In the present study, we characterized the distinctive signatures of the gut microbiota (GM) from overweight/obese patients (OB), and normal-weight controls (NW), both of Sardinian origin. Fecal bacterial composition of 46 OB patients (BMI = 36.6 ± 6.0; F/M = 40/6) was analyzed and compared to that of 46 NW subjects (BMI = 21.6 ± 2.1; F/M = 41/5), matched for sex, age and smoking status, by using 16S rRNA gene sequencing on MiSeq Illumina platform. The gut microbial community of OB patients exhibited a significant decrease in the relative abundance of several Bacteroidetes taxa (i.e. Flavobacteriaceae, Porphyromonadaceae, Sphingobacteriaceae, Flavobacterium, Rikenella spp., Pedobacter spp., Parabacteroides spp., Bacteroides spp.) when compared to NW; instead, several Firmicutes taxa were significantly increased in the same subjects (Lachnospiraceae, Gemellaceae, Paenibacillaceae, Streptococcaceae, Thermicanaceae, Gemella, Mitsuokella, Streptococcus, Acidaminococcus spp., Eubacterium spp., Ruminococcus spp., Megamonas spp., Streptococcus, Thermicanus, Megasphaera spp. and Veillonella spp.). Correlation analysis indicated that body fatness and waist circumference negatively correlated with Bacteroidetes taxa, while Firmicutes taxa positively correlated with body fat and negatively with muscle mass and/or physical activity level. Furthermore, the relative abundance of several bacterial taxa belonging to Enterobacteriaceae family, known to exhibit endotoxic activity, was increased in the OB group compared to NW. The results extend our knowledge on the GM profiles in Italian OB, identifying novel taxa linking obesity and intestine.

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.

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.

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)

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.

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.

(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.

Patients suffering from obesity and metabolic syndrome (OMS) manifest a dysregulation in hemodynamic response during exercise, with an exaggerated systemic vascular increase. However, it is not clear whether this is the consequence of metabolic syndrome per se or whether it is due to concomitant obesity. The aim of the present investigation was to discover whether OMS and noncomplicated obesity resulted in different hemodynamic responses during the metaboreflex. Twelve metabolically healthy but obese subjects (MHO; 7 women), 13 OMS patients (5 women), and 12 normal age-matched controls (CTL; 6 women) took part in this study. All participants underwent a postexercise muscle ischemia protocol to evaluate the metaboreflex activity. Central hemodynamics were evaluated by impedance cardiography. The main result shows an exaggerated increase in systemic vascular resistance from baseline during the metaboreflex in the OMS patients as compared with the other groups (481.6 ± 180.3, -0.52 ± 177.6, and -60.5 ± 58.6 dynes·s(-1)·cm(-5) for the OMS, the MHO, and the CTL groups, respectively; P < 0.05). Moreover, the MHO subjects and the CTL group showed an increase in cardiac output during the metaboreflex (288.7 ± 325.8 and 703.8 ± 276.2 ml/m increase with respect to baseline), whereas this parameter tended to decrease in the OMS group (-350 ± 236.5 ml/m). However, the blood pressure response, which tended to be higher in the OMS patients, was not statistically different between groups. The results of the present investigation suggest that OMS patients have an exaggerated vasoconstriction in response to metaboreflex activation and that this fact is not due to obesity per se