Effects of Metformin on TSH Levels and Benign Nodular Goiter Volume in Patients Without Insulin Resistance or Iodine Insufficiency

Objectives: To evaluate the impact of metformin (MTF) use on TSH levels, thyroid volume and volume of benign thyroid nodules (TNs). Additionally, to study if iodine status influences the outcomes. Methods: A total of 23 euthyroid patients (42 TNs) with benign thyroid nodules, diagnosed by fine needle aspiration biopsy, were randomly assigned to MTF or placebo (P) use for 6 months. Serum TSH, homeostatic model assessment for insulin resistance (HOMA-IR), and urinary iodine concentrations (UIC) were assessed. Ultrasound was used to evaluate TNs and thyroid volumes (TV) and their variations throughout the study. Diabetic patients, those undergoing levothyroxine replacement, and/or using thyroid- or insulin level-influencing drugs were excluded. Results: The sample consisted predominantly of patients without IR. Both intervention groups were similar regarding several confounding variables and showed a comparable median UIC. Serum TSH decreased significantly after MTF (-0.21 vs. 0.09 mUI/L in the P group; p = 0.015). At 6 months, no significant variations were found between groups with respect to TN volumes, TV, HOMA-IR, or body mass index (BMI). However, a tendency toward enlargement of TV with placebo (16.0%; p = 0.09) and a protective effect of MTF on growing TN (OR: 0.25; CI 0.05-1.20) was detected after excluding patients with IR (a lower UIC subgroup). The reduction on TSH levels with MTF maintained in the population without iodine insufficiency (-0.24 vs. +0.07 in the P group; p = 0.046) and was accentuated in those with excessive or more than adequate UIC (-0.69; p = 0.043). A protective effect of MTF on growing TN was suggested (OR: 0.11; IC: 0.02-0.84) in those with higher UIC. Conclusions: This study demonstrated that MTF caused a reduction in TSH levels in benign nodular goiter. This effect was more accentuated in patients with higher levels of UIC and was accompanied by a suggested protective effect on TN enlargement.

Prevalence of hypothyroidism in patients with frozen shoulder

BACKGROUND

Hypothyroidism and frozen shoulder (FS) have been associated, although this relationship remains uncertain. The main objective of this study was to determine the prevalence of hypothyroidism in patients with FS.

METHODS

A case-control study was performed to compare FS patients (cases) with patients who visited an orthopedic service for other clinical conditions (controls). FS was diagnosed according to specific criteria based on anamnesis, physical examination, and shoulder radiographs. A specific questionnaire was applied, and measurements of serum thyroid-stimulating hormone (TSH) and free tetraiodothyronine were performed in all subjects.

RESULTS

We evaluated 401 shoulders from 93 FS patients and 151 controls. The prevalence of hypothyroidism diagnosis was significantly higher in the FS group (27.2% vs. 10.7%; P = .001). There was also a tendency for higher prevalence of bilateral FS among patients with elevated TSH levels (P = .09). Mean serum TSH levels were higher in patients with bilateral FS compared with those with unilateral compromise (3.39 vs. 2.28; P = .05) and were higher in patients with severe FS compared with those with mild and moderate FS together (3.15 vs. 2.21; P = .03). Multivariate analysis showed that FS was independently related to a diagnosis of hypothyroidism (odds ratio, 3.1 [1.5-6.4]; P = .002). There was a trend toward independent association between high serum TSH levels and both severe (odds ratio, 3.5 [0.8-14.9]; P = .09) and bilateral (odds ratio, 11.7 [0.9-144.8]; P = .05) compromise.

CONCLUSION

The prevalence of hypothyroidism was significantly higher in FS patients than in controls. The results suggest that higher serum TSH levels are associated with bilateral and severe cases of FS.

Clinical aspects of pancreatogenic diabetes secondary to hereditary pancreatitis

BACKGROUND

Hereditary pancreatitis is a rare inherited form of pancreatitis, characterized by recurrent episodes of acute pancreatitis with early onset and/or chronic pancreatitis, and presenting brittle diabetes, composed of episodes of nonketotic hyperglycemia and severe hypoglycemia. The existing literature regarding this form of diabetes is scarce. In this report, clinical features of pancreatogenic diabetes secondary to hereditary pancreatitis are presented along with recommendations for appropriate medical treatment.

