Genetic screening of patients with medullary thyroid cancer in a referral center in Greece during the past two decades.

OBJECTIVE: Mutations in the RET gene are responsible for hereditary medullary thyroid cancer (MTC) and may vary between ethnic groups. We report the spectrum of mutations detected in patients with MTC in a referral center in Greece. PATIENTS AND METHODS: Screening for RET mutations was performed in 313 subjects from 188 unrelated families: 51 patients had clinical suspicion for familial disease, 133 were apparently sporadic, four patients had only C cell hyperplasia, and 125 were family members. Exons 8, 10, 11, and 13-16 were screened. RESULTS: A total of 58 individuals (30.85%) were RET mutations carriers, 120 (63.8%) were finally classified as sporadic, 13 apparently sporadic cases (9.8%) were identified with RET mutation: ten carried the exon 8 at codon 533 mutation (previously reported), two the exon 14 at codon 804 mutation, and one the exon 13 at codon 768 mutation. Six patients (3.19%) with clinical features of multiple endocrine neoplasia type 2A and negative for RET mutations were classified as 'unknown cause'. The mutations of hereditary cases were as follows: 21 cases (36.2%) in exon 8 codon 533, 19 (32.8%) in exon 11 codon 634, nine (15.5%) in exon 10, five (8.6%) in exon 16, three (5.2%) in exon 14 codon 804, and one in exon 13 codon 768 (1.7%). CONCLUSION: The spectrum of RET mutations in Greece differs from that in other populations and the prevalence of familial cases is higher. The exon 8 (Gly533Cys) mutation was the most prevalent in familial cases unlike other series, followed by exon 11 (codon 634) mutations which are the most frequent elsewhere. The wide application of genetic screening in MTC reveals new molecular defects and helps to characterize the spectrum of mutations in each ethnic group.

Hormonal parameters and sex hormone receptor gene polymorphisms in men with autoimmune diseases.

Autoimmune diseases (ADs) are more common in women than in men. Sex hormones may play a role. Sex hormone receptors (SHR) are expressed in cells of the immune system. We investigated the possible role of hormonal parameters and of common polymorphisms of the estrogen receptor alpha (ESR1), beta (ESR2), and androgen receptor (AR) genes in the appearance of AD in men. 277 men were studied; 125 with ≥1 AD: Hashimoto's autoimmune thyroiditis (n = 65), Graves' disease (n = 12), SLE (n = 10), and RA (n = 38). 152 were controls. Hormonal and biochemical parameters were measured after discontinuation for ≥1 month of any corticosteroid therapy. ESR1 PvuII, ESR2 AluI, and the AR (CAG)n repeats polymorphisms were analyzed. AD patients had higher estradiol levels (31.32 ± 12.10, controls 20.37 ± 7.91 pg/ml, p < 0.001). In multivariate analysis, significant predictors for AD were estrogen and BMI. The allele frequency of ESR1 PvuII and ESR2 AluI did not differ between patients and controls (AD: 47.8 %, 37.6 %; controls 49.8 %, 39.9 %). The distribution of (CAG)n did not differ between groups. In AD group, shorter (CAG)n alleles were associated with younger age of AD onset (short: 38.52 ± 14.8, long: 47.14 ± 17.34 years, p = 0.048). Carriers of ESR1 PvuII presented less frequently ≥2 AD (carriers 6.5 %, non-carriers 25.1 %, p = 0.019); carriers of AluI had lower SHBG levels and higher ΒΜΙ compared to non-carriers (p < 0.04). Higher estradiol may play a role in AD in men. Distribution of SHR gene polymorphisms is similar between patients and controls. Shorter AR (CAG)n repeats may predispose for younger AD onset. Coexistence of ≥2 AD is less frequent in carriers of ESR1 PvuII. ESR2 AluI may adversely affect obesity parameters.

Clinical and biochemical impact of BCL1 polymorphic genotype of the glucocorticoid receptor gene in patients with adrenal incidentalomas.

BACKGROUND: Adrenal incidentaloma (AI) is a common clinical problem. Subtle hormonal abnormalities are present in a substantial proportion of patients. BCL1 gene polymorphism of the glucocorticoid receptor (GR) is associated with increased sensitivity to glucocorticoid action. The genotype- phenotype associations of this polymomorphism in patients presenting with AI has not been extensively investigated. AIM: A cross-sectional study in secondary/tertiary care centers. SUBJECTS/METHODS: Ninety-five subjects with AI were genotyped for the BCL1 GR gene polymorphism. Patients underwent an oral glucose tolerance test and a dexamethasone suppression test (DST). The presence of subclinical hypercortisolism, features of metabolic syndrome, and osteoporosis/ osteopenia were also assessed. RESULTS: No significant differences in markers of adrenal function between BCL1 carriers and non-carriers were revealed. Also, no difference was found in the features of metabolic syndrome, as well as in bone metabolism and density between these 2 groups. However, DST suppressor patients belonged more frequently to the BCL1 carriers group (41 out of 69 patients, 59.4% vs 9 out of 26 patients, 34.6%, p=0.0039), had smaller total adenoma size (2.4±0.2 cm vs 3.5±0.4 cm, p=0.04), and lower incidence of bilateral adrenal masses (18.8% vs 46.2%, p=0.01). CONCLUSIONS: AI patients who also carry the polymorphic BCL1 variant exhibit smaller size adrenal nodules. Those AI patients with complete DST suppression had a higher incidence of the polymorphic BCL1 variant. However, this study failed to demonstrate any significant impact of BCL1 GR polymorphism on the frequency of cortisol-dependent co-morbidities in patients with AI.

Cortisol levels and metabolic parameters in middle- and advanced- age subjects: associations with age.

