Miquel Gussinyé

Clinical and biochemical determinants of bone metabolism and bone mass in adolescent female patients with anorexia nervosa.

Among pathologies prevalent in western societies, anorexia nervosa has increased over the last decade. Its effects on bone mass need to be defined, and prognostic factors, either clinical or biochemical, could aid clinicians in individual patient management. To determine which clinical and/or biochemical parameters could be related to bone mass status in adolescent female anorexia nervosa patients, 73 female patients were classified according to different stages of their illness and studied in terms of clinical and biochemical parameters and bone densitometric mineral content at lumbar spine. Patients (age 17.2 ± 1.7 y, mean ± SD) with Tanner pubertal stage 5, regular menstruation for more than 3 mo before the onset of secondary amenorrhea, and diagnosed with anorexia nervosa were consecutively studied and classified in three clinical situations:I) active phase (34 patients): undernourished and amenorrheic;II) weight recovered but still amenorrheic (20 patients);III) fully recovered (19 patients). Clinical data were recorded at the time of bone density measurement, concomitant with blood sample extraction for study of IGF-I, IGF-binding protein 3 (IGFBP-3), IGFBP-1, estradiol, sex hormone-binding globulin, dehydroepiandrosterone sulfate, prealbumin, amino-terminal propeptide of procollagen III, osteocalcin, bone alkaline phosphatase, carboxy-terminal propeptide of procollagen I, amino-terminal propeptide of procollagen I, carboxy-terminal telopeptide of collagen I, 25-OH-vitamin D, 1,25(OH)2-vitamin D, and parathormone. In addition, a 24-h urine collection was made for cortisol, GH, deoxypyridinoline, amino-terminal telopeptide of collagen I, and calcium and creatinine content analysis. IGF-I, estradiol, and biochemical bone formation markers were higher and IGFBP-1, sex hormone-binding globulin, and biochemical bone resorption markers were lower in the weight-recovered stages (stages II and III) compared with the active phase (stage I). Bone formation markers correlated positively with body mass index SD score and IGF-I, whereas bone resorption markers correlated negatively with body mass index SD score and estradiol. Although no statistically significant differences regarding lumbar spine bone mineral density SD score values were recorded among the three stages of the illness, the proportion of osteopenic patients was clearly lower among stage III patients. The actual bone mineral density was inversely related to the duration of amenorrhea and directly related to duration of postmenarcheal menses before amenorrhea. In addition, a subset of osteopenic patients (five of 19) in the fully clinically recovered group with accelerated bone turnover was identified. Normal circulating estrogen level exposure time predicts actual bone mineral density at lumbar spine in young adolescent anorexia nervosa patients. In addition to psychiatric and nutritional interventions, estrogen-deprivation periods must be shortened to less than 20 mo. Patients remaining osteopenic at full clinical recovery require additional follow-up studies.

Novel (60%) and recurrent (40%) androgen receptor gene mutations in a series of 59 patients with a 46,XY disorder of sex development.

BACKGROUND Androgen receptor (AR) gene mutations are the most frequent cause of 46,XY disorders of sex development (DSD) and are associated with a variety of phenotypes, ranging from phenotypic women [complete androgen insensitivity syndrome (CAIS)] to milder degrees of undervirilization (partial form or PAIS) or men with only infertility (mild form or MAIS). OBJECTIVE The aim of the study was to characterize the contribution of the AR gene to the molecular cause of 46,XY DSD in a series of Spanish patients. SETTING We studied a series of 133 index patients with 46,XY DSD in whom gonads were differentiated as testes, with phenotypes including varying degrees of undervirilization, and in whom the AR gene was the first candidate for a molecular analysis. METHODS The AR gene was sequenced (exons 1 to 8 with intronic flanking regions) in all patients and in family members of 61% of AR-mutated gene patients. RESULTS AR gene mutations were found in 59 individuals (44.4% of index patients), of whom 46 (78%) were CAIS and 13 (22%) PAIS. Fifty-seven different mutations were found: 21.0% located in exon 1, 15.8% in exons 2 and 3, 57.9% in exons 4-8, and 5.3% intronic. Twenty-three mutations (40.4%) had been previously described and 34 (59.6%) were novel. CONCLUSIONS AR gene mutation is the most frequent cause of 46,XY DSD, with a clearly higher frequency in the complete phenotype. Mutations spread along the whole coding sequence, including exon 1. This series shows that 60% of mutations detected during the period 2002-2009 were novel.