RESULTS

Clinical data from five patients of a family with pancreatogenic diabetes secondary to hereditary pancreatitis were analyzed. The average time between hereditary pancreatitis and diabetes diagnosis was 80 ± 24 months (range: 60-180 months) with a mean age of 25.6 ± 14.7 years (range: 8-42 years), four patients used antidiabetic agents for 46 ± 45 months and all progressed to insulin therapy with a mean dose of 0.71 ± 0.63 IU/kg (range: 0.3-1.76 IU/kg). The glycemic control had a high variability with average capillary blood glucose of 217.00 ± 69.44 mg/dl (range: 145-306 mg/dl) and the average HbA1c was 9.9 ± 1.9% (range: 7.6-11.6%). No ketoacidosis episodes occurred and there were several episodes of hospitalization for severe hypoglycemia.

CONCLUSIONS

Diabetes mellitus secondary to hereditary pancreatitis presents with early onset, diverse clinical presentation and with extremely labile glycemic control. Diabetes treatment varies according to the presentation and insulin is frequently necessary for glycemic control.

Hereditary Pancreatitis Associated With the N29T Mutation of the PRSS1 Gene in a Brazilian Family: A Case-Control Study

Hereditary pancreatitis (HP) is an autosomal-dominant disease with incomplete penetrance manifesting as early-onset chronic relapsing pancreatitis. A mutation in the PRSS1 gene is present in greater than 70% of HP kindreds and leads to a gain-of-function characterized by the increased autocatalytic conversion of trypsinogen to active trypsin, promoting autodigestion and damage to acinar cells. Other genetic defects observed in the pathogenic mechanism of pancreatitis include mutations in the genes encoding SPINK1, CTRC, and CPA1. There are few reports of HP in Latin America, and no families have been investigated in Brazil. A case-control observational study was conducted at Clementino Fraga Filho University Hospital in Brazil. Patients with suspected HP and healthy controls were enrolled in this study, and a detailed questionnaire was administered to patients with HP. PRSS1 and SPINK1 genes were analyzed by DNA sequencing, and a family that fit the HP diagnostic criteria was identified. The neutral polymorphism c.88-352A > G in the SPINK1 gene was found to be prevalent in the individuals studied, but no important alterations were found in this gene. Ten out of 16 individuals in this family carried the N29T mutation in the PRSS1 gene, with 2 clinically unaffected mutation carriers. The median age of HP onset was 6 years. Pancreatic exocrine failure occurred in 6 patients, 5 of whom also had diabetes mellitus. Surgical procedures were performed on 3 affected members, and no cases of pancreatic cancer have been reported thus far. This study identified the first PRSS1 gene mutation in a Brazilian family with HP.

Pituitary development: a complex, temporal regulated process dependent on specific transcriptional factors

Pituitary organogenesis is a highly complex and tightly regulated process that depends on several transcription factors (TFs), such as PROP1, PIT1 (POU1F1), HESX1, LHX3 and LHX4. Normal pituitary development requires the temporally and spatially organised expression of TFs and interactions between different TFs, DNA and TF co-activators. Mutations in these genes result in different combinations of hypopituitarism that can be associated with structural alterations of the central nervous system, causing the congenital form of panhypopituitarism. This review aims to elucidate the complex process of pituitary organogenesis, to clarify the role of the major TFs, and to compile the lessons learned from functional studies of TF mutations in panhypopituitarism patients and TF deletions or mutations in transgenic animals.

Acute thyroiditis due to septic emboli derived from infective endocarditis

Acute infectious thyroiditis is a rare condition of the thyroid gland, most often arising in children with congenital conditions connecting the thyroid directly to the oropharynx, such as a piriform fistula or thyroglossal duct. We report a case of acute thyroiditis due to septic emboli derived from infective endocarditis.

Is there a relationship between spontaneous GH secretion, anthropometric parameters and exercise capacity in healthy men over 50 years?

BACKGROUND

The use of growth hormone (GH) in deficient adults has already been demonstrated to result in several benefits regarding metabolic parameters, body composition and quality of life. Due to the similarities between GH deficiency in adults and the aging process, the concept of somatopause has emerged.

OBJECTIVES

Correlate the GH secretion profile in healthy men older than 50 years with anthropometric parameters and exercise capacity.

