Contribution of weight cycling to serum leptin in human obesity

OBJECTIVE

To investigate to what extent serum leptin concentrations in obese humans are influenced by a history of weight cycling.

DESIGN

Cross-sectional study on serum leptin concentrations and body composition in a cohort of obese subjects in whom a retrospective recall of weight and diet history was made.

SUBJECTS

One hundred and twenty-eight obese patients (89 females and 39 males), aged 18-61 y, body mass index (BMI) 31.2-63.4 kg/m(2).

MEASUREMENTS

Serum leptin; various fatness and fat distribution parameters (by anthropometry and bioelectrical impedance analysis); history of overweight at puberty; number, magnitude and timing of previous diet episodes and of consequent weight regain by interview.

RESULTS

By univariate analysis, serum leptin concentrations were significantly correlated with weight, waist-hip ratio, percentage body fat, maximal percentage weight loss in a single diet episode, cumulative percentage weight loss in all diet episodes, cumulative weight regained in all diet episodes, but not with the number of diet episodes. All correlations related to anthropometric and body composition parameters were stronger for men, compared to women, although the male subgroup was smaller. On the contrary, there was a strong positive correlation between weight cycling parameters and serum leptin in women but not in men. Leptin concentrations were significantly higher in patients who were overweight at puberty than in those who were not overweight at puberty. After correction for percentage body fat, presence of overweight at puberty did not correlate any longer with leptin concentrations in either gender. In women, cumulative percentage weight loss in all diet episodes contributed an additional 5% to the variance of serum leptin in the overall model.

CONCLUSION

The positive correlation between weight cycling and leptin concentration in obesity is mainly accounted for the higher percentage body fat in obese weight cyclers, although in women weight cycling per se independently contributes to the variance of serum leptin.

Subclinical hypothyroidism in obese patients: relation to resting energy expenditure, serum leptin, body composition, and lipid profile

OBJECTIVE

To evaluate whether subclinical hypothyroidism (SH) affects resting energy expenditure (REE) as well as body composition, lipid profile, and serum leptin in obese patients.

RESEARCH METHODS AND PROCEDURES

A total of 108 obese patients with SH defined as normal free thyroxine levels and thyroid-stimulating hormone (TSH) values of > 4.38 microU/ml (mean +/- 2 SD of the values of our reference group of obese patients with normal thyroid function) were compared with a group of 131 obese patients matched for age, sex, and body mass index (BMI) but with normal TSH levels. We assessed estimated daily caloric intake by 7-day recall, REE by indirect calorimetry, body composition by bioelectrical impedance analysis, serum leptin by radioimmunoassay, and lipid profile (i.e., total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides).

RESULTS

All of the variables measured were not different between the euthyroid obese patients and those with SH. In a multiple regression model with REE expressed for kilograms of fat free mass (REE/kgFFM) as a dependent variable and percentage of fat mass, BMI, waist-to-hip ratio, age, TSH, free thyroxine, serum leptin, and caloric intake as independent variables, only percentage of fat mass was significantly correlated with REE/kgFFM in both groups. In the SH group only, BMI, waist-to-hip ratio, age, and TSH were related to REE/kgFFM and explained 69.5% of its variability. After dividing the patients with SH using a cutoff TSH value of 5.7 microU/ml, which represents 3 SD above the mean of TSH levels of the group of obese patients with normal thyroid function, only REE/kgFFM was significantly different and lower in the group of more severely hypothyroid patients.

DISCUSSION

In patients with obesity, SH affects energy expenditure only when TSH is clearly above the normal range; it does not change body composition and lipid profile. We suggest that, at least in obese patients, evaluation of TSH levels may be useful to rule out a possible impairment of resting energy expenditure due to a reduced peripheral effect of thyroid hormones.

Relationship between blood pressure and glucose tolerance in acromegaly

BACKGROUND

Hypertension represents a well-known risk factor for cardiovascular diseases. The pathogenesis of hypertension in acromegaly is commonly viewed as multifactorial, but the possible influence of metabolic disorders on blood pressure (BP) in affected patients is largely unknown.

OBJECTIVE

The aim of the present study was to evaluate the impact of glucose metabolism abnormalities on BP values in a series of patients with active acromegaly.

DESIGN

An open multicentre prospective study.

PATIENTS

Sixty-eight patients with active disease, aged 47.5 +/- 11.7 years, have been studied. Thirty-nine had normal glucose tolerance (NGT), 16 impaired glucose tolerance (IGT) and 13 suffered from diabetes mellitus (DM).

MEASUREMENTS

Mean clinical BP values were calculated as the mean of BP values obtained by sphygmomanometric measurement in three separate occasions and mean 24-h, diurnal and nocturnal systolic (SBP) and diastolic (DBP) values were obtained by 24-h ambulatory blood pressure monitoring (ABPM).

RESULTS

Patient's age and the degree of glucose tolerance abnormalities were found to significantly and independently influence BP values. All clinical and ABPM SBP and DBP values significantly increased with age by linear regression (P < 0.02 for all BP values, 0.30 < or = R < or = 0.43), and the independent influence of this parameter on BP values was confirmed by mutivariate analysis. Similarly, the independent influence of glucose tolerance abnormalities on BP values was confirmed when introducing age as a covariable in a multivariate analysis, and patients with DM presented significantly higher clinical SBP and 24-h, diurnal and nocturnal SBP and DBP than patients with NGT (P < 0.02 for clinical SBP, P < 0.015 for all ABPM values, respectively). In addition, patients with DM showed significantly higher 24-h, diurnal and nocturnal DBP than those with IGT (P < 0.05 in all cases). In contrast, no significant difference was found between NGT and IGT patients. No significant influence of disease duration, BMI, GH, IGF-I, or fasting and 2-h post glucose load insulinaemia on BP values was observed.

CONCLUSIONS

Abnormalities of glucose metabolism significantly contribute to increase systolic blood pressure and especially diastolic blood pressure in acromegalic patients. Careful control of blood pressure and of risk factors for developing systemic hypertension, with special reference to glucose tolerance, is mandatory to decrease cardiovascular morbidity and mortality in such patients.

Radioiodine and percutaneous ethanol injection in the treatment of large toxic thyroid nodule: a long-term study

Surgery is generally recommended for large thyroid toxic nodules (TTNs). When surgery is not applicable, both radioactive iodine (RAI) and percutaneous ethanol injection (PEI) are alternative treatments. In this retrospective study, the long-term efficacy of nonsurgical treatments was evaluated in 43 patients with TTN, selected on the basis of presence of hyperthyroidism and a fairly large nodule (3- and 4-cm in diameter) completely inhibiting controlateral lobe captation during scintigraphy. Twenty-one patients were treated by RAI (administered dose 670+/-160 MBq; range 555-925) and twenty-two were treated by PEI (6+/-1 sessions; range 5-9). FT4, FT3, thyrotropin (TSH), and nodule volume were assessed before and at fixed intervals after treatment. Median follow-up was 36 months (range, 12-84). Compared to baseline values, with both therapies, serum FT4, FT3, and nodule volume were decreased (p < 0.01) and serum TSH was increased (p < 0.01), after 3 months and during the entire follow-up. Nodule volume reduction percentage was 66.8+/-22.0 and 78.4+/-18.0, in the RAI- and PEI-treated groups, respectively. At the end of follow-up, 34 patients were euthyroid (16 RAI- and 18 PEI-treated). Four RAI-treated patients (19%) showed slightly high TSH levels (4.2-5.3 mU/L), whereas three PEI-treated patients (13.6%) still had suppressed TSH levels, although being clinically asymptomatic. One RAI-treated patient (4.8%) showed overt hypothyroidism during the follow-up period and was then treated with L-thyroxin. One patient (4.6%), who was initially cured by PEI, became newly hyperthyroid during the follow-up period. Both treatments were well-tolerated. In conclusion, both of these nonsurgical treatments are effective and may be chosen also for relatively large TTNs. Specifically, RAI seems to be more effective for treating hyperthyroidism but has minimal sequelae of subclinical or clinical hypothyroidism, while, after PEI treatment the possibility of stable subclinical hyperthyroidism or hyperthyroidism relapse should be taken into account.

