe Hypoglycaemia in Type 1 Diabetes Mellitus. Antepartum Pituitary Failure: A Case Report and Literature Review

We describe an unusual cause of severe hypoglycaemia, secondary to hypopituitarism as a result of antepartum pituitary failure, in a pregnant patient with type 1 diabetes mellitus (T1DM). Antepartum pituitary failure is a very rare condition, which has been reported only in a very small number of pregnant patients with diabetes and presents with an acute onset headache and a sub-arachnoid haemorrhage-like picture. It is a potentially fatal condition to the mother and the child if not recognised and treated. Our case report highlights the importance of thinking about hypopituitarism, as a cause of recurrent hypoglycaemia in pregnant patients with T1DM as missing the diagnosis could be fatal to the mother and child.

Unmasking of central hypothyroidism following growth hormone replacement in adult hypopituitary patients

BACKGROUND

The effect of GH replacement on thyroid function in hypopituitary patients has hitherto been studied in small groups of children and adults with conflicting results.

OBJECTIVE

We aimed to define the effect and clinical significance of adult GH replacement on thyroid status in a large cohort of GH-deficient patients.

PATIENTS AND METHOD

We studied 243 patients with severe GH deficiency due to various hypothalamo-pituitary disorders. Before GH treatment, 159 patients had treated central hypothyroidism (treated group) while 84 patients were considered euthyroid (untreated group). GH dose was titrated over 3 months to achieve serum IGF-1 concentration in the upper half of the age-adjusted normal range. Serial measurements of serum T4, T3, TSH and quality of life were made at baseline and at 3 and 6 months after commencing GH replacement.

RESULTS

In the untreated group, we observed a significant reduction in serum T4 concentration without a significant increase in serum T3 or TSH concentration; 30/84 patients (36%) became hypothyroid and needed initiation of T4 therapy. Similar but lesser changes were seen in the treated group, 25 of whom (16%) required an increase in T4 dose. Patients who became hypothyroid after GH replacement had lower baseline serum T4 concentration, were more likely to have multiple pituitary hormone deficiencies and showed less improvement in quality of life compared with patients who remained euthyroid.

CONCLUSION

GH deficiency masks central hypothyroidism in a significant proportion of hypopituitary patients and this is exposed after GH replacement. We recommend that hypopituitary patients with GH deficiency and low normal serum T4 concentration should be considered for T4 replacement prior to commencement of GH in order to provide a robust baseline from which to judge the clinical effects of GH replacement.

Hormonal, pituitary magnetic resonance, LHX4 and HESX1 evaluation in patients with hypopituitarism and ectopic posterior pituitary lobe

OBJECTIVE

LHX4 and HESX1 are important in early stages of pituitary development and their mutations can be associated with an ectopic posterior lobe (EPL) in the pituitary of patients with hypopituitarism. The EPL can be located at the median eminence or at the path of the pituitary stalk. The aim of this study was to analyse LHX4 and HESX1 and characterize the hormonal deficiency profiles, establishing relationships with magnetic resonance imaging (MRI) findings in these patients.

PATIENTS AND DESIGN

Sixty-two patients with hypopituitarism associated with EPL were submitted to evaluation of pituitary function, analysis of MRI with EPL location and molecular analysis of LHX4 and HESX1 using polymerase chain reaction (PCR), digestion with restriction enzyme and automatic sequencing.

RESULTS

Forty-two patients had a nonvisualized pituitary stalk (NPS), and 20 a visualized pituitary stalk (VPS). Most patients (95%) with NPS had combined pituitary hormone deficiency (CPHD), with ACTH deficiency in 85%. In patients with VPS, CPHD was found in 50% and ACTH deficiency occurred in only 20%. The frequency of the location of EPL was similar in patients with VPS and NPS: 35% at median eminence and 65% at the path of the stalk. No mutations in LHX4 and HESX1 were identified. Three new polymorphisms in LHX4 were found.

CONCLUSIONS

ACTH deficiency is frequent in patients with hypopituitarism and NPS (85%), the location of EPL at the median eminence was not predictive of the hormonal profile [isolated GH deficiency (IGHD) or CPHD], and LHX4 and HESX1 genes mutations remain rare causes of hypopituitarism associated with EPL.

