Direct-acting antivirals used in HCV-related liver disease do not affect thyroid function and autoimmunity

PURPOSE

It is well known that interferon-α (IFN-α), used for long time as the main therapy for HCV-related disease, induces thyroid alterations, but the impact of the new direct-acting antivirals (DAAs) on thyroid is not established. Aim of this prospective study was to evaluate if DAAs therapy may induce thyroid alterations.

METHODS

A total of 113 HCV patients, subdivided at the time of the enrollment in naïve group (n = 64) and in IFN-α group (n = 49) previously treated with pegylated interferon-α and ribavirin, were evaluated for thyroid function and autoimmunity before and after 20-32 weeks of DAAs.

RESULTS

Before starting DAAs, a total of 8/113 (7.1%) patients showed Hashimoto's thyroiditis (HT) all belonging to IFN-α group (8/49, 16.3%), while no HT cases were found in the naïve group. Overall, 7/113 (6.2%) patients were hypothyroid: 3/64 (4.7%) belonging to naïve group and 4/49 (8.2%) to IFN-α group. Furthermore, a total of 8/113 patients (7.1%) showed subclinical hyperthyroidism: 2/64 (3.1%) were from naïve group and 6/49 (12.2%) from IFN-α group. Interestingly, after DAAs therapy, no new cases of HT, hypothyroidism and hyperthyroidism was found in all series, while 6/11 (54.5%) patients with non-autoimmune subclinical thyroid dysfunction became euthyroid. Finally, the only association between viral genotypes and thyroid alterations was genotype 1 and hypothyroidism.

CONCLUSIONS

This study supports evidence that DAAs have a limited or missing influence on thyroid in patients with HCV-related diseases. Moreover, it provides preliminary evidence that subclinical non-autoimmune thyroid dysfunction may improve after HCV infection resolution obtained by DAAs.

Thyroid autoimmunity and hypothyroidism are associated with deep molecular response in patients with chronic myeloid leukemia on tyrosine kinase inhibitors

PURPOSE

Thyroid alterations including de novo appearance of thyroid autoimmunity are adverse effects of tyrosine kinase inhibitors, used in solid and hematologic cancer therapy, but the relationship between thyroid alterations during this treatment and the outcome of chronic myeloid leukemia remains unclear. Aim of this study was to investigate whether the presence of thyroid alterations may affect the clinical outcome of chronic myeloid leukemia on tyrosine kinase inhibitors.

METHODS

We evaluated thyroid function and autoimmunity in 69 chronic myeloid leukemia patients on long-term therapy looking at the association between thyroid abnormalities and disease molecular response.

RESULTS

Overall, 24 of 69 (34.8%) had one or more thyroid abnormalities during therapy. A high percentage of patients (21/69, 30.4%) showed thyroid autoimmunity (positive thyroid autoantibodies with ultrasound hypoechogenicity), while clinical and subclinical hypothyroidism and subclinical hyperthyroidism were, respectively, found in 4 of 69 (5.8%) and 3 of 69 (4.3%) of cases. Second-generation tyrosine kinase inhibitors resulted significantly associated (14/32, 43.7%) with Hashimoto's thyroiditis, compared to first generation (7/37, 18.9%; p = 0.03). Interestingly, we also found a significant association between euthyroid (14/26, 53.8%) and hypothyroid Hashimoto's thyroiditis (4/26, 15.4%) in patients with deep molecular response, as compared to euthyroid (3/43, 7%; p = 0.0001) and hypothyroid (0/43, 0%; p = 0.02) Hashimoto's thyroiditis patients with major molecular response.

CONCLUSIONS

Our study confirms and extends our knowledge on the tyrosine kinase inhibitors effects on thyroid, showing that thyroid autoimmunity is frequently observed in chronic myeloid leukemia patients on long-term therapy and is associated with a better oncological response.

Prevalence of less severe hypercortisolism in fractured patients admitted in an outpatient clinic for metabolic bone diseases

PURPOSE

To evaluate the prevalence of less severe hypercortisolism (LSH) in fractured patients, and its association with hypertension, hyperglicemia, dyslipidemia, and obesity.

METHOD

From July 2015 to October 2018 we enrolled all fractured patients admitted in our outpatient center for metabolic bone diseases, after exclusion of patients with secondary osteoporosis apart from diabetes and taking drugs known to affect bone metabolism. In all enrolled patients we collected data regarding gonadal status, history of diabetes, high blood pressure, dyslipidemia, and measured blood pressure, lipid profile, fasting glycaemia. Bone mass was measured with DXA at lumbar spine and femoral neck and the presence of fractures was evaluated with X-ray of thoracic and lumbar spine. All patients performed twice, 1 mg overnight dexametasone suppression test (DST) and, as confirmatory, 2day low-dose DST for diagnosing hypercortisolism.

RESULTS

We enrolled 101 fractured patients (75 females, 26 males), aged 65 ± 10.3 years. Five out of 101 (5.0%) patients were diagnosed as LSH. Fifty-five (54.5%) out of 101 were hypertensive, 57 (56.4%) dyslipidemic, 17 (16.8%) hyperglicaemic, 28(27.7%) obese patients. LSH tended to be associated to blood hypertension [5/5 vs 50/96 (Fisher exact test, p = 0.06) hypertensive patients]. Four out five LSH patients were hypogonadic.

CONCLUSIONS

Our study confirms that a nonnegligible percentage of fractured subjects actually presents an unrecognized hypercortisolism. Accordingly, regardless of age, we suggest to screen for hypercortisolism all patients with established osteoporosis and in particular hypertensive subjects.

Electrical Impedance to Easily Discover Undeclared Freeze-thaw Cycles in Slaughtered Bovine Meat

A portable electrical impedance spectroscopy device was developed to monitor the bioimpedance resistive component of bovine meat by injecting a sinusoidal current of 1 mA at 65 kHz. Both right and left longissimus dorsi muscles were trimmed from 4 slaughtered cows. The left muscle portions were frozen to -18 °C for 7 days while the right ones were meantime maintained at 5 °C. Mean value of impedance per length (Ω/cm) of frozen and thawed left samples was 31% lower than that of right non-frozen one (P = 0.0001). It was concluded that the device is reliable for monitoring the maturation of beef meat in situ with the possibility of revealing undeclared freeze-thaw cycles.

Mental disorders in patients with metabolic syndrome. The key role of central obesity

BACKGROUND

The Authors sought to evaluate current prevalence of mental disorders in patients affected by metabolic syndrome compared with patients affected by central obesity alone.