The A19G polymorphism in the 5' untranslated region of the human obese gene does not affect leptin levels in severely obese patients

Recently, the presence of different polymorphisms in the regulatory region of the ob gene has been associated with variations in leptin levels. However, the results of these studies are still contradictory. The aim of the present investigation was to evaluate the presence of the A19G polymorphism in an Italian population of obese patients and to verify its association with leptin levels and anthropometric, metabolic, and clinical parameters. Two hundred five obese patients [body mass index (BMI) > 36 kg/m2; 135 women and 70 men; mean age, 46.9+/-14.23 yr] were screened for presence of the polymorphism; 61 normal-weight controls (mean BMI, 21.05 kg/m2; 53 women, 8 men) were also screened to compare polymorphism frequency. For obese patients, BMI, waist-to-hip ratio, resting energy expenditure, body composition, fasting leptin, total cholesterol, high-density lipoproteins, triglycerides, and caloric intake were determined. Genotype frequencies in obese and control subjects were compared using the contingency table chi-square test; in obese subjects an ANOVA was performed to evaluate association between the polymorphism and several clinical parameters. No significant differences in genotype distribution between control and obese subjects were found. No significant correlations were found between this polymorphism and serum leptin levels and the other parameters considered. These findings confirm the results obtained in both a Finnish and a French population; taken together, these observations might rule out a significant role for the A19->G polymorphism in the regulation of leptin levels and other clinical, anthropometric, and metabolic parameters.

Leptin plasma concentrations are dependent on body fat distribution in obese patients

AIM

To evaluate whether fat distribution plays a role in determining serum leptin concentrations.

PATIENTS AND METHODS

One-hundred and forty-seven obese patients, 77 males and 70 females, aged 45.1 +/- 13.2 y (mean +/- s.d.; range 21-73 y), with body mass index (BMI) ranging from 30 to 55 kg/m2 (mean 42.3 +/- 5.9). Ultrasound assessment of the thickness of subcutaneous and preperitoneal fat was carried out and calculation of their ratio as abdominal fat index (AFI), waist-hip ratio (WHR), body composition by bioelectrical impedance to evaluate the percentage of fat mass (FM%) and total amount of fat (FMKg) were also determined. Plasma leptin was measured by radio immuno assay (RIA).

RESULTS

In the whole group of patients, serum leptin concentrations were 37.2 +/- 18.4 ng/ml (range 6-101.3 ng/ml); in spite of BMI values not being significantly different, women had leptin values significantly higher (47.4 +/- 17.4 ng/ml) (P < 0.01) than males (28.1 +/- 15.1 ng/ml), also after correction for fat mass. The mean thickness of abdominal subcutaneous fat was 33.7 +/- 12.9 mm and it was significantly (P < 0.001) higher in female (40.9 +/- 10.6 mm) than in male (27.1 +/- 11.2 mm) patients; preperitoneal thickness was 22.9 +/- 7.1 mm, with significantly (P < 0.05) higher values in males (24.2 +/- 6.8 mm) than in females (21.7 +/- 7.3 mm). Accordingly, AFI (in all patients 0.84 +/- 0.6) was significantly higher in males (1.09 +/- 0.6) than in females (0.56 +/- 0.2). In the overall population, leptin concentrations were directly and significantly related to subcutaneous but not preperitoneal fat; they showed a strong inverse relationship with AFI and WHR. When the results were evaluated dividing the patients according to gender, subcutaneous fat thickness showed a stronger association with leptin levels in males than in females, whereas no association was found with preperitoneal fat thickness. Leptin and AFI values were significantly related only in men. WHR values were not correlated with leptin concentrations in either sex. When fat mass was added to the model, subcutaneous fat thickness, AFI and WHR remained independently associated with leptin concentrations. Age and diabetes did not influence these measures.

CONCLUSIONS

Fat distribution contributes to the variability in serum leptin in obese patients. In particular, subcutaneous abdominal fat is a determinant of leptin concentration, also independently of the amount of fat mass, whereas the contribution of preperitoneal visceral fat is not significant.

Role of insulin-like growth factor (IGF)-1 in the modulation of renal haemodynamics in Type I diabetic patients

AIMS/HYPOTHESIS

We investigated in normotensive Type I (insulin-dependent) diabetic patients with normoalbuminuria the role of growth hormone-induced IGF-1 in the modulation of renal haemodynamics.

METHODS

We measured glomerular filtration (GFR) and renal plasma flow (RPF) at baseline and at 24 h after injection of different doses of growth hormone (0.1, 0.2, 0.4 U x kg(-1) x body weight(-1) in six patients with normal GFR under a euglycaemic clamp. We also examined a 24 h profile of plasma growth hormone and IGF-1 during usual insulin therapy in two other groups each with seven patients with a lower (from 93 to 114 ml x min(-1) x (1.73 m2)(-1) and higher (from 121 to 146 ml min(-1) x (1.73 m2)(-1) GFR.

RESULTS

Plasma growth hormone concentrations peaked 2 h after its injection and plasma concentrations of IGF-1 peaked about 24 h after the growth hormone injection. There was a significant increase in GFR and RPF 24 h after the highest dose of the growth hormone injection (corresponding to the highest IGF-1 concentration), from baseline values of 115 +/- 24 and 536 +/- 141 ml x min(-1) x (1.73 m2)(-1) to 160 +/- 33 and 657 +/- 137 ml x min(-1) x (1.73 m2)(-1), respectively (p < 0.01 for GFR and p < 0.05 for RPF). No differences were observed in the 24 h profile of growth hormone and IGF-1 plasma concentrations between the two groups; growth hormone and IGF-1 concentrations were lower than those obtained after the injection of 0.4 U x kg(-1) x body weight(-1) of growth hormone.

CONCLUSION/INTERPRETATION

These results show that pharmacological growth hormone-induced IGF-1 concentrations are required to modify renal haemodynamics in Type I diabetic patients and suggest that, under the "physiological" conditions of diabetes, IGF-1 has no role as a mediator of glomerular hyperfiltration.

Systemic hypertension and impaired glucose tolerance are independently correlated to the severity of the acromegalic cardiomyopathy

Increased mortality from cardiovascular diseases has been reported in acromegaly. Our objective was to evaluate the impact of glucose tolerance abnormalities and/or systemic hypertension in further worsening the acromegalic cardiomyopathy. The study design was open transversal. The subjects studied were 130 consecutive naive acromegalic patients (74 women and 56 men; age, 17-80 yr). Interventricular septum (IST) and left ventricular (LV) posterior wall thickness (PWT), LV mass index (LVMi), maximal early to late diastolic flow velocity ratio (E/A), isovolumic relaxation time (IRT), and LV ejection fraction (EF) were measured by echocardiography. The results were analyzed in line with the presence of glucose tolerance abnormalities (normal in 60, impaired in 38, diabetes mellitus in 32) and the presence (in 46) or absence (in 84) of hypertension. Patients with impaired glucose tolerance and diabetes mellitus had significantly higher age (P = 0.01), and systolic (P = 0.01) and diastolic (P = 0.01) blood pressures and lower E/A (P = 0.01) and EF (P = 0.01) than those with normal glucose tolerance. Disease duration, circulating GH and insulin-like growth factor I (IGF-I) levels, IST, LVPWT, LVMi, and IRT were similar in the 3 groups. Normotensive patients had significantly lower age (P<0.001), LVPWT (P<0.001), IST (P = 0.003), LVMi (P<0.001), and IRT (P = 0.02) and significantly higher E/A (P<0.001) and EF (P<0.001) than hypertensive subjects. Disease duration, circulating GH, and IGF-I levels were similar in the 2 groups. Multiple regression analysis showed that systolic blood pressure was the strongest predictor of LVMi (P = 0.0004), followed by GH levels (P = 0.02), whereas diastolic blood pressure was the strongest predictor of LVEF reduction (P<0.0001), followed by glucose tolerance status (P = 0.02). Age was the strongest predictor of both E/A impairment (P<0.0001) and IRT (P = 0.01), followed by IGF-I levels (P = 0.02). Compared to patients with uncomplicated acromegaly, those with hypertension but without abnormalities of glucose tolerance had an increased prevalence of LV hypertrophy (75% vs. 37.2%) as well as of impaired diastolic (50% vs. 7.8%) and systolic function (18.7% vs. 3.9%), whereas patients with glucose tolerance abnormalities but without hypertension had only an increased prevalence of impaired diastolic (39.7%) and systolic function (31.7%). The subgroup of acromegalic patients suffering from hypertension and diabetes mellitus had the highest prevalence of LV hypertrophy (84.6%), diastolic filling abnormalities (69.2%), and impaired systolic function at rest (53.9%). A careful cardiac investigation should thus be performed in all acromegalic patients showing these complications.

