Bone Mineral Status In Children Research Articles

Vitamin A Nutritional Status Is a Key Determinant of Bone Mass in Children.

The bone mass increases that occur during the period of childhood are of great significance for maximizing the peak bone mass in adults and preventing for osteoporosis. Studies have reported that VA can improve the bone health in adults. Moreover, limited studies have assessed such associations in children. In this cross-sectional study including 426 children, we assessed the children's plasma retinol concentration by liquid chromatography-mass spectrometry and the dietary intake of VA and carotenoids using a structured Food Frequency Questionnaire. Their bone mineral content and bone mineral density (BMD) were measured using dual-energy X-ray absorptiometry. After adjusting for potential confounders, the restricted cubic spline revealed an inverted U-shaped association between plasma retinol concentration and BMD; the estimated effects on the TBLH BMD per μmol/L increase in the plasma retinol concentration were 1.79 × 10-2 g/cm2 below 1.24 μmol/L and -5.78 × 10-3 g/cm2 above this point (p for non-linearity = 0.046). A multiple linear regression analysis revealed a positive association between the plasma retinol concentration and the TBLH BMC (β = 1.89, 95% CI: 1.64 × 10-1-3.62, p = 0.032). In conclusion, an appropriate plasma retinol concentration and greater intakes of dietary VA and β-carotene may enhance the bone mineral status of children who are aged 6-9 years.

Irisin serum levels are positively correlated with bone mineral status in a population of healthy children.

Irisin is a myokine secreted by skeletal muscle during physical activity. Irisin treatment increased cortical bone mineral density (BMD) in young healthy mice and restored bone and muscle mass loss in a mouse model of disuse-induced osteoporosis and muscular atrophy. In humans, Irisin was positively correlated with BMD in young athletes. Considering that the bone mass reached during childhood is one of the most important determinants of lifelong skeletal health, we sought to determine if Irisin levels were correlated with bone mineral status in children. Irisin and bone metabolic markers were quantified in sera and bone mineral status was evaluated by quantitative ultrasound in a population of 34 healthy children (9.82 ± 3.2 years). We found that Irisin levels were positively correlated with the amplitude-dependent speed of sound Z-score (r = 0.305; p < 0.001), bone transmission time Z-score (r = 0.375; p < 0.001) and osteocalcin (r = 0.370; p < 0.001), and negatively with Dickkopf WNT Signaling Pathway Inhibitor 1 (r = -0.274; p < 0.001). In a regression analysis model, Irisin was one of the determinants of bone mineral status to a greater extent than bone alkaline phosphatase and parathyroid hormone, indicating that Irisin might be considered as one of the bone formation markers during childhood.

Bone Mineral Status in Children with Epilepsy: Biochemical and Radiologic Markers.

Objective:The aim of this study is to assess bone mineral status in children with epilepsy, on different antiepileptic drugs (AEDs) regimen, using dual-energy X-ray absorptiometry (DXA) and routine biochemical bone markers.Patients and Methods:This is observational prospective controlled cohort study, conducted at Mansoura University Children Hospital, from January 2014 to June 2015. In this study, we had 152 participants with ages 3–13 years, 70 children diagnosed with epilepsy and 82 were controls. Children classified into two groups according to the duration of treatment, Group 1 children maintained on AEDs for 6–24 months, Group 2 children ≥24 months. Bone mineral density (BMD) measured by DXA and biochemical markers includes serum calcium, phosphorus, alkaline phosphatase (ALP), and parathyroid hormone (PTH).Results:In this study, we found that the serum level of calcium and phosphate were significantly low (P > 0.05) in total cases versus control. We found that the serum level of and ALP and PTH were significantly high (P > 0.05) in total cases versus control. Regarding the DXA markers, there was a significant decrease of BMD and Z-score for the total body and lumbar area in the total cases versus control (P > 0.05).Conclusion:The present study showed that all AEDs (new and old) affect bone mineral status in children receiving therapy for more than 6 months, altering both biochemical markers (serum calcium, phosphorus, ALP, and PTH) and radiologic markers (BMD assessed using DXA). Children on AEDs for a longer duration (≥2 years) showed more severe side effects on BMD. Children receiving multiple AEDs are more prone to altered bone mineral status, especially with long duration of therapy. The study also highlights the role of DXA as a safe noninvasive method to assess BMD in children on long-term AEDs.

