SummaryThe mechanism of disease progression in Hashimoto's thyroiditis (HT) is still unclear. Anti-thyroid peroxidase antibody (TPOAb), a diagnostic hallmark of HT, is principally of the immunoglobulin G (IgG) isotype, and it appears to be a response to thyroid injury. The aim of our study was to evaluate the distribution of IgG subclasses of TPOAb in sera from patients with HT with different thyroid functional status. Sera from 168 patients with newly diagnosed HT were collected and divided into three groups according to thyroid function: patients with hypothyroidism (n = 66), subclinical hypothyroidism (n = 60) and euthyroidism (n = 42). Antigen-specific enzyme-linked immunosorbent assay was used to detect the distribution of TPOAb IgG subclasses. The prevalence of TPOAb IgG subclasses in all patients' sera with HT was IgG1 70·2%, IgG2 35·1%, IgG3 19·6% and IgG4 66·1% respectively. The prevalence of IgG2 in sera from patients with hypothyroidism (51·5%) was significantly higher than that of subclinical hypothyroidism (33·3%) (P < 0·05), and the latter was also significantly higher than that of euthyroidism (11·9%) (P < 0·05). The positive percentage of IgG2 subclass in sera from patients with hypothyroidism and subclinical hypothyroidism was significantly higher than that of euthyroidism (P < 0·05), the prevalence and positive percentage of IgG4 subclass in sera from patients with hypothyroidism and subclinical hypothyroidism was significantly higher than that of euthyroidism respectively (P < 0·05). The predominant TPOAb IgG subclasses in sera from patients with HT were IgG1 and IgG4. Patients with high levels of TPOAb IgG2, IgG4 subclasses might be at high risk of developing overt hypothyroidism.

Hereditary hemochromatosis (HH) is a genetic disorder that causes excess absorption of iron and can lead to a variety of complications including liver cirrhosis, arthritis, abnormal skin pigmentation, cardiomyopathy, hypogonadism, and diabetes. Hemojuvelin (HJV) is the causative gene of a rare subtype of HH worldwide. This study aims to systematically review the genotypic and phenotypic spectra of HJV-HH in multiple ethnicities, and to explore the genotype-phenotype correlations. A comprehensive search of PubMed database was conducted. Data were extracted from 57 peer-reviewed original articles including 132 cases with HJV-HH of multiple ethnicities, involving 117 biallelic cases and 15 heterozygotes. Among the biallelic cases, male and female probands of Caucasian ancestry were equally affected, whereas males were more often affected among East Asians (P=1.72×10 -2 ). Hepatic iron deposition and hypogonadism were the most frequently reported complications. Hypogonadism and arthropathy were more prevalent in Caucasians than in East Asians (P=9.30×10 -3 , 1.69×10 -2 ). Among the recurrent mutations, G320V (45 unrelated cases) and L101P (7 unrelated cases) were detected most frequently and restricted to Caucasians. [Q6H; C321*] was predominant in Chinese patients (6 unrelated cases). I281T (Chinese and Greek), A310G (Brazilian and African American), and R385* (Italian and North African) were reported across different ethnicities. In genotypephenotype correlation analyses, 91.30% of homozygotes with exon 2-3 mutations developed early-onset HH compared to 66.00% of those with exon 4 mutations (P=2.40×10 -2 ). Hypogonadism occurred more frequently in homozygotes with missense mutations (72.55%) than in those with nonsense mutations (35.71%; P=2.43×10 -2 ). Liver biopsy was accepted by more probands with frame-shift or missense mutations (85.71% and 60.78%, respectively) than by those with nonsense mutations (28.57%; P=2.37×10 -2 , 3.93×10 -2 ). The present review suggests that patients' ethnicity, geographical region, and genetic predisposition should be considered in the diagnosis, prognosis and management of HJV-HH.

The sex difference in the prevalence rates of diabetes and cardiovascular diseases (CVDs) among the middle-aged population in China remain largely unknown. Therefore, we analyzed differences in the prevalence of diabetes, self-reported CVDs, and some CVD risk factors among men and women in the middle-aged population (30–49 years) and in individuals aged 50 years and older using data from the China National Diabetes and Metabolic Disorders Study of 2007–2008. Middle-aged men appeared to have significantly a higher prevalence of diabetes and self-reported CVDs than middle-aged women (8.07% vs 5.06% for diabetes, P < 0.001; 0.64% vs 0.22% for CVDs, P < 0.001). Men also showed higher rates of central obesity, hypertension, and dyslipidemia than women (all P < 0.01). Compared with women, men were more likely to drink alcohol and smoke cigarettes but less likely to be under diet control. The sex-specific differences in prediabetes, CVD, and CVD risk factors between men and women were diminished or even reversed in the population aged 50 years and older. No sex-specific differences were found in the prevalences of a family history of diabetes, coronary heart disease, and hypertension (P > 0.05) in middle-aged population. Specific strategies to reduce modifiable risk factors for the prevention and control of diabetes and CVD may be warranted in this population.

SummaryThe mechanism of disease progression in Hashimoto's thyroiditis (HT) is still unclear. Thyroglobulin antibody (TgAb) is a diagnostic hallmark of HT. The aim of our study was to evaluate the avidity of TgAb in sera from HT patients with different thyroid functional status. Sera from 50 patients with newly diagnosed HT were collected and divided into three groups according to thyroid function: patients with hypothyroidism (H, n = 18), subclinical hypothyroidism (sH, n = 18) and euthyroidism (Eu, n = 14). Titres and avidity of TgAb were determined by enzyme-linked immunosorbent assays (ELISAs). Avidity constant (aK) was determined as the reciprocal value of the thyroglobulin molar concentration in the liquid phase resulting in 50% inhibition of TgAb binding to thyroglobulin in solid-phase ELISAs. The titres and aK of TgAb were performed using log-transformation, and expressed as lgT and lgaK, respectively. Mean lgT of TgAb in sera was 4·19 Ϯ 0·60 in H, 3·77 Ϯ 0·63 in sH, and 3·29 Ϯ 0·64 in Eu, respectively. The median avidity of TgAb was 2·30 ¥ 10 9 in H, 8·80 ¥ 10 8 in sH, 2·00 ¥ 10 7 in Eu, respectively. lgT and lgaK of TgAb were at significantly lower levels in Eu than in sH and H (P < 0·05). Correlation was found between lgT and lgaK (r = 0·594, P < 0·05). lgaK was also related to TSH (r=0·308, P < 0·05). Our study indicated that patients with high-avidity TgAb might be at high risk of developing subclinical, even to overt, hypothyroidism.