Effect of thyroxine replacement on serum IGF-I, IGFBP-3 and the acid-labile subunit in patients with hypothyroidism and hypopituitarism

OBJECTIVE

To describe the effect of T4 replacement in patients with primary and central hypothyroidism on components of the IGF binding protein complex: IGF-I, the acid-labile subunit (ALS) and IGFBP-3.

PATIENTS AND METHODS

We determined IGF-I, ALS and IGFBP-3 (by 125I-IGF-II ligand blots and immunoblots) in serum of 19 patients with primary and 11 patients with central hypothyroidism.

RESULTS

Mean (+/- SD) free T4 (fT4) increased from 4.4 +/- 2.4 pmol/l at baseline to 18.6 +/- 5.2 pmol/l following T4 therapy. In patients with primary hypothyroidism, IGF-I concentrations increased from 101 +/- 57 to 158 +/- 60 microg/l (P < 0.001) and ALS from 12.6 +/- 4.7 to 15.6 +/- 5.2 mg/l (P = 0.001). IGFBP-3 levels (in arbitrary units, AU), assessed by 125I-IGF-II ligand blot and by Western blot (the intensity of the 45/42-kDa doublet following T4 replacement defined as 1 AU) increased from 0.74 +/- 0.47 to 1 (P = 0.029) and from 0.76 +/- 0.42 to 1 (P = 0.018), respectively. In patients with hypopituitarism, IGF-I and ALS concentrations increased on T4 therapy from 49 +/- 23 to 97 +/- 36 microg/l (P < 0.001) and from 7.8 +/- 4.1 to 11.0 +/- 2.7 mg/l (P = 0.010), respectively. IGFBP-3 remained unchanged during T4 replacement.

CONCLUSIONS

T4 replacement increases the serum levels of IGF-I and ALS in patients with primary as well as central hypothyroidism. IGFBP-3 levels increase in response to T4 replacement in patients with primary hypothyroidism but not in those with central hypothyroidism, suggesting that thyroid hormones increase IGF-I and ALS but not IGFBP-3 in patients with GH deficiency.

Hyponatremia as the presenting manifestation of Sheehan's syndrome in elderly patients

BACKGROUND AND AIMS

Hyponatremia is not a disease in itself, but a manifestation of a variety of disorders and side-effects of diuretics; alternatively, it may be the only manifestation of hypopituitarism or hypothyroidism. In our experience, diagnosis of hypopituitarism in hyponatremic patients is often overlooked, especially in the elderly.

METHODS

We report here data from five elderly multiparous women (mean age 69 yr; range 62-78 yr) with a past history of complicated delivery, in whom initial symptoms were due to hyponatremia (serum sodium less than 128 mEq/L) who went undiagnosed and untreated for a long time (up to 42 years) after the initial event.

RESULTS

Initial hormonal levels indicated hypopituitarism, and magnetic resonance imaging led to diagnosis of empty sella in all patients, so that they were diagnosed as suffering from Sheehan's syndrome (SS). The occurrence of sodium and water disorders associated with SS depends on the degree of pituitary damage, time of onset since the initial pituitary insult, and concurrent medical conditions which also play a role in sodium and water balance. In these patients, clinical condition and hyponatremia improved rapidly after glucocorticoid substitution. L-thyroxine was appropriately substituted subsequently.

CONCLUSIONS

We suggest that, especially in elderly patients, much more attention should be paid to patients' past history. Early recognition of severe hyponatremia due to hypopituitarism with adrenal insufficiency is critical, and treatment with hydrocortisone results in safe and improved quality of life.

The natural history of the R120C PROP1 mutation reveals a wide phenotypic variability in two untreated adult brothers with combined pituitary hormone deficiency

BACKGROUND

Combined pituitary hormone deficiency (CPHD) corresponds to impaired production of growth hormone (GH) and other anterior pituitary hormones. The genetic form of CPHD may result from mutations in pituitary transcription factor genes, and PROP1 is the most commonly mutated gene in these cases. Patients with PROP1 mutations may have variable CPHD phenotypes but, because they are usually treated in childhood, the wide phenotypic variability caused by these mutations may not be thoroughly appreciated.

METHODS

Clinical follow-up and molecular analysis of PROP1 in two adult brothers with CPHD, born from consanguineous parents, and not treated until late adulthood.

RESULTS

The homozygous R120C mutation was identified in the brothers. Their clinical follow-up showed a wide phenotypic variability: hypogonadism was severe and prevented pubertal development in both, but their final heights were remarkably different, pointing to different degrees in severity of GH/TSH deficiencies; cortisol deficiency developed late in both, but at least 10 yr apart.

