NORMAL PLASMA INSULIN-LIKE GROWTH-FACTOR-I LEVELS AND IMPAIRED FINAL STATURE IN ADULT BLIND SUBJECTS

This aim of this study was to determine if changes in IGF-1 levels and in final stature occur in blind adult subjects. Eighteen subjects (4 females and 14 males) with total blindness (Group 1) and 26 subjects ( 5 females and 21 males) with only light perception (Group 2), living a t an Institute for blind adult subjects in Naples, Italy, were studied . Their height and weight were compared to British standards. Plasma m orning IGF-1 levels, measured by IRMA method were compared to those of 18 normal controls (6 females and 12 males) matched for age and weigh t. A high prevalence of short stature was demonstrated especially in G roup 1 (p=0.00005 by chi-square for trend test) but was also present i n Group 2 (p=0.02). No alterations in weight distribution were observe d in both groups. Basal IGF-I levels in both Group 1 and Group 2 were similar to those of controls: 37.9+/-2.7 nmol/L, respectively, vs 33.3 +/-2.9 nmol/L, NS. High prevalence of final short stature in both grou ps confirms a negative influence of total or partial blindness on grow th. These complex mechanisms appear to involve more than alterations i n GH and IGF-I secretion.