Hyperinsulinemia in Pre- and Post-Pubertal Children Born Small for Gestational Age

Background: Reduced fetal growth is a potential risk factor for development of metabolic abnormalities in later life. The relationship between low birthweight and impaired glucose tolerance, type 2 diabetes and insulin resistance in adulthood has been well documented. Purpose: Assuming that fetal undernutrition is associated with insulin resistance in middle age, we elected to study whether this process may already be present in young adults andadolescents born small for gestational age (SGA). Subjects and Methods: Children born in Vall d’Hebron Hospital Infantil, Barcelona, between 1986 and 1989 and between 1978 and 1983 with birthweights below the third centile for the local standard values, were invited to participate in the present study. Of those, 51 (22 girls and 29 boys) were pre-pubertal with 9.4 ± 0.2 years of age and 49 (29 girls and 20 boys ) were post-pubertal, with 17.3 ± 0.3 years of age. All patients underwent a standard, 2-hour oral glucose tolerance test. Insulin and glucose responses were compared with our previously published data in control children with normal birthweight. Results: The insulin response at 30 min after glucose load was significantly higher (p < 0.001) in pre- and post-pubertal girls and boys formerly SGA than in controls. In addition, the girls also had a higher insulin response at 60 and 120 min. Mean serum insulin (MSI), the area under the insulin curve during the glucose challenge, was statistically increased in pre- and post-pubertal boys and girls born SGA when compared to controls. Conclusion: The presence of high insulin levels after an oral glucose challenge in children and adolescents born SGA might be considered as an early marker of subsequent insulin resistance in adulthood. Furthermore, our population offers the opportunity to study the natural course of hyperinsulinemia and its outcome. Follow-up of this cohort may be helpful in distinguishing a subset of young children and adolescents in whom therapeutic intervention could be done.

Growth hormone, insulin-like growth factor-I axis, and insulin secretion in hyperandrogenic adolescents * †

OBJECTIVE To assess GH and insulin-like growth factor I (IGF-I) axis variability in hyperandrogenic adolescents with different sources of androgen excess and their relationship with insulin resistance. DESIGN Baseline IGF-I, insulin-like growth factor binding protein-1 (IGFBP-1), IGFBP-3, GH response to the exercise-propranolol test, and insulin responses to a standard oral glucose tolerance test were compared among patients with functional ovarian hyperandrogenism, hyperandrogenic nonfunctional ovarian hyperandrogenism patients, and age-matched controls. SETTING Outpatient clinic in a medical center. PATIENTS Twenty-one adolescents with ovarian (group A) and 17 with nonovarian (group B) hyperandrogenism, and 20 controls. RESULTS Serum IGF-I and poststimulated GH levels were similar among groups, whereas serum IGFBP-3 levels were significantly lower in group A than in controls. Mean serum insulin levels were significantly higher in patients than in controls, whereas 24% of patients had abnormal insulin responses to glucose and/or insulin sensitivity indexes. Serum IGFBP-3 levels correlated negatively with the free androgen index (free androgen index = T/sex hormone-binding globulin [SHBG] x 100), whereas mean serum insulin levels correlated positively with the free androgen index and negatively with SHBG levels in all subjects. CONCLUSIONS Hyperinsulinemia is common in hyperandrogenic adolescents and correlates with the degree of hyperandrogenism and not with the androgen source. Hyperinsulinemia and decreased IGFBP-3 levels may enhance IGF-I bioavailability, which in turn may both decrease SHBG levels and increase androgen production.