Bone Mineral Status in Children and Adolescents with Klinefelter Syndrome

Objective. Klinefelter syndrome (KS) has long-term consequences on bone health. However, studies regarding bone status and metabolism during childhood and adolescence are very rare. Patients. This cross-sectional study involved 40 (mean age: 13.7 ± 3.8 years) KS children and adolescents and 80 age-matched healthy subjects. For both patient and control groups, we evaluated serum levels of ionised and total calcium, phosphate, total testosterone, luteinising hormone, follicle stimulating hormone, parathyroid hormone (PTH), 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D, osteocalcin, bone alkaline phosphatase, and urinary deoxypyridinoline concentrations. We also calculated the z-scores of the phalangeal amplitude-dependent speed of sound (AD-SoS) and the bone transmission time (BTT). Results. KS children and adolescents showed significantly reduced AD-SoS (p < 0.005) and BTT (p < 0.0005) z-scores compared to the controls. However, KS patients presented significantly higher PTH (p < 0.0001) and significantly lower 25(OH)D (p < 0.0001), osteocalcin (p < 0.05), and bone alkaline phosphatase levels (p < 0.005). Interestingly, these metabolic bone disorders were already present in the prepubertal subjects. Conclusions. KS children and adolescents exhibited impaired bone mineral status and metabolism with higher PTH levels and a significant reduction of 25-OH-D and bone formation markers. Interestingly, this impairment was already evident in prepubertal KS patients. Follow-ups should be scheduled with KS patients to investigate and ameliorate bone mineral status and metabolism until the prepubertal ages.

Areal bone mineral density in children and adolescents with Marfan syndrome: Evidence of an evolving problem

Marfan syndrome (MFS), an autosomal dominant disorder of connective tissue, is due to defective fibrillin-1. Defects involve the cardiovascular system, the eye, the lungs, and the skeleton. The aim of the current study was to characterize the bone mineral status in children and adolescents with MFS. We performed an observational cross-sectional study and a longitudinal follow-up of two years.We enrolled 73 young patients with MFS (3–17years). A subset of 44 patients participated in the longitudinal study. Healthy children were studied as controls for biochemical analyses. Bone mineral density (BMD) was measured at lumbar spine, femoral neck and total femur by dual-energy X-ray absorptiometry. BMD values were expressed as Z-scores adjusted for height using height-for-age Z-scores. BMD measurements corrected for height were significantly lower than reference at all skeletal sites (P<0.0001). Patient on cardiac treatment with losartan had lower BMD measurements corrected for height compared to non-treated patients. Total femur BMD decreased significantly over time (P=0.027). BMD at the other two skeletal sites did not change significantly during follow-up, but remained significantly low compared to reference (P<0.0001). In conclusion, young patients with MFS have markedly low BMD at the lumbar spine and femur, and values show a tendency to decrease over time in the peripheral skeleton. Because increased life expectancy of MFS patients, the reduced BMD during childhood may lead to a low peak bone mass, increasing the fracture risk during adult life.

Assessment of bone mineral status in children with Marfan syndrome

Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder with skeletal involvement. It is caused by mutations in fibrillin1 (FBN1) gene resulting in activation of TGF-β, which developmentally regulates bone mass and matrix properties. There is no consensus regarding bone mineralization in children with MFS. Using dual-energy X-ray absorptiometry (DXA), we evaluated bone mineralization in 20 children with MFS unselected for bone problems. z-Scores were calculated based on age, gender, height, and ethnicity matched controls. Mean whole body bone mineral content (BMC) z-score was 0.26 ± 1.42 (P = 0.41). Mean bone mineral density (BMD) z-score for whole body was −0.34 ± 1.4 (P = 0.29) and lumbar spine was reduced at −0.55 ± 1.34 (P = 0.017). On further adjusting for stature, which is usually higher in MFS, mean BMC z-score was reduced at −0.677 ± 1.37 (P = 0.04), mean BMD z-score for whole body was −0.82 ± 1.55 (P = 0.002) and for lumbar spine was −0.83 ± 1.32 (P = 0.001). An increased risk of osteoporosis in MFS is controversial. DXA has limitations in large skeletons because it tends to overestimate BMD and BMC. By adjusting results for height, age, gender, and ethnicity, we found that MFS patients have significantly lower BMC and BMD in whole body and lumbar spine. Evaluation of diet, exercise, vitamin D status, and bone turnover markers will help gain insight into pathogenesis of the reduced bone mass. Further, larger longitudinal studies are required to evaluate the natural history, incidence of fractures, and effects of pharmacological therapy. © 2012 Wiley Periodicals, Inc.

