Pretreatment insulin-like growth factor-I concentrations predict radiographic osteoarthritis in acromegalic patients with long-term cured disease.

OBJECTIVE: The aim of the study was to identify factors influencing the development of osteoarthritis during long-term control of acromegaly, focusing on disease-specific parameters, GH and IGF-I concentrations, and duration of disease, adjusted for the well-known determinants of primary osteoarthritis.
DESIGN: We conducted a follow-up study.
METHODS: We studied 67 patients with adequate biochemical control of acromegaly for a mean of almost 13 yr. Study parameters were the results of radiological assessment of the spine, hip, knee, and hand. Osteoarthritis was defined as radiological osteoarthritis using the scoring system developed by Kellgren and Lawrence. Correlations between potential factors of influence and osteoarthritis were performed by analysis of covariance and adjusted for age, gender, and body mass index.
RESULTS: Patients with pretreatment IGF-I sd scores in the highest tertile had an almost 4-fold increased risk for radiological osteoarthritis of the hip when compared with patients in the lowest tertile. After adjustment for age, gender, BMI, and disease duration, pretreatment IGF-I sd scores predicted radiographic osteoarthritis in all joint sites. Osteoarthritis was not predicted by other factors, including pretreatment GH levels, type of treatment, and duration of follow-up.
CONCLUSION: This is the first study to document pretreatment IGF-I concentration as a predictor of radiographic osteoarthritis in acromegalic patients with long-term disease control.