A Randomized, Open-Label Study to Assess Efficacy of Weekly Assumption of Cholecalciferol versus Calcifediol in Older Patients with Hypovitaminosis D

The aim of this single-center, open-label, randomized controlled study was to evaluate which formulation of vitamin D—between cholecalciferol and calcifediol—is most effective in the treatment of hypovitaminosis D in older adults. Demographic characteristics, clinical history, and comprehensive geriatric assessment were recorded at admission. Eligible patients were randomly assigned an equivalent vitamin D supplement, either with cholecalciferol or calcifediol, from the time of hospital admission to three months after discharge. Among the 140 older patients included (mean age 83 ± 6.6 years, 57.8% females), 69 received cholecalciferol and 71 received calcifediol. The mean plasma values of 25-hydroxyvitamin D3 (25OH-vitamin D3) found at the time of enrollment were 16.8 ± 9.9 ng/mL in patients receiving cholecalciferol and 18.8 ± 13.3 ng/mL in those treated with calcifediol (p = 0.31). At the three month follow-up, the mean concentration of 25OH-vitamin D3 was significantly higher in patients treated with calcifediol than in those receiving cholecalciferol (30.7 ± 8.4 vs. 45.4 ± 9.8 ng/mL, respectively; p < 0.001). Supplementation with either cholecalciferol or calcifediol effectively results in reaching the optimal circulating values of 25OH-vitamin D3 in older patients suffering from hypovitaminosis D. However, supplementation with calcifediol led to average circulating values of 25OH-vitamin D3 that were significantly higher (over 50%) than those obtained with cholecalciferol.

Prognostic Value of Glycated Hemoglobin in Frail Older Diabetic Patients With Hip Fracture

BACKGROUND

Previous studies have shown increased risk of fracture in older patients with poor or strict glycemic control (glycated hemoglobin, HbA1c, ≥ 8% or < 6-7% respectively); however, these reports did not investigate the oldest-old population. Comprehensive geriatric assessment (CGA) and a patient-centered approach have been proven to improve the quality of care in the management of Type 2 Diabetes Mellitus (T2DM) in the older patients, but data regarding T2DM in patients with fragility fractures are still lacking.

AIM

To investigate the prognostic role of HbA1c and frailty level in older diabetic patients admitted for hip fracture.

METHODS

Prospective observational cohort study conducted on diabetic geriatric patients consecutively hospitalized for hip fracture in the orthogeriatric unit of a tertiary care hospital. Preoperative comprehensive geriatric assessment (CGA) was performed. Using the Clinical Frailty Scale (CFS), diabetic patients were categorized in robust (CFS < 5) and frail (CFS ≥ 5), and further stratified according to HbA1c values [Tertile 1 (T1) HbA1c < 48 mmol/mol, Tertile 2 (T2) 48-58 mmol/mol and Tertile 3 (T3) > 58 mmol/mol). Comparisons between continuous variables were performed with analysis of non-parametric test for independent samples, while relationships between categorical variables were assessed by chi-square test. Using logistic multivariate regression, we evaluated the determinants of 1-year all-cause mortality in diabetic older patients with hip fracture.

RESULTS

Among the 1319 older patients (mean age 82.8 ± 7.5 years, 75.9% females) hospitalized for hip fracture, 204 (15.5%) had a previous diagnosis of T2DM. T2DM patients showed an increased proportion of multiple concurrent fractures occurred during the accidental fall or syncope (12.7% vs 11.2%, p=0.02). One-year mortality after hip fracture surgery was significantly higher in T2DM as compared to not diabetic patients (21.2% vs 12.5%, p<0.001). No significant difference in mortality was found across HbA1c tertiles; however, frail diabetic patients in the second and third HbA1c tertiles showed higher mortality risk compared to the robust counterparts (26.9% vs 5%, p=0.001 for T2 and 43.5% vs 13.3%, p=<0.05 for T3), while no difference was observed among those in T1.

CONCLUSIONS

Frail patients with HbA1c ≥ 48 mmol/L showed an increased mortality risk as compared to robust counterparts. CFS represents an important tool to select diabetic subjects with higher likelihood of adverse outcome.

Overt and Subclinical Hypothyroidism in the Elderly: When to Treat?

Hypothyroidism is characterized by increased thyrotropin (TSH) levels and reduced free thyroid hormone fractions while, subclinical hypothyroidism (sHT) by elevated serum TSH in the face of normal thyroid hormones. The high frequency of hypothyroidism among the general population in Western Countries made levothyroxine (LT4) one of the 10 most prescribed drugs. However, circulating TSH has been demonstrated to increase with aging, regardless the existence of an actual thyroid disease. Thus, when confronting an increase in circulating TSH levels in the elderly, especially in the oldest old, it is important to carry an appropriate diagnostic path, comprehensive of clinical picture as well as laboratory and imaging techniques. In the current review, we summarize the recommendations for a correct diagnostic workup and therapeutic approach to older people with elevated TSH value, with special attention to the presence of frailty, comorbidities, and poly-therapy. The treatment of choice for hypothyroid patients is hormone replacement with LT₄ but, it is important to consider multiple factors before commencing the therapy, from the age dependent TSH increase to the presence of an actual thyroid disease and comorbidities. When treatment is necessary, a tailored therapy should be chosen, considering poly-pharmacy and frailty. A careful follow-up and treatment re-assessment should be always considered to avoid the risk of over-treatment. It is important to stress the need of educating the patient for a correct administration of LT₄, particularly when poly-therapy is in place, and the importance of a tailored therapeutic approach and follow-up, to avoid overtreatment.

Hypothyroidism in the Elderly: Who Should Be Treated and How?

Hypothyroidism is among the most frequent chronic diseases in the elderly, and levothyroxine (l-T4) is worldwide within the 10 drugs more prescribed in the general population. Hypothyroidism is defined by increased serum thyroid-stimulating hormone (TSH) values and reduced circulating free thyroid hormones, whereas subclinical hypothyroidism (sHT) is characterized by free hormone fractions within the normal ranges and has been divided into two classes, depending on circulating TSH levels (above or below 10 mIU/L). Given that during aging, a natural trend toward higher values of circulating TSH has been reported, it is necessary to verify carefully the diagnosis of sHT to tailor an appropriate follow-up and ad hoc therapy, avoiding unnecessary or excessive treatment. In the current review, we evaluate the state of the art on hypothyroidism in the elderly with special focus on the effect of sHT on cognition and the cardiovascular system function. We also summarize the recommendations for a correct diagnostic workup and therapeutic approach to older people with an elevated TSH value, with special attention to the presence of frailty, comorbidities, and poly therapy. In conclusion, personalized therapy is crucial in good clinical practice, and in the management of older patients with sHT, multiple factors must be considered, including age-dependent TSH cutoffs, thyroid autoimmunity, the burden of comorbidities, and the possible presence of frailty. l-T4 is the drug of choice for the treatment of hypothyroid older people, but the risk of overtreatment, potential adverse drug reactions, and patient compliance should always be considered and thyroid status periodically reassessed.

Degree of Peripheral Thyroxin Deiodination, Frailty, and Long-Term Survival in Hospitalized Older Patients

CONTEXT

Although the association between low free triiodothyronine (FT3) and poor outcome has been extensively reported in literature, the degree of peripheral thyroxin deiodination and its relationship with frailty and survival in hospitalized older patients has not yet been fully established. The aim of the current study was to evaluate the possible correlation between FT3/free thyroxine (FT4) ratio reduction, an indirect marker of thyroxin deiodination impairment, and frailty status and survival in hospitalized older patients.

METHODS

We consecutively enrolled older patients, hospitalized in the geriatrics ward of the University of Pisa. At admission, Multidimensional Geriatric Assessment (MGA) and Multi Prognostic Index (MPI), an indirect measure of frailty, were obtained from all the patients. Causes of hospitalization and prevalence of delirium were recorded. Blood samples for FT3, FT4, and thyrotropin value evaluation were drawn after an overnight fast.

RESULTS

A total of 643 patients (83.8 ± 7.4 years, 53% women) were studied. FT3 was inversely and strongly correlated, whereas FT4 was moderately positively correlated with MGA parameters, MPI score (P < 0.001 and P < 0.05, respectively), and survival (P < 0.001 and P = 0.09, respectively). FT3/FT4 ratio reduction was highly associated with worse MGA (P < 0.001) and MPI scores (P < 0.0001), even in patients without low FT3. The inclusion of FT3 in the final model of multivariate Cox regression confirmed the independent role of FT3/FT4 ratio in predicting survival (P = 0.005).

CONCLUSION

Overall, our study documented a strong association between FT3/FT4 ratio reduction, a surrogate marker of peripheral thyroxin deiodination, and frailty. Moreover, FT3/FT4 ratio value emerged as independent marker of survival, even in patients with normal FT3 values.

Thyroid Disrupting Chemicals

Endocrine disruptor compounds are exogenous agents able to interfere with a gland function, exerting their action across different functional passages, from the synthesis to the metabolism and binding to receptors of the hormone produced. Several issues, such as different levels and time of exposure and different action across different ages as well as gender, make the study of endocrine disruptors still a challenge. The thyroid is very sensitive to the action of disruptors, and considering the importance of a correct thyroid function for physical and cognitive functioning, addressing this topic should be considered a priority. In this review, we examined the most recent studies, many of them concentrating on maternal and child exposure, conducted to assess the impact of industrial chemicals which showed an influence on thyroid function. So far, the number of studies conducted on that topic is not sufficient to provide solid conclusions and lead to homogeneous guidelines. The lack of uniformity is certainly due to differences in areas and populations examined, the different conditions of exposures and the remarkable inter-subject variability. Nonetheless, the European Commission for Health and Food Safety is implementing recommendations to ensure that substances identified as endocrine disruptors will be withdrawn from the market.