Serum leptin concentration in moderate and severe obesity: relationship with clinical, anthropometric and metabolic factors

OBJECTIVE

To study clinical, anthropometric and metabolic determinants of serum leptin concentrations in a series of patients with a wide range of obesity.

SUBJECTS

400 patients, 116 males and 284 females, aged 44+/-12.3 years with body mass index (BMI) ranging from 31 to 82 kg/m2 (mean 41.4+/-7.1).

MEASUREMENTS

Energy intake by 7-day recall, resting energy expenditure (REE) by indirect calorimetry, body composition determined by bioelectrical impedance; C index, an anthropometric index of abdominal fat distribution, and waist-hip ratio (WHR), blood glucose serum leptin concentrations, total cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, uric acid, and insulin concentrations HOMA IRI (homeostastis model assessment of insulin resistance index).

RESULTS

Leptin concentrations were higher in obese than in normal subjects and in females than in males without differences between diabetic and non-diabetic patients; leptin concentrations were not related to age and showed a strong negative association with energy intake only in the group of women with BMI less than 40. Leptin concentrations showed a direct correlation with BMI and body fat values (expressed either as percentage of total body mass or absolute fat mass) independent of age and sex. After adjustment for fat mass, leptin values higher than predicted were found in women whereas concentrations lower than predicted were found predominantly in men. Leptin showed an inverse correlation with WHR and C-index, the latter persisting also after correction for gender and fat mass. REE, but not REE/kg fat-free mass (FFM) was inversely related to leptin also after correction for sex and absolute fat mass. Leptin concentrations were directly associated with HOMA IRI, insulin and HDL cholesterol and inversely associated with triglycerides and uric acid. The relationship of leptin with HOMA IRI was still evident after adjusting for sex but was lost when absolute fat mass was added to the model; HDL cholesterol and triglycerides appeared to be variables independent of leptin concentrations even when both sex and fat mass were added to the model.

CONCLUSIONS

In a large group of obese patients (half of whom had severe obesity, gender, BMI and fat mass accounted for the largest proportion of serum leptin concentrations variability. We found that in obese subjects there is an effect of fat distribution on leptin concentrations and that, after excluding variability due to absolute fat mass, patients with a greater amount of abdominal fat have relatively low leptin concentrations which in turn relates to a metabolic profile compatible with an increased cardiovascular risk. Women with milder obesity may retain some degree of control of food intake by leptin.

Alterations of bone turnover and bone mass at different skeletal sites due to pure glucocorticoid excess: study in eumenorrheic patients with Cushing's syndrome

The aim of the present investigation was to study the effect of glucocorticoid excess on bone mass and turnover not influenced by other diseases known to affect skeleton and/or by different gonadal status and sex. We studied several markers of bone turnover and bone mineral density (BMD) by both quantitative computed tomography (at spine and forearm) and dual x-ray absorptiometry (at spine and three femoral sites) in 18 eugonadal female patients affected by Cushing's syndrome (CS) compared to 24 eugonadal healthy female subjects matched for age and body mass index. In CS patients, serum bone Gla protein, a marker of osteoblastic function, was reduced (3.28 +/- 2.3 vs. 6.47 +/- 2.5; P < 0.01), and bone resorption was increased, as indicated by increased urinary hydroxyproline (36.6 +/- 12 vs. 29.0 +/- 9.1, P < 0.05) and urinary deoxypyridinoline (22.1 +/- 8.0 vs. 16.4 +/- 6.3; P < 0.05). BMD was significantly (P < 0.05 or P < 0.01) reduced at all sites, except cortical forearm, in CS patients compared to controls. By comparing z-scores of reduced BMD in CS patients, spinal trabecular BMD was found to be the most severely affected. Furthermore, disease activity, as measured by urinary free cortisol, was significantly correlated with bone Gla protein (r = -0.57; P < 0.02), urinary hydroxyproline (r = 0.57; P < 0.02), urinary deoxypyridinoline (r = 0.48, P < 0.05), and BMD measured at spine and femur. Our results show that compared to matched control subjects, female eumenorrheic CS patients have reduced osteoblastic function, increased bone resorption, and reduced BMD, and that the severity of these abnormalities is statistically related to the severity of disease activity, as indicated by urinary free cortisol. Moreover, our data suggest a site and tissue specificity of the effect of glucocorticoid excess on bone mass.

High prevalence of risk factors for cardiovascular disease in parents of IDDM patients with albuminuria

Life expectancy is shorter in the subset of insulin-dependent diabetic (IDDM) patients who are susceptible to kidney disease. Familial factors may be important. In this study the prevalence of cardiovascular disease mortality and morbidity and of risk factors for cardiovascular disease was compared in the parents of 31 IDDM patients with elevated albumin excretion rate (AER > 45 microg/min; group A) with that of parents of 31 insulin-dependent diabetic patients with normoalbuminuria (AER < 20 microg/min; group B). The two diabetic patient groups were matched for age and duration of disease. Information on deceased parents was obtained from death certificates and clinical records and morbidity for cardiovascular disease was ascertained using the World Health Organization questionnaire and Minnesota coded ECG. Hyperlipidaemia was defined as serum cholesterol higher than 6 mmol/l and/or plasma triglycerides higher than 2.3 mmol/l and/or lipid lowering therapy; arterial hypertension as systolic blood pressure higher than 140 mmHg and/or diastolic blood pressure higher than 90 mmHg and/or antihypertensive treatment. The percentage of dead parents was similar in the two groups (26 vs 20% for parents of group A vs group B, respectively), but the parents of the diabetic patients with elevated AER had died at a younger age (58 +/- 10 vs 70 +/- 14 years; p < 0.05). Parents of diabetic patients with nephropathy had a more than three times greater frequency of combined mortality and morbidity for cardiovascular disease than that of the parents of diabetic patients without nephropathy (26 vs 8%; odds ratio 3.96, 95% CI 1.3 to 12.2; p < 0.02). Living parents of group A had a higher prevalence of arterial hypertension (42 vs 14% p < 0.01) and hyperlipidaemia (49 vs 26% p < 0.05) as well as higher levels of lipoprotein (a) [median (range) 27.2 (1-107) vs 15.6 (0.2-98) mg/dl; p < 0.05]. They also had reduced insulin sensitivity [insulin tolerance test: median (range) K(itt) index: 3.7 (0.7-6.2) vs 4.8 (0.7-6.7)% per min; p < 0.05]. In the families of IDDM patients with elevated AER there was a higher frequency of risk factors for cardiovascular disease as well as a predisposition to cardiovascular disease events. This may help explain, in part, the high prevalence of cardiovascular disease mortality and morbidity in those IDDM patients who develop nephropathy.

