Body composition and bone mass among 5-year-old survivors of necrotizing enterocolitis.

BACKGROUND: Necrotizing enterocolitis (NEC) affects the intestine of preterm infants. Preterm infants risk inadequate bone mineralization. This risk may increase if the intestinal uptake of minerals is affected after NEC. METHODS: This is a study of growth, bone mineral density (BMD), bone mineral content (BMC), and body composition at 5 years of age among Swedish children born before gestational week 37 + 0 with a history of NEC, minimum stage IIA, compared to matched controls. Fifty children, 25 NEC cases and 25 controls, were examined with dual energy X-ray absorptiometry (DXA) and DXA with laser. RESULTS: The NEC cases had lower weight, -1.3 SDS vs -0.7 SDS, a lower fat mass and fat percent, 23.4 vs 29.1%, compared to the controls. NEC cases had lower BMC total body head excluded, 355.6 g vs 416.7 g. BMD Z-scores were lower among NEC cases in total body head excluded, -0.7 vs -0.1, and in lumbar spine. CONCLUSIONS: Preterm NEC survivors at 5 years of age had reduced growth, an altered body composition, and indications of a lower bone mass compared to matched controls. The study suggests that preterm infants diagnosed with NEC need special attention during childhood regarding growth and bone health. IMPACT: A follow-up longitudinal study of growth, bone health, and body composition at 5 years of age among children born preterm with a history of NEC compared to matched controls. The NEC cases had lower weight than controls. NEC cases had an altered body composition with lower fat mass compared to controls. The DXA results showed that the NEC cases had lower bone mineral content and a tendency to lower bone mineral density. The study suggests that preterm infants diagnosed with NEC need special attention at follow-up regarding growth and bone health compared to preterm infants without NEC.

Bone mass and biomarkers in young women with anorexia nervosa: a prospective 3-year follow-up study.

INTRODUCTION: Anorexia nervosa (AN) increases the risk of impaired bone health, low areal bone mineral density (aBMD), and subsequent fractures. This prospective study investigated the long-term effects of bone and mineral metabolism on bone and biomarkers in 22 women with AN. MATERIALS AND METHODS: Body composition and aBMD were measured by dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography. Total and free 25-hydroxyvitamin D (25OHD), C-terminal collagen cross-links (CTX), osteocalcin, bone-specific alkaline phosphatase (BALP), leptin, sclerostin, and oxidized/non-oxidized parathyroid hormone (PTH) were analyzed before and after 12 weeks of intensive nutrition therapy and again 3 years later. An age-matched comparison group of 17 healthy women was recruited for the 3-year follow-up. RESULTS: Body mass index (BMI) and fat mass increased from baseline to 3 years in women with AN. Sclerostin decreased during nutrition therapy and further over 3 years, indicating reduced bone loss. CTX was elevated at baseline and after 12 weeks but decreased over 3 years. BALP increased during nutrition therapy and stabilized over 3 years. Free 25OHD was stable during treatment but decreased over 3 years. Non-oxidized PTH was stable during treatment but increased over 3 years. Trabecular volumetric BMD in AN patients decreased during the first 12 weeks and over 3 years despite stable BMI and bone biomarkers implying increased BMD. CONCLUSION: Our findings highlight the importance of early detection and organized long-term follow-up of bone health in young women with a history of AN.

Impaired renal clearance among Swedish adolescents born preterm.

AIM: To determine whether adolescents born before 28 gestational weeks have an increased risk for renal impairment. METHODS: Swedish infants, born before 28 gestational weeks in 2001 and 2002, were identified from a local register. A total of 16 children, 12 females and 4 males, were examined at 16-17 years of age with 51 Cr-EDTA clearance. A comparison group (n = 26) was used. RESULTS: Most study participants (n = 13) had normal blood pressure; one individual had hypertension stage 1. All study participants had results within the reference interval for ionised calcium, parathyroid hormone, intact fibroblast growth factor-23 and for urinary albumin-to-creatinine ratio. Four out of 16 participants (25%) had a 51 Cr-EDTA clearance less than 90 ml/min/1.73 m2 , indicating a reduced kidney function. Measured 51 Cr-EDTA clearance values were significantly lower in the study group than in the comparison group (p = 0.0012). Five study participants (31%) were referred for further investigations. CONCLUSION: Swedish children born before 28 gestational weeks have an increased risk of renal impairment later in life, suggesting that the kidney function in these individuals should be assessed, at least once, during adolescence.

