Osteopenia and phenylketonuria

Carson, Dennis; Greeves, L. G.; Sweeney, L; Crone, Michael

doi:10.1007/bf02129064

Cited by 29 publications

(18 citation statements)

References 3 publications

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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: 98%

Peak bone mass in patients with phenylketonuria

Modan‐Moses

Vered

Schwartz

et al. 2007

J of Inher Metab Disea

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Section: Introductionmentioning

confidence: 98%

Peak bone mass in patients with phenylketonuria

Modan‐Moses

Vered

Schwartz

et al. 2007

J of Inher Metab Disea

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“…Higher intake of food phenylalanine correlated to a BTM ratio favoring resorption (p-value ¼ 0.017) while better compliance with medical food correlated to a BTM ratio favoring formation (p-value ¼ 0.056) suggesting following diet is critical. DXA showed normal BMD for age in all subjects and a mean total BMD Z-score of 0.045 (range À1.9-2.3) contradicting low BMD found in previous studies (Carson et al 1990;Zeman et al 1999;Perez-Duenas et al 2002;Koura et al 2011) but in line with more recent reports (Demirdas et al 2015;Geiger et al 2016). We defined low BMD by ISCD criteria (Z-score <À2) instead of alternative definitions used in previous studies (Demirdas et al 2015).…”

Section: Discussionmentioning

confidence: 58%

“…Other studies also find no correlations between dietary calcium, protein, and energy intake and BMD, BMD Z-score or BTM in patients of any age (Carson et al 1990;McMurry et al 1992;Hillman et al 1996;Modan-Moses et al 2007;Lage et al 2010). Positive correlations have been reported, however, between total calcium and phosphorus intake and BMD Z-score (PerezDuenas et al 2002) and calcium and protein from medical food and spine BMD (Geiger et al 2016).…”

Section: Discussionmentioning

confidence: 96%

Impact of Dietary Intake on Bone Turnover in Patients with Phenylalanine Hydroxylase Deficiency

et al. 2017

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Phenylalanine hydroxylase (PAH) deficiency is a genetic disorder characterized by deficiency of the PAH enzyme. Patients follow a phenylalanine-restricted diet low in intact protein, and must consume synthetic medical food (MF) to supply phenylalanine-free protein. We assessed relationships between dietary intake and nutrient source (food or MF) on bone mineral density (BMD) and bone turnover markers (BTM) in PAH deficiency. Blood from 44 fasted females 11-52 years of age was analyzed for plasma phenylalanine, serum BTM [CTx (resorption), P1NP (formation)], vitamin D, and parathyroid hormone (PTH). BTM ratios were calculated to assess resorption relative to formation (CTx/P1NP). Dual energy X-ray absorptiometry measured total BMD and age-matched Zscores. Three-day food records were analyzed for total nutrient intake, nutrients by source (food, MF), and compliance with MF prescription. Spearman's partial coefficients (adjusted for age, BMI, energy intake, blood phenylalanine) assessed correlations. All had normal BMD for age (Z-score >À2). Sixty-four percent had high resorption and normal formation indicating uncoupled bone turnover. CTx/P1NP was positively associated with food phenylalanine (r 2 ¼ 0.39; p-value ¼ 0.017), energy (r 2 ¼ 0.41; p-value ¼ 0.011) and zinc (r 2 ¼ 0.41; pvalue ¼ 0.014). CTx/P1NP was negatively associated with MF fat (r 2 ¼ À0.44; p-value ¼ 0.008), MF compliance (r 2 ¼ À0.34; p-value ¼ 0.056), and positively with food sodium (r 2 ¼ 0.43; p-value ¼ 0.014). CTx/ P1NP decreased significantly with age (p-value ¼ 0.002) and higher PTH (p-value ¼ 0.0002). Phenylalanine was not correlated with any bone indicator. Females with PAH deficiency had normal BMD but elevated BTM, particularly resorption. More favorable ratios were associated with nutrients from MF and compliance. Younger females had less favorable BTM ratios. Promoting micronutrient intake through compliance with MF may impact bone metabolism in patients with PAH deficiency. Synopsis: Bone mineral density was normal in 44 females with PAH deficiency; however, bone turnover markers suggested uncoupling of bone resorption and formation, particularly in younger patients. Adequate nutrient intake from medical food and overall medical food compliance may positively impact bone turnover.

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“…Carson et al 42 , utilizando o método de tomografia computadorizada de espinha lombar, verificaram uma significativa redução do conteúdo mineral ósseo trabecular de 4 dos 11 pacientes com fenilcetonúria estudados, com faixa etária entre 19 a 34 anos. Os autores verificaram correlação positiva entre o conteúdo mineral ósseo e a proporção adequada de calorias, proteínas, cálcio e cobre da dieta.…”

Section: Fenilcetonúria E Perda óSseaunclassified

Metabolismo do cálcio na fenilcetonúria

et al. 2009

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A Fenilcetonúria é um erro inato do metabolismo do aminoácido fenilalanina. O tratamento é essencialmente dietético e envolve uma restrição severa no consumo de alimentos contendo aminoácido fenilalanina. Embora a alimentação seja complementada com fórmulas a fim de suprir as necessidades de vitaminas, minerais e aminoácidos essenciais, carências nutricionais ainda ocorrem. Isto se deve, principalmente, à restrição de fontes protéicas, que acarreta deficiência na ingestão de diversos nutrientes, dentre eles o cálcio. O cálcio possui importante relação com a formação mineral óssea. Estudos recentes demonstram que portadores de fenilcetonúria apresentam freqüentemente osteopenia e fraturas, sendo a maior incidência em crianças acima de 8 anos de idade. O rápido aumento da estatura, a dieta deficiente em cálcio e níveis de aminoácido fenilalanina elevados têm sido descritos como os principais fatores para a aquisição de massa óssea inadequada. A suplementação de cálcio em crianças saudáveis mostrou um efeito positivo sobre a aquisição de massa óssea na fase da pré-puberdade. Assim, torna-se relevante compreender a necessidade da suplementação de cálcio em pacientes fenilcetonúria, a fim de favorecer o desenvolvimento ósseo esperado. Termos de indexação: Densidade óssea. Fenilcetonúria. Metabolismo de cálcio. A B S T R A C T Phenylketonuria is an inborn error of the metabolism of the amino acid phenylalanine. The treatment is essentially dietetic and involves a severe restriction in the consumption of foods containing aminoacid phenylalanine. Although the diet is complemented with supplements in order to

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Osteopenia and phenylketonuria

Cited by 29 publications

References 3 publications

Peak bone mass in patients with phenylketonuria

Peak bone mass in patients with phenylketonuria

Impact of Dietary Intake on Bone Turnover in Patients with Phenylalanine Hydroxylase Deficiency

Metabolismo do cálcio na fenilcetonúria

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