Skeletal involvement in female acromegalic subjects: the effects of growth hormone excess in amenorrheal and menstruating patients

Bone involvement is a common clinical feature in acromegalic patients, though previous studies gave divergent results possibly because of the different gonadal status of the patients studied. To study the influence of estrogen milieu in these patients, we evaluated 23 acromegalic patients with active disease, subdivided into two groups: menstruating and amenorrheal patients, comparable for duration and activity of disease. Forty-two matched women served as controls. Skeletal involvement was studied by measuring: (a) the main biomarkers of bone turnover: serum alkaline phosphatase total activity (AP), bone GLA protein (BGP), serum carboxy-terminal propeptide of type I collagen (PICP), serum type I cross-linked N-telopeptide (ICTP), and urinary pyridinoline and deoxypyridinoline corrected for creatinine (Pyr/Cr, D-Pyr/Cr) and urinary calcium/creatinine ratio (Ca/Cr); (b) bone mineral density (BMD), as measured by quantitative computed tomography both at lumbar spine and distal radius, and by dual X-ray absorptiometry both at lumbar spine and at three femoral sites (Ward's triangle, femoral neck, and great trochanter). AP, BGP, ICTP, Pyr/Cr, D-Pyr/Cr were significantly higher in patients than in controls, independent of the menstrual pattern. Higher PICP levels were found in the whole group and in menstruating acromegalics when compared with control women; no difference was found in amenorrheal patients, who in turn showed higher urinary Ca/Cr values. When patients were considered all together, BMD at spine, femoral neck, and trochanter was higher than in controls. In contrast, when the gonadal status was taking into account and, menstruating and amenorrheal subjects were considered separately, BMD at spine, but not in other sites, was significantly higher in menstruating patients than in controls. In contrast, no difference of BMD values at any site was observed between amenorrheal patients and controls. The mean BMD Z scores allowed us to detect an unequal involvement of different skeletal sites. Our results show that bone turnover is increased in acromegalic women and suggest that GH anabolic effect on bone is more evident in the presence of estrogens and that different skeletal sites may be affected differently by hormone excess.

Pre-Cushing's syndrome not recognized by conventional dexamethasone suppression-tests in an adrenal "incidentaloma" patient

Pre-Cushing's syndrome has been recently diagnosed in 6-12% of patients affected with incidentally discovered adrenal masses. Some of these patients have been described to show transient hypoadrenalism after surgery, similarly to those affected with overt Cushing's syndrome. We studied a 70-year-old male patient with a large left adrenal mass, incidentally discovered, who displayed 24-h urinary free cortisol levels at the upper limit of the normal range, normal dexamethasone overnight and low-dose suppression tests and not suppressed ACTH levels, increased 17-hydroxyprogesterone response to ACTH stimulation and low upright plasma renin activity with normal serum aldosterone levels; furthermore, DHEAS level was low and 75 Selenium-cholesterol scintigraphy showed unilateral uptake concordant with the side of the mass. Soon after left adrenalectomy, he complained of acute hypoadrenalism requiring cortisol replacement therapy: ten months after surgery he is still hypoadrenal. Moreover, stimulated 17-hydroxyprogesterone and plasma renin activity in clino- and orthostatic posture have become normal. We propose that conventional dexamethasone suppression-tests may be not enough sensitive in this kind of patients and that in selected cases the absence of controlateral uptake at scintigraphy may be more reliable in predicting post-surgical hypoadrenalism.

Intensification of 111In-DTPA-octreotide scintigraphy by means of pretreatment with cold octreotide in small cell lung cancer

Small cell lung cancer (SCLC) expresses somatostatin receptors that can be traced with 111In-DTPA-octreotide scintigraphy. Although this technique is currently employed for staging and follow-up of neuroendocrine tumors of the gastrointestinal tract, its role in the clinical work-up of SCLC is at present under discussion. A better imaging contrast is desirable and recent reports suggest that this aim could be achieved by pretreatment with cold octreotide. Here we report on the results of 111In-DTPA-octreotide scintigraphy in 12 SCLC patients carried out before and after octreotide treatment. The patients were treated for 7 days with octreotide 200 micrograms three times a day s.c. Uptake was studied at 5 h with whole body planar and SPET imagings. In all cases studied, pretreatment with octreotide was followed by enhancement of tumor imaging. In one patient a better contrast of the lesions was found at the parenchymal and mediastinal levels as well as at brain level, allowing a clear definition of otherwise questionable metastases. After octreotide treatment, a decrease in background uptake in the subdiaphragmatic area was observed in most cases, allowing a better imaging of liver metastases. The enhancement effect was confirmed by semiquantitative analysis of scintigraphic uptake. Taken together, our results seem to indicate that cold octreotide enhancement can improve 111In-DTPA-octreotide imaging and optimize its clinical role in SCLC.

Clinical results of long-term slow-release lanreotide treatment of acromegaly

Medical therapy is frequently needed to normalize growth hormone/insulin-like growth factor I secretion in acromegaly. The aim of this study was to determine the long-term effects of the slow-release (SR) somatostatin analogue lanreotide in 57 acromegalic patients. SR lanreotide (30 mg) was given every 14 days for 12 months. In 33% of patients, the drug dosage was raised to 60 mg and/or the time interval was shortened to 10 days. Two months of clinical evaluation followed drug discontinuation in 47 out of 48 (84%) patients who completed the 12-month period. A drug-related decrease in GH/IGF-I levels was observed. Basal GH/IGF-I levels were significantly (P < 0.001) reduced at 12 months, IGF-I was normalized in 35% of patients and GH levels were < 5 micrograms L-1 in 54%. There was a clinical improvement in patients complaining of joint pain, rachialgias, headache, digital paraesthesias and hyperhidrosis. Soft-tissue changes were documented by significant (P < 0.001) decreases in finger size. In 52 (91%) patients without overt diabetes, a slight but significant increase in integrated glycaemia (P < 0.001) was noted, while integrated insulin levels were reduced (P < 0.001). Of 33 (58%) patients with normal basal ultrasound examination of the gall bladder, three (9%) had developed asymptomatic gall stones or biliary sludge after 12 months. Adverse events were generally mild. They frequently (52%) occurred after the first SR lanreotide administration; only 28% were recurrent and 20% appeared for the first time during therapy. SR lanreotide is an effective treatment in most unselected acromegalic patients. Tolerance towards the drug is high. Subjective benefits seem to override the simple biochemical control of the disease. Glucose homeostasis more than the incidence of gall stones seems to require monitoring on therapy. SR lanreotide is clearly advantageous in improving patient compliance with medical treatment for acromegaly.

Percutaneous ethanol injection of large thyroid cystic nodules

To evaluate the effect of percutaneous ethanol injection (PEI) in the treatment of large compressive thyroid cystic nodules (TCN), we studied 20 patients, potential candidates for surgery (tracheal displacement, nodule volume over 10 mL at ultrasonography) and not cured by aspiration alone: 14 experienced a recurrence after two complete evacuations of cystic fluid (watery nodules, WN); in six an aspiration was impossible because the cystic fluid was very thick (viscous nodules, VN). To exclude malignancy, both cytocentrifugate from WN and the smears from VN were examined. WN were treated with 1-4 sessions of conventional PEI; in VN a first PEI session was performed with the purpose of reducing the density of cystic fluid; then if cystic fluid was successfully aspirated, one or more PEI sessions were performed. Thyroid palpation, ultrasonography with nodule volume assessment, and assays for FT3, FT4, and TSH were performed 1 and 6 months after the last PEI. At month 6, 17 patients (85%) had volume reduction of more than 90% of the initial nodule volume; in 2 patients (10%) there was a reduction between 50 and 90%, and in one patient (5%) an appreciable swelling persisted after 3 injections. Nodule volume was significantly decreased below baseline at month 1 (10.9 +/- 13.3 vs 39 +/- 24 mL, p < 0.001), with a further reduction at month 6 (5 +/- 11.7 mL, p < 0.01 vs 1st month value). In most of the nodules the cystic portion completely disappeared; the residual tissue showed fibrous features, often with calcifications. In 11 patients follow-up was prolonged over the sixth month (15 +/- 4 months); the nodule volume did not significantly differ from the sixth month (3 +/- 2.2 mL) and the end of the follow-up (2.8 +/- 2.3 mL). In conclusion, we demonstrate that PEI may be a safe and effective procedure in the treatment of large TCN.

Thyroid hypoechogenicity after methimazole withdrawal in Graves' disease: a useful index for predicting recurrence?