Does Whole-Body Vibration Treatment Make Children's Bones Stronger?

PURPOSE OF REVIEW: To summarize the last 10 years of literature regarding the effects of whole-body vibration (WBV) on bone in children, and if WBV results in increased bone acquisition. RECENT FINDINGS: WBV intervention appears to be a safe intervention with beneficial effects on bone mass in some diseases and syndromes, but there is still low evidence for WBV in clinical practice. The positive effects on muscle strength, balance, and walking speed are more conclusive. One of the takeaways of this review is that well-trained individuals may not further improve bone mass with WBV; thus, interventions are more beneficial in pediatric individuals with Down syndrome or severe motor disabilities with low bone mass and reduced activity levels. WBV appears to be a safe non-pharmacological anabolic approach to increase bone mass in some pediatric populations; however, longer (> 6 months) and larger prospective studies are needed to elucidate the efficacy of WBV on bone health in young individuals.

Intensive weight gain therapy in patients with anorexia nervosa results in improved serum tartrate-resistant acid phosphatase (TRAP) 5a and 5b isoform protein levels.

AIM: Tartrate-resistant acid phosphatase (TRAP) exists as isoforms 5a and 5b. TRAP 5a is a biomarker of chronic inflammation and influences adipose tissue and 5b associates with bone metabolism/pathologies. The aim was to investigate the association of serum TRAP 5a/5b isoforms with fat and bone markers and anthropometric parameters in patients with anorexia nervosa (AN) during weight gain therapy. METHODS: Twenty-five Swedish female AN patients, age 16-24 years, were treated for 12 weeks with a high-energy diet with six meals daily. Serum TRAP 5a/5b, markers of fat/glucose metabolism, markers of bone resorption and formation were measured. Parameters of bone and body composition were assessed by dual-energy X-ray absorptiometry and peripheral quantitative computed tomography. RESULTS: BMI increased from median 15.4 kg/m2 to 19.0 kg/m2, p < 0.0001. TRAP 5a and 5a/5b ratio increased but TRAP 5b decreased during the study. TRAP Δ5a and Δ5b correlated with Δinsulin and Δadiponectin, respectively. TRAP 5b correlated with trabecular density at start but not at week 12. At 12 weeks, TRAP 5b correlated with CTX, and Δ decrease in TRAP 5b correlated to Δ increase in bone-specific alkaline phosphatase. CONCLUSIONS: This clinical interventional study resulted in increased BMI in patients with AN. The decreased TRAP 5b protein levels confirm a role for TRAP 5b as a marker of bone resorption, whereas increased TRAP 5a seemed to derive from systemic changes in bone as well as metabolic changes. The combined detection of TRAP 5a and TRAP 5b in serum could be an indicator of improved bone metabolism. LEVEL OF EVIDENCE: Level III, prospective interventional cohort study.

Increased risk of rickets but not fractures during childhood and adolescence following necrotizing enterocolitis among children born preterm in Sweden.

BACKGROUND: The aim was to clarify whether children born preterm with a history of necrotizing enterocolitis (NEC) had an increased risk of rickets, fractures, and/or vitamin D deficiency during childhood and adolescence compared to controls without NEC, matched for gestational age. METHODS: All infants born in Sweden between 1987 and 2009 with a gestational age <32 + 0 weeks and a diagnosis of NEC were identified. Totally, 465 children with a history of NEC and 2127 controls were included. International Classification of Diseases codes for all categories of fractures, rickets, vitamin D deficiency, and malnutrition were analyzed. RESULTS: In total, 94 of the 465 children with NEC died within 28 days. Of the 2127 controls, 288 died within 28 days. Among the remaining 371 NEC cases, 39 fracture occasions were identified. The 1839 controls had 204 fracture occasions. There was no significant difference in fractures. Rickets was diagnosed in 11 (3%) of the children with a history of NEC compared to 21 (1%) of the controls (odds ratio 2.65, 95% CI 1.26-5.53, p = 0.007). CONCLUSIONS: This study showed an increased risk of rickets but not fractures during childhood and adolescence in children born preterm and with a history of NEC, compared to matched controls.