Osteocalcin, Cortisol Levels, and Bone Mineral Density in Prepubertal Children with Asthma Treated with Long-Term Fluticasone Propionate

Aims: The objective of this study is to determine the effects of the long-term treatment with inhaled fluticasone propionate on osteocalcin, cortisol levels, and bone mineral status in children with asthma. Methods: This cross-sectional study examined 230 prepubertal children with asthma (aged 6–11) who had intermittently used inhaled fluticasone propionate for at least 5 years at a mean daily dose of 200 µg (range: 200–350 µg). Serum osteocalcin, cortisol, and bone mineral density (BMD) of the lumbar spine were obtained from each participant. The control group consisted of gender- and age-matched children (n = 170) who were newly diagnosed with asthma and who were not being treated with corticosteroid. Results: The average age (±SEM) was 8.9 ± 0.7 years, their mean (±SEM) daily steroid dose was 180.3 ± 55.0 µg, with 236.5 ± 17.2 g total steroid use during treatment. Between the study and the control groups, no significant differences were observed in cortisol, osteocalcin levels, and BMD (p > 0.05). Conclusion: Long-term treatment with inhaled fluticasone propionate (100 µg twice daily) revealed no negative effects on serum osteocalcin, cortisol levels, and BMD in children with asthma.

Bone mineral density and associated parameters in pre-pubertal children with asthma treated with long-term fluticasone propionate

AimsThe primary aim of the objective of the study was to determine the effects of long-term treatment with the recommended dose of inhaled fluticasone propionate spray usage on bone mineral status in children with asthma. MethodsThis cross-sectional, case–control study was of 270 pre-pubertal children with asthma, who had used inhaled fluticasone propionate at a mean daily dose of 200μg (range: 200–350μg) for at least 5 years. The bone mineral density (BMD) of the lumbar spine was measured by dual-energy X-ray absorptiometry (DEXA). The results were compared to untreated controls (n=200), who were newly diagnosed children with asthma without any corticosteroid treatment. ResultsThe 270 study patients (175 males) were aged between 6 and 13 years. The average age (±SEM) was 9.2±0.6 years, and the mean (±SEM) steroid dosage used was 183.3±57.0μg daily, with 236.5±17.2g total steroid use during treatment. Between the study and the control groups, no significant difference was observed in BMD (p>0.05). ConclusionThe findings suggest that long-term periodical treatment for 5 years with inhaled fluticasone propionate, 100μg twice daily, in children with asthma revealed no negative effect on bone mineral density by using DEXA.

Erratum to: How does long-term parenteral nutrition impact the bone mineral status of children with intestinal failure?

Erratum to: How does long-term parenteral nutrition impact the bone mineral status of children with intestinal failure?

How does long-term parenteral nutrition impact the bone mineral status of children with intestinal failure?

Patients on long-term parenteral nutrition (PN) are at significantly increased risk for the development of metabolic bone disease (MBD); this condition is characterized by incomplete mineralization of osteoid with consequent disturbances ranging from osteopenia to severe bone disease with fractures. The aim of the study was: (1) to evaluate the prevalence of MBD, (2) to identify the PN- or intestinal failure (IF)-related factors and (3) to assess annual changes of bone mineral status. Since September 2005 all patients affected by IF and treated with PN started a BMD evaluation program using dual-energy X-ray absorptiometry (DXA). Twenty-four IF patients were included [15 with short bowel syndrome (SBS), 5 with severe protracted diarrhea and 4 with chronic intestinal pseudostruction]. The bone mineral density (BMD) Z-score was significantly lower in patients than in the control group. In our series SBS patients showed a BMD Z-score significantly higher in comparison with the medical causes of IF. No significant correlations were found between bone mineral status and PN duration and nutrient intake. Nine IF patients were submitted to a second DXA evaluation after 1 year from the baseline. All bone mineral variables were significantly increased at the second DXA evaluation. The high prevalence of MBD in IF patients undergoing long-term treatment with PN requires that these patients undergo careful and periodic monitoring of their bone mineral status; patients with congenital gut dysfunctions, such as epithelium defects and motility anomalies, are at major risk of developing this complication, probably due to the association with extra-intestinal causes of bone loss.