OBJECTIVE

A characteristic thyroid ultrasonographic picture with diffuse or scattered low echogenicity has been described in Graves' disease (GD). Thyroid hypoechogenicity in GD at onset has been considered a prognostic index of relapse after medical treatment; moreover, thyroid hypoechogenicity is regularly observed in GD at the onset, but not in patients with 'burned-out' disease. The aim of this study was to evaluate the usefulness of thyroid hypoechogenicity changes in predicting GD relapse.

DESIGN

Longitudinal prospective study of previously untreated patients with GD.

PATIENTS

Thirty-nine consecutive patients aged 10-72 years were treated with methimazole (MMI) for 12-24 months on a titration regimen. Evaluation of patients in remission or with relapse was done 12 and 24 months after MMI withdrawal.

MEASUREMENTS

Thyroid ultrasonography and TSH receptor antibodies (TRAb) were evaluated in basal conditions and then one month after MMI withdrawal. Thyroid hypoechogenicity score (assessed by the same observer with the same equipment) was graded as: 0 absent; 1 mild; 2 moderate; 3 marked. At the withdrawal evaluation a score < 2 and a TRAb value < 10 U/l were considered as normal.

RESULTS

Twelve and 24 months after withdrawal, there were 10 (25.6%) and 17 (44.7%) relapses, respectively. Neither thyroid hypoechogenicity score nor TRAb values evaluated in basal conditions, showed significant differences between patients remaining euthyroid and those who became again hyperthyroid. In the whole group, the thyroid hypoechogenicity score was significantly lower at the withdrawal than in basal conditions (1.1 +/- 1.1 vs 2 +/- 0.8; P < 0.0001); it was significantly lower in patients in remission (P < 0.001), but not in those who relapsed. The thyroid hypoechogenicity score at withdrawal was normal in 23/29 (79.3%) of patients still euthyroid and in 4/10 (40%) of those who relapsed up to the 12th month (P < 0.05); it was normal in 19/21 (90.4%) of patients still euthyroid and in 7/17 (41.2%) of those who relapsed up to the 24th month (P < 0.05). A normal thyroid hypoechogenicity score at withdrawal of MMI had a higher specificity (0.95) and sensitivity (0.59) with respect to TRAb values (0.86 and 0.53, respectively) for the prediction of the relapse of hyperthyroidism at the 24th month.

CONCLUSIONS

Basal thyroid hypoechogenicity cannot be used as an index of relapse of GD. MMI treatment induces evident changes in thyroid hypoechogenicity, mainly in patients who subsequently go into remission. The absence or a low grade of thyroid hypoechogenicity after MMI treatment seems to be a favourable prognostic index of remission of hyperthyroidism in GD.

Nonfunctioning adenomas of the pituitary

The term "nonfunctioning" pituitary adenomas (NFPA) implies heterogeneity, since it relies on a clinical definition that is mainly related to tumor mass. The first complaint is often of impaired visual function, and despite the secretion of gonadotropins, hypogonadism is frequent. NFPA must be differentiated from prolactinomas, because of the therapeutic implications, but although prolactin (PRL) levels greater than 200 ng/mL indicate prolactinoma, PRL levels of 100 to 150 ng/mL are equivocal. An assessment of gonadotropin response to gonadotropin-releasing hormone (GnRH) is of no use, but the thyrotropin-releasing hormone (TRH) test is invaluable. NFPA are monoclonal in origin, but genetic mutations data have not clarified their etiology, which remains largely unknown. Proliferating cell nuclear antigen expression is increased in recurrent adenomas, as is abnormality and overexpression of the protein kinase C family in aggressive tumors. Mutations of tumor-suppressor genes, such as the p53 and Rb genes, and of the metastasizing suppressor gene nm23, have been found in invasive tumors. Immunohistochemistry data confirm that most NFPA originate from gonadotroph cells; many NFPA are negative for all anterior pituitary hormones tested, although isolated or clustered cells are often positive for glycoprotein hormones or their subunits. Silent gonadotroph and also silent growth hormone (GH) or corticotroph tumors can constitute the anatomical basis for clinical NFPA. The heterogeneity of the immunohistochemistry data is reflected in the receptor complex of these tumors. Dopaminergic receptors have recently been visualized in vivo and there are also receptors for TRH or GnRH, since levels of alpha or beta subunits and intact gonadotropins increase after TRH or GnRH stimulation. As a result, three second-line pharmacological approaches have been tried: dopamine agonists, octreotide, and GnRH superagonists or antagonists, with tumor shrinkage of up to 11% to 20%. However, surgery should be tried first.

Effects of terguride on anterior pituitary function in parkinsonian patients treated with L-dopa: a double-blind study versus placebo

In a randomized double-blind study, 20 parkinsonian patients (suffering from the disease for 2-18 years), chronically treated with levodopa (500-750 mg/day for 0.5-12 years), received terguride (1 mg b.i.d.) or placebo for 4 weeks. Growth hormone (GH), prolactin (PRL), thyroid-stimulating hormone (TSH), and insulin-like growth factor (IGF-I) secretions were studied before and after the morning dose of levodopa (250 mg p.o.), both before and at the end of study period. At the beginning of the study, basal hormonal levels were within normal limits, and levodopa administration induced a significant suppression in PRL and TSH levels (both p < 0.01)) and a significant increase in GH (p < 0.01). The same results were observed at the end of the study period in the placebo group. Addition of terguride induced a significant suppression in basal PRL levels (p < 0.01), whereas levodopa-induced hormonal changes were unaffected. These data suggest that the hypothalamic dopaminergic function that controls anterior pituitary hormones is preserved in parkinsonian patients, regardless of both the duration of the disease and the long-term treatment with levodopa. The strong additional prolactin-lowering effect of terguride indicates long-lasting dopaminergic effects, as is already known from hyperprolactinemic conditions. The dopaminergic effects of levodopa on TSH, GH, and IGF-I secretion were unchanged by terguride treatment. The anti-dopaminergic effects of terguride observed in the motor system in animal studies, as well as in levodopa-induced dyskinesias in parkinsonian patients, could not be observed in the case of the dopaminergic control of anterior pituitary hormones under the conditions of this study.

A thyroid hormone receptor beta gene polymorphism associated with Graves' disease

Autoimmune thyroid diseases (AITDs) are clustered in families, but the nature of this clustering is still poorly understood. One possible approach to the identification of genetic factors interacting with the AITDs is the study of the association between polymorphic markers and AITDs themselves. In the present study we have shown an association between an allele of a HindIII restriction fragment length polymorphism (EA beta H) intragenic to c-erbA beta, which codes for the thyroid hormone beta receptor, and Graves' disease. This polymorphism can be detected by PCR followed by digestion with the restriction enzyme HindIII. The allelic frequencies were analysed in a panel of DNAs extracted from a population of individuals affected by thyroid disease and originating from southern Italy. A control group (n = 120) from the same area was also analysed. The distribution of EA beta H alleles was significantly different (P < 0.001) in Graves' disease (n = 94) but not in autoimmune thyroiditis (n = 60), as compared with controls. Also the distribution of the EA beta H genotypes was significantly different in Graves' patients (P = 0.003), as compared with controls, the homozygous state EA beta H+/EA beta H+ being more frequent in Graves' patients than in all the other groups. We did not find any association between EA beta H genotypes and clinical parameters in Graves' patients, including eye signs, thyroid volume and level of TSH-binding inhibiting immunoglobulins. Our data support the idea that Graves' disease is a genetically distinct group within the AITDs.

Thyroperoxidase microsatellite polymorphism in thyroid diseases

Autoimmune thyroid diseases (AITD) cluster in families, although the nature of this phenomenon is still poorly understood. One possible approach to the identification of genetic factors contributing to the pathogenesis of AITD is the study of association between polymorphic markers and AITD themselves. In the present study we have analyzed the allelic distribution of sRA-1, a TPO tetranucleotide repeat, among patients with AITD, in comparison with patients with nonautoimmune thyroid diseases and the general population. The polymorphic marker was analyzed by PCR followed by electrophoresis on polyacrylamide denaturant gel. Our data show that no association exists between AITD and any of sRA-1 alleles, despite the important role that TPO plays as a thyroid autoantigen.