Ezetimibe as Monotherapy in the Treatment of Hypercholesterolemia in Children and Adolescents

BACKGROUND A prospective study was conducted to evaluate low-density lipoprotein-cholesterol (LDL-C) lowering efficacy and tolerability of ezetimibe as monotherapy in children and adolescents with polygenic hypercholesterolemia (PH) or familial hypercholesterolemia (FH). METHODS AND RESULTS Children with PH (n=6) or FH (n=11) aged 5-15 years were consecutively enrolled to receive ezetimibe as monotherapy at 10 mg/day for 11.3 +/- 7.3 and 15.9 +/- 10.1 months, respectively. Plasma biochemical and lipid profiles were assessed before and after treatment. Ezetimibe significantly lowered total cholesterol (TC) and LDL-C in patients with PH and FH: TC from 260.5 +/- 12.4 to 180.0 +/- 21.6 mg/dl (p = 0.02) and from 315.3 +/- 41.8 to 233.3 +/- 36.8 mg/dl (p = 0.003), respectively, and LDL-C from 177.1 +/- 17.7 to 102.6 +/- 16.7 mg/dl (p = 0.02) and from 243.0 +/- 41.8 to 170.0 +/- 29.8 mg/dl (p = 0.003), respectively. However, high-density lipoprotein-cholesterol (HDL-C) only decreased significantly (from 58.1 +/- 10.0 to 49.3 +/- 9.1 mg/dl) (p < 0.01) in patients with FH and remained unaltered in patients with PH. Triglyceride levels remained unchanged in both groups. Biochemical profile (hemogram, transaminases, creatinine, calcium, phosphorus and liposoluble vitamins A and E) remained unchanged; no adverse effects were observed. CONCLUSIONS Our data show that ezetimibe as monotherapy significantly lowered TC and LDL-C in children with PH and FH.

Intolerancia a la glucosa en niños y adolescentes obesos

Fundamento y objetivo: El incremento de la prevalencia de la intolerancia a la glucosa y de la diabetes mellitus tipo 2 en la infancia y adolescencia en las ultimas decadas parece estar asociado al aumento de la incidencia de obesidad en las sociedades desarrolladas. El objetivo del estudio fue conocer la frecuencia de la intolerancia a la glucosa y de la diabetes tipo 2 en una poblacion de ninos y adolescentes obesos evaluados en un hospital. Pacientes y metodo: Estudio prospectivo de 145 pacientes obesos (60 varones con un indice de masa corporal [IMC] medio [desviacion estandar] de 29,5 [4,9] kg/m2 y una puntuacion z del IMC de 4,4 [1,7]; y 85 mujeres con IMC medio de 28,8 [4,6] kg/m2 y una puntuacion z del IMC 3,8 [1,4] de edades comprendidas entre los 4 y 18 anos, a quienes se les practico un test de tolerancia oral a la glucosa (TTOG) entre 1998 y 2003. Los resultados del TTOG se evaluaron segun los criterios de la Organizacion Mundial de la Salud y se calcularon parametros de secrecion y sensibilidad a la insulina (Homeostasis Model Assessment [HOMA], Quantitative Insuline Sensitivity Check Index [QUICKI]), area bajo la curva de glucemia, area bajo la curva de insulina e indice insulinogenico). Resultados: La frecuencia de la intolerancia a la glucosa fue del 19,2%. Sin embargo, esta vario con la edad y el estadio puberal (prepuberal: 7,0%; puberal: 28,2%; pospuberal: 26,5%) y con el IMC (puntuacion z del IMC entre +2 y +3: 8,9%; entre +3 y +4: 21,9%; mayor de +4: 25%). Ninguno de los pacientes cumplia criterios de diabetes tipo 2. Conclusiones: Los ninos y adolescentes obesos de nuestro medio presentan una elevada incidencia de estados de intolerancia a la glucosa que parecen estar muy directamente relacionados con el grado de adiposidad.

SRD5A2 gene mutations and polymorphisms in Spanish 46,XY patients with a disorder of sex differentiation.

