Tania Weber Furlanetto

Role of Estrogen in Thyroid Function and Growth Regulation

Thyroid diseases are more prevalent in women, particularly between puberty and menopause. It is wellknown that estrogen (E) has indirect effects on the thyroid economy. Direct effects of this steroid hormone on thyroid cells have been described more recently; so, the aim of the present paper was to review the evidences of these effects on thyroid function and growth regulation, and its mechanisms. The expression and ratios of the two E receptors, α and β, that mediate the genomic effects of E on normal and abnormal thyroid tissue were also reviewed, as well as nongenomic, distinct molecular pathways. Several evidences support the hypothesis that E has a direct role in thyroid follicular cells; understanding its influence on the growth and function of the thyroid in normal and abnormal conditions can potentially provide new targets for the treatment of thyroid diseases.

Hipovitaminose D em adultos: entendendo melhor a apresentação de uma velha doença

Vitamin D is synthesized in skin through a reaction mediated by sunlight, and it is metabolized to 25-hydroxyvitamin D, in liver, and in 1,25-dihydroxyvitamin D, in kidney. This last reaction has a tight feedback mechanism. 1,25-dihydroxyvitamin D is the active hormone, and its actions are mediated mainly by nuclear receptors. Its major functions are in calcium metabolism and bone mass maintenance. Hypovitaminosis D, as a disease in adult people, manifests itself with hypocalcemia and secondary hyperparathyroidism with subsequent loss of trabecular bone, thinning of cortical bone, and, eventually, a higher risk of fractures. Hypovitaminosis D is a very common condition in Europe, Africa, North America and some South American countries, such as Chile and Argentina. Measurement of serum total 25-hydroxyvitamin D concentration is the gold standard to diagnose vitamin D deficiency. Serum concentrations below 50 nmol/L are associated with an increase in parathyroid hormone concentration, and bone loss. Risk factors for vitamin D deficiency, like poor sunlight exposition, aging skin and factors that interfere with normal vitamin D metabolism, are well established. Oral vitamin D supplementation, an easy and inexpensive treatment, is needed to treat this illness.

Hyperparathyroidism secondary to hypovitaminosis D in hypoalbuminemic is less intense than in normoalbuminemic patients: a prevalence study in medical inpatients in southern Brazil.

Hypovitaminosis D has been reported in tropical countries, but this hormone has seldom been studied in Brazil. Our purpose was to study the prevalence of hypovitaminosis D in patients hospitalized in internal medicine wards in Southern Brazil. Possible associated factors were studied. We studied 81 adult patients in early spring. Mean serum 25(OH)D was 12±8.57 ng/mL; hypovitaminosis D was severe (<10 ng/mL) in 27 (33.3%) patients, and moderate (≥10 ng/mL and <20 ng/mL) in 36 (44.5%) patients. Clinical evaluation did not yield any data associated with hypovitaminosis D. Serum 25(OH)D levels of up to 20 ng/mL were associated with decreased mean serum total calcium (p=0.001), ionized calcium (p=0.01), and phosphorus (p=0.044) levels, and increased mean serum PTH level (p=0.001). In a multiple regression model, serum PTH level was independently affected by serum total calcium (p=0.01), phosphorus (p=0.009), and albumin (p=0.009) levels. Hypovitaminosis D patients had lower mean serum albumin levels (p=0.004), and serum 25(OH)D levels were directly correlated to serum albumin levels (p<0.0001). Albumin influenced independently PTH response to hypovitaminosis D; normoalbuminemic hypovitaminosis D patients had higher mean serum PTH than hypoalbuminemic patients. Conclusion: Hypovitaminosis D prevalence was very high in medical inpatients in Southern Brazil, in early spring. Nevertheless, secondary hyperparathyroidism was less intense in hypoalbuminemic hypovitaminosis D patients suggesting that in these patients free serum 25(OH)D was closer to normal.

Hypovitaminosis D and secondary hyperparathyroidism in resident physicians of a general hospital in southern Brazil