In vivo visualization of pituitary dopaminergic receptors by iodine-123 methoxybenzamide (IBZM) correlates with sensitivity to dopamine agonists in two patients with macroprolactinomas

We performed in two patients with macroprolactinoma, pituitary scintigraphy with 123 iodine-methoxybenzamide (IBZM), a dopaminergic antagonist that specifically binds to the D2 dopaminergic receptors. In a 34-yr-old woman with basal PRL levels of about 2000 ng/mL, 7.5 mg/day of Bromocriptine (Br) for a month neither reduced PRL levels nor affected tumor size; in this patient single photon emission tomography SPECT failed to show any pituitary accumulation of the tracer. In the other patient, a 27-yr-old man presenting with cerebrospinal fluid rhinorrhea, basal PRL levels were at 5000 ng/mL; magnetic resonance imaging (MRI) demonstrated a huge pituitary tumor, and SPECT showed a very intense concentration of IBZM at the level of the adenoma. PRL levels fell dramatically to 530 ng/mL with only 2.5 mg/day of Br after 4 days; after 6 days with 7.5 mg/day Br, PRL levels were 63 ng/mL, and the patient underwent surgery to correct cerebrospinal fluid leakage. We conclude that, in these two patients, the pituitary scintigraphy with IBZM has given information on the density of dopamine receptors on the adenoma and has correlated with the inhibitory effect of Br on PRL secretion. Whether this tool might be of value in identifying patients with pituitary tumors potentially responsive to Br treatment is still to be investigated.

Persistence of somatostatinergic tone in acromegaly

It is a matter of debate whether hypothalamic somatostatin (SRIH) secretion in acromegaly is preserved and still regulated by the physiological feedback mechanisms of growth hormone (GH) and insulin-like growth factor I. To gather further information on this, the reproducibility of plasma GH changes induced by growth hormone-releasing hormone (GHRH) administration was evaluated in 15 acromegalic patients. There was a highly significant correlation between the peak/basal ratio (P/B) GH response in the 15 patients administered GHRH on two separate occasions (r = 0.99, p < 0.001). The test was performed also before and after the administration of drugs able to inhibit or stimulate hypothalamic SRIH release, by activating (pyridostigmine) or inhibiting (pirenzepine) cholinergic pathways, respectively. The GHRH-induced GH response (P/B = 2, range 1.1-26.1) was increased significantly by pyridostigmine pretreatment in 30 patients (P/B = 2.6, range 1.3-34.8; p = 0.0045). In nine out of 30 patients an increase of greater than 2 SD of within-subject GHRH variability was observed in response to GHRH plus pyridostigmine when compared to GHRH alone. An inverse correlation (r = -0.37, p < 0.05) was observed between GH response to GHRH alone and after pyridostigmine pretreatment. On the contrary, no change of GHRH-induced GH response was observed in 12 patients after pirenzepine pretreatment (P/B = 1.9, range 1.1-5 and P/B = 2, range 1.3-6 without and after pirenzepine pretreatment, respectively). These data suggest that in acromegaly the somatostatinergic tone does not seem to fluctuate, and that it can be inhibited often by cholinergic pathway activation but not increased further by cholinergic suppression.

CV 205-502 in acromegaly

In a series of acromegalic patients the effects of CV 205-502, a new long-acting dopamine-agonist drug, on growth hormone (GH), insulin-like growth factor I (IGF-I) and prolactin (PRL) levels were evaluated in an open study. After acute administration of CV 205-502 (0.0375 mg, po) in 12 patients. GH levels did not change, whereas PRL values significantly decreased and remained suppressed for 24 h. In the 14 patients who underwent chronic CV 205-502 treatment (at daily doses of 0.150-0.600 mg/day given at bedtime or b.i.d. for up to 12 months). GH and IGF-I levels fell significantly from 60 +/- 17 (mean +/- SEM) micrograms/l to 28 +/- 10 micrograms/l and from 1127 +/- 84 micrograms/l to 738 +/- 57 micrograms/l, respectively (p < 0.05). A retrospective comparison with the results obtained for the same patients during a previous chronic bromocriptine treatment (at daily doses of 5-20 mg given t.i.d. or q.i.d.) did not show any significant difference in the suppression of GH levels between the two treatments; no bromocriptine-resistant patient was CV 205-502 sensitive, even at the highest CV 205-502 dose used. We conclude that in acromegaly chronic treatment with this new dopaminergic drug has a GH- and PRL-lowering effect that is similar to but more prolonged than that of bromocriptine, and normal or near-normal GH and IGF-I levels may be obtained in a few patients with b.i.d. administration. However, no GH-lowering effect is observed in bromocriptine-resistant patients.

Proceedings of the workshop, "Practical approaches to the diagnosis and treatment of acromegaly"

Practical approaches to the management of acromegaly are discussed. The roles of surgery, radiotherapy, and medical treatment with oral dopamine agonists such as bromocriptine or the long-acting somatostatin analogue octreotide given subcutaneously are reviewed. Most cases need surgery, but cure is rare in patients with macroadenomas, although common with microadenomas. Radiotherapy should be considered in surgical failures, but takes several years to be effective. Medical treatment with octreotide is effective in the majority, for whom it represents a major advance, but it needs to be administered subcutaneously and the development of gallstones and gastritis in long-term treatment are problems. Bromocriptine is usually less effective, but occasionally still plays a role in the therapeutic program. Combinations of the different modalities are usually required in the management of acromegalic patients.

The brain as a target for adrenocortical steroids: cognitive implications

It is well established that a reciprocal control exists between the brain and glucocorticoid hormones. The brain regulates adrenocortical function via hypothalamic corticotrophin releasing hormone-41 (CRH-41), glucocorticoids act at specific receptors in the hippocampus, thus promoting negative feedback mechanisms. Because the hippocampus is a major site for memory processes, a role for excessive/long-lasting plasma glucocorticoid levels has been suggested in conditions of mental impairment. Major depression, Cushing's disease, and dementia of the Alzheimer type are disorders which share hyperactivity of the hypothalamo-pituitary-adrenal axis, as well as symptoms of cognitive decline. Although the mechanisms leading to hypercortisolemia appear to be different in each case, the neuropsychological features of these three disorders accord with the hypothesis of glucocorticoid-associated brain damage. It therefore is important to find pharmacological strategies that will avert or reduce these potential consequences on brain function.

Doxorubicin for acromegaly: a case report

We report the case of an acromegalic woman, aged 35 years, with a huge GH-secreting tumor, repeatedly treated with neurosurgery and radiotherapy, not responsive to bromocriptine (Br) and octreotide (SMS), whose clinical picture evolved to coma due to endocranic hypertension. Since remnant size was too large to be further treated by surgery, chemotherapy with doxorubicin (DOX) (100 mg i.v. every three weeks up to 0.5 mg/m2 over 7 months) was started. Treatment was followed by a rapid improvement of clinical picture with resumption out of coma, progressive decline of GH levels (from 800 ng/ml to 15 ng/ml) and a slight shrinkage of tumor. No side effects were observed during DOX administration. We suggest that in those few acromegalic patients resistant both to SMS and Br, and with poor prognosis, DOX may be effectively used.

Prolactin response to growth hormone-releasing hormone during chronic thyrotropin-releasing hormone infusion in the treatment of amyotrophic lateral sclerosis

In six patients suffering from amyotrophic lateral sclerosis we evaluated changes of T4, T3, TSH, PRL, and GH during treatment by continuous iv infusion of TRH for at least 15 days. No clinical improvement was detected. A significant rise of thyroid hormone levels was observed, as well as an upward trend of basal TSH levels and no change of basal PRL and GH levels. TRH acute test-induced TSH and PRL responses became blunted. Treatment provoked also the onset of a responsiveness of PRL to GHRH. The reduced TSH and PRL responses to acute TRH test during treatment could be explained by a down-regulation of TRH pituitary receptors. On the contrary, the onset of PRL responsiveness to GHRH is at present without a satisfactory explanation.