METHODS

186 (63.5%) patients affected by central obesity and 107 (36.5%) affected by metabolic syndrome according to ICF criteria were interviewed by means of SCID I.

RESULTS

Axis I current prevalence was respectively 45.7% and 44.9% among patients with central obesity and patients with metabolic syndrome, differences which were not significant. No statistically significant differences were found between groups as far as each single axis I diagnostic category was concerned. Moreover, current prevalence of any axis I, anxiety and mood disorders were independent of the number of components of metabolic syndrome.

CONCLUSION

metabolic syndrome is associated to an higher risk for current mental disorders, which seems to be mainly due to the strong association of central obesity to psychopathology.

Mental disorders in obese patients with and without metabolic syndrome

OBJECTIVE

The authors sought to evaluate lifetime prevalence of mental disorders in patients affected by metabolic syndrome compared with patients affected by central obesity alone.

METHODS

One hundred eighty-six (63.5%) patients affected by central obesity and 107 (36.5%) affected by metabolic syndrome according to ICF criteria were interviewed by means of SCID I and SCID II.

RESULTS

Axis I and axis II lifetime prevalence were respectively 53.8% and 30.1% among patients with central obesity, 50.5% and 28% among patients with metabolic syndrome, differences which were not significant. No statistically significant differences were found between groups as far as each single axis I and II diagnostic category was considered.

CONCLUSION

Metabolic syndrome is not associated with a higher risk of mental disorders compared to central obesity alone.

Obesity, alexithymia and psychopathology: a case-control study

OBJECTIVE

The relationship between psychopathology and alexithymia in obese patients is uncertain. The present study was performed to evaluate this relationship in a clinical sample of patients attending a centre for the diagnosis and treatment of obesity compared to a matched sample of non-obese subjects.

METHODS

293 consecutive obese patients (48 males, 245 females, mean age 45, 41±13.55 yrs; mean BMI 35.60±6.20) were compared with a control group made of 293 non-obese subjects (48 males, 245 females, mean age 45, 66±13.86 yrs; mean BMI 21.8±2.06); all subjects were interviewed by means of SCID I and SCID II together with several self-evaluation instruments including the TAS-20 (Toronto Alexithymia Scale) and SCL-90 (Symptom Check List, Revised).

RESULTS

Alexithymia was significantly more frequent among obese patients compared to "normal" controls (12.9% vs 6.9%, p=0.010); moreover obese patients achieved significantly higher mean scores on subscales 1 and 2 and on overall scale of the Toronto Alexithymia Scale; comorbidity with axis I/II disorders, in particular Binge Eating Disorder, was associated with a significantly higher frequency of alexithymic traits and higher scores at TAS.

CONCLUSIONS

Alexithymia and psychopathology are strongly correlated among obese patients seeking treatment. Routine evaluation of personality traits and comorbid psychopathology may be relevant in treatment of obesity.

Serum transforming growth factor β1 during diabetes development in non-obese diabetic mice and humans

Recent data show that regulatory cells with transforming growth factor (TGF)-β1-dependent activity are able to restore self-tolerance in overtly diabetic non-obese diabetic (NOD) mice. Thus, TGF-β1 seems to have a relevant role in protection from autoimmune diabetes. Our aim was to investigate the possible significance of serum TGF-β1 measurement in the natural history of diabetes in NOD mice, as well as in children positive for at least one islet-related antibody. Serum TGF-β1 (both total and active) was measured by enzyme-linked immunosorbent assay at monthly intervals in 26 NOD mice during the spontaneous development of diabetes and, on a yearly basis, in nine siblings of patients with type 1 diabetes (T1D) with a follow-up of 4 years. Diabetes appeared between the 12th week of age and the end of the study period (36 weeks) in 17 mice. TGF-β1 serum level variations occurred in the prediabetic period in both NOD mice and humans and diabetes diagnosis followed a continuing reduction of active TGF-β1 (aTGF-β1) serum levels. In mice, aTGF-β1 serum levels measured at 4 weeks of age correlated positively with severity of insulitis, and negatively with percentage of insulin-positive cells. Our findings suggest that in NOD mice serum TGF-β1 levels during the natural history of the diabetes reflect the course of islet inflammation. The measurement of aTGF-β1 in islet-related antibody-positive subjects may provide insights into the natural history of prediabetic phase of T1D.

Prevalence of overweight and obesity in Sardinian adolescents

BACKGROUND

To estimate the prevalence of overweight and obesity among adolescents in Sardinia and to examine the association with several biological and geographic factors.

METHODOLOGY

A cross-sectional study was performed in 3,946 unselected adolescents (2,011 boys, 1,935 girls; aged 11-15 years) attending the public secondary schools in 33 Sardinian municipalities: 28 semi-rural, 5 urban, sub-grouped according to their geographic location (mountain, hillside and plain). Oversized children were measured and their BMI defined as being above normal values according to parameters provided by the International Obesity Task Force (IOFT) by Cole et al. (BMI for age > or = 95th percentile). Relative risk for overweight and obesity was calculated using Poisson regression analysis: risks associated to each covariate were reciprocally adjusted. The 95% confidence interval (CI) of the estimated risk was calculated using Wald's formula (RR, RR = log(n) beta +/- 1.96 se(beta)).

MAIN FINDINGS

The overall prevalence rate found for overweight and obesity was 14.9% (95% C.I.: 13.7-16.1%) and 3.7% (95% C.I. 3.1-4.3%), respectively. Overweight rate showed no association with gender, whereas belonging to the female sex constituted a significant protection against obesity. Increasing age in the range 12-14 years was protective against both overweight and obesity in the whole sample. A similar finding however was not observed for obesity in girls or overweight in boys, when considered separately. Boys, but not girls, living in urban areas displayed a modest though significant 20% increase in overweight and a 40% decrease in obesity risk. Living in a mountainous area conveyed a 30% decrease in risk of overweight and a 50% decrease in risk of obesity, when compared to living on the plains and hillside combined. However, the small sample size of study subjects living in mountainous areas generated extremely wide 95% confidence intervals, thereby preventing the drawing of any significant conclusions.

CONCLUSION

In comparison with other surveys performed by the IOFT, Sardinian adolescents show a low prevalence rate for oversize, emphasizing a marked discrepancy with the general north-south rising trend of oversize observed throughout Europe. Geographic location, aesthetic or other age related factors seem to exert a different gender-specific influence on overweight and obesity.