The Utility of DXA Assessment at the Forearm, Proximal Femur, and Lateral Distal Femur, and Vertebral Fracture Assessment in the Pediatric Population: 2019 ISCD Official Position.

Dual-energy X-ray absorptiometry (DXA) is widely used in the evaluation of bone fragility in children. Previous recommendations emphasized total body less head and lumbar spine DXA scans for clinical bone health assessment. However, these scan sites may not be possible or optimal for all groups of children with conditions that threaten bone health. The utility of DXA scans of the proximal femur, forearm, and radius were evaluated for adequacy of reference data, precision, ability of predict fracture, and applicability to all, or select groups of children. In addition, the strengths and limitations of vertebral fracture assessment by DXA were evaluated. The new Pediatric Positions provide guidelines on the use of these additional measures in the assessment of skeletal health in children.

Randomised study of children with obesity showed that whole body vibration reduced sclerostin.

AIM: New strategies are required to increase physical activity and improve metabolic profiles in children with obesity. We studied the effect of whole body vibration (WBV) on children with obesity on biochemical markers of energy and bone metabolism, anthropometric measurements, muscle parameters and calcaneal bone mineral density (BMD). METHODS: This was a randomised, prospective, controlled study of 30 children with a median age of 13 years (range 7-17) at Queen Silvia Children's Hospital, Gothenburg, Sweden, from 2013 to 2015. The target for the intervention group was to perform WBV three times a week for 12 weeks, and the study parameters were assessed at baseline and 12 weeks. RESULTS: The 16 in the WBV group achieved 51% of the planned activity, mainly at home, and were compared with 14 controls. Sclerostin, bone-specific alkaline phosphatase and carboxy-terminal collagen cross-links decreased in the WBV group (p < 0.05) and balance improved (p < 0.006), but osteocalcin and insulin remained unchanged. Anthropometric data, muscle strength and calcaneal BMD did not differ between the groups. CONCLUSION: WBV did not affect most of the clinical parameters in children with obesity, but the reduction in sclerostin implies that it had direct effects on osteocytes, which are key players in bone mechanotransduction.

A 3-year longitudinal study of skeletal effects and growth in children after kidney transplantation.

This prospective study investigated growth and skeletal development for 3 years after kidney transplantation in pediatric patients, 3.4-15.0 years of age. Growth, BMD, bone resorption markers (CTX and TRACP5b), bone formation markers (PINP, ALP, and osteocalcin), PTH, and vitamin D were assessed at start, 3, 12, and 36 months after transplantation. Median GFR was 63 (range 37-96) mL/min/1.73 m2 after 3 years. The median height SDS increased from -1.7 to -1.1, and median BMI SDS increased from -0.1 to 0.6 over 3 years, which shows that transplantation had a favorable outcome on growth. Fat mass increased after transplantation at all time points, whereas lean mass increased after 1 year and 3 years. Total BMC increased at all time points. No changes were observed for total BMD. Bone resorption markers decreased initially after 3 months and remained stable throughout the study, whereas the bone formation markers decreased initially, but successively increased over the study period. In conclusion, this study demonstrates that height SDS and BMI SDS increased, along with the increased formation markers that reveal a positive bone acquisition after kidney transplantation, which was reflected by the significant increase in total body BMC.

Vitamin D status in young Swedish women with anorexia nervosa during intensive weight gain therapy.