CONCLUSIONS

The lack of treatment in childhood and adolescence allowed the appreciation of the entire natural history of the CPHD caused by the R120C mutation, and it revealed a remarkable phenotypic variability even in siblings with a very similar genetic background.

Primary "empty sella" in adults: endocrine findings

Increasing evidence of impaired pituitary function in many subjects with primary empty sella (PES) has been reported. We conducted a retrospective analysis of our patients with PES, in order to ascertain presenting symptoms and endocrine status on diagnosis and during follow-up. Magnetic resonance imaging (MRI) of the pituitary leading to the diagnosis of PES was performed in 8 patients (5 F and 3 M, age: 60.1 +/- 3.3 years, M +/- SE; group 1) after the diagnosis of global anterior hypopituitarism (H), and in 20 patients (F, age 56.9 +/- 2.2 years, group 2) for other clinical reasons. Baseline determinations of pituitary and target gland hormones and of IGF-I were performed. GH response to GHRH plus arginine stimulation was also evaluated. Ten age- and BMI-matched subjects (7 F, 3 M, age: 53.0 +/- 4.0 years) with normal pituitary function served as controls (C). In group 1, the presenting symptoms leading to the diagnosis of H were consciousness disturbances, hyponatremia and chronic fatigue. The GH response to stimulation was absent (peak:1.0 +/- 0.3 ng/ml) and IGF-I levels (60.1 +/- 9.3 ng/ml) were significantly lower (p<0.001) than in C and group 2 PES patients. Among group 2 PES patients, the main presenting symptoms were headache and visual alterations. Baseline hormone levels proved normal in 17 subjects, while slight hyperprolactinemia was observed in 2 and hypogonadotropic hypogonadism in one. The GH response to stimulation (12.9 +/- 3.4 ng/ml) and IGF-I levels (141.7 +/- 12.0 ng/ml) were lower (p<0.05) than in C (GH: 33.4 +/- 8.8 ng/ml, IGF-I: 193.1 +/- 20.3 ng/ml). PES is a heterogeneous condition that ranges from hypopituitarism to various degrees of isolated GH deficiency, and which needs careful endocrine assessment, treatment and follow-up.

Dehydroepiandrosterone (DHEA) replacement reduces growth hormone (GH) dose requirement in female hypopituitary patients on GH replacement

OBJECTIVE

GH dose requirement is lower in ACTH replete compared with ACTH deficient hypopituitary patients suggesting that adrenal androgens may augment IGF-I generation for a given GH dose. This study aimed to determine the effect of dehydroepiandrosterone (DHEA) administration on GH dose requirements in hypopituitary adults.

DESIGN

A double blind placebo controlled trial was conducted adding 50 mg DHEA to the standard replacement of hypopituitary patients, including GH, over an initial 6 months, followed by an open phase study of 6 months DHEA replacement and a final 2 month washout phase after DHEA withdrawal. The dose of GH was adjusted to achieve a constant serum IGF-I.

PATIENTS

Thirty female and 21 male hypopituitary patients were enrolled. Data from 26 women and 18 men were analysed after patient withdrawal.

MEASUREMENTS

The primary outcome objective was the GH dose required to achieve a stable serum IGF-I. Secondary outcome measures were lipoprotein profiles, insulin, insulin sensitivity, IGFBP-3, waist/hip ratio and indices of bone remodelling.

RESULTS

DHEA replacement in female patients lead to a 14.6 +/- 20% reduction in the dose of GH for a constant serum IGF-I (P < 0.05, 95% CI: 1.8, 32.7). This was maintained for 12 months and there was a significant fall in serum IGF-I two months after withdrawal of DHEA. There was no change in the male group.

CONCLUSIONS

DHEA replacement may reduce GH dose requirements in female hypopituitary patients.

Investigation of the skin characteristics in patients with severe GH deficiency and the effects of 6 months of GH replacement therapy: a randomized placebo controlled study

OBJECTIVE

The presence of GH receptor in human skin and its appendages suggests a direct effect of GH on skin characteristics. The skin is usually thin and dry in patients with GH deficiency (GHD). Sheehan's syndrome classically refers to postpartum hypopituitarism and GH is one of the earliest pituitary hormones lost. While severe GHD is a well-established feature of Sheehan's Syndrome, skin characteristics and the effects of GH replacement therapy (GHRT) have been investigated neither in Sheehan's syndrome nor in other disorders of GHD. The aim of this study was to investigate the skin characteristics, including the sebum content, hydration (skin capacitance), transepidermal water loss (TEWL), pH and skin temperature, and particularly the effects of 6 months of GHRT on these parameters in GH deficient patients with Sheehan's syndrome.