Cognitive Function and the Ageing Process: The Peculiar Role of Mild Thyroid Failure

BACKGROUND

Over the last decades an increasing body of evidence suggested a possible relationship between thyroid hormone (TH) and the ageing process, and several efforts have been made to determine the actual role of TH dynamic during human life. It is still unclear whether the serum level shift of Thyroid Stimulating Hormone toward higher value, observed during ageing, is a normal adaptive response associated with senescence or an actual mild thyroid dysfunction. A growing body of evidence supports the hypothesis of a reset of the hypothalamus-pituitary-thyroid axis in order to contrast the catabolic status of the ageing process. On the other hand, several meta-analyses showed a direct link between subclinical hypothyroidism (sHT) and cardiovascular events (both ischemic heart disease and stroke), although mainly in individuals younger than 65 years. Similarly, a recent meta-analysis documented consistent data on a positive relationship between sHT and cognitive impairment, but only in individuals younger than 75 years.

CONCLUSION

The available data suggest a complex relationship between mild thyroid failure and the ageing process as well as the development and progression of several cardiovascular and neurological diseases. In this paper, we reviewed the scientific English literature on sHT and the ageing process focusing on experimental evidences related to cognitive impairment and dementia. Moreover, we focused on new patents of treatments potentially able to improve the care of sHT patients, especially in the elderly, where treatment drawbacks may have negative impact on the long term outcome.

Subclinical hypothyroidism and heart failure risk in older people

CONTEXT

Although the negative impact of subclinical hypothyroidism (sHT) in terms of cardiovascular risk in young adults is mostly acknowledged it remains to be established in the elderly, especially in the oldest old.

EVIDENCE ACQUISITION

We searched Medline for reports published with the following search words: hypothyroidism, sHT, ageing, elderly, L-thyroxin, thyroid, guidelines, treatment, quality of life, cardiovascular risk, heart failure (HF), ischemic heart disease (IHD), endothelial dysfunction. The search was restricted to reports published in English since 1980, but some reports published before 1980 were also incorporated. We supplemented the search with records from personal files and references of relevant articles and textbooks. Parameters analyzed included epidemiology of sHT and thyroid failure the effect of thyroid hormone on ageing process and cardiovascular function as well as the potential benefits of L-thyroxin therapy on quality of life, HF progression and events.

EVIDENCE SYNTHESIS

TSH levels increase with age, even in older patients without thyroid disease, in whom higher TSH value might favor longevity; better quality of life and lower IHD mortality in the oldest old population has been reported yet. However, at odds with the relationship between sHT and IHD risk and mortality, which shows a clear age dependent feature, vanishing in the last decades of life, the detrimental effect of sHT on HF progression and events remains evident also in older patients, although no data are available in the oldest old population.

CONCLUSIONS

The lack of specific randomized trials enrolling either old or very old subjects, aimed at evaluate the efficacy of hormonal replacement on overall survival and cardiovascular risk reduction along with the negative effects of possible over-treatment, makes the decision to treat older people a still unresolved clinical challenge. Moreover, the possibility that restoring euthyroidism may be harmful in the elderly should be always taken into account.

Cardiovascular risk and quality of life in elderly people with mild thyroid hormone deficiency

Subclinical hypothyroidism (sHT) is a common condition in the general population, the prevalence increases with age, especially in women. An association between sHT and increased coronary heart disease (CHD) and heart failure (HF) risk and mortality has been described. However, this association is far to be established in older people (>65 years), especially in the oldest old (>85 years). Individuals with sHT may experience symptoms that resemble those observed in the overt form of the disease, leading to an impaired quality of life (QoL). Although very old people are frequently frail and potentially more susceptible to the effects of a disease, few studies were designed to assess the effect of sHT on QoL in this subset of population. Interestingly, the serum TSH concentration curve of general population has a skewed distribution with a "tail" toward higher values, which is amplified with aging. Thus, the diagnosis of sHT and the interpretation of its potential effects on CV function and QoL in older people may be a challenge for the clinician. Giving these premises, we reviewed the English scientific literature available on National Library of Medicine (www.pubmed.com) since 1980 regarding hypothyroidism, sHT, elderly, cardiovascular risk, CHD or HF events and mortality, health-related QoL, and LT4 therapy. Consistent results among large prospective cohort studies suggest an age-independent relationship between sHT and HF progression, while an impact of sHT on CHD events and mortality is essentially reported in young adults (aged below 65-70 years) with long-lasting disease. Scanty data are available on QoL of older people with sHT (>65 years) and, generally, no significant alterations are described.

Is subclinical hypothyroidism a cardiovascular risk factor in the elderly?

CONTEXT

The negative impact of subclinical hypothyroidism (sHT) on cardiovascular risk, widely recognized in young adults (aged <55-60 y), is still debated in the elderly (>65 y), especially in the oldest olds (>80 y).

EVIDENCE ACQUISITION

We searched Medline for reports published with the following search terms: "hypothyroidism," "subclinical hypothyroidism," "ageing," "elderly," "L-thyroxin," "thyroid," "guidelines," "treatment," "quality of life," "cardiovascular risk," "heart failure," "coronary heart disease" (CHD), "atherosclerosis," and "endothelial dysfunction." We limited our search to reports in English published after 1980, although we incorporated some reports published before 1980. We supplemented the search with records from personal files, textbooks, and relevant articles. Analyzed parameters included the epidemiology of thyroid failure, the effect of thyroid hormone on the aging process, cardiovascular function, and CHD risk factors. We also included the potential benefits of L-T4 therapy on the quality of life, cardiovascular events, and survival.

EVIDENCE SYNTHESIS

TSH levels increase with age, even in older people without thyroid disease. Most longitudinal studies show an increased risk for CHD events and mortality in sHT participants. This increase is less evident in the elderly, mainly in cases of serum TSH values above 10 mIU/L. Lower mortality rate in a cohort of the oldest olds (>85 y) has been reported.

CONCLUSIONS

sHT in older people should be not regarded as a unique condition, and moderately old patients (aged <70-75 y) could be considered clinically similar to the adult population, albeit with a higher optimal TSH target value. Conversely, the oldest old subjects should be carefully followed with a wait-and-see strategy, generally avoiding hormonal treatment. The decision to treat elderly people is still an unresolved clinical challenge--first, due to a lack of appropriately powered randomized controlled trials of L-T4 in sHT patients, examining cardiovascular hard endpoints in various classes of age; and second, because of the negative effects of possible overtreatment.

Age and gender substantially influence the relationship between thyroid status and the lipoprotein profile: results from a large cross-sectional study

BACKGROUND

Conflicting data are reported on the association between mild thyroid failure and lipid profile, primarily regarding serum triglyceride values and patients with slightly elevated thyrotropin (TSH, <10 mIU/L). In this study, we assessed the possible influence of gender and age on this relationship.

METHODS

The study included 2308 consecutive patients who were seen for suspected or diagnosed thyroid disease (1874 women, 434 men, mean age 47.5±14.1 and 46.9±14.0 years, respectively) and on whom studies of thyroid status and lipoprotein profile were conducted after an overnight fast. Patients with uncontrolled diabetes mellitus and those taking lipid-lowering drugs were excluded.

RESULTS

There were 628 patients receiving L-thyroxine who had a diagnosis of hypothyroidism: 200 were hyperthyroid, and 120 were still hypothyroid. Overall, 648 patients were hypothyroid, and 290 were hyperthyroid. No gender difference in the frequency of TSH values in the ranges studied (i.e., TSH frequency distribution) was observed. Total cholesterol (TC) and low-density lipoprotein cholesterol (LDLc) values (p<0.0003 and p<0.003, respectively) as well as the LDL/high-density lipoprotein cholesterol (HDLc) ratio (p<0.03) were elevated not only in unselected women with TSH values in the 4th TSH group (>10 mIU/L) but also in those of the 3rd group (3.6-10.0 mIU/L) who were older than 50 years (TC and LDLc p=0.01, LDL/HDLc ratio p=0.02 vs. euthyroid women). Among unselected men, only those of the 4th TSH group had elevated triglyceride (p<0.0001) but not cholesterol values. However, men of the 3rd and 4th TSH group who were older than 65 years had significantly higher TC, LDLc, and LDL/HDLc values as well (p=0.03, p=0.02 and p=0.01, respectively vs. euthyroid men). In the final model of stepwise regression for predicting each lipid parameter variation on the basis of age, TSH, free thyroxine (FT4), and body mass index (BMI) analysis, age had the highest standardized coefficient (0.36 and 0.37, respectively), followed by TSH (0.20 and 0.11, respectively) and FT4 (-0.11 and -0.09, respectively) when looking at TC and LDLc; whereas BMI had the highest standardized coefficient (0.28), followed by age (0.15) and TSH (0.11) when looking at triglyceride variation.

CONCLUSIONS

This study confirms a gender differentiation in the relationship between hypothyroidism and the lipid profile, which is substantially influenced by age, especially in patients with mild thyroid impairment (TSH<10 mIU/L).