PURPOSE: Anorexia nervosa (AN) is associated with reduced bone mass and an increased fracture risk. The aim was to evaluate the vitamin D status and the association with body mass index (BMI), fat mass and bone mineral density (BMD) in patients with severe AN during a prospective intervention study of intensive nutrition therapy. METHODS: This study comprised 25 Swedish female AN patients (20.1 ± 2.3 years), who were treated as inpatients for 12 weeks with a high-energy diet. Serum 25-hydroxyvitamin D (25(OH)D), calcium, phosphate and parathyroid hormone (PTH) were measured. BMD and body composition were assessed by dual-energy X-ray absorptiometry at study start and after 12 weeks. RESULTS: Twenty-two patients completed the study. The mean weight gain was 9.9 kg and BMI (mean ± SD) increased from 15.5 ± 0.9 to 19.0 ± 0.9 kg/m2, P < 0.0001. Fat mass increased from median 12 to 27 %. The median serum 25(OH)D level was 84 nmol/L at baseline, which decreased to 76 nmol/L, P < 0.05. PTH increased from median 21.9 to 30.0 ng/L, P < 0.0001. BMC increased during the study period, P < 0.001. CONCLUSIONS: Serum 25(OH)D levels were adequate both at study start and completion, however, nominally decreased after the 12-week nutritional intervention. PTH increased subsequently, which coincide with the decreased 25(OH)D levels. The reduction in 25(OH)D could be due to an increased storage of vitamin D related to the increase in fat mass since vitamin D is sequestered in adipose tissue.

Population-based study showed that necrotising enterocolitis occurred in space-time clusters with a decreasing secular trend in Sweden.

AIM: This study investigated space-time clustering of neonatal necrotising enterocolitis over three decades. METHODS: Space-time clustering analyses objects that are grouped by a specific place and time. The Knox test and Kulldorff's scan statistic were used to analyse space-time clusters in 808 children diagnosed with necrotising enterocolitis in a national cohort of 2 389 681 children born between 1987 and 2009 in Sweden. The municipality the mother lived in and the delivery hospital defined closeness in space and the time between when the cases were born - seven, 14 and 21 days - defined closeness in time. RESULTS: The Knox test showed no indication of space-time clustering at the residential level, but clear indications at the hospital level in all the time windows: seven days (p = 0.026), 14 days (p = 0.010) and 21 days (p = 0.004). Significant clustering at the hospital level was found during 1987-1997, but not during 1998-2009. Kulldorff's scan statistic found seven significant clusters at the hospital level. CONCLUSION: Space-time clustering was found at the hospital but not residential level, suggesting a contagious environmental effect after delivery, but not in the prenatal period. The decrease in clustering over time may reflect improved routines to minimise the risk of contagion between patients receiving neonatal care.

Short-term changes in bone formation markers following growth hormone (GH) treatment in short prepubertal children with a broad range of GH secretion.

OBJECTIVES: Growth hormone (GH) promotes longitudinal growth and bone modelling/remodelling. This study investigated the relationship between levels of bone formation markers and growth during GH treatment in prepubertal children with widely ranging GH secretion levels. METHODS: The study group comprised 113 short prepubertal children (mean age ± SD, 9·37 ± 2·13 years; 99 boys) on GH treatment (33·0 ± 0·06 µg/kg/day) for 1 year. Blood samples were taken at baseline and 1 and 2 weeks, 1 and 3 months, and 1 year after treatment start. Intact amino-terminal propeptide of type I procollagen (PINP), bone-specific alkaline phosphatase (BALP) and osteocalcin were measured using an automated IDS-iSYS immunoassay system. RESULTS: Intact amino-terminal propeptide of type I procollagen (PINP), BALP and osteocalcin, increased in the short-term during GH treatment. PINP after 1 week (P = 0·00077), and BALP and osteocalcin after 1 month (P < 0·0001 and P = 0·0043, respectively). PINP levels at 1 and 3 months correlated positively, and osteocalcin levels at 1 week and percentage change after 1 month correlated negatively, with first year growth response. No significant correlations were found between BALP and first year growth. Multiple regression analysis showed that bone marker levels together with auxological data and insulin-like growth factor binding protein-3 explained the variation in first year growth response to 36% at start, 32% after 2 weeks and 48% at 3 months. CONCLUSION: Short-term increases in levels of the bone formation markers PINP, BALP and osteocalcin showed different temporal patterns, but all correlated with first year growth response during GH treatment. These markers may be a useful addition to existing prediction models for growth response.