SIGNIFICANCE

The present report is cross sectional and the consequences of overweight and obesity on individuals over time are not traceable. However, the outcome of the study suggests the need to implement suitable policies and public health programs leading to increased awareness.

Fifteen-year follow-up of thyroid function in lithium patients

OBJECTIVE

To study prospectively the course of clinically relevant thyroid dysfunction in a cohort of patients on long-term lithium treatment.

METHOD

Patients (no.=150) who had undergone a cross-sectional evaluation of their thyroid function in 1989, when they were at different stages of lithium treatment, were followed up for thyroid circulating thyroid antibodies, hypothyroidism, hyperthyroidism, and thyroidectomy, during a further period of lithium exposure of up to 15 yr.

RESULTS

Annual rates of newly developed circulating thyroid antibodies and hypothyroidism were 1.7 and 1.5%, respectively. Subjects with thyroid antibodies had a higher chance of requiring substitution treatment with levothyroxine for hypothyroidism compared with subjects with no evidence of thyroid antibodies (6.4% annual rate compared to 0.8%; relative risk: 8.4; 95% confidence interval: 2.9-24.0). One case of hyperthyroidism was observed over 976 patient-yr. Three patients underwent thyroidectomy during followup (two for multinodular goiter and one for multicentric papillary carcinoma).

CONCLUSIONS

Lithium may be associated with hypothyroidism in particular in the presence of circulating thyroid antibodies. Incidence of thyroid antibodies is comparable with that reported for the general population. Hyperthyroidism and thyroid cancer are rare.

High serum circulating telopeptide type I in multinodular goiter

Recently, concentrations of serum carboxy-terminal-1-telopeptide (ICTP), a marker of bone collagen resorption, were found to be more sensitive than sex hormone-binding globulin (SHBG) in identifying peripheral overexposure to thyroid hormones in exogenous subclinical hyperthyroidism. The aim of the present study was to assess serum ICTP and SHBG in multinodular goiter with (pretoxic goiter) or without biochemical evidence of endogenous subclinical hyperthyroidism. Forty-five women affected by multinodular goiter were enrolled in this study. They were subdivided into two groups: group 1, consisting of 27 patients affected by pretoxic goiter; group 2, consisting of 18 patients affected by non toxic goiter; group 3, consisting of thirty-six euthyroid women matched with the other groups for age and lifestyle. In group 1, serum ICTP (mean +/- SD: 5.8 +/- 2.9 microg/l) concentrations were significantly higher when compared either to group 2 (3.6 +/- 1.2 microg/l; p < 0.02) or controls (2.7 +/- 0.7 microg/l; p < 0.0001); serum ICTP concentrations were also slightly but significantly higher in patients of group 2 compared to controls (p < 0.003). In contrast, mean serum SHBG concentrations did not show any difference among the three groups. No significant correlation was found between serum TSH and ICTP concentrations, while a weak positive correlation (p < 0.05) was only found between serum FT 3 and ICTP concentrations when data from the two patient groups were analyzed together. Moreover, when we subdivided patients into pre- and postmenopausal patients, we observed that SHBG but not ICTP serum concentrations were influenced by estrogenic status. In summary, the measurement of serum ICTP seems to be more suitable than SHBG for identifying those with a higher degree of peripheral thyroid hormone exposure in women affected by endogenous subclinical hyperthyroidism.

Ten-year follow-up of thyroid function in lithium patients

The objective of this paper was to study prospectively the course of clinically relevant thyroid dysfunction in a cohort of patients on long-term lithium treatment. Patients (N = 150) who had undergone a cross-sectional evaluation of their thyroid function in 1989, when they were at different stages of lithium treatment, were followed up for the presence of thyroid autoimmunity, hypothyroidism, and goiter during a further period of lithium exposure of up to ten years. The following annual rates of newly developed thyroid dysfunction were observed: autoimmunnity (1.4%), subclinical hypothyroidism (1.7%), and goiter (2.1%). Subjects with thyroid autoimmunity had a higher chance of requiring substitution treatment with levothyroxine for subclinical hypothyroidism compared with subjects with no evidence of thyroid autoimmunity (13/32 = 41% versus 7/118 = 6%). Subjects (N = 15) who were prescribed carbamazepine in addition to lithium showed a significant decrease of TSH concentrations. In patients already being treated with lithium for several years, the overall incidence of hypothyroidism, goiter, and thyroid autoimmunity were comparable with those reported for the general population. However, lithium exposure may represent an additional risk factor for hypothyroidism in women and/or in the presence of thyroid autoimmunity.

The Sardinian Autoimmunity Study: 3. Studies on circulating antithyroid antibodies in Sardinian schoolchildren: relationship to goiter prevalence and thyroid function

The relationship among iodine intake, goiter prevalence, and thyroid autoimmunity remains controversial. In the present article, we report the prevalence of antithyroid antibodies (ATA) in relation to iodine intake, frequency of goiter, and thyroid function in a large group of Sardinian schoolchildren living in areas with borderline iodine sufficiency, or mild to moderate iodine deficiency. A total of 8,040 schoolchildren (4,194 males, 3,846 females, ages 6-15 years) from 29 communities were examined between 1986-1994. Thyroid size was assessed by palpation, according to the Pan American Health Organization (PAHO) criteria. In all cases antimicrosomal (MAb) or antithyroid peroxidase antibodies (TPOAb) and thyrotropin (TSH) were assayed. Urinary iodine was determined in a subgroup of 820 children. ATA was detected in 235 (2.92%) sera (88 males, 2.12%; 147 females, 3.82%; chi2 = 20.41, p < 0.0001). ATA prevalence ranged between 0.0%-7.3% in the 29 communities without any geographical correlation with goiter prevalence and urinary iodine excretion. However, ATA was more frequently detected in goitrous children, especially in females. The presence of ATA was not age-dependent in males, whereas a significant increase of ATA was observed in females older than 11 years of age. Seventy-seven (0.96%) children showed borderline to slightly increased serum TSH (>5.2-32 mU/L). Increased serum TSH concentration was more frequently found in children with ATA, especially at higher titers. In summary, our study in Sardinian schoolchildren indicates: (1) ATA display geographical heterogeneity, which seems to be unrelated to goiter prevalence and/or to iodine supply; (2) ATA are more frequently detected in females older than 11 years of age, suggesting that puberty has a role in determining the predominance in females of thyroid autoimmunity; (3) although most goitrous children are ATA-negative, the prevalence of ATA is increased in children with enlarged glands; (4) ATA is associated with an increased prevalence of subclinical hypothyroidism.