Resistance to a long-acting somatostatin analog (SMS 201-995) reversed by surgery in acromegaly

A 42-year-old woman had acromegaly and a large macroadenoma with supra- and parasellar extension. Her GH levels (median 85 ng/ml, range 63-170 ng/ml) were not responsive to TRH (200 micrograms iv), GHRH (100 micrograms iv) and bromocriptine (Br 2.5 mg po) acute tests; Sm-C level was 8 U/ml. She was treated with octreotide (SMS) (up to 1500 micrograms daily) for 3 months. No changes of clinical, biochemical and radiological findings were seen, therefore she underwent transsphenoidal surgery. After surgery, hypopituitarism and diabetes insipidus appeared: GH levels remained high (median 45 ng/ml; range 37-56 ng/ml), but became responsive to Br acute test. The patient was given SMS again, and this resulted in clinical improvement, marked reduction of GH and Sm-C levels and slight shrinkage of the residual tumor. Speculative hypotheses about this previously unreported phenomenon might be either an excess of both GHRH and somatostatin, caused by a primary increase of dopaminergic tone, or a primary excess only of GHRH; in both cases the surgical lesion of the hypothalamic-pituitary region might have impaired the neurohormones inflow to the residual pituitary and so let SMS and Br exert their inhibitory actions on GH secretion.

[Medical treatment of acromegaly with dopaminergic agents]

The medical treatment of acromegaly with dopaminergic drugs has its physiopathological premise in the observation that agents capable of stimulating dopaminergic receptors directly are capable of determining GH secretion inhibition in a large percentage of acromegalic patients. Chronic administration of 5-20 mg/die of bromocryptin, long acting dopaminergic agonist, leads to a stable reduction in the levels of GH and somatomedin C (SmC) in about 50% of patients. However, these are only normalised in 20%. Treatment induces marked improvement in the clinical and metabolic changes typical of acromegalic disease. The therapeutic effect of dopaminergics may be maintained for periods of treatment lasting years but upon suspension of treatment pH levels return quickly to pretreatment levels. The antitumoral effect of the dopaminergic frequently encountered in prolactinomas is a rarer event in acromegaly and occurs more readily in patients with mixed secreting GH and PRL tumours than in pure GH. Currently octractide, a long lasting somatostatin analogue, is the most effective drug in the medical treatment of acromegaly; however the dopaminergic agonists remain a valid alternative.

Medical treatment of acromegaly with SMS 201-995, a somatostatin analog: a comparison with bromocriptine

We studied the effects of acute and chronic sc administration of SMS 201-995 (SMS), a long-acting somatostatin analog, in acromegalic patients. The results were compared with those obtained in the same patients treated with oral bromocriptine (Brc). A single dose of 50 micrograms SMS administered to 28 patients induced a more rapid, greater, and more prolonged reduction in plasma GH levels than did 2.5 mg Brc. Chronic treatment [60-330 days; mean 208 +/- 23 (+/- SEM)] with SMS (100-300 micrograms/day) induced in 16 patients a significantly greater decrease in mean plasma GH and somatomedin-C levels than did 20 mg Brc. Combined treatment with the 2 agents had an additional effect. The clinical and metabolic parameters of acromegaly dramatically improved in all patients whose plasma GH and somatomedin-C levels decreased even if they were not normalized by SMS. Reduction in tumor size occurred in 3 of the 10 patients examined by computed tomography before and during SMS treatment. We conclude that SMS is more effective than Brc and that the 2 drugs may be complementary in the medical treatment of acromegaly.

Relationship between somatomedin-C and growth hormone levels in acromegaly: basal and dynamic evaluation

The relationship between basal and stimulated plasma GH and somatomedin-C (SmC) levels in acromegalic patients was evaluated. The basal plasma SmC levels of 66 patients were significantly correlated (P less than 0.01) with mean daily plasma GH levels, but not with the percent GH increase after GH-releasing hormone or TRH or the GH decrease after acute bromocriptine administration. Bromocriptine (7.5-15 mg/day) administration for 9.2 +/- 0.9 (+/- SD) months in 20 patients significantly (P less than 0.05) decreased GH levels. SmC decreased significantly [from 9.8 +/- 1.9 to 5.1 +/- 0.7 U/ml (mean +/- SE)] only in the 10 patients who had the more marked GH inhibition. The administration of a somatostatin analog, SMS 201-995 (100 micrograms twice daily), to 12 patients for 16 weeks significantly decreased plasma GH and SmC levels beginning on the second day of therapy; normal SmC levels were achieved in 5 of 12 patients. Pituitary adenomectomy resulted in normal GH and SmC levels in 10 of 12 and 8 of 12 patients, respectively. Our data indicate an overall dependency of plasma SmC levels on plasma GH levels in acromegaly, although similar GH levels may have differing somatomedin-stimulating activities. A derangement in the feedback mechanisms controlling GH secretion is indicated by the failure of elevated SmC levels to influence the GH responsiveness to releasing hormones. In evaluating pharmacological or surgical treatments of acromegaly, a single plasma SmC value can reliably replace several plasma GH determinations.

Serum type III procollagen propeptide levels in acromegalic patients

Serum type III procollagen propeptide (PIIIP) is a reliable index of tissue collagen synthesis. Since in acromegaly there is increased collagen production, we measured serum PIIIP in acromegalic patients before any treatment (basal), during medical treatment with the somatostatin analog SMS 201-995, and after pituitary adenomectomy. In all patients, serum GH and plasma somatomedin-C (SmC) levels were also measured. Basal serum PIIIP levels were significantly (P less than 0.01) higher in acromegalic patients (mean +/- SEM, 22.7 +/- 2.1 ng/ml) than in normal subjects (n = 30; 9.7 +/- 0.5 ng/ml), and they were significantly correlated with plasma SmC values (r = 0.31; P less than 0.05). A significant (P less than 0.01) reduction in PIIIP levels occurred in patients treated with SMS 201-995 or surgery (from 24.3 +/- 2.7 to 12.4 +/- 1 ng/ml) as well as in GH and SmC levels. The maximum percent decrease in serum PIIIP was significantly correlated with those in GH (r = 0.65; P less than 0.01) and SmC (r = 0.60; P less than 0.01). Serum PIIIP levels did not change in those patients in whom neither GH nor SmC were decreased by treatment. In conclusion, serum PIIIP levels are elevated in acromegalic patients, and they decline in parallel with GH and SmC during medical or surgical treatment. Serum PIIIP measurements may be useful in the evaluation of acromegalic patients to gain information on the biological activity of GH and in monitoring the course of the disease.

Chronic treatment of pathological hyperprolactinemia and acromegaly with the new ergot derivative terguride

The long term effectiveness and tolerance of terguride, a new ergot derivative, as initial therapy were evaluated in 20 patients with pathological hyperprolactinemia (PHP; group A) and 7 patients with acromegaly. We also studied 10 patients with PHP whose treatment was changed from bromocriptine or lisuride to terguride (group B). Terguride, given for at least 6 months in divided doses ranging from 0.25-1.50 mg/day to group A patients, resulted in normal (11 patients) or markedly reduced plasma PRL levels. Gonadal function was restored in all but 2 patients in this group, and the tumors shrank in 3 of 5 patients with a macroprolactinoma and in 1 of 3 patients with a microprolactinoma. In group B patients, positive effects of the previous treatment on PRL levels, gonadal function, and tumor growth were maintained by terguride. Terguride suppressed plasma GH levels below 50% of baseline in 4 of the 7 acromegalic patients. Two of the 27 patients initially treated with terguride complained of mild nausea and postural hypotension only after the first dose (0.25 mg) of the drug. No patient in group B had any side-effects during terguride, with the exception of 1 patient who was also intolerant to bromocriptine. We conclude that terguride is an effective well tolerated dopaminergic agent in PHP.

