Adipose tissue assessed by magnetic resonance imaging in growth hormone-deficient adults: the effect of growth hormone replacement and a comparison with control subjects

Abstract

The visceral and subcutaneous abdominal adipose tissue (AT) area and the subcutaneous hip AT area were assessed by magnetic resonance imaging (MRI) in 12 growth hormone-deficient adults before and after 6 mo of replacement with recombinant human growth hormone (rhGH) and in 12 healthy control subjects. The data obtained by MRI were compared with circumference measurements of waist and hip. Growth hormone-deficient patients compared with control subjects had a higher visceral AT area (P = 0.003) and subcutaneous AT area (P = 0.013); there was no significant difference in subcutaneous hip AT area. Six months of rhGH replacement reduced the subcutaneous hip AT area (19.8%), the subcutaneous abdominal AT area (15.6%), and particularly the visceral AT area (38.2%), resulting in fat areas that were not different from those of control subjects. Furthermore, this study shows that in contrast with control subjects, circumference measurements are not useful to predict AT areas in growth hormone-deficient patients and cannot be used to assess changes in AT areas during rhGH replacement.

The favourable effects of growth hormone (GH) substitution on hypercholesterolaemia in GH-deficient adults are not associated with concomitant reductions in adiposity. A 12 month placebo-controlled study

“…It is noteworthy, that insulin levels usually increase with GH administration and become suppressed during IGF-I administration. The importance of studies that evaluate the long-term effect of GH treatment in a maintenance dose as low as possible, is underlined by the fact that Lp(a) is known to be an independent risk factor for atherosclerotic vascular disease, 6 even though Ridker et al, 38 in a large prospective study, recently found no evidence of such an association.…”

“…Subsequently, it was revealed that visceral fat mass was increased in GHD patients, and that GH treatment caused a 30% reduction of visceral fat mass and a smaller reduction in subcutaneous fat. 5,6 Visceral fat is a well known risk factor for cardiovascular disease and death, 7 but it is not known whether the increased prevalence of ischaemic heart disease (IHD) in GHD is secondary to the excess visceral fat mass.…”

“…6 Most 2Y 9À12 but not all 13 studies agree that GHD patients exhibit hypercholesterolaemia caused by an increased concentration of LDL cholesterol. Serum HDL cholesterol is reported in the normal range, 2,10 decreased 11,13,14 or even increased 12 in GHD patients.…”

Hormones and body composition in humans: clinical studies

“…16 As a consequence an interaction between GH and leptin could be expected. GH therapy in 14 adults with GH de®ciency showed a parallel decrease of leptin levels and of the percentage of body fat.…”

“…GH de®cient subjects showed higher values of both visceral and subcutaneous adipose tissue volume than controls. 16 The second paper studied the effects of 12 month GH treatment of GH de®ciency in a double-blind, parallel design: 14 patients received GH and 15 received placebo. Body fat (by DXA) and both visceral and subcutaneous abdominal adipose tissue (by single slice computed tomography) signi®cantly decreased in the intervention group.…”