Bone mineral and body composition alterations in paediatric cystic fibrosis patients

With the increased life span of cystic fibrosis (CF) patients, CF-related bone diseases could have an increased prevalence and morbidity in this group. In children, previous retrospective and prospective studies have yielded conflicting results on bone mineralization. To monitor body composition and bone mineral status of children with CF. We reviewed the dual-energy X-ray absorptiometry (DXA) data of 161 children with CF (age 10 +/- 4.8 years). Total body bone mineral content (BMCt), total lean tissue mass (LTMt) and total fat mass (FMt) were measured and compared to expected data calculated from ideal weight for height (Wi; e.g. BMCti, LTMti, FMti). The bt (BMCt/BMCti), lt (LTMt/LTMti) and ft (FMt/FMti) ratios were used as quantitative variables. Low bt ratio was found at all ages (mean bt ratio 0.94 +/- 0.10; P < 0.001), even in children <6 years of age. However, the children's BMCt was satisfactorily adapted to their weight. lt and ft ratios were not constant across age groups. Children <10 years had 8% reduction of their lt ratio, maintaining normal levels thereafter. The opposite trend was found for ft ratio. Poor clinical, nutritional status and vitamin A levels were correlated with bt and lt ratios. Our results indicate that children with CF could have early alterations in their bone status and that lt and ft ratios did not have constant values across ages. Interpreting DXA data using this approach is suitable in children with CF.

Analysis of quantitative ultrasound graphic trace and derived variables assessed at proximal phalanges of the hand in healthy subjects and in patients with cerebral palsy or juvenile idiopathic arthritis.: A pilot study

Amplitude-dependent speed of sound (AD-SoS) and bone transmission time (BTT) are the quantitative ultrasound (QUS) variables usually assessed at proximal phalanges of the hand to estimate bone mineral status. The aim of the study was to provide a reference database for some additional QUS variables reflecting morphology of the ultrasound graphic trace according to gender, age, height, weight, and body mass index (BMI), and to assess their clinical usefulness. Fifty-two patients (age 3.1–20.9 years) affected by cerebral palsy with spastic tetraplegia (CPST, n = 38) or polyarticular active juvenile idiopathic arthritis (JIA, n = 14) were examined. In addition to AD-SoS and BTT, two QUS variables derived from the morphological analysis of ultrasound graphic trace, such as energy, extrapolated from the area under the ultrasound signal received, and weighted-slope (W-slope), derived from the angular coefficient of the regression line fitting the top point of the peaks of the ultrasound signal, were measured by phalangeal QUS (DBM Sonic, IGEA). The values of all the QUS variables measured in the patients were compared with our own sex- and age-reference values ( n = 1083, 587 males and 496 females, aged 3–21 years). The mean values of AD-SoS, BTT, energy, and W-slope were reduced ( P < 0.0001) in patients as a whole compared with normative data (− 2.4 ± 1.2, − 2.7 ± 1.5, − 2.5 ± 1.1, − 2.5 ± 1.1 Z-score, respectively). Fractured patients showed lower ( P < 0.001– P < 0.0001) values of the QUS variables than fracture-free patients (AD-SoS, − 3.3 ± 1.2 and − 1.8 ± 0.9; BTT, − 3.9 ± 1.7 and − 1.8 ± 1.1; energy, − 3.2 ± 1.2 and − 2.2 ± 0.7; W-slope, − 3.4 ± 1.4 and − 2.2 ± 0.9 Z-score, respectively). There was no difference ( P = NS) between patients with CPST and those with JIA. Age and height were positively correlated with all the QUS variables ( r = 0.55–0.79, P < 0.01– P < 0.0001). QUS variables were positively correlated among them ( r = 0.74–0.94, P < 0.0001). Age and number of fractures were independent predictors of the QUS variables (coefficients: AD-SoS, 11.466 and − 17.642; BTT, 0.049 and − 0.045; energy, 1.072 and − 1.303; W-slope, 0.046 and − 0.067; respectively). In conclusion, measurement of QUS variables derived from the morphological analysis of the ultrasound signal could give additional information in estimating bone mineral status in children and adolescents, probably reflecting some aspect related to bone structure.

Quantitative Ultrasound Methods to Assess Bone Mineral Status in Children: Technical Characteristics, Performance, and Clinical Application

Measurement of bone mineral status may be a useful tool in identifying the children who could be exposed to an increased risk of osteoporosis in adulthood. Dual energy x-ray absorptiometry and peripheral quantitative computed tomography may be used to this purpose, but the exposure to ionizing radiation is a limiting factor for preventive studies in large populations of children. In the last years, quantitative ultrasound (QUS) methods have been developed to assess bone mineral status in some peripheral skeletal sites such as calcaneus, phalanges of the hand, and tibia. QUS techniques are safe, easy to use, radiation-free, and devices are portable, so that they are particularly indicated to assess bone mineral status in children. This review will concentrate on the main methodological principles of ultrasounds and the QUS variables derived from their application to bone tissue, technical differences and performance of QUS methods, factors influencing QUS measurements, normative data and results obtained in children with disturbances of growth or affected by disorders of bone and mineral metabolism, including the assessment of fracture risk, and comparison among QUS, dual energy x-ray absorptiometry, and peripheral quantitative computed tomography methods.

