Table 1.
Median and peak ACTH and cortisol concentrations during normal and low-cortisol feedback
| Group
|
ACTH (ng/L)
|
Cortisol (μg/dL)
|
||
|---|---|---|---|---|
| Median | Peak | Median | Peak | |
| Control (N = 11) | ||||
| baseline | 22 (16–34)A | 46 (31–94)A | 7.1 (5.3–11)A | 18 (14–22)A |
| metyrapone | 153 (81–373)B | 388 (216–1195)B | 2.4 (1.5–5.5)B | 5.2 (2.7–8.9)B |
| increment or decrement | 129 (55–351) | 322 (143–1148) | −4.9 (−7.0 to −1.6) | −12.7 (−16.8 to −8.4) |
| Depression High Cortisol (N = 7) | ||||
| baseline | 30 (18–32)A | 48 (42–57)A | 11 (9.7–14)A | 20 (18–24)A |
| metyrapone | 143 (78–267)B | 390 (234–868)B | 3.7 (2.4–4.6)B | 6.3 (4.4–8.6)B |
| increment or decrement | 115 (49–235) | 335 (187–811) | −7.0 (−10.8 to −6.2) | −14.0 (−16.6 to −11.1) |
| Depression Low Cortisol (N = 5) | ||||
| baseline | 18 (16–37)A | 36 (26–91)A | 4.1 (1.9–6.7)A | 11 (5.8–15)A |
| metyrapone | 129 (25–217)B | 383 (66–701)B | 1.9 (0.89–2.9)B | 4.2 (2.3–6.1)B |
| increment or decrement | 111 (10–180) | 347 (40–610) | −2.8 (−4.2 to −1.0) | −6.5 (−8.6 to −3.5) |
| ANCOVA P value: | < 0.001 | < 0.001 | < 0.001 | < 0.001 |
Data are the median (range) for the indicated groups over the interval 0000 – 1000 h.
Values after metyrapone were significantly different from the matching baseline values. The overall P value for the latter contrast is indicated on the bottom line of the table.
Data were first natural-log transformed before ANCOVA. Accordingly, given the skewed distributions, the median and range of values are presented.
The mean concentrations and peak concentrations were calculated as single values in each person over the 10 hours. From the set of mean and peak values, the median and absolute range were taken, representing the values printed in the table.
ANOVA confirms lower cortisol values in each group on the metyrapone day compared to the baseline day. On the metyrapone day the cortisol values were similar among the 3 subject groups. The decrements were significantly less for cortisol in the low cortisol group.
P values for median vs peak (paired column comparisons) were all P<0.01, and hence are not marked separately.
Means with unique (unshared) alphabetic superscripts differ between paired baseline and metyrapone rows within each of the three separate groups. Thus, A differs from B.