The sardinian autoimmunity study. 4. Thyroid and islet cell autoantibodies in sardinian pregnant women at delivery: a cross-sectional study

A high incidence of autoimmune Type 1 diabetes mellitus (DM) has been clearly established in Sardinia. Although systematic epidemiological studies are still not available, an increased prevalence of thyroid autoantibodies (ATA) has been documented in the Sardinian adult population as compared to other Italian regions, suggesting that thyroid autoimmune disease may also have increased. We carried out a preliminary study with the aim of determining the prevalence of serological markers of thyroid (anti-thyroperoxydase antibodies, TPOAb) and islet cell (ICA) autoimmunity in a large number (no.=2249) of sera obtained from cord-blood of Sardinian pregnant women at delivery. The prevalence of TPOAb was 11.9%, while ICA were detected in 59 cases (2.6%). A higher prevalence of TPOAb (6/17=35.3%) was found in sera with high ICA titers (> or = 20 JDF-U), as compared to sera with low ICA titers (5-19 JDF-U) and to ICA-negative sera (3/42=7,1%; chi2=5.4, p=0.02 and 258/2190=11,8%; chi2=6.8, p=0.009 respectively). Fourteen women (all ICA-negative) were diabetic: 4 had Type 1 and 10 had gestational DM; due to the low number, no correlation could be established between DM type and TPOAb prevalence and/or titer. These preliminary data indicate that ATA are frequently observed in the general population of Sardinian pregnant women at term. As a consequence, even the frequency of postpartum thyroiditis is expected to be high. Although ATA were not increased in women with clinical overt diabetes, a higher prevalence of ATA was found in women with high titers of circulating ICA. Our results also confirm that Sardinia represents, perhaps for its peculiar genetic characteristics, an ideal place to study organ-specific autoimmunity.

Independent expression of serological markers of thyroid autoimmunity and hepatitis virus C infection in the general population: results of a community-based study in north-western Sardinia

To assess the relationship between serological markers of thyroid autoimmunity and chronic hepatitis C, we surveyed the general population of two villages in the region of Sardinia, Italy, where infection with hepatitis viruses is endemic and the prevalence of autoimmune diseases is elevated. A total of 1310 subjects aged 6-88 years (65% of the total resident population) participated in the survey, and 1233 (94%; 444 males and 789 females) agreed to provide a blood sample. Autoantibodies to thyroid peroxidase (anti-TPO) were measured by radioimmunoassay; antibodies to HCV (anti-HCV) by a third generation enzyme immunoassay and borderline positive results confirmed by recombinant immunoblot assay. For both anti-HCV and anti-TPO the age- and gender-standardized prevalence rates (SPR) were calculated and the significance of the association between the two antibodies tested by Yates corrected chi2 test. The overall SPR for anti-HCV was 50.7x10(-3) (86/1,233), similar between men [49.1x10(-3) (22/444)] and women [52.3x10(-3) (64/789)]. The overall SPR for anti-TPO was 136.9x10(-3) (204/1,233), and that among women [201x10(-3) (174/789)] was almost 3-fold that among men [71.6x10(-3) (30/444)]. A concurrent anti-HCV and anti-TPO positivity was found in a small minority of subjects [8/1,233 (0.65%)], all women aged 57-81 years. The SPR for the two concurrent events was 3.3x10(-3), which was not significantly different (Yates corrected chi2 test = 0.65) from that expected under the assumption of unrelated events. To explore whether HCV infection is a risk factor for anti-TPO positivity, we designed a case-control study with anti-TPO positive subjects as the cases, and anti-TPO negative subjects as the controls. The age- and gender-adjusted odd ratio (OR) was 0.4 (95% CI 0.2,0.7), indicating a negative association. In conclusion, no evidence for epidemiological association of circulating thyroid autoantibodies and antibodies to HCV was found. Our findings do not therefore support a pathogenetic link between HCV infection and thyroid autoimmunity.

Thyroid and celiac disease: clinical, serological, and echographic study

OBJECTIVE

We sought to reevaluate the prevalence of thyroid dysfunction and thyroid autoimmunity in 47 patients with celiac disease; 91 healthy subjects were studied as controls. Both patients and controls were from Sardinia, Italy.

METHODS

Diagnosis of celiac disease was made on the basis of clinical history, presence of positive antigliadin IgA (AGA-A) and IgG (AGA-G) antibodies, antireticulin antibodies (ARA), antiendomysium antibodies (EMA), and was confirmed by jejunal biopsy. HLA class II typing for DQB1 and DQA1 alleles was performed in 36/47 celiac patients. Thyroid was evaluated by palpation and echography; serum free thyroid hormones (FT4, FT3), thyrotropic hormone (TSH), and antithyroid peroxidase autoantibodies (anti-TPO) were assayed by radioimmunoassays.

RESULTS

The prevalence of anti-TPO was higher in celiac patients (29.7%) than in healthy controls (9.6%) (p < 0.001) and thyroid echography frequently displayed (42.5%) a hypoechogenic pattern. Five anti-TPO-positive celiac patients were hypothyroid (two overt, three subclinical). A higher but not significantly different prevalence of anti-TPO (3/7 = 42.8%) was found in celiac patients displaying the DQB1*0502 genotype, when compared with the remaining patients (8/29 = 27.6%).

CONCLUSIONS

An elevated prevalence of clinical and subclinical autoimmune thyroid autoimmunity was found in Sardinian celiac patients, especially in those displaying the DQB1*0502 genotype; this finding could be related to a particular genetic background of the Sardinian population.

Visual evoked potentials in hypothyroidism: a long-term evaluation

Visual Evoked Potentials (VEP) were measured in 9 new-diagnosed hypothyroid female patients--mean age 46 +/- 12 ys--before treatment, during (with monthly evaluations) thyroid hormone replacement therapy and after long-term therapy, at the achievement as well as one year after having achieved and maintained euthyroidism. Three of the hypothyroids had abnormally prolonged latencies (m.v. 131.7 +/- 7.9 ms), while 7 had lower than normal amplitude (m.v. 2.3 +/- 2.8 microV). No remarkable change of amplitude was observed after the achievement of euthyroidism, after a mean time of 5.9 +/- 4.9 months (range 2-14 months). A significant shortening of latency (m 128.3 +/- 7.6 ms), even still higher than the control value (m 122.7 +/- 3.7 ms) was found. Significant correlation between P100 latency and thyroid hormone levels was found for TT4 (r = 0.3353; p = 0.005), TT3 (r = 0.2568; p = 0.032) and FT4 (r = 0.3572; p = 0.002). No further improvement in P100 latency (m 129.5 +/- 7.2 ms; p = 0.037) was found one year after the achievement of euthyroidism, while a remarkable amplitude increase (m 9.2 +/- 3.4 micro; p = 0.001) was observed. Our findings indicate that, as well as other studied parameters, VEP are reversibly alterated in hypothyroidism, probably in relation to metabolic rather than to structural alterations. Moreover, VEP can represent a useful neurophysiologic parameter for quantitation of SNC involvement in hypothyroidism.

