Growth hormone-releasing hormone is produced by adipocytes and regulates lipolysis through growth hormone receptor.

BACKGROUND: Growth hormone-releasing hormone (GHRH) has a crucial role in growth hormone (GH) secretion, but little is known about its production by adipocytes and its involvement in adipocyte metabolism. OBJECTIVES: To determine whether GHRH and its receptor (GHRH-R) are present in human adipocytes and to study their levels in obesity. Also, to analyze the effects of GHRH on human adipocyte differentiation and lipolysis. METHODS: GHRH/GHRH-R and GH/GH-R mRNA expression levels were analyzed in human mature adipocytes from non-obese and morbidly obese subjects. Human mesenchymal stem cells (HMSC) were differentiated to adipocytes with GHRH (10-14-10-8 M). Adipocyte differentiation, lipolysis and gene expression were measured and the effect of GH-R silencing was determined. RESULTS: Mature adipocytes from morbidly obese subjects showed a higher expression of GHRH and GH-R, and a lower expression of GHRH-R and GH than non-obese subjects (P<0.05). A total of 10-14-10-10 M GHRH induced an inhibition of lipid accumulation and PPAR-γ expression (P<0.05), and an increase in glycerol release and HSL expression (P<0.05) in human differentiated adipocytes. A total of 10-12-10-8 M GHRH decreased GHRH-R expression in human differentiated adipocytes (P<0.05). A total of 10-10-10-8 M GHRH increased GH and GH-R expression in human differentiated adipocytes (P<0.05). The effects of GHRH at 10-10 M on adipocyte differentiation and lipolysis were blocked when GH-R expression was silenced. CONCLUSIONS: GHRH and GHRH-R are expressed in human adipocytes and are negatively associated. GHRH at low doses may exert an anti-obesity effect by inhibiting HMSC differentiation in adipocytes and by increasing adipocyte lipolysis in an autocrine or paracrine pathway. These effects are mediated by GH and GH-R.

Iodine status and thyroid function among Spanish schoolchildren aged 6-7 years: the Tirokid study.

I deficiency is still a worldwide public health problem, with children being especially vulnerable. No nationwide study had been conducted to assess the I status of Spanish children, and thus an observational, multicentre and cross-sectional study was conducted in Spain to assess the I status and thyroid function in schoolchildren aged 6-7 years. The median urinary I (UI) and thyroid-stimulating hormone (TSH) levels in whole blood were used to assess the I status and thyroid function, respectively. A FFQ was used to determine the consumption of I-rich foods. A total of 1981 schoolchildren (52 % male) were included. The median UI was 173 µg/l, and 17·9 % of children showed UI<100 µg/l. The median UI was higher in males (180·8 v. 153·6 µg/l; P<0·001). Iodised salt (IS) intake at home was 69·8 %. IS consumption and intakes of ≥2 glasses of milk or 1 cup of yogurt/d were associated with significantly higher median UI. Median TSH was 0·90 mU/l and was higher in females (0·98 v. 0·83; P<0·001). In total, 0·5 % of children had known hypothyroidism (derived from the questionnaire) and 7·6 % had TSH levels above reference values. Median TSH was higher in schoolchildren with family history of hypothyroidism. I intake was adequate in Spanish schoolchildren. However, no correlation was found between TSH and median UI in any geographical area. The prevalence of TSH above reference values was high and its association with thyroid autoimmunity should be determined. Further assessment of thyroid autoimmunity in Spanish schoolchildren is desirable.

Changes in thyroid function with age: results from the Pizarra population-based longitudinal study.

BACKGROUND: Results of studies examining the influence of age on thyroid function and TSH levels, in the absence of thyroid disease, remain controversial. The aim of this study was to determine the course of thyroid function over 11 years in a population with normal thyroid function. METHODS: This is a population-based prospective study started in 1995-1997 (first phase), and reassessed 6 (second phase) and 11 years later (third phase). RESULTS: The TSH and FT4 in the third phase were significantly increased (p=0.001 and p=0.001, respectively), with the values being higher particularly from the age of 50 years. In those persons with a baseline TSH≥1.2 and <3 µIU/mL, the OR of having a TSH of 3-5 µIU/mL in the third phase was 6.10 (p=0.004). In those with a baseline TSH≥3 and ≤5 µIU/mL, the OR of having a TSH of 3-5 µIU/mL in the third phase was 20.8 (p<0.0001). Similar results were found for FT4. CONCLUSION: In a population free of clinical thyroid disease, TSH and FT4 values rise over the years. This increase occurs in all age groups, but depends mainly on the basal concentrations of TSH and FT4.