The effect of Ginkgo biloba extract on genotoxic damage in patients with differentiated thyroid carcinoma receiving thyroid remnant ablation with iodine-131

BACKGROUND

Radioiodine ((131)I) therapy is usually performed in patients with differentiated thyroid cancer (DTC). Although (131)I is generally considered safe, genotoxic damage has been demonstrated both in vivo and in vitro. The aim of the current study was to evaluate the effect of Ginkgo biloba extract (GBE) on the time-course of appearance, after (131)I therapy for DTC, of plasma factors with chromosome-damaging properties (so-called "clastogenic" factors [CFs]) and of micronuclei (MN) in lymphocytes.

METHODS

Twenty-three patients (median age 42 years, range 18-73) with DTC receiving (131)I activity (3.7 GBq) for thyroid remnant ablation were randomly assigned to receive GBE (120 mg/day for one month; n=10) or placebo (n=13) in a double-blind manner. Blood samples were taken at various intervals (from baseline to 90 days) after (131)I therapy. The frequency of MN in blood lymphocytes was determined, and CFs were assayed in plasma by a method that used MN increase in lymphocytes from an healthy donor as the endpoint of the assay.

RESULTS

MN in blood lymphocytes increased significantly after (131)I treatment in the placebo group, peaking at the 7th day (p=0.002) and slowly declining thereafter. In contrast, in similarly treated patients who were also treated with GBE both before and after (131)I treatment, a significant increase of blood lymphocyte MN level was not observed. In addition, only the placebo group showed a significant, progressive increase in CFs activity. This peaked at the 14th day (p=0.003 vs. baseline) and was still noted for the last plasma sample. The differences in the change in lymphocyte MN and CFs activity between the placebo and GBE-treated groups were significant (p<0.01 and p<0.05, respectively). Thyroid function tests, including serum thyroglobulin (Tg) and anti-Tg antibody levels, were never significantly different.

CONCLUSIONS

GBE may protect from possible oxidative and genotoxic damage associated with (131)I treatment in patients requiring (131)I therapy for thyroid cancer, without affecting the clinical outcome. Further studies with larger cohorts of patients are needed to confirm this report and verify the beneficial effect of GBE in patients requiring (131)I therapy, particularly for those in whom repeated treatments and high activities of (131)I are required.

Oxidative and genotoxic damage after radio‐iodine therapy of Graves' hyperthyroidism

PURPOSE

To evaluate genetic damage and oxidative stress following a single therapeutic dose of 131I in Graves' disease patients monitored up to 180 days after treatment.

MATERIALS AND METHODS

Genetic damage induction was estimated as the increase in micronuclei in peripheral lymphocytes of patients. As indicators of radiogenic oxidative stress, vitamin E and lipoperoxide levels were assessed in the plasma of patients, as well as the release of plasmic clastogenic factors measured by the induction of micronuclei in vitro in peripheral lymphocytes of a healthy donor.

RESULTS

Vitamin E depletion lasted at least 3 days and the basal level was restored within 7 days. No statistically significant variations were observed in lipoperoxide plasma levels. A sharp increase of micronuclei in the peripheral lymphocytes of patients was correlated (p < 0.001) with the release of clastogenic factor in the plasma. The highest micronucleus value was negatively correlated (p < 0.03) with the lowest vitamin E level observed in each patient.

CONCLUSIONS

Micronuclei induction was the direct consequence not only of the energy deposition of 131I on the genetic material, but also of oxidative stress, likely via the release of clastogenic factor.

1513A>C polymorphism in the P2X7 receptor gene in patients with papillary thyroid cancer: correlation with histological variants and clinical parameters

INTRODUCTION

The modulation of the purinergic receptor P2X7 may be implicated in human carcinogenesis. The 1513A>C and 489C>T polymorphisms of P2X7R gene induce loss of function and gain of function, respectively.

AIM

The aim of the study was to assess the frequency of both 1513A>C and 489C>T polymorphisms in patients with papillary thyroid carcinoma (PTC) and to evaluate the possible association with clinical and histological features.

PATIENTS AND METHODS

P2X7R analysis was performed in lymphocytes from 121 PTC patients (100 women, 21 men; aged 43.4 +/- 13.6 yr), 100 matched healthy subjects, and 80 patients with nodular goiter.

RESULTS

The minor allele frequency for 1513A>C polymorphism in PTC patients with the classical variant was similar to controls (0.21 and 0.20, respectively), whereas it resulted in a significant increase in patients with the follicular variant (0.36; P = 0.01 vs. classical variant, and P = 0.005 vs. controls). In detail, 13.6% of patients with PTC follicular variant were homozygous for the 1513C allele, compared to 2.6% of patients with the classical variant and 2% of controls. Moreover, a positive relationship between 1513A>C polymorphism and either cancer diameter (Rho = 0.22; P = 0.02) or TNM stage (Rho = 0.38; P < 0.001) was found. No significant difference in the genotype frequency of 489C>T polymorphism between PTC patients and healthy controls was observed (0.42 and 0.47, respectively).

CONCLUSIONS

Our data show, for the first time, a strong association between 1513A>C polymorphism of P2X7R gene and the follicular variant of PTC. Further studies are needed to confirm the possible role of this polymorphism as a novel clinical marker of PTC follicular variant and its usefulness in selecting patients with different clinical outcome.

Effect of type I interferon(s) on cell viability and apoptosis in primary human thyrocyte cultures

BACKGROUND

Interferon (IFN) therapy may induce a generalized activation of the immune system, hence triggering or exacerbating autoimmune disease. Apoptosis contributes to the development of hypothyroidism in autoimmune thyroiditis. IFN can affect all phases of the cell cycle and may induce apoptosis in several cell lines from varied histologies. To date, no data exist on the possible effect of type I IFN(s) on FAS/FASL system and cell apoptosis of human thyroid follicles. Therefore, we evaluated the effect of both IFN-alpha and -beta on apoptosis in primary human thyrocyte cultures and the potential role of the FAS/FASL pathway.

METHODS

Thyrocytes were cultured in monolayers and FAS, FASL, and Bcl-2 mRNA expression was determined by reverse transcriptase polymerase chain reaction after exposure to 10 mIU/mL bovine thyroid-stimulating hormone alone or in combination with increasing doses of IFN-alpha or -beta for 24, 48, and 72 hours. The percentage of apoptotic hypodiploid cells was evaluated by flow cytometry.

RESULTS

Thyroid-stimulating hormone significantly decreased FAS and increased Bcl-2 mRNA expression while reducing the percentage of hypodiploid cells. The concomitant addition of either IFN-alpha or -beta reduced cell viability and increased the number of hypodiloid cells, but only IFN-beta modulated the expression of FAS and Bcl-2 mRNA expression in a proapoptotic sense.

CONCLUSIONS

Both type I IFN(s) increase apoptosis in primary thyrocyte cultures, but only IFN-beta modulates FAS and Bcl-2 gene expression toward a proapoptotic pathway. Because apoptosis plays an important role in thyroid homeostasis and disease, this mechanism may contribute to the development and progression of type I IFN(s) therapy-associated thyroid disease.

Anticlastogenic effect of Ginkgo biloba extract in Graves' disease patients receiving radioiodine therapy

BACKGROUND

Chromosomal damage, as assessed by clastogenic factors (CFs) and micronuclei (MN) appearance, after radioiodine therapy of Graves' disease has been reported.

OBJECTIVE AND METHODS

Our objective was to evaluate the effect of Ginkgo biloba extract (EGb 761) supplementation on the time course (up to 120 d) of CFs and MN appearance in lymphocytes from patients with Graves' disease after iodine-131 ((131)I) therapy. Patients were randomly assigned to EGb 761 or placebo, in a blinded manner.

RESULTS

In the placebo group, MN increased early (P < 0.001) after (131)I, peaking at the 21st day (P = 0.0003) and declining thereafter. In EGb 761-treated patients, MN increased early (P < 0.05), while returning toward baseline value thereafter. Therefore, mean MN increment was significantly higher in the placebo group as compared with EGb 761-treated patients (P < 0.01). Moreover, an early (P < 0.0001) and sustained (up to 35 d; P < 0.001) MN increase induced by CFs was observed in the placebo group. Conversely, in EGb 761-treated patients, MN increase induced by CFs never reached the statistical significance; therefore, the mean of the MN increments was significantly lower than in placebo (P < 0.05). A significant positive correlation between MN maximum increment and the bone marrow dose was observed in the placebo group only (P = 0.03). No significant difference was observed in clinical outcome between the two groups.

CONCLUSIONS

EGb 761 supplementation neutralized genotoxic damage induced by radioiodine treatment, without affecting the clinical outcome. Although (131)I therapy is generally safe, our data suggest that Gingko biloba extracts may prevent genetic effects of radioiodine therapy for hyperthyroid Graves' disease.

Early abnormalities of left ventricular myocardial characteristics associated with subclinical hyperthyroidism

The aim of the present study was to analyze heart function in subclinical hyperthyroidism (sHT) in otherwise healthy subjects by new methods using intramyocardial ultrasonic techniques. Twenty-four newly diagnosed and untreated sHT patients (20 women, 4 men; mean age: 42+/-4 yr) and 24 sex- and age-matched healthy volunteers were studied. All subjects were submitted to conventional 2D color-Doppler echocardiography, pulsed wave tissue Doppler imaging (PWTDI) for the analysis of diastolic function, color Doppler myocardial imaging (CDMI) for the analysis of regional strain and strain rate (SR) expression of regional myocardial deformability, and to integrated backscatter (IBS) for the evaluation of intrinsic contractility and tissue characterization. Regional myocardial systolic strain findings were significantly higher in sHT patients when compared with controls (p<0.001). Considering diastolic SR, the early phase of diastolic SR was compromised in sHT subjects as compared with controls (p<0.001). Cyclic variation index (CVI), expression of intrinsic contractility, was significantly higher in sHT subjects in comparison with controls (p<0.0001). IBS values were comparable between the 2 study groups. In conclusion, the present study suggests that in patients with sHT early systolic hyperdeformability and hypercontractility are present, together with impairment of both active and passive phases of diastole. On the contrary, no left ventricular hypertrophy or other structural alterations are documented.