Bone Mineral Status in Children with Congenital Adrenal Hyperplasia

Congenital adrenal hyperplasia (CAH) is caused by a deficiency in an adrenal enzyme resulting in alterations in cortisol and aldosterone production. Bone status is affected by chronic glucocorticoid therapy and excess androgen exposure in children with CAH. This cross-sectional study enrolled participants with 21-hydroxylase deficiency from a pediatric referral center. Bone mineral density in the participants was normal when compared to age, gender and ethnicity adjusted standards, with respect to chronological age or bone age. Lean body mass was positively correlated with bone mineral content (BMC), independent of fat mass (p < 0.001). There was no significant correlation between glucocorticoid dose or serum androgen levels and skeletal endpoints. In conclusion, lean body mass appears to be an important correlate of BMC in patients with CAH. The normal bone status may be explained by the differential effects of glucocorticoids on growing bone, beneficial androgen effects, or other disease specific factors.

44 Bone Density in Children with Hemangiomas Treated with Systemic Glucocorticoids.

Purpose: To evaluate the long-term effects of systemic glucocorticoid therapy on bone mineral status in children previously treated for complicated infantile hemangiomas. Methods: Bone density was evaluated by tibial ultrasound (Omnisense 7000P) and DEXA bone scan (Lunar Prodigy 10667) in children with hemangiomas previously treated with glucocorticoids (off treatment ≥ 1 year) and healthy controls. In addition, Tanner stage, bone age, and body mass index (BMI) were determined for all patients. Results: The control group consisted of 24 patients with a mean age of 52 months (range 16-104). The treated group consisted of 30 patients with a mean age of 44 months (range 20-75). Mean duration of glucocorticoid treatment was 8.6 months (range 4-15.5) and mean maximum dose of prednisolone was 2.2 mg/kg/day (range 1-4.3). All patients were Tanner stage I and there were no significant differences in bone age or BMI between the treated and control groups. Mean spinal (L2-L4) bone mineral density (BMD) did not differ between the treated group (0.6 g/m2, S.D.=0.07) and the control group (0.58 g/m2, S.D.=0.11) (95% C.I. for mean difference of -0.07 to 0.03). There were also no significant differences between treated and control groups for mean total body BMD or tibial ultrasound z-scores. Conclusion: Preliminary data analysis reveals no significant differences in bone density between children who received systemic glucocorticoids and children who did not.

Bone mineral status in children with cow milk allergy

To investigate bone mineral status in children with verified cow milk allergy for more than 4 yr compared with a large reference population of 343 local healthy controls. Whole body bone mineral content (BMC), projected bone area and bone mineral density (BMD) were determined by dual energy x-ray absorptiometry in nine children (8-17 yr old, one girl and eight boys). All children had cow milk allergy for more than 4 yr. All children had asthma and was treated with corticosteroids. BMC and BMD were reduced for age (p < 0.01). Height for age was significantly reduced (p < 0.01), indicating 'short' bones. BMC for bone area was borderline reduced (p = 0.05), indicating reduced bone mineralization. The growth of the children was reduced compared with there parents and siblings (p < 0.01), and the bone age was retarded (mean 1.4 yr, p < 0.01). Calcium consumption calculated from food intake was about 25% of the recommended. All laboratory tests were normal. Short bones were the main reason for reduced BMC and BMD for age in children with cow milk allergy, but a borderline low BMC for bone area indicated reduced bone mineralization of the bones. A supplementation of calcium to children with cow milk allergy is recommended.

The role of dietary calcium in bone health.

