Table 2.

Associations between the corticotroph tumour volume and plasma ACTH, serum cortisol and ACTH/cortisol ratios.

	Macro and microadenoma (n=59)	Macroadenoma (mm3)			Microadenoma (n=39)	Pmacro vs micro	Ptrend
Total (n=20)	≥2500 (n=10)	<2500 (n=10)
ACTH (pg/ml)
Mean	104.0	166.4	215.1	117.6	72.1	<0.001	<0.001
s.d.	91.2	130.0	159.8	69.7	34.2
Median	80.0	119.5	192.0	93.7	65.8
Range	23.0–563.0	38.0–563.0	41.9–563.0	38.0–265.0	23.0–187.1
Cortisol8:00 (μg/dl)
Mean	26.2	29.2	33.3	25.1	24.6	0.370	0.352
s.d.	11.9	16.2	21.0	8.9	8.8
Median	24.2	26.8	26.8	25.8	22.9
Range	10.9–73.4	10.9–73.4	14.4–73.4	10.9–39.2	13.5–45.5
Cortisol0:00 (μg/dl)
Mean	18.6	20.1	21.5	18.8	17.8	0.399	0.330
s.d.	7.0	8.5	9.7	7.5	6.1
Median	16.4	17.8	21.0	15.8	16.3
Range	9.6–42.8	9.6–42.8	10.1–42.8	9.6–32.7	9.7–35.0
CortisolODST (μg/dl)
Mean	15.6	14.6	14.3	15.0	16.2	0.672	0.662
s.d.	9.4	8.5	8.6	8.9	10.0
Median	14.5	13.9	14.1	13.3	15.8
Range	1.6–40.8	1.6–29.8	1.6–29.8	2.6–27.7	1.6–40.8
ACTH/cortisol
Mean	4.1	6.0	6.9	5.2	3.1	0.002	0.001
s.d.	3.0	4.1	4.6	3.6	1.4
Median	3.3	5.0	5.3	4.6	2.7
Range	1.2–16.7	1.6–16.7	2.9–16.7	1.6–14.3	1.2–5.8