Low-grade systemic inflammation causes endothelial dysfunction in patients with Hashimoto's thyroiditis

OBJECTIVE

The objective of this study was to assess whether low-grade systemic inflammation might contribute to the pathogenesis of endothelial dysfunction in patients with subclinical hypothyroidism (sHT) and autoimmune thyroiditis.

BACKGROUND

sHT patients are characterized by peripheral endothelial dysfunction and low-grade inflammation.

METHODS

In 53 sHT and 45 healthy subjects, we studied the forearm blood flow (strain-gauge plethysmography) response to intrabrachial acetylcholine (Ach) (0.15-15 microg/min.dl) with and without local vascular COX inhibition by intrabrachial indomethacin (50 microg/min.dl) or nitric oxide synthase blockade by N-mono methyl arginine (L-NMMA) (100 microg/min.dl) or the antioxidant vitamin C (8 mg/min.dl). The protocol was repeated 2 h after systemic nonselective COX inhibition (100 mg indomethacin) or selective COX-2 blockade (200 mg celecoxib) oral administrations.

RESULTS

sHT patients showed higher C-reactive protein and IL-6 values. In controls, vasodilation to Ach was blunted by L-NMMA and unchanged by vitamin C. In contrast, in sHT, the response to Ach, reduced in comparison with controls, was resistant to L-NMMA and normalized by vitamin C. In these patients, systemic but not local indomethacin normalized vasodilation to Ach and the inhibition of L-NMMA on Ach. Similar results were obtained with celecoxib. When retested after indomethacin administration, vitamin C no longer succeeded in improving vasodilation to Ach in sHT patients. Response to sodium nitroprusside was unchanged by indomethacin or celecoxib.

CONCLUSIONS

In sHT patients, low-grade chronic inflammation causes endothelial dysfunction and impaired nitric oxide availability by a COX-2-dependent pathway leading to increased production of oxidative stress.

Recombinant human thyrotropin reduces endothelium-dependent vasodilation in patients monitored for differentiated thyroid carcinoma

AIM

We evaluated endothelial-dependent vasodilation after administration of recombinant human TSH (rhTSH) in patients monitored for differentiated thyroid carcinoma. The role of inflammation and oxidative stress was also assessed.

PROTOCOL

Twenty-four patients (21 women, mean age 40.5 +/- 9.2 yr) received rhTSH (0.9 mg daily) on 2 consecutive days. At baseline and the day after the second rhTSH injection, endothelium-dependent vasodilation as flow-mediated dilation (FMD, induced by 5 min of forearm ischemia) and endothelium-independent vasodilation (glyceril trinitrate 25 microg, sublingual) were evaluated by high-resolution ultrasound in the brachial artery. At each experimental time, blood was drawn for the evaluation of thyroglobulin, TSH, free T(3), free T(4), as well as IL-6, C reactive protein, TNFalpha, lipoperoxides, and ferric reducing antioxidant power levels as markers of inflammation and oxidative stress.

RESULTS

At baseline, patients' serum TSH values were below the normal range [0.12 mIU/liter (range 0.01-0.30)] in the face of normal free T(4) and free T(3) levels; FMD (8.9 +/- 3.4 vs. 9.2 +/- 3.1%, respectively) and response to glyceril trinitrate (11.0 +/- 4.3 vs. 10.8 +/- 4.7%, respectively) were similar in patients and controls. All the patients had serum thyroglobulin value less than 1 ng/ml, suggesting the absence of cancer recurrences. Besides the expected elevation of serum TSH, rhTSH induced a significant impairment of FMD (7.4 +/- 3.0 vs. 8.9 +/- 3.4%; P < 0.01) along with a significant elevation of blood IL-6 (P = 0.01), TNFalpha (P < 0.001), and lipoperoxide levels (P = 0.01), as well as a reduction of ferric reducing antioxidant power (P = 0.01).

CONCLUSIONS

rhTSH administration acutely impaired endothelium-dependent vasodilation, possibly through the induction of low-grade inflammation and reduced nitric oxide availability by oxidative stress.

Early textural and functional alterations of left ventricular myocardium in mild hypothyroidism

The aim of the present study was to evaluate cardiac function and texture in patients with subclinical hypothyroidism (sHT) both by conventional and new ultrasonic intramyocardial tissue techniques. sHT was characterized by normal serum free tetraiodotironine and free triiodotironine levels and slightly increased serum TSH level. Twenty-four patients affected by sHT and 24 sex- and age-matched healthy volunteers were studied. All subjects were submitted to conventional two-dimensional (2D)-color Doppler echocardiography, pulsed wave tissue Doppler imaging (PWTDI) for the analysis of the diastolic function, color Doppler myocardial imaging (CDMI) for the analysis of regional strain and strain-rate and integrated backscatter (IBS) for the evaluation of intrinsic contractility and tissue characterization. The results of the present study were: (a) the detection in sHT subjects of a lower cyclic variation index (CVI) indicating an altered myocardial intrinsic contractility; (b) a higher ultrasonic myocardial reflectivity indicating an altered myocardial texture; (c) the detection of lower systolic strain and strain-rate indicating an alteration of myocardial regional deformability; (d) an initial impairment of left ventricular diastolic function indicated by a decrease of peak E mitral flow velocity and an increase of peak A mitral flow velocity. All parameters studied with conventional 2D-echo in sHT patients were comparable with controls, except for a mild alteration in diastolic function. A significant correlation among systo-diastolic modifications detected by CDMI and IBS and serum TSH levels were found. The CVI at septum, the PWDTI S-peak wave and the systolic strain at septum were inversely related to the serum TSH levels. In conclusion, the new intramyocardial ultrasonic techniques confirm and extend the previous knowledge on the effect of the sHT on the heart, allowing the detection of early ultrastructural and regional functional systolic and diastolic abnormalities.

A study of the possibility of curing Graves?? disease based on the desired reduction of thyroid mass (volume) as a consequence of 131I therapy: a speculative paper

PURPOSE

The possibility of predicting the final volume of Graves' disease thyroids submitted to 131I therapy could allow the physician to decide what activity to administer based on the desired volume reduction instead of on a fixed value of the thyroid radiation absorbed dose. In this paper the relationship between maximum uptake of 131I, fractional reduction of thyroid volume and outcome of Graves' disease is discussed.

METHODS

The results are based on ultrasonography thyroid volume measurements before administration of therapy and at the moment of recovery from Graves' disease (thyroid stimulating hormone >0.3 microIU x ml(-1) in the absence of anti-thyroid drug therapy) and on measurements of 131I uptake in 40 patients. It is shown that the possibility of curing Graves' disease may be individually related to the final volume of the patient's thyroid. An equation is presented to calculate the 'optimal' final thyroid volume.

RESULTS

A comparison between the traditional method, based on absorbed dose, and the final method, based on volume, has been carried out retrospectively. In the first case a median activity of 529 MBq has been administered; in the second, a median activity of 394 MBq (non-parametric Wilcoxon test, P<0.05) should be administered. The corresponding thyroid median absorbed doses are, respectively, 353 Gy and 320 Gy (non-parametric Wilcoxon test, P<0.02).

CONCLUSION

A method to evaluate individually the 'optimal' final thyroid mass is presented and discussed. The method based on 'volume reduction' could probably reduce the activity and the thyroid absorbed dose compared to the method based on 'empirical' calculations, thus allowing the administration of 131I therapy to be optimized.

Does Treating Subclinical Hypothyroidism Improve Markers of Cardiovascular Risk?

Subclinical hypothyroidism is defined as an elevated serum thyroid-stimulating hormone (TSH) level in the face of normal free thyroid hormone values. The overall prevalence of subclinical hypothyroidism is 4-10% in the general population and up to 20% in women aged >60 years. The potential benefits and risks of therapy for subclinical hypothyroidism have been debated for 2 decades, and a consensus is still lacking. Besides avoiding the progression to overt hypothyroidism, the decision to treat patients with subclinical hypothyroidism relies mainly on the risk of metabolic and cardiovascular alterations. Subclinical hypothyroidism causes changes in cardiovascular function similar to, but less marked than, those occurring in patients with overt hypothyroidism. Diastolic dysfunction both at rest and upon effort is the most consistent cardiac abnormality in patients with subclinical hypothyroidism, and also in those with slightly elevated TSH levels (>6 mIU/L). Moreover, mild thyroid failure may increase diastolic blood pressure as a result of increased systemic vascular resistance. Restoration of euthyroidism by levothyroxine replacement is generally able to improve all these abnormalities. Early clinical and autopsy studies had suggested an association between subclinical hypothyroidism and coronary heart disease, which has been subsequently confirmed by some, but not all, large cross-sectional and prospective studies. Altered coagulation parameters, elevated lipoprotein (a) levels, and low-grade chronic inflammation are regarded to coalesce with the hypercholesterolemia of untreated patients with subclinical hypothyroidism to enhance the ischemic cardiovascular risk. Although a consensus is still lacking, the strongest evidence for a beneficial effect of levothyroxine replacement on markers of cardiovascular risk is the substantial demonstration that restoration of euthyroidism can lower both total and low-density lipoprotein-cholesterol levels in most patients with subclinical hypothyroidism. However, the actual effectiveness of thyroid hormone substitution in reducing the risk of cardiovascular events remains to be elucidated. In conclusion, the multiplicity and the possible reversibility of subclinical hypothyroidism-associated cardiovascular abnormalities suggest that the decision to treat a patient should depend on the presence of risk factors, rather than on a TSH threshold. On the other hand, levothyroxine replacement therapy can always be discontinued if there is no apparent benefit. Levothyroxine replacement therapy is usually safe providing that excessive administration is avoided by monitoring serum TSH levels. However, the possibility that restoring euthyroidism may be harmful in the oldest of the elderly population of hypothyroid patients has been recently raised, and should be taken into account in making the decision to treat patients with subclinical hypothyroidism who are aged >85 years.