PATIENTS AND METHODS

Twenty-nine healthy male were selected, with a mean age of 57.9+/-4.2 years (range 50-66). After hospital admission, body mass index (BMI), body composition (fat mass) and abdominal circumference, 24-h GH profile, GH peak and basal IGF-I were evaluated, and all the patients underwent a treadmill stress testing to estimate exercise capacity with the Bruce protocol, with evaluation of the maximum oxygen peak, maximum heart rate and METs. All the results are shown as mean+/-Std deviation: BMI -26.5+/-4.9kg/m2, percent fat mass -27.1+/-6.2%, abdominal circumference -92.1+/-10.1cm, 24h GH profile -0.3+/-0.2ng/dl, peak GH -2.5+/-2.0ng/dl, IGF-I -202.4+/-72.4ng/dl, maximum oxygen peak -31.9+/-6.8L, maximum heart rate - 161.4+/-7.5 bpm and METs - 9.1+/-1.9. After regression analysis using the GH secretion profile (mean GH in 24h, spontaneous peak GH and basal IGF-I) as dependent variable, no correlations were found between these and the other evaluated parameters.

Association of insulin resistance and nocturnal fall of blood pressure in GH-deficient adults during GH replacement

The GH deficiency syndrome in adults is characterized by changes in body composition, metabolic, cardiovascular and psychological profile. Such alterations fit the metabolic syndrome. Changes of blood pressure (BP) levels related to the presence of insulin resistance (IR) may be present in the GH-deficient adult prior to or after therapy with recombinant GH (hGH). The purpose of the study was to assess the relationship between BP and IR in GH-deficient adults after 24 months of replacement with hGH. Thirteen GH-deficient adults were studied [7 men and 6 women, with an average age of 38.6+/-14.14 yr body mass index (BMI) 25.83+/-2.26 kg/m2]. The BP was assessed by means of ambulatory monitoring of BP (AMBP), prior to the treatment and 12 and 24 months after replacement with hGH. Glucose metabolism was assessed by the homeostatic model assessment (HOMA), during the same periods. The average dosage of hGH utilized was 0.67+/-0.15 mg/day. In the analysis of BP levels, we observed a decrease of the diurnal systolic BP (SB P) (p=0.043) and a reduction of the diurnal systolic (p=0.002) and diastolic pressure loads (p=0.038). During the night there were no changes in BP levels. We observed an increase in the percentage of patients with a non-physiological nocturnal fall (non dippers) after replacement with hGH (61.53%). The mean HOMA, insulin and glucose in the fasting state did not present any statistically significant changes. Although the patients within the nondipper group had higher HOMA and insulin levels throughout the study, there were no changes in any of these parameters after GH replacement. All patients with HOMA >2.5 were within the non-dipper group, whereas all dippers had HOMA <2.5. In conclusion, 24 months of therapy with hGH do not seem to have affected glucose homeostasis, and since there is no relationship with the increase of the percentage of non-physiological nocturnal fall, we will need a longer observation time to discover the effects of this finding.

Insulin-like growth factor I levels during growth hormone (GH) replacement in GH-deficient adults: a gender difference

To evaluate the variation of serum IGF-1 levels during GH replacement and observe gender differences, 29 adults with GH deficiency (mean age 42.5 +/- 10.1 year), were studied. Serum IGF-1 was assessed every 4 weeks during the titration period and afterwards every 3 months of GH therapy. At baseline 77.7% of women and 45.4% of men had serum baseline IGF-1 levels below the lower limit of normal age-related reference range. The time to reach the maintenance dose was lower in men than women (p < 0.05). There was an increase in IGF-1 levels after one year of GH therapy, significant only in men (p < 0.01). IGF-1 concentrations were higher in men than women (p < 0.05), at the 12th and 18th months of GH therapy. GH dose was reduced by 25% in men (p < 0.01). At the end of the study the mean GH dose was lower in men than in women (p < 0.05). The factor responsible for these findings is not known, however a possible role of androgens has been suggested.

Evaluation of growth hormone stimulation tests in cured acromegalic patients

We have evaluated the GH peak response to insulin tolerance test (ITT) and to GHRH+arginine in 11 patients cured of acromegaly after treatment with surgery/radiotherapy and compared them to a control group matched for age and sex. GH peak response was significantly higher in the control group than in the patient group (11.21+/-6.98 vs. 4.46+/-6.90 ng/ml, p=0.010). Seven patients had a GH peak response of less than 3 ng/ml, compatible with the diagnosis of GH deficiency. Peak GH response after GHRH+arginine was significantly lower in the group of patients with GH peak of less than 3 ng/ml during ITT as compared to the group with GH peak of more than 3 ng/ml, and in all cases the diagnosis of GH deficiency was confirmed. Mean IGF-I level was not different between the patients and controls, as well as between patients with and without GH deficiency diagnosed by the stimulation tests.

CONCLUSION

The incidence of GHD diagnosed by stimulation tests is high in patients cured of acromegaly.