Bone and fat mass in relation to postnatal levels of insulin-like growth factors in prematurely born children at 4 y of age.

BACKGROUND: Children born prematurely may be at risk of developing osteopenia. This study investigated whether insulin-like growth factors (IGFs) in the early postnatal period influence bone mass and body composition in prematurely born children. METHODS: A total of 74 control (gestational age >36 wk; n = 37) and preterm (gestational age <32 wk; n = 37) infants were investigated (mean age ± SD: 4.59 ± 0.31 y). Bone mineral density, body composition, and markers of bone and mineral metabolism were investigated in relation to postnatal IGF levels. RESULTS: After adjusting for confounders, we found no differences in bone mass, but significantly less lean mass, increased fat mass, and increased osteocalcin levels in ex-preterm infants. Forward stepwise multiple analysis revealed that higher late postnatal IGF-II levels predict lumbar spine bone mineral content (P < 0.05) and lean mass (P < 0.05). When the birth weight standard deviation score was included in the analysis, higher early postnatal IGF-I levels predicted both lumbar spine bone mineral density and bone mineral content (P < 0.05). Higher early postnatal IGF binding protein-3 (P < 0.01) predicted increased fat mass at 4-y follow-up. CONCLUSION: Ex-preterm children have normal bone mass but different body composition compared with full-term controls. Higher early IGF-I and late postnatal IGF-II concentrations are positive predictors of lumbar spine bone mass.

Skeletal effects and growth in children with chronic kidney disease: a 5-year prospective study.

This study was designed to follow the evolving process of growth, bone modeling and remodeling in children with chronic kidney disease (CKD) who are at risk of developing CKD-mineral bone disorder (CKD-MBD). Fifteen patients, 4-15 years, were included with a median glomerular filtration rate of 46 (range 12-74) mL/min/1.73 m(2). Growth, bone mineral density (BMD) and markers of bone and mineral metabolism were investigated over a 5-year period. The median height standard deviation score was -0.65 at the start and 0.1 after 5 years, with a range from -1.7 to 1.7, which implies that growth was acceptable. Total body, femoral neck, and lumbar spine BMD increased over the study period (p < 0.0001). None had total body BMD Z-scores and lumbar spine Z-scores below -2.0 at follow-up. Most bone markers were within the reference intervals, but the formation markers of alkaline phosphatase and type I procollagen intact amino-terminal propeptide (PINP) were slightly increased in about one-third of the patients after 5 years. Eleven out of 15 CKD patients had increased parathyroid hormone levels at baseline and 10 patients after 5 years had increased parathyroid hormone levels. Taken together, this is the first 5-year longitudinal study of skeletal effects, growth and bone turnover in children with CKD. Growth and BMD Z-scores were well preserved on a group basis; however, these parameters varied significantly on an individual basis. We suggest, therefore, that it is difficult to state an overall recommendation and growth, bone mass, and markers of bone and mineral metabolism should be monitored and treated individually in CKD children.

Circulating microRNAs in young individuals with long-duration type 1 diabetes in comparison with healthy controls.

