The utility of alkaline phosphatase measurement as a screening test for rickets in breast-fed infants and toddlers: a study from the puget sound pediatric research network.
To determine if alkaline phosphatase (AP) levels are a useful screening test for rickets, the authors measured serum AP levels in children 6 to 15 months old who were predominantly breast-fed for > 6 months without vitamin D supplementation. Radiographs were obtained on children with elevated AP levels to determine the presence of rickets. AP levels were obtained on 246 children; levels were elevated in 33 (13.4%). Rickets was present in 4 of 18 children with elevated levels on whom radiographs were obtained. The sensitivity and specificity of AP levels as a test for rickets was maximal at a cutoff value of 552 U/L. Using this cutoff value, the specificity of AP levels as a test for rickets was 97.4%, and the positive predictive value (PPV) was 40.0%. These results suggest that AP levels may be a useful screening test for rickets in children who are breast-fed for prolonged periods without vitamin D supplementation.
Taylor
James A
JA
University of Washington School of Medicine and Seattle Children's Hospital, Seattle, WA 98195, USA. uncjat@u.washington.edu
Richter
Monica
M
Done
Stephen
S
Feldman
Kenneth W
KW
D000469:Alkaline Phosphatase / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D001942:Breast Feeding; D002675:Child, Preschool; D055812:Community-Based Participatory Research; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008403:Mass Screening / Q000379:methods*; D011237:Predictive Value of Tests; D012279:Rickets / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D012680:Sensitivity and Specificity; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D014861:Washington
D015415:Biomarkers; D000469:Alkaline Phosphatase