PATIENTS AND DESIGN

Sixteen severely GH deficient women with Sheehan's syndrome (48.1 +/- 10.9 years), and 20 age and menopausal status similar women as control subjects were included. Ten patients received recombinant GH for 6 months (treatment group) and 6 patients received placebo (placebo group) during this period. Skin properties were measured at baseline and after 6 months of GHRT using noninvasive and well-established measuring methods.

RESULTS

At baseline the skin capacitance was significantly decreased on the forehead and forearm, and sebum content was significantly decreased on forehead in patients with Sheehan's syndrome compared to control subjects (P < 0.05). In the treatment group there was a significant increase in sebum content on forehead after 6 months of GHRT compared to the baseline value (P < 0.05). However there were no significant changes in other parameters including sebum content on the forearm, TEWL, Ph, skin capacitance and temperature of both the forearm and forehead. In the placebo group there were no changes in any of the evaluated parameters after 6 months of treatment compared to baseline values.

CONCLUSIONS

The present study clearly shows that the sebum content on the forehead and skin hydration of the forehead and forearm are significantly decreased in GH deficient patients with Sheehan's syndrome. However 6 months of GHRT significantly increased only the sebum content on the forehead. These data suggest that GH and/or IGF-I may have a modulatory role on several skin characteristics.

Serum ghrelin levels are suppressed in hypopituitary patients following insulin-induced hypoglycaemia irrespective of GH status

OBJECTIVE

Circulating ghrelin is suppressed during insulin-induced hypoglycaemia in healthy subjects, but it is unknown whether this is determined by feedback inhibition from counter-regulatory hormones. We therefore investigated the impact of GH and cortisol on ghrelin secretion during insulin-induced hypoglycaemia.

DESIGN

Serum levels of ghrelin, GH, and cortisol were measured in 41 adult patients with suspected hypopituitarism during insulin-induced hypoglycaemia. Based on their peak GH response (cut-off level: 3 microg/l), the patients were divided into a GH-sufficient group (GHS) and a GH-deficient group (GHD).

RESULTS

The GHS patients (n = 16) were younger (P < 0.01), had lower baseline cortisol levels [255 +/- 37 vs. 372 +/- 38 nmol/l (P = 0.04)], and tended to have a lower body mass index (P = 0.09) as compared to GHD patients (n = 25). By definition, peak GH (microg/l) was higher in GHS patients [15.0 +/- 1.8 vs. 1.0 +/- 0.2 (P < 0.0001)]. The increase in serum cortisol during the ITT (insulin-tolerance test) was higher and occurred later in GHS patients [Cmax (nmol/l): 561 +/- 41 vs. 412 +/- 50 (P = 0.04); Tmax (minutes): 65 +/- 5 vs. 49 +/- 5 (P = 0.03)]. Serum ghrelin levels changed significantly with time during ITT in both groups (P < 0.0001), characterized by a moderate decline during the initial 50-60 min and a return to baseline after 2 h. No significant differences were recorded in AUCghrelin during the ITT between the two groups. No gender differences in ghrelin levels were recorded.

CONCLUSIONS

(i) Like in healthy subjects serum ghrelin levels are suppressed during an ITT in patients with suspected hypopituitarism. (ii) The suppression of ghrelin was similar in GHD and GHS subjects and was not determined by cortisol. (iii) We hypothesize that insulin rather than hypoglycaemia accounts for ghrelin suppression during an ITT.

Effects of testosterone replacement in androgen-deficient women with hypopituitarism: a randomized, double-blind, placebo-controlled study

CONTEXT

Hypopituitarism in women is characterized by profound androgen deficiency due to a loss of adrenal and/or ovarian function. The effects of testosterone replacement in this population have not been reported.

OBJECTIVE

The objective of the study was to determine whether physiologic testosterone replacement improves bone density, body composition, and/or neurobehavioral function in women with severe androgen deficiency secondary to hypopituitarism.

DESIGN

This was a 12-month randomized, placebo-controlled study.

SETTING

The study was conducted at a general clinical research center.