MicroRNAs (miRNAs) are short non-coding RNAs that are involved in post-transcriptional control of gene expression and might be used as biomarkers for diabetes-related complications. The aim of this case-control study was to explore potential differences in circulating miRNAs in young individuals with long-duration type 1 diabetes (T1D) compared to healthy controls, and how identified miRNAs are expressed across different tissues. Twelve adolescents, age 15.0-17.9 years, with T1D duration of more than 8 years (mean 11.1 years), were enrolled from the Swedish diabetes quality registry. An age-matched control group was recruited. Circulating miRNAs (n = 187) were analyzed by quantitative PCR. We observed that 27 miRNAs were upregulated and one was downregulated in T1D. Six of these miRNAs were tissue-enriched (blood cells, gastrointestinal, nerve, and thyroid tissues). Six miRNAs with the largest difference in plasma, five up-regulated (hsa-miR-101-3p, hsa-miR-135a-5p, hsa-miR-143-3p, hsa-miR-223-3p and hsa-miR-410-3p (novel for T1D)) and one down-regulated (hsa-miR-495-3p), with P-values below 0.01, were selected for further in-silico analyses. AKT1, VEGFA and IGF-1 were identified as common targets. In conclusion, 28 of the investigated miRNAs were differently regulated in long-duration T1D in comparison with controls. Several associations with cancer were found for the six miRNAs with the largest difference in plasma.

Bone mass development in patients with Duchenne and Becker muscular dystrophies: a 4-year clinical follow-up.

AIM: To investigate the longitudinal development of bone mass in patients with Duchenne and Becker muscular dystrophies and to study the impact of muscle strength and motor function on bone mass in these patients. METHODS: Eighteen patients with Duchenne muscular dystrophy (2.3-19.7 years at baseline) and six patients with the milder Becker muscular dystrophy (10.8-18.9 years at baseline) were followed during a 4-year period with respect to areal bone mineral density (BMD), motor function and muscle strength. RESULTS: Greater bone mineral accretion was observed in the Becker patient group compared with the age-related Duchenne group above 10 years of age, and the older patients with Duchenne experienced decreased femoral neck BMD during the study period. In the study group, significant correlations were found between BMD in the lower extremities and muscle function parameters. CONCLUSIONS: The differences in BMD between patients with Duchenne and Becker as well as between different bone measurement sites demonstrated in the present study point out the importance of preserving muscle strength and motor function in patients with muscular dystrophy. Moreover; it highlights the value of performing region-specific analysis of the bone quality in these patients.

The Significance of the FTO Gene for Weight and Body Composition in Swedish Women With Severe Anorexia Nervosa During Intensive Nutrition Therapy.

OBJECTIVE: The aim of this prospective study was to investigate the potential influence of the fat mass and obesity-associated gene (FTO), SNP rs9939609, on body mass index (BMI) and body composition in women with anorexia nervosa (AN) undergoing intensive nutrition therapy. METHOD: Twenty-five female patients with AN (20.1 ± 2.3 years; BMI, 15.5 ± 0.9 kg/m2) were included for 12 weeks of treatment with a high-energy diet. FTO was genotyped and body composition parameters were assessed by dual-energy X-ray absorptiometry and peripheral quantitative computed tomography at baseline and after 12 weeks. RESULTS: The distribution of the different FTO genotypes were as follows: AA, 24%; TA, 48%; and TT, 28%. Patients gained a median of 9.8 kg (range, 5.5-17.0 kg) and BMI increased to 19.0 ± 0.9 kg/m2. The increase in BMI, fat mass, and the quotient fat/muscle area was significant for the TT and TA genotype groups. Total lean mass was stable in all genotype groups. We could not demonstrate any difference among the 3 FTO genotypes related to the increases in BMI during nutrition therapy when the additive, dominant, and recessive models of inheritance were applied. CONCLUSIONS: Irrespective of the FTO genotype, there was no difference in weight response during nutrition therapy. Hence, in this small study there was limited support for individualized nutrition therapy for AN based on FTO genotype.

Dietary intake and nutritional status in adolescents and young adults with anorexia nervosa: A 3-year follow-up study.