Extracellular adenosine 5'-triphosphate modulates interleukin-6 production by human thyrocytes through functional purinergic P2 receptors

We investigated the presence of P2 receptors (P2Rs) in human thyrocytes and their possible involvement in the modulation of cytokine release. P2Rs expression was assessed by RT-PCR and, when possible, by immunoblotting. Human primary thyrocytes express the mRNA for the following P2X and P2Y subtypes: P2X(3), P2X(5), P2X(6), P2X(7), and P2Y(1), P2Y(2), P2Y(4), and P2Y(11). Stimulation with extracellular nucleotides of fura-2-loaded thyrocytes triggered an intracellular Ca(2+) signal, suggesting expression of functional receptors. Thyrocytes spontaneously released the proinflammatory cytokine IL-6. The ATP-hydrolyzing enzyme apyrase reduced basal IL-6 release, whereas extracellular ATP dose-dependently increased IL-6 secretion. Uridine 5'-triphosphate was also an effective stimulus, whereas benzoyl-ATP was ineffective, suggesting a P2Y- rather than P2X-modulated response. Finally, TSH reduced both the intracellular Ca(2+) ([Ca(2+)](i)) rise and IL-6 release triggered by P2Rs stimulation. In conclusion, we provide functional, pharmacological, and biochemical evidence that human primary thyrocytes express P2YR and P2XR subtypes, coupled to increases in ([Ca(2+)](i)) and secretion of IL-6. P2R-dependent modulation of IL-6 release from human thyrocytes suggests a novel mechanism whereby an inflammatory and/or immune-mediated damage can be initiated and amplified in the thyroid.

Muscle metabolism and exercise tolerance in subclinical hypothyroidism: a controlled trial of levothyroxine

BACKGROUND

Neuromuscular symptoms and impaired muscle energy metabolism have been described in subclinical hypothyroidism (sHT).

AIM

The aim of the study was to evaluate the energy and substrate response to exercise in sHT patients using a standardized protocol and to test the effect of L-T(4) replacement in a double-blind, randomized, placebo-controlled fashion.

PATIENTS AND METHODS

We studied 23 sHT patients and 10 matched euthyroid controls. Oxygen uptake (VO(2)), carbon dioxide output, and heart rate were measured during incremental step-up exercise. Blood glucose, lactate, pyruvate, free fatty acid, glycerol, and beta-hydroxybutyrate concentrations were measured at rest, every 2 min during exercise, and during 20 min of recovery. The exercise protocol was repeated after 6 months of placebo or L-T(4)-restored euthyroidism.

RESULTS

Maximal power output (P = 0.02) and VO(2) max (P = 0.04) were reduced in sHT, and, with increasing workload, patients achieved higher heart rates (P < 0.03) at VO(2) values equivalent to those of controls. The respiratory quotient increments were significantly higher in patients than controls (P < 0.04). Blood lactate and pyruvate and their ratio rose with a steeper slope (P < 0.0001, P < 0.001, and P < 0.01, respectively) in patients than controls. Resting plasma free fatty acid and blood glycerol levels were significantly higher in patients than controls (P < 0.0003 and P < 0.003, respectively) throughout baseline, exercise, and recovery. L-T(4) replacement, while improving neuromuscular symptoms, did not produce significant changes in the energy or substrate response to exercise.

CONCLUSIONS

The response to exercise is altered both in terms of tolerance and pattern of substrate utilization in sHT patients. Restoring stable euthyroidism does not correct this defect over a 1-yr period.

Long-term follow-up of 106 multiple sclerosis patients undergoing interferon-beta 1a or 1b therapy: predictive factors of thyroid disease development and duration

BACKGROUND

Conflicting data have been reported on the association between interferon (IFN)-beta therapy of multiple sclerosis (MS) patients and thyroid disease development.

AIMS

The goals of this study are as follows: to assess the actual occurrence of thyroid dysfunction and autoimmunity during long-term IFN-beta therapy; to establish the possible presence of predictive factors for thyroid dysfunction development and duration; and to suggest an effective follow-up protocol for patients receiving long-term IFN-beta therapy.

STUDY PROTOCOL

A total of 106 MS patients (76 women) underwent IFN-beta 1a or 1b therapy for up to 84 months (median, 42 months). Thyroid function and autoimmunity were assessed at baseline and every 3-6 months throughout the treatment course.

RESULTS

Baseline thyroid autoimmunity was detected in 8.5% of patients and hypothyroidism in 2.8%. Thyroid dysfunction (80% hypothyroidism, 92% subclinical, 56% transient) developed in 24% (68% with autoimmunity) of patients and autoimmunity in 22.7% (45.5% with dysfunction), without significant differences between the two cytokines; 68% of dysfunctions occurred within the first year. Autoimmunity emerged as the only predictive factor for dysfunction development (relative risk, 8.9), whereas sustained disease was significantly associated with male gender (P < 0.003).

CONCLUSIONS

Both incident thyroid autoimmunity and dysfunction frequently occur in MS patients during IFN-beta therapy, particularly within the first year of treatment. Thyroid dysfunction is generally subclinical and transient in over than half of cases; preexisting or incident autoimmunity emerged as the only significant predictive factor for thyroid dysfunction development. Thyroid function and autoimmunity assessment is mandatory within the first year of IFN-beta therapy; thereafter, serum TSH measurement only in patients with thyroid disease could be sufficient.

A predictive mathematical model for the calculation of the final mass of Graves' disease thyroids treated with 131I

Substantial reductions in thyroid volume (up to 70-80%) after radioiodine therapy of Graves' hyperthyroidism are common and have been reported in the literature. A relationship between thyroid volume reduction and outcome of 131I therapy of Graves' disease has been reported by some authors. This important result could be used to decide individually the optimal radioiodine activity A0 (MBq) to administer to the patient, but a predictive model relating the change in gland volume to A0 is required. Recently, a mathematical model of thyroid mass reduction during the clearance phase (30-35 days) after 131I administration to patients with Graves' disease has been published and used as the basis for prescribing the therapeutic thyroid absorbed dose. It is well known that the thyroid volume reduction goes on until 1 year after therapy. In this paper, a mathematical model to predict the final mass of Graves' diseased thyroids submitted to 131I therapy is presented. This model represents a tentative explanation of what occurs macroscopically after the end of the clearance phase of radioiodine in the gland (the so-called second-order effects). It is shown that the final thyroid mass depends on its basal mass, on the radiation dose absorbed by the gland and on a constant value alpha typical of thyroid tissue. Alpha has been evaluated based on a set of measurements made in 15 reference patients affected by Graves' disease and submitted to 131I therapy. A predictive equation for the calculation of the final mass of thyroid is presented. It is based on macroscopic parameters measurable after a diagnostic 131I capsule administration (0.37-1.85 MBq), before giving the therapy. The final mass calculated using this equation is compared to the final mass of thyroid measured 1 year after therapy administration in 22 Graves' diseased patients. The final masses calculated and measured 1 year after therapy are in fairly good agreement (R = 0.81). The possibility, for the physician, to decide a therapeutic activity based on the desired decrease of thyroid mass instead of on a fixed thyroid absorbed dose could be a new opportunity to cure Graves' disease.

Type I interferons modulate the expression of thyroid peroxidase, sodium/iodide symporter, and thyroglobulin genes in primary human thyrocyte cultures

We evaluated in primary human thyrocyte cultures the effect of interferon (IFN)-alpha and -beta on the expression of thyroid peroxidase (TPO), sodium/iodide symporter (NIS), and thyroglobulin (Tg) as well as T(4) release. Human thyrocyte cultures were carried out with fresh normal thyroid tissue. Gene and protein expression of Tg, TPO, and NIS were assessed by RT-PCR and Western blot analysis after 24, 48, and 72 h of treatment with TSH alone (10 mIU/ml) and in combination with IFN alpha or -beta (10(4) U/ml). IFN inhibited the TSH-stimulated gene expression of Tg, TPO, and NIS in a time-dependent manner without significant differences between IFN alpha and -beta. Moreover, the addition of both type I IFNs clearly reduced the TSH-stimulated protein expression of Tg, TPO, and NIS after 72 h of exposure. Finally, this down-regulation was associated with a reduction of T(4) release by almost 50%. In conclusion, our study shows that both IFN alpha and -beta down-regulate the TSH-stimulated expression of Tg, TPO, and NIS as well as T(4) release. Indeed, the development of hypothyroidism during type I IFN therapy may be related, at least in part, to an abnormal expression and function of key proteins involved in iodine uptake and organification.

