Impact of Growth Hormone on Adult Bone Quality in Turner Syndrome: A HR-pQCT Study.

Women with Turner syndrome (TS) are known to be at risk of osteoporosis. While childhood growth hormone (GH) treatment is common in TS, the impact of this therapy on bone health has been poorly understood. The objective of this study was to determine the influence of childhood GH treatment on adult bone quality in women with TS. 28 women aged 17-45 with confirmed TS (12 GH-treated) agreed to participate in this cross-sectional study. Dual X-ray absorptiometry (DXA) of lumbar spine, hip, and radius and high-resolution peripheral quantitative computed tomography (HR-pQCT) scans of the radius and tibia were used to determine standard morphological and micro-architectural parameters of bone health. Finite element (FE) analysis and polar moment of inertia (pMOI) were used to estimate bone strength. GH-treated subjects were +7.4 cm taller (95% CI 2.5-12.3 cm, p = 0.005). DXA-determined areal BMD of hip, spine, and radius was similar between treatment groups. Both tibial and radial total bone areas were greater among GH-treated subjects (+20.4 and +21.2% respectively, p < 0.05), while other micro-architectural results were not different between groups. pMOI was significantly greater among GH-treated subjects (radius +35.0%, tibia +34.0%, p < 0.05). Childhood GH treatment compared to no treatment in TS was associated with an increased height, larger bones, and greater pMOI, while no significant difference in DXA-derived BMD, HR-pQCT micro-architectural parameters, or FE-estimated bone strength was detected. The higher pMOI and greater bone size may confer benefit for fracture reduction in these GH-treated patients.

Endocrine complications following pediatric bone marrow transplantation.

Pediatric bone marrow transplantation (BMT) for various diseases can lead to endocrine system dysfunction owing to preparative regimens involving chemotherapy and radiation therapy. We assessed the prevalence of post-BMT endocrine complications in children treated at the Alberta Children's Hospital (ACH) from 1991 to 2001. Time of onset of endocrine dysfunction, underlying disease processes, chemotherapy, radiation therapy and age at BMT were characterized. Subjects of <18 years of age at the time of allogeneic or autologous BMT for whom 1-year follow-up through the ACH and a chart were available for review were included in the study. Subjects with a pre-existing endocrine condition were excluded. Of the 194 pediatric BMT procedures performed at the ACH between January 1, 1991 and December 31, 2001, 150 complete charts were available for review. Sixty five subjects received follow-up care at other centers and were excluded. Therefore, a total of 85 subjects were included in the review. The prevalence of endocrine complications identified was: primary hypothyroidism 1.2%, compensated hypothyroidism 7.0%, hyperthyroidism 2.4%, hypergonadotrophic hypogonadism 22.4%, abnormal bone density 2.4%, and secondary diabetes mellitus 1.2%. These findings emphasize the need to screen for endocrine system dysfunction, particularly hypergonadotrophic hypogonadism, in children who have undergone BMT. Children need long-term follow-up so that endocrine complications can be diagnosed and treated promptly.

Vitamin D concentrations among healthy children in Calgary, Alberta.

OBJECTIVE: To examine the relationship between serum vitamin D concentrations, dietary intake and body mass index among healthy children living in Calgary, Alberta. METHODS: The present cross-sectional study included healthy children two to 13 years of age who presented to the Alberta Children's Hospital for elective surgery during a 12-month period. Data including the child's weight, height, age, sex, ethnicity, dietary intake, use of vitamin supplements, physical activity and time spent outdoors were collected. Serum concentrations of 25-hydroxyvitamin D (25[OH]D) were measured using commercial immunoradiometric assay kits. RESULTS: Serum 25(OH)D concentrations were available for 1442 of 1862 participants, of whom 862 (59.8%) were boys. The mean (± SD) serum 25(OH)D concentration was 86.1±35.1 nmol/L (range 10 nmol/L to 323 nmol/L). Five hundred thirty-nine (37.4%) participants had insufficient vitamin D status (25[OH]D between 25 nmol/L and lower than 75 nmol/L), and vitamin D deficiency (25[OH]D 25 nmol/L or lower) was present in 29 subjects (2.0%). Children in the older age group (nine to 13 years) were more likely to have suboptimal vitamin D (P<0.001). Other risk factors significantly associated with suboptimal vitamin D status included overweight or obesity, nonwhite ethnicity, winter months, dietary vitamin D intake of less than 200 IU/day and less time spent outdoors. CONCLUSION: A high rate of suboptimal vitamin D concentrations was observed among the participants. Beyond promoting a vitamin D-enriched diet, physicians should also consider the body mass index and other risk factors to determine the optimal vitamin D intake for children living in the area studied.