The "Sardinia-IDDM study": an attempt to unravel the cause of insulin-dependent diabetes mellitus in one of the countries with the highest incidence of the disease in the world

Sardinia and Finland have the highest incidence of IDDM in the world. Thus, both regions represent ideal observatories for investigating the environmental, genetic and immunological factors, which have led to this dramatic increase. We have concentrated our efforts in Sardinia. Among several projects, there is the mapping of the Island for hot and cold spots for overt IDDM. In order to map the Island for pre-IDDM, we have collected and bled around 10,000 school children (age 6-14 years) and we are now in the process to enroll around 30,000 newborn. We report here our initial results, which show that progression to IDDM is accompanied in both cohorts by the presence of a combination of ICA with either GAD and IA-2 antibodies or both. This approach should lead to design reliable models of IDDM prediction in the general population, which will benefit an early insulin treatment and, hopefully, an effective prevention of the disease.

Sardinia: a battlefield approach to type I diabetes epidemiology. Sardinia-IDDM Study Groups

Sardinia and Finland have the highest incidence of insulin-dependent diabetes mellitus (IDDM) in the world. Therefore, both regions represent ideal observatories for investigating the environmental, genetic and immunological factors which have led to this dramatic increase. We have concentrated our efforts on Sardinia. Among several projects, there is the mapping of the island for hot and cold spots for overt IDDM. In order to map the island for pre-IDDM, we have collected and bled around 10,000 school children (age 6-14 years) and we are now in the process of enrolling around 30,000 new-born babies. We report here our initial results, which show that progression to IDDM is accompanied in both cohorts by the presence of a combination of islet-cell antibodies with either glutamic acid decarboxylase or IA-2 antibodies or both. This approach should lead to the design of reliable models of IDDM prediction in the general population, which will benefit an early insulin treatment and, hopefully, an effective prevention of the disease.

Circulating telopeptide type I is a peripheral marker of thyroid hormone action in hyperthyroidism and during levothyroxine suppressive therapy

The aim of the present investigation was to evaluate the clinical performance of serum carboxy-terminal-1-telopeptide (ICTP), a new marker of bone resorption, in identifying peripheral overexposure to thyroid hormones, as compared with serum osteocalcin (OC) and serum sex hormone binding globulin (SHBG). Serum ICTP, SHBG, and OC were assayed by specific radioassays in three study groups. Group 1: 50 perimenopausal women on long-term levothyroxine (LT4) suppressive treatment; group 2: 29 women with untreated hyperthyroidism; group 3: 36 normal euthyroid women matched with group 1 patients for age, alcohol, smoking habits, and lifestyle. Serum concentrations of SHBG, ICTP, and OC were markedly increased in hyperthyroid patients, whereas only serum ICTP was slightly but significantly increased in LT4 treated patients. Serum ICTP had higher diagnostic value for hyperthyroidism when compared with SHBG and to OC (sensitivity: 100%, 71%, 55%; accuracy: 97%, 88%, and 76%, respectively). In group 1, increased serum ICTP was observed in 30 of 50 patients, whereas increased SHBG and OC were found only in 11 of 50 (p < .001). Serum free thyroid hormone concentrations correlated with circulating ICTP and SHBG, and the correlation with serum OC was of lower significance. In conclusion, serum ICTP is a sensitive and reliable marker of peripheral thyroid hormone activity at the bone level; its clinical performance is higher than OC and even better than SHBG. Thus, serum ICTP is better than other peripheral markers in monitoring LT4 suppressive therapy in patients at increased risk for osteoporosis such as perimenopausal women.

Value of thyroid echography in the long-term follow-up of lithium-treated patients

Psychiatric patients on long-term lithium (Li) therapy frequently develop goiter and/or hypothyroidism. It has also been suggested that Li may trigger/exacerbate thyroid autoimmunity. Previous studies provided evidence that underlying thyroid diseases represent important predisposing factors for the development of Li-induced thyroid dysfunction. The aim of the present paper was to assess the value of thyroid ultrasound-a simple and reliable tool to detect subtle thyroid abnormalities-in the longitudinal evaluation of 23 Li-treated psychiatric patients without evidence of biochemical thyroid abnormalities before therapy. For this purpose, thyroid ultrasound was associated with a clinical and laboratory (serum thyroxine, serum triiodothyronine, serum TSH, antithyroglobulin (AbTg), antithyroid microsomal (AbM) and antithyroid peroxidase autoantibodies) evaluation prior to and at 6- to 12-month intervals during Li treatment. On the basis of thyroid ultrasound before Li, patients were subdivided into two groups: group A (n = 15, 7 males, 8 females) with a normal echography and group B (n = 8, 5 males, 3 females) with mild ultrasound abnormalities. In group A the development of a small diffuse goiter was confirmed by physical examination during Li therapy; 2 patients displayed a transient increase of serum TSH concentration and none developed detectable serum antithyroid autoantibodies. Beside the small volumetric increase, no other ultrasound abnormalities were observed during the entire follow-up. In all group B patients a mild diffuse goiter was clinically detected before and on Li administration and no significant volumetric changes were observed during follow-up. Two patients developed high titers of AbM and AbTg 12 and 18 months after the beginning of Li, respectively; in 1 a persistent increase of serum TSH concentration was also observed. Thyroid echography before Li displayed different degrees of scattered or diffuse hypoechogenicity and a further decrease in echogenicity was detected during Li therapy in 2 patients. In conclusion, we provided further evidence that long-term Li administration is not associated with de novo appearance of thyroid autoimmune phenomena in humans, but rather with an exacerbation of underlying thyroid autoimmunity. In addition to thyroid autoantibody and TSH measurements, thyroid echography appears to be a sensitive tool in the identification of patients at risk of developing autoimmune hypothyroidism during long-term Li therapy.