Effect of levothyroxine replacement on lipid profile and intima-media thickness in subclinical hypothyroidism: a double-blind, placebo- controlled study

Subclinical hypothyroidism (sHT) is associated with dyslipidemia and enhanced cardiovascular risk. We assessed carotid artery intima-media thickness (IMT, high-resolution ultrasonography) and lipoprotein profile in 45 sHT patients (aged 37 +/- 11 yr) at baseline and after 6 months of randomized, placebo-controlled L-T(4) replacement. In comparison with 32 age- and sex-matched controls, sHT patients had elevated total and low-density lipoprotein (LDL) cholesterol and ApoB levels (P = 0.002, P = 0.0007, and P = 0.01, respectively) and higher mean-IMT values (P < 0.0001). In stepwise regression analysis, mean-IMT was positively related (r(2) = 0.71, P < 0.0001) to age, TSH, and LDL cholesterol. L-T(4) replacement significantly reduced both total and LDL cholesterol (P < 0.0001 for both) and mean-IMT (by 11%, P < 0.0001). The decrement in IMT was directly related to the decrements of both total cholesterol and TSH (P = 0.02 and P = 0.0001, respectively). We conclude that early carotid artery wall alterations are present in sHT patients. Whether such IMT increase is related to an early atherosclerotic involvement of the arterial wall cannot be clearly decided on the basis of the present results. However, the fact that L-T(4) replacement therapy was able to improve both the atherogenic lipoprotein profile and intima-media thickening suggests that lipid infiltration of arterial wall may represent a major mechanism underlying IMT increase in subclinical hypothyroidism.

Thyroid autoimmunity and dysfunction associated with type I interferon therapy

Type I interferons are currently used for the treatment of chronic viral hepatitis, multiple sclerosis and several hematological and solid tumors. Side effects are not uncommon, and include multiple alterations in thyroid function, some of which are unrelated to autoimmunity. Review of the literature revealed an overall mean prevalence of incident thyroid dysfunction of 6.2%, hypothyroidism occurring more frequently (3.9%) than hyperthyroidism (2.3%). Destructive thyroiditis characterized by early transient thyrotoxicosis followed by hypothyroidism has also been described. Thyroid dysfunction was mainly subclinical, and spontaneous resolution occurred in almost 60% of patients with or without withdrawal of interferon. Risk factors for developing thyroid abnormalities were female sex and the presence of pre-existing autoimmune thyroiditis. Whether prolonged interferon therapy will increase the likelihood of experiencing thyroid dysfunction, as well as the relationship between incident thyroid autoimmunity and the efficacy of interferon therapy, are still open questions. Although the most-likely explanation for thyroid disease occurring with type I interferon therapy remains an autoimmune reaction or immune system dysregulation, a direct inhibitory effect on thyrocytes may be presumed in patients who developed hypothyroidism without autoimmunity. However, the mechanisms of thyroid damage induced by type I interferons have not yet been clarified in detail. We recommend routine evaluation of serum thyroid-stimulating hormone during interferon therapy. A systematic thyroid assessment is useful only for those patients with pre-existing thyroiditis or incident dysfunction. Although discontinuation of interferon therapy is seldom required, it may be necessary in patients who develop Graves' disease and overt hyperthyroidism.

Laparoscopic treatment of pancreatic insulinoma

Laparoscopy and laparoscopic ultrasonography (LUS) have been proposed for the diagnosis and treatment of pancreatic insulinoma. We present for cases of pancreatic insulinoma approached by laparoscopy guided by LUS. In three cases, insulinomas were in the pancreatic body and in one case in the pancreatic head. All lesions were detected preoperatively by abdominal US and confirmed by computed tomography. Laparoscopy was performed under general anesthesia. LUS was performed using a 10-mm flexible probe. In two cases the adenoma was enucleated using scissors and electrocoagulation, major vessels were controlled using clips, and enucleation was completed using a 30-mm endo-GIA. In one case a laparoscopic distal pancreatectomy with spleen preservation was performed. In one case the adenoma was deep in the pancreatic head; minilaparotomy was performed and the adenoma enucleated. Patients were discharged in good health 5-7 days after surgery. The postoperative course was complicated in one case of enucleation by peripancreatic fluid collection that was treated percutaneously. Our experience confirms that accurate localization followed by excision of tumors via the laparoscopic approach constitute a significant advance in the management of insulinoma.

Impaired endothelium-dependent vasodilatation in subclinical hypothyroidism: beneficial effect of levothyroxine therapy

Subclinical hypothyroidism (sHT) is associated with enhanced cardiovascular risk. To test the hypothesis that patients with sHT are characterized by endothelial dysfunction and impaired nitric oxide (NO) availability, in 14 patients [serum cholesterol, 218 +/- 41 mg/dl (5.6 +/- 0.9 mM)] and 28 euthyroid subjects, subdivided into groups A and B [serum cholesterol, 170 +/- 19 mg/dl (4.4 +/- 0.5 mM) and 217 +/- 21 mg/dl (5.6 +/- 0.5 mM), respectively], we studied the forearm blood flow (strain-gauge plethysmography) response to intrabrachial acetylcholine, an endothelium-dependent vasodilator, at baseline and during infusion of N(G)-monomethyl-L-arginine (L-NMMA), a NO synthase inhibitor. Response to sodium nitroprusside and minimal forearm vascular resistances were also evaluated. In sHT patients, vasodilation to acetylcholine was reduced, compared with group B (+358 +/- 29% vs. +503 +/- 19%, P = 0.0003) and group A (663 +/- 65%, P = 0.02 vs. group B and P = 0.0002 vs. sHT). L-NMMA blunted the vasodilation to acetylcholine in groups A and B (49.1 +/- 6.3% and 42.7 +/- 5.5% maximal forearm blood flow reduction, respectively, P < 0.0001 vs. acetylcholine), whereas it was ineffective in sHT patients (12.8 +/- 2.5%). Response to sodium nitroprusside and minimal vascular resistances were similar. In sHT (n = 9) patients, 6 months of euthyroidism by levothyroxine replacement increased acetylcholine-vasodilation and restored L-NMMA inhibition. Patients with sHT are characterized by endothelial dysfunction resulting from a reduction in NO availability, an alteration partially independent of dyslipidemia and reversed by levothyroxine supplementation.

Prevalence of cancer in follicular thyroid nodules: is there still a role for intraoperative frozen section analysis?

The optimal surgical management of follicular thyroid nodules and the effectiveness of frozen section (FS) analysis in planning the operation are still controversial. In this study, we reviewed the prevalence of cancer in 309 consecutive patients (230 females, 79 males, aged 42 +/- 13 years) with follicular nodules at fine-needle aspiration cytology (FNAC) and the efficacy of FS evaluation in selecting cancers. On the whole, the prevalence of cancer was 20.1%; the occurrence of follicular variants of papillary cancer (14.9%) was threefold higher than follicular cancers (5.2%). The presence of atypical features at FNAC selected nodules with a significantly higher prevalence of cancer (46.7%, p = 0.01). FS analysis was performed in 142 patients and recognized only 8 of 27 (30%) cancers, one fourth of them with atypia at FNAC. In conclusion, this study confirms a 20% overall prevalence of malignancy in patients with follicular thyroid nodules. The association of cell atypia with a follicular pattern may define a subgroup of nodules more likely to be malignant. FS was seldom effective in recognizing cancer confirming the doubt on its cost effectiveness in planning the surgical approach. Protocols aimed at a better cytologic identification of follicular variants of papillary cancer should be considered.

Discordant effect of IFN-beta1a therapy on anti-IFN antibodies and thyroid disease development in patients with multiple sclerosis

Interferon-beta1b (IFN-beta1b) therapy is associated with a relatively high risk of developing thyroid disease. IFN-beta1a is regarded as less immunogenic than IFN-beta1b because of its structural homology to natural IFN-beta. We assessed the effect of 1 year of IFN-beta1a treatment on thyroid function and autoimmunity in 14 multiple sclerosis (MS) patients. The results were compared with those obtained in a series of 31 MS patients treated with IFN-beta1b. The prevalence of positive binding antibody (BAb) titer and neutralizing (NAb) anti-IFN antibody titer in the two groups was also assessed. The BAb and NAb positivity rate in IFN-beta1a-treated patients was significantly lower than in the group submitted to IFN-beta1b therapy (7% vs. 84% and 0% vs. 30%, respectively). Although the incidence of thyroid dysfunction was slightly higher in IFN-beta1b-treated patients than in those undergoing IFN-beta1a treatment (33% vs. 23%, respectively), it did not reach statistical significance. Thyroid disease was unrelated to the presence of positive serum BAb or NAb titer in both the group undergoing IFN-beta1a therapy and in that treated with IFN-beta1b. In both groups, thyroid disease developed mostly in women (71%) against a background of preexisting thyroiditis and a diffuse hypoechoic ultrasound thyroid pattern (80%). IFN-beta1a treatment was associated with a significantly lower prevalence of both BAb and NAb-positive titers than was IFN-beta1b. Conversely, thyroid disease was similar and unrelated to the presence of positive anti-IFN-beta antibody titer. Therefore, routine thyroid assessment may be advised during IFN-beta1a treatment, especially in patients with preexisting thyroiditis.