Approximately 99% of body Ca is found in bone, where it serves a key structural role as a component of hydroxyapatite. Dietary requirements for Ca are determined by the needs for bone development and maintenance, which vary throughout the life stage, with greater needs during the periods of rapid growth in childhood and adolescence, during pregnancy and lactation, and in later life. There is considerable disagreement between expert groups on the daily Ca intake levels that should be recommended, reflecting the uncertainty in the data for establishing Ca requirements. Inadequate dietary Ca in early life impairs bone development, and Ca supplementation of the usual diet for periods of < or = 3 years has been shown to enhance bone mineral status in children and adolescents. However, it is unclear whether this benefit is long term, leading to the optimisation of peak bone mass in early adulthood. In later years inadequate dietary Ca accelerates bone loss and may contribute to osteoporosis. Ca supplementation of the usual diet in post-menopausal women and older men has been shown to reduce the rate of loss of bone mineral density at a number of sites over periods of 1-2 years. However, the extent to which this outcome reduces fracture risk needs to be determined. Even allowing for disagreements on recommended intakes, evidence indicates that dietary Ca intake is inadequate for maintenance of bone health in a substantial proportion of some population groups, particularly adolescent girls and older women.

Bone status in cystic fibrosis

AIMTo investigate bone mineral status of children with cystic fibrosis (CF).METHODSIn 29 children with CF and 49 matched controls, bone mineral content (BMC), projected bone area (BA), and areal bone...

Bone mineral status in children with phenylketonuria under treatment.

Bone mineral status was assessed in 48 children with phenylketonuria (PKU) (20M, 28 F, aged 2.5-17 y). Bone density was measured in the distal third of the right forearm using single photon absorptiometry and was expressed as +/-SD with respect to age- and gender-matched controls. Serum calcium (Ca), magnesium (Mg), phosphorus (P), alkaline phosphatase (ALP), parathyroid hormone and 25-hydroxyvitamin D were measured in morning samples. The ratios of urinary Ca/creatinine (UCa/UCr), UP/UCr, UMg/UCr and hydroxyproline (OH-Pr)/UCr were calculated in urine samples collected over a period of 3 h. Patients' data were compared with those of 50 controls (22 M, 28 F, aged 3-15 y). The data showed severe osteopenia (below -2SD) in 22/48 patients. Bone loss was more prominent in patients over 8 y old. Bone density correlated significantly with age (r=-0.56,p < 0.001) and with Phe (r=-0.49, p < 0.007) but did not correlate with the other biochemical indices studied. Comparing PKU children with controls, significantly higher serum calcium and magnesium (p=0.04, p < 0.001, respectively), lower ALP (p=0.01), higher UCa/UCr ratio (p < 0.001), lower UP/UCr (p < 0.001) and lower UOH-Pr/UCr (p < 0.001) were found. Dietary compliance was poor in patients over the age of 8y, as only 3/22 of < or = 8y had mean serum phenylalanine >10mgdl(-1), in contrast to 21/26 in the older group. It is clear from the data that osteopenia is commonly found in PKU patients from early life. The biochemical data indicate a metabolic state of low bone turnover in PKU patients. In conclusion, a better, more restricted diet may correct osteopenia.

Bone mineral status in children with phenylketonuria under treatment

Bone mineral status was assessed in 48 children with phenylketonuria (PKU) (20 M, 28 F, aged 2.5‐17 y). Bone density was measured in the distal third of the right forearm using single photon absorptiometry and was expressed as ±SD with respect to age‐ and gender‐matched controls. Serum calcium (Ca), magnesium (Mg), phosphorus (P), alkaline phosphatase (ALP), parathyroid hormone and 25‐hydroxyvitamin D were measured in morning samples. The ratios of urinary Ca/creatinine (UCa/ UCr), UP/UCr, UMg/UCr and hydroxyproline (OH‐Pr)/UCr were calculated in urine samples collected over a period of 3h. Patients' data were compared with those of 50 controls (22M, 28F, aged 3‐15y). The data showed severe osteopenia (below ‐2 SD) in 22/48 patients. Bone loss was more prominent in patients over 8y old. Bone density correlated significantly with age (r=– 0:56, p &lt; 0.001) and with Phe (r=– 0:49, p &lt; 0.007) but did not correlate with the other biochemical indices studied. Comparing PKU children with controls, significantly higher serum calcium and magnesium (p= 0:04, p&lt; 0.001, respectively), lower ALP (p= 0:01), higher UCa/UCr ratio (p &lt; 0.001), lower UP/UCr (p &lt; 0.001) and lower UOH‐Pr/UCr (p &lt; 0.001) were found. Dietary compliance was poor in patients over the age of 8y, as only 3/22 of ≤ 8y had mean serum phenylalanine &gt;10mgdl−1, in contrast to 21/26 in the older group. It is clear from the data that osteopenia is commonly found in PKU patients from early life. The biochemical data indicate a metabolic state of low bone turnover in PKU patients. In conclusion, a better, more restricted diet may correct osteopenia.