One hundred and forty-six index patients with 46,XY DSD in whom gonads were confirmed as testes were consecutively studied for a molecular diagnosis during the period 2002-2010. AR gene was analysed in all patients as the first candidate gene, yielding a mutation in 42.5% of cases and SRD5A2 gene was analysed as the second candidate gene, resulting in the characterization of 10 different mutations (p.Y91D, p.G115D, p.Q126R, p.R171S, p.Y188CfsX9, p.N193S, p.A207D, p.F219SfsX60, p.R227Q and p.R246W) in nine index patients (6.2% of the total number of 46,XY DSD patients). One of the mutations (p.Y188CfsX9) has never been reported. In addition, we genotyped SRD5A2 gene p.V89L and c.281+15T>C polymorphisms in 46,XY DSD and in 156 normal adult males and found that patients with SRD5A2 mutations or without a known molecular diagnosis presented a higher frequency of homozygous p.L89, homozygous TT and combined CCTT genotypes compared with controls. This result suggests that 46,XY DSD patient phenotypes may be influenced by SRD5A2 polymorphism genotypes. SRD5A2 gene mutations may not be as infrequent as previously considered in 46,XY DSD patients with variable degrees of external genitalia virilization at birth and normal T production and appears to be the second aetiology in our series.

Longitudinal Pubertal Growth According to Age at Pubertal Growth Spurt Onset: Data from a Spanish Study Including 458 Children (223 Boys and 235 Girls)

BACKGROUND Age at pubertal growth spurt (PGS) onset varies and is sex-dependent. We present anthropometric pubertal growth data for five 1-year interval age maturity groups: very early, early, intermediate, late and very late. METHODS Longitudinal growth study of 458 healthy children (223 boys, 235 girls). Ages at PGS onset and at adult height attainment, total pubertal growth (TPG), and peak height velocity (PHV) were evaluated. PGS begins between the ages of 10 and 15 in boys and 8 and 13 in girls; children were allocated to the corresponding 1-year interval age maturity group. RESULTS For each sex, the earlier the start of PGS onset, the higher were PHV and TPG gain. However, adult heights were similar among the five pubertal maturity groups. Height SDS values for mean values of the very early, early, late and very late maturity groups calculated according to data from the five pubertal maturity groups taken together as a single group differed from zero in both sexes, mainly during the pubertal years for the very early (> +1) and very late (> -1) maturers. These differences disappeared at adult height. CONCLUSIONS Our data might contribute to better clinical evaluation of pubertal growth according to individual pubertal maturity tempo.

Hypoglycaemia-Insulin Test: Discordant Growth Hormone and Cortisol Response in Paediatric Patients Regarding Recovery from Hypoglycaemia with or without Oral Glucose Solution

Background: Hypoglycaemia-insulin test (HIT) is the ‘gold standard’ for the diagnosis of adrenal–pituitary–hypothalamic axis disorders. Controversy exists on the convenience of recovery from an insulin-induced hypoglycaemia since this test is not risk-free. Objective: To ascertain whether recovery from insulin-induced hypoglycaemia with an oral glucose solution produces a different response of growth hormone (GH) and cortisol at different times of the study compared with spontaneous recovery from hypoglycaemia. Patients and Methods: Prospective study of 100 children and adolescents with growth delay who underwent an HIT. Patients were consecutively assigned to two groups of 50. In one group recovery from hypoglycaemia occurred spontaneously and in the other recovery was achieved with an oral glucose solution (20 g of glucose) when glycaemia was under 30 mg/dl. The two groups did not differ in age, sex, pubertal status, weight, height and IGF-I levels. Results: The response of GH at 30, 60, 90 and 120 min and cortisol at 10, 60, 90 and 120 min was lower and statistically significant in patients with recovery from hypoglycaemia with oral glucose solution. GH deficiency was diagnosed more frequently in patients recovered with glucose solutions (94%) compared to those with spontaneous recovery (68%). Conclu sions: Oral glucose solution administration when glycaemia was under 30 mg/dl in HIT produced a lower GH and cortisol response to insulin stimulus and a greater frequency of GH deficit diagnosis.

Contribution of human growth hormone-releasing hormone receptor (GHRHR) gene sequence variation to isolated severe growth hormone deficiency (ISGHD) and normal adult height

Molecular causes of isolated severe growth hormone deficiency (ISGHD) in several genes have been established. The aim of this study was to analyse the contribution of growth hormone‐releasing hormone receptor (GHRHR) gene sequence variation to GH deficiency in a series of prepubertal ISGHD patients and to normal adult height.