Human mitochondrial transcription factor A reduction and mitochondrial dysfunction in Hashimoto's hypothyroid myopathy

BACKGROUND

Mitochondrial changes have been described in muscle tissue in acquired hypothyroidism. Among the molecular mechanisms by which thyroid hormones regulate expression of nuclear genes encoding for regulatory proteins of mitochondrial respiratory function, the mitochondrial transcription factor A (h-mtTFA) has been proposed to be a target of thyroid hormone action. The aim of this study has been to relate h-mtTFA levels in the skeletal muscle of patients affected by Hashimoto's hypothyroidism and myopathy (HHM) to muscle disease and thyroid status.

PATIENTS AND METHODS

Eleven HHM patients underwent complete thyroid status and neurologic assessment, along with determination of exercise lactate anaerobic threshold (LT) and muscle biopsy in which h-mtTFA levels were measured and mtDNA was analyzed.

RESULTS

Decreased exercise lactate threshold, presence of cytochrome c oxidase negative fibers, reduction of cytochrome c oxidase activity, and mitochondrial DNA copy number at muscle biopsy were indicative of mitochondrial involvement in these patients. Furthermore, muscle h-mtTFA levels were reduced to a variable extent in comparison with a group of euthyroid controls. The h-mtTFA levels were inversely correlated with TSH and LT lactate, and positively correlated with FT4.

CONCLUSIONS

These results indicate that low levels of the h-mtTFA occur in skeletal muscle of HHM and suggest that abnormal h-mtTFA turnover may be implicated in the pathogenesis of mitochondrial alterations in this disease.

Lipoprotein profile in subclinical hypothyroidism: response to levothyroxine replacement, a randomized placebo-controlled study

The relationship between subclinical hypothyroidism (SCH) and an atherogenic lipoprotein profile is still controversial. We measured lipoproteins in 49 SCH patients by comparison with 33 euthyroid controls. Total cholesterol (TC), triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol (LDLc), apolipoprotein A(1), apolipoprotein B, and lipoprotein (a) [Lp(a)] were measured after an overnight fast. Patients were randomly assigned to levothyroxine therapy or placebo and re-evaluated after 6 months of euthyroidism. SCH patients showed significantly higher TC (P < 0.01), LDLc (P = 0.01), and apolipoprotein B (P = 0.001) levels than controls, positively correlated with baseline TSH levels (P = 0.003, P = 0.01, and P = 0.03, respectively). Elevated Lp(a) levels were significantly more frequent in SCH (P < 0.05) and associated with familial diabetes mellitus and/or coronary heart disease (P < 0.01). Levothyroxine treatment resulted in a significant decrease of both TC and LDLc concentrations (P = 0.003), in direct proportion to the respective baseline values (P < 0.05 and P < 0.01, respectively), whereas no change in Lp(a) level was observed. No changes occurred in the placebo group. In conclusion, only serum LDLc levels are increased specifically and reversibly in association with SCH. Altered Lp(a) values reflect a genetic influence rather than a reduced thyroid hormone action.

Effect of levothyroxine on cardiac function and structure in subclinical hypothyroidism: a double blind, placebo-controlled study

Subclinical hypothyroidism (sHT) affects 5-15% of the general population; however, the need of lifelong L-T(4) therapy is still controversial. As myocardium is a main target of thyroid hormone action, we investigated whether sHT induces cardiovascular alterations. Twenty sHT patients were randomly assigned to receive placebo or L-T(4) therapy and were followed for 1 yr. Twenty sex- and age-matched normal subjects served as controls. Doppler echocardiography and videodensitometric analysis were performed in all subjects. Myocardium textural parameters were obtained as mean gray levels, which were then used to calculate the cyclic variation index (CVI; percent systolic/diastolic change in mean gray levels). Patients had a significantly higher isovolumic relaxation time (3.1 +/- 0.5 vs. 2.6 +/- 0.6; P < 0.03), peak A (0.77 +/- 0.16 vs. 0.56 +/- 0.13 m/s; P < 0.01), and preejection/ejection time (PEP/ET) ratio (0.72 +/- 0.05 vs. 0.57 +/- 0.06; P < 0.03) and a lower CVI (P < 0.0001) than controls. CVI was inversely related to TSH level (P < 0.0001) and PEP/ET ratio (P < 0.01). L-T(4)-treated patients showed a significant reduction of the PEP/ET ratio (P < 0.05), peak A (P < 0.05), and isovolumic relaxation time (P < 0.05) along with a normalization of CVI. Conversely, no changes were observed in the placebo-treated group. In conclusion, sHT affects both myocardial structure and contractility. These alterations may be reversed by L-T(4) therapy.

Surgical and pathological changes after percutaneous ethanol injection therapy of thyroid nodules

Few data exist on the operative and pathological findings in patients having undergone previous percutaneous ethanol injection (PEI) therapy of thyroid nodules. We report here our experience with 13 patients operated on by the same surgical team. Two pathologists, both blinded to the previous PEI treatment, carried out histological evaluation. Reasons for surgery included PEI failure, suspicion of malignancy, and tracheal compression. The operations did not pose any special problem from the technical point of view, and the postoperative courses were uneventful. One patient who had a second operation developed hypoparathyroidism, and laryngeal nerve palsy was never observed. The histological diagnosis was hyperplastic or adenomatous nodule in 12 cases and papillary thyroid cancer in 1. No difficulty was found in evaluating the nodule capsule and surrounding vessels. In two lesions, nuclear enlargement and clearing were identified in thyroid follicles immediately adjacent to necrotic or scarred areas. These changes were considered reactive. In conclusion, patients previously treated by PEI were operated on without special technical problems. Histological diagnosis was not hindered, and there was no difficulty in ruling out malignant lesions. PEI, however, should be performed only by skilled operators, and incidental ethanol seepage throughout the nodule capsule must be carefully avoided.

Ultrasonic myocardial textural analysis in subclinical hypothyroidism

BACKGROUND

In subclinical hypothyroidism (sHT), a condition in which impaired hormone synthesis is compensated by thyroid-stimulating hormone (TSH) hypersecretion, previous studies have suggested the presence of disturbances in left ventricular (LV) function.

OBJECTIVES

Our goal was to investigate LV structure and function through the combined use of conventional Doppler echocardiography and ultrasonic videodensitometry.

METHODS

We studied 16 patients with sHT (aged 32+/-12 [mean +/- SD] years) who had raised TSH levels (> 3.6 mIU/L) but normal levels of free thyroid hormones (free thyroxine [FT(4)] and free triiodothyro-nine [FT(3)]), and 16 carefully age- and sex-matched euthyroid subjects. Transmitral flow Doppler analysis and quantitative analysis of the echocardiographic digitized images were performed in all study subjects. Textural parameters of the septum and posterior wall were obtained as mean gray levels, which were then used to calculate the cyclic variation index (CVI), that is, the percent change in mean gray levels between diastole and systole.

RESULTS

Patients with sHT had a significantly higher LV mass index (92 +/- 16 versus 76 +/- 16 g.m(2), P<.01) and isovolumic relaxation time corrected for heart rate (IVRTc) (2.9 +/- 0.6 versus 2.5 +/- 0.6, P<.04) than did controls. On videodensitometry, patients had lower CVIs both for the septum (-5% +/- 22% versus 33% +/- 9%, P<.0001) and the posterior wall (10% +/- 26% versus 49% +/- 18%, P<.0001). IVRTc discriminated only 25% of the patients from the controls, whereas CVI analysis correctly identified 85% of the patients with sHT (P<.002). Furthermore, CVI values were found to be significantly related to serum FT(4) and FT(3) concentrations in a direct fashion, and to serum TSH levels in an inverse fashion.

CONCLUSIONS

Subclinical hypothyroidism is associated with changes in videodensitometric myocardial structure. These changes, which are not accurately detected by conventional or Doppler echocardiography, are quantitatively related to loss of thyroid function and could represent an early sign of myocardial damage in hypothyroidism.

Long-term interferon beta-1b therapy for MS: is routine thyroid assessment always useful?

BACKGROUND

The authors previously reported on the development of thyroid dysfunction and autoimmunity during 1-year treatment of patients with MS with interferon-beta 1b (IFN beta-1b).

OBJECTIVE

To evaluate the evolution of incident thyroid disease and the possible development of more thyroid disease during longer term therapy.

PATIENTS

The authors studied 31 patients (aged 34 +/- 7 years; 21 women) with relapsing-remitting MS during 3 years of IFN beta-1b treatment. Systematic thyroid assessment was performed every 3 or 6 months, depending on the development of thyroid disease.

RESULTS

After the first year of IFN beta-1b treatment, no further cases of thyroid disease were observed. Among the six patients with early incident subclinical hypothyroidism, thyroid dysfunction persisted only in those with baseline autoimmune thyroiditis (n = 2). The three patients who developed transient hyperthyroidism remained euthyroid throughout the treatment course. A positive autoantibody titer was continually detected in only two out of five patients without baseline autoimmunity.

CONCLUSIONS

The risk of thyroid disease seems related to IFN beta-1b treatment during the first year only, particularly in patients with preexisting thyroiditis. Furthermore, incident thyroid dysfunction is generally transient and mild in degree. Indeed, we recommend a routine systematic thyroid assessment only in patients with baseline thyroiditis. During the first year of therapy, serum thyroid-stimulating hormone measurement should suffice as first line test; a systematic thyroid assessment is only useful for those patients with incidental and persistent dysfunction. Further studies with many patients will be necessary to confirm our suggestions as broad clinical guidelines.