Six-year follow-up of thyroid function during lithium treatment

A cohort of patients at various stages of lithium treatment was followed up for 6 years in order to evaluate the course of thyroid abnormalities. Ultrasonography confirmed that lithium can increase thyroid size, especially in cigarette smokers, and that it can affect the texture of the gland. However, the incidence of clinical hypothyroidism or specific thyroid autoimmunity does not exceed that found in the general population. Repeated determinations of thyrotrophin (TSH) concentrations can prevent clinically relevant consequences. Addition of carbamazepine to lithium can counteract lithium-induced subclinical hypothyroidism, possibly improving prophylactic efficacy in recurrent affective disorders.

Study of serum 3,5,3'-triiodothyronine sulfate concentration in patients with systemic non-thyroidal illness

Sulfation is an important pathway of triiodothyronine (T3) metabolism. Increased serum T3 sulfate (T3S) values have been observed during fetal life and in pathological conditions such as hyperthyroidism and selenium deficiency. Similar variations have also been reported in a small number of patients with systemic non-thyroidal illness, but the underlying mechanisms have not been elucidated. In this study, serum T3S concentrations have been measured by a specific radioimmunoassay in 28 patients with end-stage neoplastic disease (ESND) and in 44 patients with chronic renal failure (CRF); 41 normal subjects served as controls. Both ESND and CRF patients had lower serum total T4 (TT4) and total T3 (TT3) than normal controls, while serum reverse T3 (rT3) was increased significantly in ESND (0.7 +/- 0.5 nmol/l; p < 0.001 vs. controls) but not in CRF (0.3 +/- 0.1 nmol/l). The TT3/rT3 ratio, an index of type I iodothyronine monodeiodinase (type I MD) activity, was reduced significantly in both groups of patients. Serum T4-binding globulin (TBG) was decreased in CRF but not in ESND patients. Serum T3S was significantly higher both in ESND (71 +/- 32 pmol/l) and CRF (100 +/- 24 pmol/l) than in controls (50 +/- 16 pmol/l, p < 0.001). Serum T3S values showed a positive correlation with rT3 values and a negative correlation with both TT3 and FT3 values in ESND, but not in CRF. In the latter group a positive correlation was observed between T3S and TBG values. The T3S/FT3 ratio was higher both in CRF (18 +/- 5) and in ESND (23 +/- 18) as compared to controls (10 +/- 4). Serum inorganic sulfate was increased and correlated positively with T3S values in CRF patients. In conclusion, the results of this study in a large series of patients confirm that patients with systemic non-thyroidal illness have increased serum T3S levels. The mechanisms responsible for these changes appear to be different in ESND and CRF patients. In ESND the increase in serum T3S levels is mainly related to reduced degradation of the hormone by type I MD, whereas in CRF it might be driven by the enhanced sulfate ion concentration, and could be partially dependent on the impaired renal excretion of T3S. Because T3S can be reconverted to T3, it is possible that increased T3S concentrations contribute to maintenance of the euthyroid state in systemic non-thyroidal disease.

Enhanced susceptibility to amiodarone-induced hypothyroidism in patients with thyroid autoimmune disease

BACKGROUND

The iodine-rich antiarrhythmic drug, amiodarone, can induce both thyrotoxicosis and hypothyroidism, the former being more frequent in iodine-deficient areas, the latter in iodine-sufficient areas. In this study we evaluated prospectively thyroid function in amiodarone-treated patients with positive or negative baseline thyroid autoantibody test results who resided in a moderately iodine-deficient area of Italy.

SUBJECTS

Two groups of patients received long-term amiodarone treatment: Group 1 included 13 patients with negative thyroid autoantibody test results. Group 2 consisted of seven patients with positive thyroid autoantibody test results and thyroid ultrasound patterns compatible with Hashimoto's thyroiditis. The control group (group 3) included 16 untreated euthyroid patients with Hashimoto's thyroiditis. All subjects resided in a mildly iodine-deficient area of Italy (Southern Sardinia) and had low urinary iodine values. Patients in groups 1 and 2 had markedly elevated urinary iodine excretion during treatment. The follow-up period ranged from 6 to 29 months in group 1, from 4 to 9 months in group 2, and from 12 to 55 months in group 3.

RESULTS

Two (15%) of 13 patients in group 1 with nodular goiter developed thyrotoxicosis. No patient in this group developed circulating thyroid autoantibodies. Five (71%) of seven patients in group 2 became hypothyroid after 4 to 9 months of amiodarone treatment associated with a rise in serum thyroid autoantibody levels. No patient in group 3 became hypothyroid.

CONCLUSIONS

(1) Amiodarone administration can cause both thyrotoxicosis and hypothyroidism. (2) Hypothyroidism is far more frequent in patients with preexisting thyroid autoimmune disease. (3) Amiodarone can modify the natural history of Hashimoto's thyroiditis. (4) Circulating thyroid autoantibodies do not appear in amiodarone-treated patients who have negative test results prior to therapy.

Endemic goiter and thyroid function in central-southern Sardinia. Report on an extensive epidemiological survey

Although the existence of endemic goiter and cretinism in Sardinia is known since to ancient time, scanty information collected according to WHO criteria is available. In the present paper the results of an extensive epidemiological survey carried out in juvenile population living in some rural and/or hilly villages in the provinces of Nuoro and Oristano in Central-Southern Sardinia and in urban area of Cagliari, are reported. In the majority of the villages the mean urinary iodine excretion was lower than 60 micrograms/L; the goiter prevalence ranged between 39% and 61% in the district of Nuoro and between 21% and 56% in the district of Oristano. In the control area the urinary iodine excretion was 105 micrograms/L with a goiter prevalence of 12%. Goiter prevalence was not always inversely related to urinary iodine excretion. No relevant thyroid function alterations were found.

IN CONCLUSION

1) in extraurban areas of Central-Southern Sardinia mild to moderate iodine deficiency and endemic goiter are still a widespread problems; 2) also in urban area endemic goiter prevalence is still higher than 10%; 3) extemporary urinary samples are inadequate for assessing the severity of goiter endemia in mild to moderate iodine deficiency; 4) in mildly affected districts palpation is inaccurate for assessing the prevalence of goiter; 5) no relevant alterations of thyroid function were documented in juvenile population.

False negative results observed in anti-thyroid peroxidase autoantibody determination by competitive radioimmunoassays using monoclonal antibodies

OBJECTIVE

Anti-thyroid peroxidase autoantibody (anti-TPO) and anti-thyroid microsomal antibody (anti-M) are strictly related, but discrepancies are sometimes observed. The aim of this study was to assess the incidence and to identify the causes of these discrepancies. DESIGN AND ANTIBODY MEASUREMENTS: Anti-M by passive hemagglutination and anti-TPO by two competitive monoclonal antibody-assisted radioimmunoassays (RIA-1 and RIA-2) were measured in 10,103 sera from 4232 subjects (663 male, 3569 female) screened for thyroid disease.

