In a selected genetic background, lifelong untreated IGHD does not affect longevity.

In patients with lifetime isolated GHD, 6-month treatment with GH has reversible beneficial effects on body composition and metabolic profile, but it causes a progressive increase in intima-media thickness and in the number of atherosclerotic carotid plaques.

Adult subjects with lifetime congenital untreated IGHD present reduced β-cell function, no evidence of IR, and higher frequency of impaired glucose tolerance.

This study further confirms the association of the IVS30+G>T mutation of the Tg gene with hypothyroidism. Computer analysis predicts that the A2215D mutation, first reported here, should cause structural instability of Tg but when present as a compound heterozygous mutation with IVS30+G>T/A its effect is unclear but is likely to be influenced by iodine intake.

Lipid profile was abnormal at baseline, while abnormal body composition was only seen in older subjects in late puberty, indicating that body composition is less sensitive to the effect of GHD than lipid profile. GHRT improves lipid profile at all ages, while it affects body composition only towards the end of growth, emphasizing its importance in achieving normal somatic development in the transition period.