Objectives: To evaluate the prevalence of hypovitaminosis D and secondary hyperparathyroidism in resident physicians of a general hospital in southern Brazil and identify associated factors. Design: Crosssectional study. Population: Resident physicians of Hospital de Clinicas de Porto Alegre, Porto Alegre, southern Brazil. Participants: Seventythree subjects age 26.4± 1.9. Measurements: Serum PTH, 25- hydroxyvitamin D [25(OH)D], total calcium, phosphorus, magnesium, creatinine, and alkaline phosphatase were measured. In addition calcium, creatinine, and magnesium were measured in urine. Fractional excretion of calcium and magnesium were calculated. Calcium intake was estimated by a food intake questionnaire. Results: Mean serum levels of 25(OH)D were 17.9± 8.0 ng/ml and 57.4% presented 25(OH)D below 20 ng/ml. Secondary hyperparathyroidism, defined as serum PTH ≥ 48 pg/ml and normal or low serum calcium, was identified in 39.7% of the individuals. Mean serum levels of magnesium were higher (p=0.02) and the fractional excretion of calcium was lower (p<0.001) in individuals with secondary hyperparathyroidism. Serum PTH levels were positively correlated with body mass index (r=0.33 and p=0.006) and serum magnesium levels (r=0.33 and p=0.02) and negatively correlated with serum 25(OH)D levels (r=− 0.33 and p=0.008), estimated calcium intake (r=− 0.25 and p=0.04), and fractional excretion of calcium (r=− 0.34 and p=0.009). Conclusion: Vitamin D deficiency and secondary hyperparathyroidism was very common in resident physicians. Therefore, measures to prevent this situation should be recommended.

Does serum 25-hydroxyvitamin D decrease during acute-phase response? A systematic review

Low levels of 25-hydroxyvitamin D, or 25(OH)D, are commonly associated with inflammatory diseases. These associations could be due to an increased prevalence of inflammatory diseases in hypovitaminosis D, although reverse causality cannot be excluded. We aimed to systematically review the longitudinal studies that reported serum 25(OH)D during an acute inflammatory response in humans. Using Ovid MEDLINE, EMBASE, and the Cochrane Library, an electronic search of the literature was conducted from database inception until January 2014 by combining the MeSH terms: vitamin D and acute-phase reactants. Other sources for obtaining articles were used as cross-referencing texts. Based on 670 titles and abstracts, 40 articles were selected for full-text review, and 8 of these studies met the final inclusion criteria. In 6 of the reviewed studies, 25(OH)D dropped after the inflammatory insult; this decrease was abrupt in the studies that measured 25(OH)D early after the insult. In 2 studies, there was no change of 25(OH)D during the course of the disease, but baseline levels were measured in both after days of symptoms onset. One study suggested that hemodilution decreased 25(OH)D, with no effect on inflammation. Serum C-reactive protein concentrations were used as inflammatory markers in almost all studies. The metabolic meaning and the functional importance of these changes are unknown. In light of the current evidence, the 25(OH)D measured during acute-phase response should be interpreted with care. Future research, including other markers of vitamin D adequacy, could help to clarify if hypovitaminosis D might be the cause or the consequence of inflammatory diseases.

High prevalence of hypovitaminosis D and secondary hyperparathyroidism in elders living in nonprofit homes in South Brazil

Objectives Hypovitaminosis D (HD) and secondary hyperparathyroidism (SHP) are common in elders, and many factors could contribute to them. The objectives of this study were to estimate the prevalence of HD, SHP, and its associated factors, in individuals living in nonprofit homes for elders in south Brazil. Design Cross-sectional study. Methods Serum 25-hydroxyvitamin D 25(OH)D, intact parathyroid hormone (PTH), total calcium, phosphorus, alkaline phosphatase, magnesium, creatinine, and albumin levels were measured in late spring, November, 2005. The presence of factors potentially related with HD and SHP—age, sex, weight, height, skin phototype, sun exposure, exercise, smoking, use of ≤5 medications or diuretics or alcohol, and daily calcium ingestion. Results 102 subjects age 77.8xa0±xa09.0 were included in the study. HD was found in 85.7% and SHP in 53% of the subjects. The estimated daily calcium ingestion was 720xa0mg. There was no association between serum 25(OH)D levels and any of the risk factors evaluated. Serum 25(OH)D levels were correlated with serum PTH (rxa0=xa0−0.358, Pxa0=xa00.000), calcium (rxa0=xa00.306, Pxa0=xa00.002), and albumin (rxa0=xa00.253, Pxa0=xa00.011) levels. In univariate analysis, SHP was positively associated with age (Pxa0=xa00.006), and female sex (0.007); and negatively associated with sunlight exposure (Pxa0=xa00.020), GFR (Pxa0=xa00.000), Ln25(OH)D (Pxa0=xa00.002), and total serum calcium (Pxa0=xa00.024). After multivariate model adjustment, age [OR 1.09 (CI 1.01–1.18); Pxa0=xa00.024], Ln25(OH)D [OR 0.92 (CI 0.08–0.74); Pxa0=xa00.013], GFR [OR 0.96 (CI 0.92–0.99); Pxa0=xa00.013], and hydrochlorothiazide treatment [OR 7.63 (CI 1.67–34.9); Pxa0=xa00.008] were independently associated with SHP. Conclusions HD and SHP are highly prevalent in elders living in old-age homes. No associations were established between common risk factors and low serum levels of 25(OH)D levels; however, SHP was independently related with age, 25(OH)D, GFR, and hydrochlorothiazide use.