RESULTS

Anti-TPO and anti-M correlated quite well (r = 0.7 and p < 0.0001 by RIA-1: r = 0.74 and p < 0.0001 by RIA-2), with discrepancies mostly limited to sera with low antibody titers. After exclusion of the latter samples, anti-TPO were detected in only 79 (1.4%) out of 5317 anti-M negative sera, but were undetectable in a more consistent proportion (130/2880 = 4.5%) of sera from patients with autoimmune thyroid disease and positive anti-M. In 61 sera of the latter group, anti-TPO was measured by a non-competitive RIA (RIA-3). Forty-one (67.7%) were positive by RIA-3, suggesting the presence of anti-TPO not competing with the monoclonal antibodies of RIA-1 and RIA-2. The remaining 20 sera had undetectable anti-TPO also by RIA-3. Nineteen (95%) of these sera had positive anti-thyroglobulin (anti-Tg) autoantibody and preincubation with thyroglobulin inhibited the agglutination reaction of anti-M tests.

CONCLUSION

Anti-TPO by competitive monoclonal antibody-assisted RIA is negative in a minority of sera of patients with autoimmune thyroid disease and positive anti-M. This could be accounted for by anti-Tg producing false positives in the anti-M assay and by a subset of anti-TPO not competing with the monoclonal antibodies in the RIA. When autoimmune thyroid disease is suspected on clinical grounds, a negative anti-TPO test with a competitive RIA should be confirmed always by a non-competitive assay.

Relationship of the increased serum interleukin-6 concentration to changes of thyroid function in nonthyroidal illness

Variations in the serum concentration of interleukin-6 (IL-6) have been reported concomitantly with thyroid dysfunction: increased serum IL-6 levels have been found in patients with thyroidal destructive processes, such as subacute thyroiditis, some forms of amiodarone-induced thyrotoxicosis, or after percutaneous ethanol injection into "hot" thyroid nodules, as a result of the cytokine release from the damaged thyrocyte. In addition, recent in vitro evidence suggests that IL-6 might account, at least in part, for changes of thyroid economy found in nonthyroidal illness (NTI). In this cross-sectional study we addressed this problem by measuring serum IL-6 levels in 71 patients with NTI, due to neoplasia (n = 25), chronic liver disease (n = 9), chronic renal failure (n = 28), or other chronic nonthyroidal disorders (n = 9). These patients had reduced mean serum total T3 (TT3) and free T3 (FT3) concentrations, normal total and free T4 levels, normal TSH values, and increased serum reverse T3 (rT3) concentration (with the exception of chronic renal failure patients, who had normal rT3 levels). Serum IL-6 concentration was increased above normal (i.e. > 100 fmol/L) in almost all NTI patients, especially in those with low T3 values (median value: 258 fmol/L, range 73-3210, vs 152 fmol/L, range < 12.5-460, in patients with normal TT3 values, p < 0.001). Serum IL-6 values in NTI patients were negatively correlated with serum FT3 values (r = 0.56, p < 0.001), and positively correlated with serum rT3 values (r = 0.78, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship between nocturnal serum thyrotropin peak and metabolic control in diabetic patients

Circadian variations in serum TSH, especially its nocturnal rise, are often blunted in nonthyroidal illness. We analyzed TSH secretion in 15 diabetic patients (7 with type I and 8 with type II diabetes mellitus). Patients were evaluated when diabetes was poorly controlled (fasting blood glucose ranging from 13.7-19.2 mmol/L with absence of ketoacidosis) and after achieving glycemic control. Before correction of hyperglycemia, the nocturnal serum TSH peak (2230-0200 h) was abolished in 11 of 15 patients (73%); the mean (+/- SE) night TSH/morning TSH x 100 was 109.0 +/- 9.5 (range, 66.7-166.7) vs. a mean of 216.5 +/- 27.0 (range, 139.8-462.5) in normal controls. The mean morning TSH value in diabetics (1.9 +/- 0.4 mU/L) did not differ from that in normal age- and sex-matched controls. The mean TSH increase after iv administration of TRH was only slightly reduced (8.4 +/- 1.2 mU/L pretreatment vs. 10.8 +/- 1.6 mU/L posttreatment), with the TRH test blunted in 3 cases. No differences were found between type I and type II patients. Correction of hyperglycemia was associated with the reappearance of a nocturnal TSH peak in all but 1 patient (mean TSH peak, 198.2 +/- 13.0; P = NS vs. controls). This change paralleled the normalization of serum total T3 and rT3, which were reduced and increased, respectively, when diabetes was poorly controlled. An inverse relationship was found between serum fructosamine levels and the nocturnal TSH peak, suggesting that metabolic decompensation accounts for the abolishment of the latter.

Circulating antibodies to DNA-related antigens in patients with autoimmune thyroid disorders

A high prevalence of antibodies to double-stranded DNA (AbDNAds) has been recently reported in serum of patients with autoimmune thyroid disorders, but the specificity of this finding has been questioned. For this reason, the prevalence of several antibodies to DNA-related nuclear antigens (AbDRENA) has been evaluated in sera of patients with autoimmune and non-autoimmune thyroid disease. The study group included: 46 Graves' disease patients, 28 Hashimoto's thyroiditis patients, 25 patients with toxic nodular goitre and 11 with non-toxic nodular goitre. Twenty-eight Graves' patients were retested during methimazole (MMI) therapy, and 5 after radioiodine administration. Twenty-two patients with systemic lupus erythematosus and 28 normal subjects served as positive and negative controls, respectively. AbDRENA included: AbDNAds by RIA or immunofluorescence (IF); antibodies to single-stranded DNA (AbDNAss) and antibodies to histone (AbHist) by ELISA methods; antibodies to nuclear antigens (ANA) by immunofluorescence. RIA values were considered to be abnormal when 2 SD above the mean of normal controls. In our study 13% of Graves' patients were positive for AbDNAds by RIA: all of them had negative tests by IF; 11% were positive for AbDNAss, 2% for AbHist and 7% for ANA. A comparable prevalence of positive results for AbDNAds by RIA, with negative IF tests, was found in Hashimoto's thyroiditis patients. No significant changes of antibody levels were observed in Graves' patients during MMI treatment or after radioiodine administration. A positivity for AbDNAds or AbDNAss was found in 8% of patients with toxic nodular goitre, but in none of those with non-toxic goitre.(ABSTRACT TRUNCATED AT 250 WORDS)

The course of thyroid abnormalities during lithium treatment: a two-year follow-up study

A total of 116 patients on lithium treatment were followed up for 2 years to determine the course and the clinical relevance of thyroid abnormalities. Elevated thyroid-stimulating hormone (TSH) concentrations were transitory in most patients, except those with serum antithyroid antibodies. The patients who initially had microsomal antibodies remained positive, with an increase in titre in two-thirds of cases. Three young patients of both sexes developed thyroid autoimmunity early in the treatment. The risk of developing hypothyroidism was higher in women, especially in the presence of antibodies. TSH concentrations were significantly lower when carbamazepine was combined with lithium.

