Table 2.

Clinical and biochemical characteristics of girls by grouping based on timing of peak growth

Girls	Group 1 (Tanner stage 1) (n = 7)	Group 2 (Tanner stages 2–3) (n = 14)	Group 3 (Tanner stages 4–5) (n = 20)	P value
Age (yrs)	10·4 ± 0·7*,†	12·2 ± 1·2*,‡	14·9 ± 1·3†,‡	<0·0001
BMI-SDS	−0·13 ± 0·81	−0·22 ± 0·61	0·28 ± 0·81	NS
GH baseline (ng/ml)§	1·55 ± 2·05	1·72 ± 2·48	1·88 ± 3·50	NS
GH nadir (ng/ml)§	0·10 ± 0·05†	0·37 ± 0·31‡	0·19 ± 0·15	0·02
GH AUC (ng/ml)	82·5 ± 86·5	235·9 ± 235·0	114·9 ± 135·2	0·09
IGF-1 (ng/ml)	155·3 ± 67·2*	229·5 ± 132·0	312·8 ± 92·0‡	0·008
P1NP (ng/ml)¶	381·9 ± 178·8 (216·6–547·3)	692·5 ± 364·0* (472·5–912·5)	239·9 ± 211·6† (239·9–211·6)	0·0009
CTX (ng/ml)¶	1·1 ± 0·6† (0·42–1·77)	2·4 ± 1·3*,‡ (1·37–3·37)	1·1 ± 0·6† (0·77–1·47)	0·006
25(OH) vitamin D (ng/ml)	34·6 ± 6·8	33·9 ± 15·9	26·9 ± 9·3	NS

Means ± SDS.

^*P < 0·05 compared with Group 3.

^†P < 0·05 compared with Group 2.

^‡P < 0·05 compared with Group 1.

^§Comparisons performed with log-transformed values to approximate a normal distribution.

^¶Ranges provided for aminoterminal propeptide of type 1 procollagen (P1NP) and carboxy-terminal collagen crosslinks (CTX) indicate the 5th and 95th confidence intervals.