Biochemical definitions of disease activity in acromegaly.
In acromegaly the therapeutic outcome is difficult to assess and depends on the biochemical method. We have ascertained disease activity in 70 acromegalic patients by means of a GH profile (8 hourly samples) and a single IGF-I measurement as compared to a healthy control group. As an estimate of the "stiffness" of the GH profile we calculated the SD/nadir(GH) from the GH profile. In the control group the following upper normal limits were obtained: IGF-I (microg/l) 217; mean GH (microg/l) 2.16; nadir GH (g/l) 0.3. Based on ROC plot analysis a value of 2.0 for the SD/nadir ratio was used as cut-off. This translated into the following surgical cure rates (%): IGF-I 47; mean GH 77; nadir GH 65; SD/nadir 30. Some of the patients post-surgery had elevated IGF-I levels despite "normal" GH levels. Abnormal SD/nadir versus normal IGF-I and vice versa were recorded in many patients post-surgery.


CONCLUSIONS
(1) cure rates of acromegaly depend strongly on the criteria being used and (2) estimates of GH secretion pattern may yield important information about GH status in acromegaly.
Medical Department M, Aarhus University Hospital, Kommunehospitalet, DK-8000 Aarhus, Denmark.
Flavia Lucia
FL
Conceição
Sanne
S
Fisker
Jens Sandahl
JS
Christiansen
Jens
J
Astrup
Jørgen
J
Weeke
Jens Otto Lunde
JO
Jørgensen
D000172:Acromegaly / Q000378:metabolism* / Q000601:surgery; D000328:Adult; D000368:Aged; D001671:Biochemistry / Q000379:methods; D016022:Case-Control Studies; D005260:Female; D019382:Human Growth Hormone / Q000097:blood*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012016:Reference Values; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I