BACKGROUND & AIMS: Patients with anorexia nervosa (AN) restrict their dietary intake leading to malnutrition. Information is scarce on nutrition status during recovery. The aim of the study was to investigate dietary intake, body composition, biochemistry, and status in young women three years after hospital treatment due to severe restrictive AN. METHODS: Dietary intake from four-day food records were compared to a reference group and the Nordic Nutrition Recommendations. Body composition was assessed by dual-energy X-ray absorptiometry (DXA). Serum levels of vitamin A, E, D, folate, and ferritin were assessed. RESULTS: Three years after hospital treatment for AN, 12 subjects (60%) were recovered or in partial remission from AN. Subnormal values of body fat and skeletal muscle mass were present in 30% and 25%. Energy intake was 1730 kcal/day (min-max 705-2441) or 33 kcal/kg/day (16-54). Most (80%) had a total energy intake/day below the estimated needs and 6 (32%) had energy intakes below 1550 kcal/day. Micronutrient intakes from food were low; 16 (85%) had intakes below recommendations of iron, folate, and vitamin D. Serum levels of vitamins A, E, D, and folate were on average adequate; but a subnormal value (<50 nmol/L) of vitamin D was found in 20%. Ferritin levels were significantly lower at follow-up, and 25% had values below reference range. Return of menstruation was dependent of energy intake and body fat. CONCLUSIONS: A regular and careful assessment of nutritional status along with nutritional counseling during recovery is recommended to reduce malnutrition in patients with AN.

A prospective study of fibroblast growth factor-23 in children with chronic kidney disease.

BACKGROUND: Fibroblast growth factor-23 (FGF-23) is a novel regulator of phosphate metabolism; however, the clinical knowledge is limited in children with chronic kidney disease (CKD) who are at risk of developing mineral bone disorder. METHODS: This prospective study over 2 years investigated the development of bone mass and bone turnover in relation to serum FGF-23 in children with CKD. Thirteen patients, 4-15 years, were included with a median corrected glomerular filtration rate (GFR) of 38 (range 7-74) mL/min/1.73 m(2). RESULTS: Median FGF-23 was 127 RU/mL at baseline and 70 RU/mL at follow-up. Five patients had FGF-23 levels exceeding the upper reference limit of 141 RU/mL for healthy children. No correlation with age or puberty was found. FGF-23 was inversely correlated with GFR, r = -0.73 (p <0.05). Four of the five patients within CKD stages 4-5 (GFR <30 mL/min/1.73 m(2)) had elevated FGF-23 levels and two patients with end-stage renal disease had markedly high levels of FGF-23 (1333 and 1700 RU/mL). One of these patients was transplanted after 1 year, which normalized FGF-23 to 70 RU/mL at follow-up. FGF-23 was significantly associated with PTH, r = 0.69 (p <0.01). FGF-23 correlated with osteocalcin, but not with other markers of bone turnover. Total body bone mineral density (BMD) was not correlated with FGF-23, however, the lumber spine BMD Z-score correlated with FGF-23 at baseline, r = 0.61 (p <0.05). CONCLUSIONS: Although a small study group, this prospective study suggests that FGF-23 is associated with GFR, PTH, and lumbar spine BMD in pediatric patients with various degrees of CKD.

Altered cortical bone strength and lean mass in young women with long-duration (19 years) type 1 diabetes.

To investigate bone health and body composition in young women with long-duration type 1 diabetes (T1D) in relation to matched controls. Twenty-three Swedish women, age 19.2-27.9 years, with a T1D duration of 10 years or more were recruited from the Swedish National Diabetes Registry (NDR). An age-, gender- and geography-matched control group was recruited. Bone mass and body composition were assessed by dual-energy X-ray absorptiometry and peripheral quantitative computed tomography. Data was retrieved from the NDR and SWEDIABKIDS registries. T1D individuals had a mean diabetes duration of 19 years. T1D individuals had reduced lean mass (40.0 ± 6.1 kg vs. 43.9 ± 4.9 kg) and were shorter (1.66 ± 0.06 m vs. 1.71 ± 0.06 m) although comparable BMI. Subjects with T1D had lower muscle area (P = 0.0045). No differences were observed for fractures; physical activity; total, lumbar spine or femur areal bone mineral density. The cortical bone strength strain index was lower for TD1 patients (1875 ± 399 mm3 vs. 2277 ± 332 mm3). In conclusion, young women with long-term diabetes duration showed reduced cortical bone strength, decreased periosteal circumference, endosteal circumference and altered body composition. These factors contribute to the health burden of TD1, which warrants further attention for advancing bone health in women with T1D.