Vitamin B12 in metformin-treated diabetic patients: a cross-sectional study in Brazil

OBJECTIVEnThe objective of this study was to evaluate the presence of vitamin B12 deficiency and the factors associated with serum vitamin B12 levels in a sample of metformin-treated Brazilian diabetic patients.nnnMETHODnCross-sectional study.nnnRESULTSn144 patients were included. Serum vitamin B12 levels were low (< 125 pmol/L) in 10 patients (6.9%) and possibly low (125 - 250 pmol/L) in 53 patients (36.8%). Serum vitamin B12 levels were negatively associated with age (B = -3.17; β= -0.171; p = 0.037) and duration of metformin use (B= -33.36; β= -0.161; p = 0.048), and positively associated with the estimated intake of vitamin B12 (B= 67.96; β= 0.249; p = 0.002).nnnCONCLUSIONnThe present findings suggest a high prevalence of vitamin B12 deficiency in metformin-treated diabetic patients. Older patients, patients in long term treatment with metformin and low vitamin B12 intake are probably more prone to this deficiency.

Low bone mineral density is associated with insulin resistance in bone marrow transplant subjects

Post-BMT subjects have an increased bone fracture risk. Additionally, several factors were associated with osteopenia and osteoporosis in these individuals. We aimed to identify other factors associated with osteopenia and osteoporosis in allogeneic post-BMT subjects. We conducted a cross-sectional study with 47 allogeneic post- BMT subjects. Serum 25-hydroxyvitamin D (25(OH)D), parathyroid hormone, ferritin, vitamin B12, insulin, glucose, cholesterol and triglyceride levels were measured. Insulin resistance and secretion were estimated through the homeostatic model assessment for insulin resistance (HOMA-IR) and homeostatic model assessment for β-cell function (HOMA-B), respectively. A bone densitometry (BMD) was also obtained. The median time after BMT was 47.7 (12–115) months. Osteoporosis was identified in 17.0% of the subjects and osteopenia in 19.7%. The mean serum ferritin (P=0.002), insulin (P<0.0001), glucose (P=0.003) and triglyceride (P=0.018) levels were higher in individuals with osteopenia/osteoporosis. HOMA-IR (P<0.0001) and HOMA-B (P<0.0001) were increased in post-BMT subjects with osteopenia/osteoporosis. There was no other factor associated with the outcome. After adjustments ferritin, serum 25(OH)D and HOMA-IR remained independently associated with osteopenia/osteoporosis; however triglycerides no longer were. In conclusion, in the present study, low serum 25(OH)D levels, high serum ferritin levels and insulin resistance were associated with osteopenia/osteoporosis in post-BMT subjects.

Prognosis of Thyroid Cancer Related to Pregnancy: A Systematic Review

Differentiated thyroid cancer (DTC) is the second most common cancer in pregnancy. Its management is a challenge for both doctors and patients, and the best timing for surgery is unclear. A systematic review evaluating the prognosis of DTC in pregnant patients was conducted. After reviewing 401 unique citations and 54 full texts, 4 studies that compared the prognosis of patients with DTC related to pregnancy (DTC diagnosed during pregnancy or within 12 months after childbirth) or not were included. In two studies the primary outcome was overall survival, in one study the primary outcomes were recurrent disease and death related to thyroid cancer, and in one study the primary outcome was recurrent or persistent disease. In the first two studies, there was no difference in overall survival in patients with pregnancy-related DTC, when compared with matched controls; in one study, there was no difference in death caused by DTC nor recurrence in DTC related to pregnancy. Nevertheless, in a recent retrospective study, a higher rate of recurrent or persistent DTC was observed in patients with DTC related to pregnancy. There are not many studies on which to base treatment decisions in pregnant patients with DTC.

Solitary fibrous tumor of the sella mimicking pituitary adenoma: an uncommon tumor in a rare location-a case report.

Solitary fibrous tumor (SFT) is rarely located in the central nervous system, and sella turcica involvement was reported in only two patients. We report the case of a 28-year-old man with a SFT of the sella turcica mimicking a pituitary nonfunctioning macroadenoma. He presented with optic nerve compression caused by a heterogeneous tumor located in the sellar and suprasellar area. At surgery, the tumor was hard and infiltrated the sellar diaphragm, so that resection resulted in a cerebrospinal fluid fistula. His postoperative course was also complicated by complete central diabetes insipidus, hypopituitarism, and two episodes of meningitis. After surgical resection, the diagnosis of SFT was reached on the basis of histological and immunohistochemical studies. He was discharged after 49xa0days. Ten months after surgery, he was clinically well, and magnetic resonance images showed no evidence of residual or recurrent tumor. SFT should be considered in the differential diagnosis of sellar and parasellar tumors.