The lack of nocturnal serum thyrotropin surge in patients with nontoxic nodular goiter may predict the subsequent occurrence of hyperthyroidism

TSH secretion, with particular regard to the nocturnal TSH surge, was evaluated in 115 subjects with non-toxic nodular goiter. All patients were clinically and biochemically euthyroid. After 18-36 months of follow-up (mean, 24 months), hyperthyroidism occurred in 21 (18%; group 1), while the remaining 94 remained euthyroid (82%; group II). The analysis of hormonal data at the time of first observation showed that the 2 groups had similar total and free T4 and T3 serum concentrations. Morning serum TSH values in group I were lower than those in group II patients (0.6 +/- 0.1 vs. 1.1 +/- 0.1 mU/L; P less than 0.001); this difference was even more striking for the nocturnal values (0.6 +/- 0.1 vs. 2.2 +/- 0.2 mU/L; P less than 0.0001); nocturnal values were significantly lower than morning values in group II, but not in group I. The mean peak TSH value after TRH was also significantly reduced in group I (5.5 +/- 0.4 vs. 9.2 +/- 0.7 mU/L; P less than 0.001). Morning TSH values in group II did not differ from those in controls (1.3 +/- 0.1 mU/L), whereas nocturnal and TRH stimulated peak TSH values were slightly but significantly lower. The nocturnal serum TSH values in control subjects were 62-390% higher than morning values. The nocturnal TSH surge was abolished in 18 of 21 (86%) group I patients and in 7 of 94 (8%) group II patients. TRH testing resulted in an absent or blunted TSH responses in 5 subjects in group I and 6 in group II. Analysis by the Galen and Gambino predictive model; comparing the abolition of the nocturnal TSH surge and the abnormal TRH test as predictors of the subsequent occurrence of hyperthyroidism, showed that the former had higher sensitivity (86% vs. 24%) and predictivity (72% vs. 45%). In conclusion, the results of the present study demonstrate that the evaluation of the nocturnal TSH surge may be useful in identifying patients with nontoxic nodular goiter in whom hyperthyroidism may eventually occur. Patients who lack the nocturnal serum TSH surge are more prone to develop thyroid hyperfunction; their thyroid status should, therefore, be more carefully and frequently monitored.

The nocturnal serum thyrotropin surge is abolished in patients with adrenocorticotropin (ACTH)-dependent or ACTH-independent Cushing's syndrome

TSH secretion was evaluated in 10 patients with ACTH-dependent (pituitary microadenoma, n = 5) or ACTH-independent [adrenal adenoma (n = 4) or carcinoma (n = 1)] Cushing's syndrome, and in 12 normal controls matched for age and sex. Serum TSH concentration was assayed at night, from 2200-0200 h, and in the morning, both basally and 30 min after iv injection of 200 micrograms synthetic TRH. Patients with hypercortisolism showed significantly reduced serum total T4 and T3 and free T3 concentrations and increased serum reverse T3 levels. Their mean baseline serum TSH concentration in the morning, albeit slightly lower, did not significantly differ from those of controls. The mean peak TSH value after TRH was significantly reduced, and a blunted TSH response to TRH was found in 4 out of 10 patients. At variance with normal controls, who showed nighttime TSH values 63-228% higher than morning values, 9 out of 10 patients had nighttime levels not different from or even lower than those in the morning; the remaining patient had nighttime TSH values marginally (33%) higher than in the morning. An inverse relationship (r = 0.80, P less than 0.001) was found between serum cortisol and TSH values both at night and in the morning. No differences were found either in the pattern of TSH secretion or in the TSH response to TRH between patients with ACTH-dependent and those with ACTH-independent Cushing's syndrome. These results show a substantial impairment of TSH secretion, and in particular the loss of the nocturnal surge of the hormone, in patients with Cushing's syndrome. Although the origin of the nocturnal TSH rise is probably multifactorial, cortisol, at least when secreted in excess, appears to play an important role in its regulation.

Thyroid abnormalities during lithium treatment

Thyroid function was evaluated in 150 Sardinian outpatients at different stages of lithium treatment. A visible and/or palpable goitre was found in 51% of patients, and there was no apparent correlation with the duration of treatment. No cases of symptomatic hypothyroidism were observed, but subclinical hypothyroidism was present in 19% of patients. The prevalence of specific antithyroid antibodies was positively correlated with age and duration of lithium treatment, and was higher in women. Subclinical hypothyroidism was observed in 53% of antibody-positive lithium-treated patients. Carbamazepine in combination with lithium was associated with significantly lower levels of total T4 and T3 than with lithium alone, and the ratios between total and free hormones were also decreased.

More on smoking habits and Graves' ophthalmopathy

Since a relationship between cigarette smoking and the occurrence of Graves' ophthalmopathy has been recently postulated, we reviewed the smoking habits of 1730 women, including subjects without thyroid disease, with nontoxic goiter (NTG), toxic nodular goiter or toxic adenoma (TNG), Hashimoto's thyroiditis (HT), Graves' disease without ophthalmopathy (GD) or with ophthalmopathy (GO). The prevalence of smokers in NTG, TNG and HT was about 30%, not different from that of controls. Smokers were 47.9% in GD and 64.2% in GO groups. The latter figures were highly different from those of the other groups and also from each other. The percentage of heavy smokers was higher in patients with more severe ophthalmopathy. No clear explanation for this phenomenon can be offered. The absence of a high prevalence of smokers among patients with non-toxic goiter, nonautoimmune hyperthyroidism and Hashimoto's thyroiditis, limits the impact that smoking might have had in the pathogenesis of goiter, hyperthyroidism and autoimmune phenomena of GD and GO.