Concordancia interobservador en la detección de bocio por palpación en población escolar / Interobserver agreement in detecting goitre by palpation in a school population

Objetivo: Estimar la concordancia interobservador en la detección de bocio por exploración física en población escolar. Metodología: Se realizó un estudio transversal para la detección de bocio en una muestra representativa de 1.134 escolares de 6 a 12 años de 20 colegios del área de salud de La Mancha Centro. La exploración fue realizada de forma enmascarada por 2 únicos observadores. Se establecieron 5 grados de tamaño tiroideo (0, I a, I b, II y III ). Se consideró bocio a partir del grado i a. La concordancia se valoró en relación con variables como edad, sexo, índice de masa corporal, talla y día de exploración. Se utilizó el índice kappa como medida de concordancia. Resultados: En los 1.097 escolares con doble exploración, en 96 (8,8%) se detectó bocio por el observador 1 y en 102 (9,3%) por el 2 (p = 0,58). El grado de acuerdo interobservador en la identificación y en la graduación del bocio fue moderado (kappa 0,55; IC del 95%, 0,46-0,64) para la primera y sustancial (kappa ponderado 0,61; IC del 95%, 0,51-0,71) para la segunda. Fue algo mayor en las niñas y en los escolares de mayor edad, peso, talla e índice de masa corporal. La concordancia entre observadores fue relativamente estable a lo largo de la realización del estudio. Conclusiones: La concordancia interobservador en la detección de bocio por palpación en nuestro estudio es moderada, aunque más baja en los niños más pequeños e invariable durante todo el periodo en el que se realizó (AU)

Objective: To estimate the agreement between observers on the detection of goitre by physical exploration in a school population. Methodology: We performed a cross-sectional study to detect goitre in a representative sample of 1134 schoolchildren aged 6 to 12 years from 20 schools in the health area of La Mancha Centro. The examination was performed blinded by two observers. Five grades in thyroid size were established (0, Ia, Ib, II and III ). Above grade Ia was considered as goitre. The agreement was assessed in relation to variables such as age, sex, body mass index, height, and day of examination. The weighted kappa was used to measure the agreement. Results: In the 1097 schoolchildren with a dual examination, 96 (8.8%) cases of goitre were detected by observer 1, and 102 (9.3%) cases by observer 2, (P=0.58). The degree of interobserver agreement in the identification and grading of goitre was moderate (kappa 0,55, 95%CI: 0,46 to 0,64) for the first, and substantial (weighted kappa 0,61; 95% CI: 0,51 to 0,71) for the second. The degree of agreement was somewhat higher in girls, older schoolchildren, increased weight, height, and body mass index. The interobserver agreement was relatively stable throughout the study. Conclusions: The interobserver agreement in detecting goitre by palpation in our study is moderate, but is lower in younger children and stable for the duration of study (AU)

[Interobserver agreement in detecting goitre by palpation in a school population]. / Concordancia interobservador en la detección de bocio por palpación en población escolar.

OBJECTIVE: To estimate the agreement between observers on the detection of goitre by physical exploration in a school population. METHODOLOGY: We performed a cross-sectional study to detect goitre in a representative sample of 1134 schoolchildren aged 6 to 12 years from 20 schools in the health area of La Mancha Centro. The examination was performed blinded by two observers. Five grades in thyroid size were established (0, Ia, Ib, II and III). Above grade Ia was considered as goitre. The agreement was assessed in relation to variables such as age, sex, body mass index, height, and day of examination. The weighted kappa was used to measure the agreement. RESULTS: In the 1097 schoolchildren with a dual examination, 96 (8.8%) cases of goitre were detected by observer 1, and 102 (9.3%) cases by observer 2, (P=.58). The degree of interobserver agreement in the identification and grading of goitre was moderate (kappa 0,55, 95%CI: 0,46 to 0,64) for the first, and substantial (weighted kappa 0,61; 95%CI: 0,51 to 0,71) for the second. The degree of agreement was somewhat higher in girls, older schoolchildren, increased weight, height, and body mass index. The interobserver agreement was relatively stable throughout the study. CONCLUSIONS: The interobserver agreement in detecting goitre by palpation in our study is moderate, but is lower in younger children and stable for the duration of study.