Glucagon stimulation test for the diagnosis of GH deficiency in adults

The insulin tolerance test (ITT) is considered the test of choice for the diagnosis of GH deficiency (GHD). However, in patients with contraindications to ITT, alternative provocative tests must be used with appropriate cut-offs. The glucagon stimulation test has proved to be a safe, low-cost and effective means of stimulating GH secretion, and therefore can be considered as a suitable alternative to the ITT. We have studied the GH response to the glucagon test in 33 patients with known pituitary disease, 12 males and 21 females, aged between 21 and 60 yr (41.18 +/- 9.47 yr); 5 had isolated GHD and 28 had panhypopituitarism. We also evaluated a control group of 25 individuals, matched for age and sex (8 males and 17 females), aged between 20 and 60 yr (39.28 +/- 12.10 yr). They were selected via the ITT if their peak GH response was > 5.0 ng/ml. GH peak after glucagon was significantly lower in the group of patients compared to the control group (0.49 +/- 0.85 vs 8.69 +/- 5.85 ng/ml, p = 0.0001). Receiver-operating characteristic (ROC) plot analyses of the control and GHD group showed an area under the curve of 0.982 for GH peak response to glucagon. The response value of 3.0 ng/ml showed the best pair of sensitivity (97%)/specificity (88%), and was chosen as the cut-off defining GHD. After evaluation of positive predictive values (PPV) and negative predictive values (NPV) through simulation of different prevalences of the disease, we concluded that the cut-off point of 3.00 ng/ml maximizes both PPV and NPV (100%). In conclusion, we have shown that the glucagon stimulation test has a good performance and great diagnostic accuracy for the diagnosis of GHD.

Biochemical definitions of disease activity in acromegaly

In acromegaly the therapeutic outcome is difficult to assess and depends on the biochemical method. We have ascertained disease activity in 70 acromegalic patients by means of a GH profile (8 hourly samples) and a single IGF-I measurement as compared to a healthy control group. As an estimate of the "stiffness" of the GH profile we calculated the SD/nadir(GH) from the GH profile. In the control group the following upper normal limits were obtained: IGF-I (microg/l) 217; mean GH (microg/l) 2.16; nadir GH (g/l) 0.3. Based on ROC plot analysis a value of 2.0 for the SD/nadir ratio was used as cut-off. This translated into the following surgical cure rates (%): IGF-I 47; mean GH 77; nadir GH 65; SD/nadir 30. Some of the patients post-surgery had elevated IGF-I levels despite "normal" GH levels. Abnormal SD/nadir versus normal IGF-I and vice versa were recorded in many patients post-surgery.

IN CONCLUSION

(1) cure rates of acromegaly depend strongly on the criteria being used and (2) estimates of GH secretion pattern may yield important information about GH status in acromegaly.

Short-term tools to measure responsiveness to growth hormone replacement

Growth hormone (GH) replacement is a prolonged and expensive treatment modality which involves daily subcutaneous injections in children and adults. Efforts have been made, therefore, to develop short-term tests to predict long-term clinical response. The so-called insulin-like growth factor I (IGF-I) generation test was originally introduced in order to select responders to GH among short children without classical GH deficiency. A positive correlation between short-term increase in serum IGF-I and linear growth has, however, only been reported in a minority of studies. There is no single outcome measure available in GH-deficient adults, and no evidence of a correlation between IGF-I and the effects of GH replacement on factors such as body composition or physical fitness. In conclusion, no reliable short-term test to predict long-term response to GH replacement is available in either children or adults. For safety reasons, however, measurement of serum IGF-I concentrations in GH-deficient patients remains an important means of monitoring during GH replacement.

Growth hormone therapy in adults

The importance of growth hormone (GH) deficiency in adults became evident 10 to 15 years ago, when the first clinical studies on GH replacement therapy in adults were published. Since then, a number of studies have been reported showing that GH replacement therapy can improve this condition. Adult GH deficiency (GHD) is now recognized as a specific clinical syndrome and the first reports of long-term use of GH (up to 10 years) are now being published. The aim of this paper was to review the accumulated data on the various clinical aspects of adult GHD.

Growth hormone treatment in adults: is there a true gender difference?

The importance of growth hormone (GH) deficiency in adults became evident at the end of the 1980s, when the first clinical studies on GH replacement therapy in adults were published. Since then, accumulated experience has shown a great individual variability in the response to GH replacement, including a potential difference in responsiveness between genders. The aim of this paper is to review the data regarding the effects of gender differences on GH pharmacokinetics, pharmacodynamics, and efficacy of replacement. In addition, we start with a short review of the possible role of GH in sexual development and sexual life.