Table 1.
Characteristics of Three Acromegaly Types as Determined by Cluster Analysis
| Acromegaly Types |
P Value | |||
|---|---|---|---|---|
| 1 | 2 | 3 | ||
| Prevalence | 147 (50) | 55 (19) | 90 (31) | |
| Parameters used by cluster analysis | ||||
| Granulation pattern* | ||||
| Densely granulated | 147 (100) | 27 (49) | 0 (0.0) | <.001a |
| Sparsely granulated | 0 (0.0) | 28 (51) | 90 (100) | <.001a |
| Tumor size** | ||||
| Microadenoma | 55 (37) | 0 (0.0) | 0 (0.0) | <.001a |
| Macroadenoma | 92 (63) | 55 (100) | 90 (100) | <.001a |
| Invasiveness*** | ||||
| Negative | 92 (63) | 55 (100) | 0 (0.0) | <.001a |
| Positive | 55 (37) | 0 (0.0) | 90 (100) | <.001a |
| Clinical and biochemical features | ||||
| Age at diagnosis, y (means ± SD) | 53.2 ± 12 | 40.6 ± 8.9 | 31.9 ± 7.8 | .001b |
| Year of diagnosis (means ± SD) | 1996 ± 9 | 1998 ± 9 | 1996 ± 7 | .20b |
| Gender | ||||
| Males | 76 (52) | 25 (45) | 45 (50) | .86a |
| Females | 71 (48) | 30 (55) | 45 (50) | |
| Disease duration, y | ||||
| Before diagnosis | 7.0 (2.8–14.2) | 7.2 (2.3–10.8) | 3.7 (0.7–7.1) | <.0001c |
| After diagnosis | 4.9 (1.7–11.1) | 5.3 (2.5–8.2) | 4.5 (2.0–12.4) | .865c |
| Disease duration | 15.5 (8.9–25.0) | 13.0 (10.5–18.5) | 9.6 (4.5–17.3) | .001c |
| Diagnosis (serum) | ||||
| GH, ng/mL | 13.0 (7.7–29.4) | 15.6 (7.3–46.1) | 17.5 (7.2–36.3) | .83c |
| Nadir GH after OGTT | 12.0 (6.8–24.2) | 8.6 (4.8–30.8) | 13.8 (5.1–32.1) | .58c |
| IGF-1, ng/mL | 638 (385–876) | 683 (381–952) | 823 (491–1027) | <.0001c |
| IGF-1, %ULN | 297 (250–349) | 307 (264–349) | 395 (332–458) | .01c |
| Prolactin, ng/mL | 13.0 (7.5–24.1) | 13.2 (8.5–24.0) | 22.0 (10.7–54.1) | .01c |
| Calcium, mg/dL | 9.6 (9.3–10.0) | 9.6 (9.5–9.9) | 9.5 (9.4–9.7) | .78c |
Data are expressed as number (percent) or median (interquartile range), unless described otherwise. %ULN represents the upper normal limit for age and gender IGF-1 levels.
*
GH-positive granules (5).
**
Microadenoma (<10 mm) and macroadenoma (≥10 mm).
***
CSI and/or ICA encasement observed on MRI using Knosp criteria (9).
a
P value from linear by linear association χ2.
b
One-way ANOVA test.
c
Kruskal-Wallis H test; P value <.05; Mann-Whitney U test between type 1 or 2 vs type 3.