Decreased bone mineral density in children with phenylketonuria

Allen, JR; Humphries, Ian R. J.; Waters, Donna; Roberts, David C.; Lipson, Anthony; Howman-Giles, R G; Gaskin, K. J.

doi:10.1093/ajcn/59.2.419

Cited by 63 publications

(73 citation statements)

References 13 publications

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“…Whether a relatively low calcium supply overcomes the self-regulatory properties of the calciumvitamin D-parathormone system should also be investigated. In fact, adolescent and adult PKU patients have been reported to show decreased bone mineral content (21)(22)(23). Whether calcium is the main contributor to these abnormalities still remains a matter of debate.…”

Section: Vitamins and Mineralsmentioning

confidence: 99%

Nutrient intake and food consumption of adolescents and young adults with phenylketonuria

Schulz

Bremer

1995

Acta Paediatrica

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Food and nutrient intake was assessed in 99 PKU patients (12-29 years old) by two food protocols (7 days and 4 days, respectively). Ninety-three patients completed at least one 7-day food record and 83 both records. Nineteen of 93 patients had already stopped taking the phenylalanine-free amino acid mixture (AAM), which is enriched with vitamins, minerals and trace elements. Plasma phenylalanine levels in this group were significantly higher than in patients who were still taking the AAM. Even without the AAM, protein intake still met the recommendations, but thiamin, riboflavin, folate, calcium and iron levels were below 80% of the US RDA in most patients. For those still taking the AAM, calorie, protein, vitamin and mineral intakes were above the recommendations. The diet was characterized by a low intake of fiber (median 14 (range 8-35) g/day), fat (27 (10-47) cal%) and cholesterol (75 (13-417) mg/day) as well as a high ratio of polyunsaturated/saturated fatty acids (0.7 (0.2-2.4)). Problems with dietary compliance in adolescents and young adults may lead to a combination of marginal nutrient intake and high phenylalanine levels.

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Section: Vitamins and Mineralsmentioning

confidence: 99%

Nutrient intake and food consumption of adolescents and young adults with phenylketonuria

Schulz

Bremer

1995

Acta Paediatrica

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“…However, most previous studies assessing bone quality in PKU (Allen et al 1994;Al-Qadreh et al 1998;Carson et al 1990;McMurry et al 1992;Schwahn et al 1998) did not evaluate bone mineral density (BMD) by the gold-standard method of DXA (Genant et al 1999), reported heterogeneous patient populations (Barat et al 2002;Perez-Duenas et al 2002;Schwahn et al 1998), or comprised only a small number of patients (Barat et al 2002;Schwahn et al 1998).…”

Section: Introductionmentioning

confidence: 99%

Peak bone mass in patients with phenylketonuria

Modan‐Moses

Vered

Schwartz

et al. 2007

J of Inher Metab Disea

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“…Dual-energy X-ray absorptiometry (DEXA) of the spine has shown that phenylketonuric children develop osteopenia [1,4,5]. While the exact reasons for low bone mineral density remain unclear, many explanations have been proposed: the diet being too restrictive [5], poor dietary compliance [2] or a direct effect of the disease [4].…”

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confidence: 99%

The impact of the control of serum phenylalanine levels on osteopenia in patients with phenylketonuria

Barat

Barthe

Redonnet‐Vernhet

et al. 2002

European Journal of Pediatrics

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Dual-energy X-ray absorptiometry (DEXA) of the spine has shown that phenylketonuric children develop osteopenia [1, 4,5]. While the exact reasons for low bone mineral density remain unclear, many explanations have been proposed: the diet being too restrictive [5], poor dietary compliance [2] or a direct effect of the disease [4]. In order to determine the role of the control of phenylalanine (Phe) blood levels in the pathogenesis of osteopenia, we performed a retrospective study of Phe levels from birth up to the present date in 13 children (5 females, 7 males) with classical phenylketonuria, diagnosed in the neonatal period by the French neonatal screening programme. Amino acid supplementation was started upon diagnosis and regularly adapted, based on the serum Phe levels.We compared the Phe values with the spine bone mineral density (BMD). DEXA was performed at the age of 12 years (range 5-21 years) using a Hologic QDR 4500A instrument. Spine BMD were interpreted according to French references values [3] and expressed as Z-score for gender and age. Patients were divided according to their spine BMD results into two groups: patients with osteopenia (Z-score <)1; n=8) and controls (Z-score ‡)1; n=5). Spine Z-scores were -2.39±0.88 (range -3.60 to -1.40) and 0.28±0.83 (range -0.70 to 1.40) for osteopenic patients and controls, respectively. All the Phe levels recorded in the patients' medical notes since the 1st month following birth up to the date the DEXA was done were used for the statistical analysis. The non-parametric MannWhitney test was used to compare continuous data between the two groups.We found that the age when DEXA was performed and the estimators of Phe levels position were similar between osteopenic patients and controls (Table 1). Nevertheless, although the difference was not significant, both the 3rd and 10th percentiles of Phe levels are lower and the percentage of Phe levels <2 mg/dl was higher in osteopenic patients. For the analysis of Phe level variations, we used the mean of cumulative variations which was defined as the sum of the differences between two successive Phe levels divided by the number of the differences studying per patient: i.e. Mean of cumulative variations = (S Phe X -Phe X+1)/(n-1); where Phe X, Phe X+1 are successive Phe levels, n, the number of the successive Phe levels studying per patient. Despite the small size of the population, osteopenic patients had a higher mean of cumulative variations (3.1±0.4 mg/dl) than controls (2.5±0.3 mg/dL, P=0.006). Linear regression analysis revealed a significant negative correlation of BMD spine (Z-score) with mean of cumulative variations (r=)0.61, P=0.025). These results suggest that the variations of serum Phe levels may contribute to osteopenia in phenylketonuric children. References 1. Allen JR, Humphries IRJ, Waters DL, Roberts DCK, Lipson AH, Howman-Giles RG, Gaskin KJ (1994) Decreased bone mineral density in children with phenyketonuria. Am J Clin Nutr 59: 419-422 2. Al-Qadreh A, Schulpis KH, Athanasopoulou H, Mengreli C, Ska...

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Decreased bone mineral density in children with phenylketonuria

Cited by 63 publications

References 13 publications

Nutrient intake and food consumption of adolescents and young adults with phenylketonuria

Nutrient intake and food consumption of adolescents and young adults with phenylketonuria

Peak bone mass in patients with phenylketonuria

The impact of the control of serum phenylalanine levels on osteopenia in patients with phenylketonuria

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