BACKGROUND: It has been reported that morning cortisol levels increase with age, although there is some controversy in the literature. AIM: The aim of this study was to examine associations of cortisol levels with advancing age in an elderly population and investigate possible interactions with metabolic and hormonal parameters. SUBJECTS AND METHODS: From 372 subjects initially evaluated, we studied 251 ambulatory subjects aged 51-90 yr, median 71 yr (169 women), all permanent residents of a small town in southern Greece. Anthropometric parameters, glucose, insulin, cortisol, and biochemical parameters were recorded. RESULTS: Fasting cortisol levels (08:00-09:00 h) varied between 150.9- 854 nmol/l (mean 362.4 nmol/l). A significant association was found between age and cortisol levels (Spearman's rho =0.170, p=0.01). There was a positive correlation between cortisol levels and creatinine (Spearman's rho =0.144, p=0.023), homocysteine (Spearman's rho =0.283, p<0.001) and a negative correlation with body mass index (Spearman's rho =-0.128, p=0.047). Multivariate analysis showed that when creatinine was taken into account, the association of cortisol with age and with homocysteine was no longer significant. When, however, diabetic subjects were included in the analysis, the adjusted for creatinine association of cortisol with age was significant (ß=0.168, p<0.05). CONCLUSIONS: It is concluded that, in elderly ambulatory subjects, the reported associations between cortisol levels, age, and homocysteine may be affected by coexisting co-morbidities or possibly by a decline in renal function. In subsequent studies it is important that fasting glycemia is taken into account.

Lower early morning plasma cortisol levels are associated with thyroid autoimmunity in the elderly.

OBJECTIVES: Thyroid autoimmunity decreases in the very old. We investigated whether glucocorticoid (GC) activity, which increases in old age, is involved in this process. SUBJECTS AND METHODS: A total of 321 ambulatory subjects (age 51-95 years, median 71, 207 female) were studied. Thyroid function tests, cortisol, glucose, insulin and biochemical parameters were measured. A modified overnight dexamethasone suppression test (0.25 mg) was performed as an index of GC sensitivity. RESULTS: Forty subjects had positive anti-thyroid peroxidase antibodies and 36 had positive anti-thyroglobulin antibodies, while 57 had either one or the other or both thyroid autoantibodies (ThAbs) positive. Mean basal cortisol levels were significantly lower in the ThAbs (+) groups (320+/-125 vs 378+/-128 nmol/l, P=0.002). Triiodothyronine, free thyroxine, post-dexamethasone cortisol levels, C-reactive protein, homeostasis model assessment-insulin-resistance-index and body mass index did not differ between these two groups. Mean age of ThAbs (+) subjects was lower compared to the ThAbs (-) group (67.38+/-7.38 vs 71.64+/-8.57 years, P=0.001). CONCLUSIONS: Reduced GC activity is associated with an increased prevalence of ThAbs positivity in older ambulatory subjects. Subjects without ThAbs in this population sample are relatively older. It is not known whether this is related to increasing GC activity with age.

Estrogen receptor beta gene variants may be associated with more favorable metabolic profile in postmenopausal women undergoing coronary angiography.

AIM: Estrogen action is exerted on the vasculature through estrogen receptors ER alpha and ER beta. We have previously reported significant association of ER alpha gene (ESR1) variants with more severe coronary artery disease (CAD) in postmenopausal women. The influence of ER beta gene (ESR2) variants on the cardiovascular system is not well established. We investigated the association of common ESR2 variants with risk factors for cardiovascular disease and with the severity of CAD in postmenopausal women. METHODS: ESR2 polymorphisms Alu I (1730 G > A) and Rsa I (1082 G > A) were studied in 174 postmenopausal women undergoing coronary angiography (age 45 - 88 yrs). The severity of CAD (0 - 3 vessels with > 50 % stenosis), indices of obesity and other predisposing risk factors for cardiovascular disease, biochemical and hormonal parameters were recorded. RESULTS: 75 women had 0, 39 had one, 37 had two and 23 had three vessels with severe stenosis in the coronary angiography. There was no association between Alu I (allele frequency = 40.2 %) and Rsa I (allele frequency = 2.6 %) variants and CAD severity. Carriers of Alu I had lower BMI (p = 0.044), lower waist perimeter (p = 0.029) and lower total cholesterol (p = 0.033) and LDL levels (p = 0.029). There was no association between Rsa I polymorphism and any metabolic risk factors. CONCLUSIONS: ESR2 Alu I polymorphism may have a favorable influence on risk factors for cardiovascular disease such as obesity indices and cholesterol levels. It does not appear to be associated with the severity of CAD in women.

Severity of cardiovascular disease in postmenopausal women: associations with common estrogen receptor alpha polymorphic variants.

OBJECTIVE: Impaired estrogen action is a risk factor for coronary artery disease (CAD). Associations of CAD with estrogen receptor alpha (ER alpha) polymorphisms, which may influence sensitivity to estrogen, have been reported for men; the data concerning women are not conclusive. We investigated the association of common ER alpha polymorphisms with the severity of CAD and with metabolic and reproductive factors in postmenopausal women undergoing coronary angiography. METHODS: ER alpha polymorphisms at positions c.454-397 T>C (PvuII) and c.454-351 A>G (XbaI) were studied in 157 women (age 45-88 years). The severity of CAD was assessed by the number of arteries with >50% stenosis in the angiography. RESULTS: There was a significant association between the TT, TC, and CC genotypes (PvuII) and the severity of CAD (P=0.008); similar results were obtained for the XbaI polymorphism (P=0.021). These associations were independent of other risk factors for CAD. Women homozygous for the C allele had significantly higher triglyceride and insulin levels; they belonged more frequently to the group with a low number of births (n