Endocrine Abstracts

Amyotrophic lateral sclerosis (ALS) is the most common motor neurone disorder in human adults. Scanty data on endocrine abnormalities have been reported. Aim of the present study was to investigate the GH-IGF-I axis in ALS patients.

22 ALS patients (12 men and 10 women), aged 46–77 years, performed GHRH+arginine test: blood samples for GH were collected at baseline, 30 and 60 minutes; IGF-I was determined at baseline. The control group consisted of 25 normal age- and sex-matched subjects (12 men, 13 women; age range, 40–77 yr). No patient was under riluzole therapy.

Mean basal GH levels (±S.D.) in ALS patients were significantly reduced compared with normal controls (0.24±0.27 vs 2.27±3.6 ng/ml, P=0.01), as well as peak GH concentrations (12.6±8.9 vs 39.9±18.7 ng/ml, P<0.001). Six patients (27.3%) showed a normal GH response to stimulus; 7 patients (31.8%) displayed moderate GH deficiency; in 9 patients (40.1%) GH response was markedly deficient. IGF-I levels (143.6±63.8 ng/ml) were significantly reduced in patients compared to normal subjects (220.4±18.6 ng/ml). No significant correlation was observed between peak GH concentrations and age, BMI, disease duration, severity or clinical form. A higher incidence of GH deficiency was observed in males compared to females (83,3% vs 60%); peak GH response in males was significantly lower than in females (8.92±6.63 vs 16.98±9.62 ng/ml, P=0.03).

In conclusion, the present data indicate a reduction of GH secretion in ALS patients and particularly in males; the mechanisms behind this finding need to be clarified.