STUDY PARTICIPANTS

Fifty-one women of reproductive age with androgen deficiency due to hypopituitarism participated.

INTERVENTION

Physiologic testosterone administration using a patch that delivers 300 microg daily or placebo was administered.

MAIN OUTCOME MEASURES

Bone density, fat-free mass, and fat mass were measured by dual x-ray absorptiometry. Thigh muscle and abdominal cross-sectional area were measured by computed tomography scan. Mood, sexual function, quality of life, and cognitive function were assessed using self-administered questionnaires.

RESULTS

Mean free testosterone increased into the normal range during testosterone administration. Mean hip (P = 0.023) and radius (P = 0.007), but not posteroanterior spine, bone mineral density increased in the group receiving testosterone, compared with placebo, as did mean fat-free mass (P = 0.040) and thigh muscle area (P = 0.038), but there was no change in fat mass. Mood (P = 0.029) and sexual function (P = 0.044) improved, as did some aspects of quality of life, but not cognitive function. Testosterone at physiologic replacement levels was well tolerated, with few side effects.

CONCLUSIONS

This is the first randomized, double-blind, placebo-controlled study to show a positive effect of testosterone on bone density, body composition, and neurobehavioral function in women with severe androgen deficiency due to hypopituitarism.

Prevalence of anterior pituitary insufficiency 3 and 12 months after traumatic brain injury

OBJECTIVE

Cross-sectional studies report a high prevalence of hypopituitarism after traumatic brain injury (TBI); however, no longitudinal studies on time of manifestation and reversibility exist. This study was conducted to assess hypopituitarism 3 and 12 months after TBI.

DESIGN

This was a prospective, longitudinal, diagnostic study.

METHODS

Seventy-eight patients (52 men, 26 women, mean age 36.0 years) with TBI grades I-III and 38 healthy subjects (25 men, 13 women, mean age 36.4 years) as a control group for the GHRH + arginine test were studied. The prevalence of hypopituitarism was assessed 3 and 12 months after TBI by GHRH + arginine test, short adrenocorticotropic hormone (ACTH) test, and basal hormone measurements in patients.

RESULTS

After 3 months, 56% of all patients had impairments of at least one pituitary axis with axes being affected as follows: gonadotropic 32%, corticotropic 19%, somatotropic 9% and thyrotropic 8%. After 12 months, fewer patients were affected, but in some cases new impairments occurred; 36% still had impairments. The axes were affected as follows after 12 months: gonadotropic 21%, somatotropic 10%, corticotropic 9% and thyrotropic 3%.

CONCLUSIONS

Hypopituitarism occurs often in the post-acute phase after TBI and may normalize later, but may also develop after the post-acute phase of TBI.

Risk factors of cardiovascular disease in GH-deficient adults with hypopituitarism: a preliminary report

BACKGROUND

We estimated the influence of GH deficiency (GHD) in adults on chosen risk factors of cardiovascular disease and bone density.

MATERIAL/METHODS

Fifty-four adults (mean age: 50.4 years) with hypopituitarism were studied. We measured blood pressure, body mass index, waist-to-hip ratio, total body fat, and bone mineral density and the serum levels of lipids, glucose, insulin, pituitary hormones, estradiol, testosterone, and thyroxine, and the excretion of free cortisol in 24-h urine. GHD was confirmed with the insulin intravenous test (IIT) with a GH response to IIT of <3 microg/ml. The control group consisted of 73 healthy adults.

RESULTS

Increased levels of LDL-cholesterol and triglycerides and decreased levels of HDL-cholesterol in the GHD group were observed. Fasting serum glucose and insulin levels were significantly higher in the GHD group than in controls. Significant differences in the QUICKI and FIRI indexes were observed. Twenty-three percent of the hypopituitary patients were hypertensive and 65% were obese. The percentage of total body fat was significantly higher in the studied group than in controls. Thirty-seven percent of the GHD patients were osteoporotic and 23% were osteopenic.

CONCLUSIONS

An atherogenic lipid profile, insulin resistance, obesity, and increased body and trunk fat in GHD adults may cause the higher risk of cardiovascular disease in these patients. GHD adults should receive human recombinant GH along with conventional replacement therapy. This may be a useful method in protecting against early onset of atherosclerosis, metabolic disturbances, and osteoporosis, especially in young patients.

