Table 3.
Correlations between Serum Phenylalanine and Bone Mineral Density in Subjects with PKU
| Country Authors |
n Age (years) |
Frequency & Method of Measuring Phenylalanine |
Correlation between Phenylalanine and Bone Mineral Density |
|---|---|---|---|
| Poland (Adamczyk et al 2010) | n=45 14 ± 5 |
Neither frequency or method was reported | Phenylalanine negatively correlated with spine BMD, 1 R 2 & p value not reported |
| Australia (Allen et al 1994) | n=32 9 ± 2 |
Once, high performance liquid chromatography | No correlation between phenylalanine and spine BMD, R & p value not reported |
| Greece (Al-Qadreh et al 1998) | n=48 9 ± 4 |
Monthly × 12 months, method not reported | Mean phenylalanine level negatively correlated with right forearm BMD by single photon absorptiometry (r = −0.49, p<0.007) |
| France (Barat et al 2002) | n=13 median 12, range 5–21 |
Age 1 month to time of BMD test, method not reported | phenylalanine levels similar in subjects with spine Z-score < −1 (n=8) and Z-score ≥ −1 (n=5), R & p value not reported |
| Netherlands (de Groot et al 2012) | n=53 17 ± 9 |
Every 2–4 weeks for one year, high performance liquid chromatography | No correlation between phenylalanine and spine Z-score R=0.034, p=0.199 (n=50) |
| United States (Hillman et al 1996) | n=11 11 ± 4 |
3 recent measures, method not reported | No correlation between phenylalanine and spine BMD after correction for age, R & p value not reported |
| Egypt (Koura et al 2011) | n=32 9 ± 5 |
monthly × 2; enzyme linked immunoassay | No correlation between phenylalanine and spine BMD, R & p value not reported |
| Spain (Lage et al 2010) | range 6–42, n=47 |
Once, fluorometric assay | No correlation between phenylalanine and spine Z-score, R & p value not reported |
| United States (McMurry et al 1992) | Range 1–25, n=26 |
Mean level over past six months, agar diffusion microbial assay | Mean phenylalanine levels over prior six months <1200 µmol/L associated with higher radius BMC, R & p value not reported |
| Spain (Millet et al 2005) | 18 (range 4– 38), n=46 |
Day of bone density test, levels for past 12 months, ion exchange chromotography | No correlation between phenylalanine level on day of bone density test and spine Z-score, No correlation between prior year phenylalanine levels and spine Z-score, R & p value not reported |
| Israel (Modan-Moses et al 2007) | 25±5 n=31 |
Once, bacterial inhibition assay and fluorometric assay | No correlation between phenylalanine and spine Z-score, R & p value not reported |
| Spain (Perez-Duenas et al 2002) | 10–33, n=28 |
Monthly × 12 months, ion exchange chromotography | No correlation between mean phenylalanine levels and spine BMD, R & p value not reported |
1
BMD indicates bone mineral density;
2
R indicates the correlation coefficient