Effect of 1-year treatment with interferon-beta1b on thyroid function and autoimmunity in patients with multiple sclerosis

OBJECTIVE

Interferon-beta (IFN-beta) is a widely used therapy for multiple sclerosis (MS), a demyelinating disease of the central nervous system. This study has evaluated the effect on thyroid function and autoimmunity of a 1-year treatment with IFN-beta1b in patients with MS.

PATIENTS

We studied 31 patients (age 34+/-7 years, 21 women) with relapsing-remitting MS during IFN-beta1b treatment of 1 year duration. Systematic thyroid assessment and measurements of serum interleukin-6 (IL-6) levels were performed at baseline and every 3 months during treatment.

RESULTS

Sixteen percent of the patients had autoimmune thyroiditis before IFN-beta1b, all positive for anti-peroxidase antibodies. The overall incidence of thyroid dysfunction was 33% over 1 year (10% hyperthyroidism, 23% hypothyroidism). Thyroid autoimmunity developed in 5/26 patients (19%), in one case without dysfunction. In addition to autoantibody positivity at baseline, female gender and the presence of an ultrasound thyroid pattern suggestive of thyroiditis were identified by multiple logistic regression as additional risk predictors for the development of thyroid dysfunction. During IFN-beta1b treatment, serum IL-6 levels rose in a consistent biphasic pattern; there was, however, no difference between patients with or without incident thyroid abnormalities.

CONCLUSIONS

We conclude that IFN-beta1b therapy can induce multiple alterations in thyroid function, some of which are unrelated to thyroid autoimmunity. IL-6 measurement is not useful to identify patients prone to develop thyroid abnormalities. Though thyroid dysfunction is generally subclinical and often transient, systematic thyroid assessment should be performed during IFN-beta1b treatment.

Neuromuscular symptoms and dysfunction in subclinical hypothyroid patients: beneficial effect of L-T4 replacement therapy

DESIGN, PATIENTS AND MEASUREMENTS

The presence of neuromuscular symptoms was ascertained by questionnaire in 33 consecutive patients with subclinical hypothyroidism (sHT) as compared to 44 age- and sex-matched controls. Blood was sampled for PTH, magnesium, phosphate, and total and ionized calcium determination. Patients reporting three or more symptoms were also studied by surface electromyography (sEMG). The study was repeated following a six-month L-T4 course.

RESULTS

Neuromuscular symptoms were significantly more frequent in patients than in controls (P = 0. 0001), and correlated with TSH values (r = 0.52; P = 0.0001). Among patients showing three or more symptoms (n = 11), sEMG documented the presence of repetitive discharges in 8 patients. L-T4 therapy led to a significant improvement of symptoms (P = 0.0001); persistent repetitive discharges were no longer observed. Total and ionized calcium values, always within the normal limits, were significantly lower in patients than controls (P < 0.0001). An inverse relationship was observed between ionized calcium and: TSH values (r = -0.69, P = 0.0001); the number of neuromuscular symptoms (r = -0.53, P = 0.0001). L-T4 replacement induced a significant increase in both total and ionized calcium levels (P < 0.01 and P < 0.0001, respectively).

CONCLUSIONS

Neuromuscular symptoms and dysfunction are rather common in subclinical hypothyroidism, and may be associated with abnormalities in serum calcium balance and surface electromyography. The ability of L-T4 treatment to reverse all these changes suggests that subclinical hypothyroidism patients may require early therapy not only to prevent progression to frank hypothyroidism, but also to improve their neuromuscular dysfunction.

Treatment of hyperfunctioning thyroid nodules with percutaneous ethanol injection: Eight years' experience

The aim of our study was to define the long-term efficacy and safety of percutaneous ethanol injection (PEI) for the treatment of autonomous thyroid nodule (ATN), and to optimise the clinical usefulness of such a therapy. We treated 132 patients with ATN (30 M and 102 F, aged 47.5+/-12.9 years; mean+/-SD), in case other established treatments were refused or contraindicated. Eighty-five patients were affected by toxic adenoma and 47 suffered from pre-toxic nodules. Ethanol was administered weekly under sonographic control, in 7 sessions (range 2-16). During PEI treatment, 26 toxic elderly patients were treated with methimazole and propranolol. Three possible outcomes were identified for statistical analysis: failure (persistent suppression of extra nodular tissue uptake, along with elevated free thyroid hormone and undetectable TSH levels); partial cure (normal free thyroid hormone and low/undetectable TSH levels); complete cure (normal thyroid hormone and TSH levels; restored extra nodular uptake). The patients were followed for up to 8.5 years (median 76 months). PEI therapy was well tolerated by all patients though a mild to moderate local pain occurred in about 30% of sessions. Complete cure was achieved in all pre-toxic patients and in 60 (70.6%) patients with toxic adenoma, while partial cure was observed in 11 cases (12.9%) and failure in 14 (16.5%). A significant shrinkage of nodule volume was observed in all patients (p = 0.0001), while those with toxic nodules larger than 30 mL showed a significantly lower response rate to PEI (p < 0.05). At controls, only one patient developed subclinical hypothyroidism while, among partially cured patients, five relapsed. The administration of methimazole and/or propranolol did not modify PEI outcome. In conclusion, we suggest that PEI therapy may be the treatment of choice in patients with pre-toxic thyroid adenoma where therapy is least necessary- despite the nodule volume. Though ethanol injection therapy of toxic thyroid nodules may be troublesome for the need of multiple sessions, it appears an effective alternative procedure in patients at poor surgical risk, and in younger patients in whom radioiodine is contraindicated. Since a special technical skill in intervention procedures is required, PEI therapy may be suitable only for patients living nearby a trained centre.

Clinical and biochemical features of muscle dysfunction in subclinical hypothyroidism

Alterations in muscle structure and function have been reported in overt hypothyroidism, with decreased activity of enzymes involved in anaerobic and oxidative glucose metabolism. To test whether similar changes in muscle energy metabolism are present in subclinical hypothyroidism (sHT), we studied 12 patients with sHT who complained of mild neuromuscular symptoms. The control group included 10 sex- and age-matched healthy volunteers. Skeletal muscle lactate and pyruvate production were determined in the resting state and during dynamic arm exercise. During exercise, blood lactate was significantly higher in sHT patients than in controls from the third exercise step onward (P = 0.02 at 30%, p = 0.008 at 40%, and P = 0.002 at 50% of maximal voluntary contraction). Moreover, the mean increment in blood lactate during exercise was positively related (r2 = 0.44; P = 0.02) to the duration of sHT, but not to serum levels of TSH, free T3, or free T4. No significant difference was found in blood pyruvate concentrations between the two groups at baseline or during exercise. Thus, the lactate/pyruvate ratio curve paralleled the lactate curve in patients as well as controls. We conclude that muscle energy metabolism is impaired in sHT in rough proportion to the known duration of the disease. Early L-T4 therapy may be useful not only to provide specific treatment for such metabolic changes, but also to avoid progression to frank hypothyroidism.

Is percutaneous ethanol injection a useful alternative for the treatment of the cold benign thyroid nodule? Five years' experience

We describe our 5-year experience with percutaneous ethanol injection (PEI) for the treatment of cold benign thyroid nodules and report its efficacy and side effects. Fifty-four euthyroid outpatients (aged 44.8+/-12.7 years, mean+/-SD) were divided into two groups matched for sex, age, and nodule volume: 27 patients treated only by PEI and 27 patients treated additionally with levothyroxine-suppressive therapy (median follow-up: 24 months, range 6-48). Mean pretreatment nodule volume was 21.0 mL (range 5.4-54.6). Ethanol (1.3+/-0.6 mL/mL nodule volume) was injected under sonographic control in 4 to 13 weekly sessions (mean 7.4). PEI therapy was well tolerated by all patients. At the end of treatment, nodule volume was 7.7+/-5.7 mL (p = .0001). A further significant shrinkage was obtained at 1-year follow-up (4.4+/-3.8 mL; p < .05). No significant differences in nodule reduction were observed between the levothyroxine treated or untreated group and between patients with pretreatment nodule volume smaller or larger than 15 mL. Our study confirms the efficacy and safety of PEI in inducing volume shrinkage of cold benign thyroid nodules. Overall our data suggest that PEI may become an interesting alternative for patients with surgical indications, if they refuse surgery or are poor surgical risks, or eventually demand treatment for aesthetic purposes. It may also be considered when levothyroxine therapy is contraindicated or ineffective.

Appearance of Graves' disease after percutaneous ethanol injection for the treatment of hyperfunctioning thyroid adenoma

In this report we describe an unusual patient with hyperfunctioning thyroid adenoma in whom percutaneous ethanol injection (p.e.i.) therapy was followed by typical Graves' disease. His history revealed the presence of a sister with Hashimoto's thyroiditis. 99-mTc thyroid scintiscan showed focal uptake in the nodule, with suppression of extranodular parenchyma. P.e.i. therapy was followed by the development of severe hyperthyroidism. One month after a second p.e.i. cycle, recurrence of hyperthyroidism associated with diffuse 99-mTc uptake by the gland was observed. TSH-receptor and thyroglobulin autoantibodies were undetectable before p.e.i. therapy, appeared during the first cycle, and showed a further increase after the second p.e.i. therapy cycle. Though spontaneous switch to Graves' disease cannot be excluded in patients with toxic nodules, the massive release of thyroid materials from follicular cells, among these TSH-receptor antigenic components partially denatured by ethanol, may indeed trigger an autoimmune response to the TSH-receptor, thus accounting for this observation. Patients with possible autoimmune disposition, as selected by familiar history and/or laboratory markers should be carefully monitored during p.e.i. treatment.