Effect of short-term therapy with recombinant human growth hormone (GH) on metabolic parameters and preclinical atherosclerotic markers in hypopituitary patients with growth hormone deficiency

OBJECTIVE

This study examines the effects of growth hormone replacement on body composition, insulin sensitivity, lipid profile, endothelial dysfunction and carotid intima media thickness in patients with adult-onset growth-hormone (GH) deficiency.

METHODS

Twelve patients with severe GH deficiency received GH replacement for one year. In all patients, the following parameters were evaluated before and after six and twelve months of therapy: fasting glucose, insulin levels and lipid profile, bone mineral density and body composition. Carotid intima media thickness and brachial flow-mediated dilatation were also evaluated by arterial ultrasonography at basal condition and after one year of therapy.

RESULTS

No significant changes were seen in body weight and blood pressure, total fat and lean mass, or bone mineral density after six months of GH replacement. There was an increase in triglycerides (p = 0.05), while total and HDL cholesterol, blood glucose, insulin levels did not change significantly. After twelve months, an increase in lean mass and a decrease in fat mass (p < 0.01 vs. baseline), a decrease in insulin resistance (p < 0.01 vs. six months; p = 0.01 vs. baseline) and a decrease in triglycerides (p < 0.01) were observed. Intima media thickness was greater in GH deficiency than in controls (p = 0.01) before therapy, and was unchanged after twelve months of therapy, whereas the flow-mediated dilatation tended to improve (p = 0.05).

CONCLUSIONS

GH replacement is able to reverse typical metabolic and body composition alterations in patients with adult GH deficiency after twelve months, but it is unable to revert the vascular alteration completely. Flow-mediated dilatation seems to be a more precocious marker of the remission of arterial damage.

Hypopituitarism

Hypopituitarism is the partial or complete insufficiency of anterior pituitary hormone secretion and may result from pituitary or hypothalamic disease. The reported incidence (12-42 new cases per million per year) and prevalence (300-455 per million) is probably underestimated if its occurrence after brain injuries (30-70% of cases) is considered. Clinical manifestations depend on the extent of hormone deficiency and may be non specific, such as fatigue, hypotension, cold intolerance, or more indicative such as growth retardation or impotence and infertility in GH and gonadotropin deficiency, respectively.A number of inflammatory, granulomatous or neoplastic diseases as well as traumatic or radiation injuries involving the hypothalamic-pituitary region can lead to hypopituitarism. Several genetic defects are possible causes of syndromic and non syndromic isolated/multiple pituitary hormone deficiencies. Unexplained gonadal dysfunctions, developmental craniofacial abnormalities, newly discovered empty sella and previous pregnancy-associated hemorrhage or blood pressure changes may be associated with defective anterior pituitary function.The diagnosis of hypopituitarism relies on the measurement of basal and stimulated secretion of anterior pituitary hormones and of the hormones secreted by pituitary target glands. MR imaging of the hypothalamo-pituitary region may provide essential information. Genetic testing, when indicated, may be diagnostic.Secondary hypothyroidism is a rare disease. The biochemical diagnosis is suggested by low serum FT4 levels and inappropriately normal or low basal TSH levels that do not rise normally after TRH. L-thyroxine is the treatment of choice. Before starting replacement therapy, concomitant corticotropin deficiency should be excluded in order to avoid acute adrenal insufficiency. Prolactin deficiency is also very rare and generally occurs after global failure of pituitary function. Prolactin deficiency prevents lactation. Hypogonadotropic hypogonadism in males is characterized by low testosterone with low or normal LH and FSH serum concentrations and impaired spermatogenesis. Hyperprolactinemia as well as low sex hormone binding globulin concentrations enter the differential diagnosis. Irregular menses and amenorrhea with low serum estradiol concentration (<100 pmol/l) and normal or low gonadotropin concentrations are the typical features of hypogonadotropic hypogonadism in females. In post menopausal women, failure to detect high serum gonadotropin values is highly suggestive of the diagnosis. In males, replacement therapy with oral or injectable testosterone results in wide fluctuations of serum hormone levels. More recently developed transdermal testosterone preparations allow stable physiological serum testosterone levels. Pulsatile GnRH administration can be used to stimulate spermatogenesis in men and ovulation in women with GnRH deficiency and normal gonadotropin secretion. Gonadotropin administration is indicated in cases of gonadotropin deficiency or GnRH resistance but is also an option, in alternative to pulsatile GnRH, for patients with defective GnRH secretion.