Iodine intake in the adult population. Di@bet.es study.

BACKGROUND & AIMS: To date no nation-wide study has yet been undertaken in Spain to estimate the iodine deficiency. The aim was to evaluate iodine intake and its conditioning factors in a representative sample of the whole adult population. METHODS: The Di@bet.es Study is a national, cross-sectional, population-based survey conducted in 2009-2010 in Spain. RESULTS: The median urinary iodine (UI) was 117.2 µg/L. Iodized salt (IS) was consumed by 43.9% of the population. The median UI in those who consumed IS and in those who did not consume IS was 131.1 and 110.8 µg/L respectively (p<0.0001). The likelihood of having UI levels above 100 µg/L was significantly associated with the intake of IS (OR=1.47) and milk at least once a day (OR=1.22). Within each individual autonomous communities, the median UI levels in those who consumed IS correlated significantly with the median levels of those who did not consume IS (r=0.76, p=0.001). CONCLUSIONS: Though strictly speaking, Spain should be considered within the category of a country having an adequate iodine intake, the current value is too close to the cut point and does not guarantee that those groups with a greater need for iodine will have the required intake of iodine.

Vitamin D deficiency in Spain: a population-based cohort study.

BACKGROUND: Vitamin D deficiency is common worldwide. No homogenous reference values have yet been established and no studies of values have been conducted in Spain involving a large number of participants. OBJECTIVE: To study the population concentrations of vitamin D in a representative sample of the Spanish population. SUBJECTS/METHODS: The study involved two cohorts from Spain, the Asturias study and the Pizarra study, which are two prospective, population-based studies involving 2260 participants. In 1262 subjects (age: 20-83 years) we studied 25-hydroxyvitamin D, intact parathyroid hormone (iPTH), calcium, phosphorus and creatinine. RESULTS: The median population values of 25-hydroxyvitamin D and iPTH were 22.46 ng/ml and 42.29 pg/ml, respectively. The values of 25-hydroxyvitamin D were significantly higher in summer and correlated with age (ß = -0.05 ± 0.01, P < 0.0001), creatinine (ß = 6.42 ± 1.17, P < 0.0001) and iPTH (-0.07 ± 0.01, P < 0.0001), but not with calcium, phosphorus or sex. The increase in iPTH with age was seen whatever the values of 25-hydroxyvitamin D, and was greater in the older persons. The concentration of iPTH rose continuously with effect from 25-hydroxyvitamin D values below ≈30 ng/ml. Values above ≈35 ng/ml were associated with a significantly lower concentration of iPTH. CONCLUSIONS: One-third (33.9%) of the Spanish population may be at risk for Vitamin D deficiency. The 25-hydroxyvitamin D values above 30 ng/ml can safely discard 'hyper PTH'. The increase in iPTH concentration is greater in older persons for similar values of 25-hydroxyvitamin D.

Jejunal wall triglyceride concentration of morbidly obese persons is lower in those with type 2 diabetes mellitus.

The overproduction of intestinal lipoproteins may contribute to the dyslipidemia found in diabetes. We studied the influence of diabetes on the fasting jejunal lipid content and its association with plasma lipids and the expression of genes involved in the synthesis and secretion of these lipoproteins. The study was undertaken in 27 morbidly obese persons, 12 of whom had type 2 diabetes mellitus (T2DM). The morbidly obese persons with diabetes had higher levels of chylomicron (CM) triglycerides (P < 0.001) and apolipoprotein (apo)B48 (P = 0.012). The jejunum samples obtained from the subjects with diabetes had a lower jejunal triglyceride content (P = 0.012) and angiopoietin-like protein 4 (ANGPTL4) mRNA expression (P = 0.043). However, the apoA-IV mRNA expression was significantly greater (P = 0.036). The jejunal triglyceride content correlated negatively with apoA-IV mRNA expression (r = -0.587, P = 0.027). The variables that explained the jejunal triglyceride content in a multiple linear regression model were the insulin resistance state and the apoA-IV mRNA expression. Our results show that the morbidly obese subjects with diabetes had lower jejunal lipid content and that this correlated negatively with apoA-IV mRNA expression. These findings show that the jejunum appears to play an active role in lipid homeostasis in the fasting state.