Differences in the age, extent of biochemical features and radiological evidence of rickets in children with hypocalcaemia and those without hypocalcaemia at presentation
| Hypocalcaemia | Normocalcaemia | p | |
|---|---|---|---|
| Total group (n) | 49 | 103 | |
| Median age at presentation (months) | 24 | 22.5 | NS |
| 5th, 95th | 1.8, 156 | 8, 130.2 | |
| Serum calcium (n) | 49 | 103 | |
| Median serum calcium (mmol/l) | 1.82 | 2.4 | <0.0001 |
| 5th, 95th | 1.32, 2.19 | 2.23, 2.53 | |
| Serum phosphate (n) | 46 | 99 | |
| Median serum phosphate (mmol/l) | 1.2 | 1.6 | <0.0001 |
| 5th, 95th | 0.7, 2.4 | 0.8, 1.9 | |
| Serum ALP (n) | 40 | 73 | |
| Median serum ALP (U/l) | 888 | 321 | <0.0001 |
| 5th, 95th | 207, 2391 | 175, 1480 | |
| Serum PTH (n) | 36 | 79 | |
| Median serum PTH (pmol/l) | 44.4 | 7.6 | <0.0001 |
| 5th, 95th | 4.1, 103 | 2.5, 53.7 | |
| Serum 25-OHD (n) | 45 | 85 | |
| Median serum 25-OHD (nmol/l) | 15 | 22 | 0.007 |
| 5th, 95th | 14, 55 | 14, 88* | |
| X-ray (n) | 44 | 82 | |
| X-ray evidence of rickets | 30 | 61 | NS |
Laboratory reference range for serum calcium is 2.20–2.70 mmol/l, serum phosphate is 0.9–2.2 mmol/l, ALP is 100–420 U/l, PTH is less than 5.5 pmol/l.
↵* Thirteen children had received vitamin D prior to measurement.
25-OHD, 25-hydroxy vitamin D; ALP, alkaline phosphatase; NS, normocalcaemic cases; PTH, parathyroid hormone.