Growth hormone-releasing hormone infusion in patients with active acromegaly

To determine GH-releasing hormone (GHRH)-stimulated GH secretion in patients with active acromegaly, nine patients received a 50-microgram GHRH-(1-44) bolus dose followed by a 2-h infusion with 100 micrograms GHRH/h, after which a second 50-microgram GHRH bolus dose was given. Serum GH, PRL, and immunoreactive GHRH levels were measured from 2 h before to 1 h after the end of the infusion and compared with hormone levels in six normal subjects subjected to the same protocol. In addition, seven of the nine acromegalic patients received 100 micrograms GHRH as an iv bolus dose, followed by a 2-h saline infusion on a different day. After the 100-micrograms GHRH bolus dose, the mean GH level increased from 55.9 +/- 18.0 (+/- SE) to 148.5 +/- 40.0 ng/ml within 15 min. Thereafter, GH levels decreased and were significantly lower at 90 and 120 min compared to the peak level 15 min after GHRH injection. After the 50-micrograms GHRH bolus dose, all acromegalic patients except two also had a clear-cut rise of GH levels, with the mean GH level increasing from 37.5 +/- 13.2 to 108.4 +/- 55.0 ng/ml at 60 min. Thereafter, elevated GH levels were sustained in the acromegalic patients throughout the GHRH infusion. In contrast, normal subjects had a significant decrease in the initially elevated GH levels, despite continuous GHRH infusion. There were no significant differences between PRL secretion and immunoreactive GHRH levels in either group. These findings suggest that patients with active acromegaly not only have elevated basal GH levels, but also have a greater ready releasable GH pool and/or accelerated GH turnover compared to those of normal subjects, which cannot be exhausted by a 2-h GHRH infusion.

Bromocriptine does not alter growth hormone (GH) responsiveness to GH-releasing hormone in acromegaly

GHRH (100 micrograms) and TRH (200 micrograms) were administered to 24 active acromegalic patients before and during chronic bromocriptine (Br) treatment (Br, 10-15 mg/day for 3-5 months) to evaluate the possible effects of the dopamine agonist on GH release induced by these releasing hormones. Mean daily plasma GH levels were reduced by Br treatment from 34 +/- 40 (SD) to 16 +/- 19 ng/ml (P less than 0.01). No significant changes were found when comparing the GH response to GHRH as mean area under the response curve (nanograms per min/ml above the basal) (pretreatment, 5453 +/- 7843; during Br, 7017 +/- 12763 ng/ml . min), and as mean individual peak GH values (pretreatment, 130 +/- 148; during Br, 126 +/- 187 ng/ml) before and during treatment. The percentage GH increase (pretreatment, 340 +/- 354; during Br, 617 +/- 539%) was however significantly higher during Br. Br treatment significantly reduced the GH response to TRH in terms of mean of individual peak levels (from 136 +/- 134 to 60 +/- 52 ng/ml; P less than 0.01) and area under the response curve (from 3142 +/- 3998 to 1331 +/- 1646 ng/min . ml; P less than 0.01). However, the percentage GH increase was not significantly different (pretreatment, 486 +/- 729; during Br, 1059 +/- 1862%). When the patients were divided into Br responders, i.e. mean daily GH reduction during Br of at least 50% below baseline, and nonresponders, the initial response to GHRH was significantly higher in the latter group, but was unaffected by Br treatment in either group. On the contrary, the response to TRH, statistically significant initially only in the Br responder group, was reduced by Br treatment. We suggest that cells sensitive to Br and TRH but not to GHRH (lactotroph-like) and cells sensitive to GHRH but not to Br (pure somatotrophs) may coexist in GH-secreting adenomas.

Free thyroid hormone levels and TSH response to TRH in patients with autonomous thyroid adenomata and normal T3 and T4

Free thyroid hormone levels together with basal and TRH stimulated TSH levels, have been determined in 50 patients with autonomous thyroid adenomata, who had normal serum total T3 and T4 values. Similar measurements were made in 33 healthy subjects. FT3 and FT4 plasma levels were significantly higher (P less than 0.01 and P less than 0.05 respectively), and basal and TRH stimulated TSH were significantly lower (P less than 0.05 and P less than 0.001 respectively) in the patients than in the controls. The TSH response to TRH was decreased in spite of normal free thyroid hormones in 25 patients and in a further ten both the delta TSH after TRH and the free fractions were normal. Eighteen patients were studied over periods from 4 37 months by repeating thyroid hormone levels and TRH tests. In six of them a change of these parameters toward toxicity was observed. The data obtained in the longitudinal study indicate that the values of free thyroid hormones and the result of the TRH test obtained by a single determination may represent different steps in the evolution of autonomous thyroid adenomata rather than a distinct pathophysiological condition.

Low doses of dopamine agonists in the long-term treatment of macroprolactinomas

To evaluate the long-term effects of dopamine agonists in the treatment of macroprolactinoma, we studied prolactin levels and tumor size for 30 to 88 months (57 +/- 14, mean +/- S.D.) in 38 patients treated with bromocriptine or lisuride. Elevated prolactin levels became normal in 30 patients, and the tumor shrank in 29. After two years of treatment, we attempted to reduce the maintenance dose (5 to 20 mg of bromocriptine per day or 0.4 to 0.8 mg of lisuride per day); in 21 patients no changes in prolactin levels or tumor size were observed over 6 to 52 months with 0.625 to 10 mg of bromocriptine per day or 0.05 mg of lisuride per day. However, it was possible to withdraw the drug in only one patient. We conclude that dopamine agonists are usually effective treatments for macroprolactinoma and that after a response has been obtained, it can be maintained in many patients with a greatly reduced dose.

Effect of the new ergot derivative terguride on plasma PRL and GH levels in patients with pathological hyperprolactinemia or acromegaly

Terguride, a derivative of lisuride, has been shown to possess a mixed dopaminergic-antidopaminergic activity in experimental models. We have studied the effects on PRL and GH levels of 0.2 mg po of terguride in 8 normal subjects, in 15 patients with pathological hyperprolactinemia (PHP) and in 17 patients with active acromegaly. In PHP, PRL levels were significantly reduced up to 300 min after terguride with a nadir (45 +/- 4.0% SE) significantly lower (p less than 0.05) than the one observed in the 8 normal subjects (72 +/- 3.5%). There was no significant difference in plasma PRL levels after 0.2 mg terguride or lisuride in 7 out of 15 patients tested with both drugs. Terguride did not significantly modify GH levels in PHP and in normals but when considering basal and peak (occurring between 60 and 150 min) GH values, a significant difference was found (p less than 0.01). Mean peak of GH did not differ significantly between PHP (5.0 +/- 1.1 ng/ml) and normals (6.8 +/- 1.7 ng/ml). Plasma GH levels of 17 acromegalics were not modified by 0.2 mg of terguride but were significantly reduced by 2.5 mg of bromocriptine. Terguride and bromocriptine reduced PRL levels in acromegalics (p less than 0.01) without any significant difference between the two drug. 0.2 mg terguride bid given for 15 days to 7 healthy volunteers significantly reduced both basal and sulpiride (25 mg im)-stimulated PRL levels. Side effects were observed only in 4 out of 47 subjects tested with terguride and in 8 out of 34 tested with bromocriptine.

Effect of chronic bromocriptine administration on tumor size in patients with "nonsecreting" pituitary adenomas

The effect of chronic bromocriptine administration (7.5-20 mg/day for 1-32 months) on the size of "nonsecreting" pituitary adenomas (NPA) was studied in 20 patients. Brain computed tomography showed a marked reduction of the adenoma in one patient after 1 month of treatment (7.5 mg/day); further scans taken 2 and 15 months later, under the same bromocriptine dose, did not show any other variations in the tumoral mass. In the remaining 19 patients, no changes in tumor size were documented by CT during the treatment. Four patients had a worsening of visual fields during bromocriptine administration and they were referred for neurosurgery. In conclusion, bromocriptine was ineffective in reducing tumor size in all but one patient with NPA and, in some cases, it did not prevent tumor growth as is suggested by the worsening of visual fields. Thus, bromocriptine treatment, at least at the doses capable of shrinking macroprolactinomas, seems to be of limited value in patients with NPA.