Effect of type 1 diabetes on psychosocial maturation in young adults.

PURPOSE: Previous research suggests that having diabetes may complicate the passage from adolescence to adulthood. The aim of this study was to establish if young adults with Type 1 diabetes (T1DM) had delays in aspects of their psychosocial maturation compared with healthy controls (HC). METHODS: A cross-sectional study compared psychosocial maturation in individuals aged 18-25 years with T1DM to age-matched healthy controls. After obtaining consent, participants completed the following measures: Responsibility and Independence Scale for Adolescents (RISA; psychosocial maturity); Social Maturation Index (SMI, social maturity); Levenson's Locus of Control Scales (LOC, internal versus external locus of control) and the Social Density Grid (SDG, social network). RESULTS: In total, 160 subjects completed the study (97 T1DM, 63 HC). Participants included 101 females. No group differences were found on the RISA total score or the Responsibility or Independence Subscales of this measure. On the SMI, the proportion of subjects within each category (good, moderate or poor) was similar for each group. The overall number of social contacts identified on the SDG was similar for all groups; however, individuals with diabetes identified fewer friends within their social network that knew each other (F (2,160) = 3.28, p < .05). No significant group differences were found for LOC. CONCLUSIONS: Young adults with Type 1 diabetes did not show delayed psychosocial maturation when compared with healthy young adult controls.

Impact of growth hormone supplementation on adult height in turner syndrome: results of the Canadian randomized controlled trial.

BACKGROUND: A randomized, controlled trial of GH supplementation to adult height in girls with short stature due to Turner syndrome was conducted in Canada. We report results in subjects who completed the protocol and subjects who participated in follow-up. METHODS: One hundred fifty-four girls with Turner syndrome, aged 7-13 yr, were randomly assigned to one of two groups: 1) GH by sc injection six times per week (0.30 mg/kg.wk), and 2) control (C), no GH treatment. Both cohorts received standardized sex steroid replacement starting at a chronological age of 13 yr. Subjects were followed until protocol completion, defined as height velocity less than 2 cm/yr and bone age 14 yr or greater. A subsequent protocol addendum requested follow-up safety and efficacy assessment in all patients at least 1 yr after the last core protocol visit. RESULTS: One hundred four patients completed the study (61 GH, 43 C), and 50 withdrew (15 GH, 35 C). At protocol completion, mean heights were 147.5 +/- 6.1 (GH) and 141.0 +/- 5.4 cm (C), respectively (P < 0.001). Of those who completed the protocol, 59 (40 GH, 19 C) had height data at least 1 yr after protocol completion; in that group, mean heights were 149.0 +/- 6.4 (GH) and 142.2 +/- 6.6 cm (C), respectively (P < 0.001). At protocol completion and follow-up, the mean height gain due to GH, estimated by analysis of covariance, was +7.2 cm (confidence interval 6.0, 8.4) and +7.3 cm (confidence interval 5.4, 9.2), respectively (both P < 0.001). CONCLUSIONS: This is the first evidence from a randomized, controlled trial to adult height that GH supplementation with induction of puberty at a near physiological age increases the adult height of girls with Turner syndrome.