SERUM APOLIPOPROTEIN(A) CORRELATES WITH GROWTH-HORMONE LEVELS IN CHINESE PATIENTS WITH ACROMEGALY

Untreated acromegaly is associated with an increased cardiovascular mo rbidity and mortality. The contribution of altered lipid metabolism re mains unclear. We investigated the relationship between serum apolipop rotein(a) (apo(a)) and growth hormone (GH) levels in 15 patients with acromegaly before and during treatment with octreotide, a long acting somatostatin analogue, 288-600 mu g/day s.c., for 6 months. Before tre atment serum apo(a) was significantly elevated in acromegalic patient' s (geometric mean being 323 U/l vs. 142 U/l in controls (n = 92; P < 0 .01)). Octreotide treatment resulted in significant reductions in seru m apo(a) concentration (F = 7.22; P < 0.01; geometric mean being 232 U /l and 248 U/l at 3 months and 6 months respectively) and apo(a) conce ntrations on treatment were not significantly different from control v alues. There were significant reductions in serum GH (F= 7.30; P < 0.0 1), insulin growth factor 1 (IGF1) (P= 31.4, P < 0.001) and insulin (F = 4.57; P < 0.05) concentrations. Plasma glycosylated haemoglobin leve ls were unchanged. Apo(a) levels correlated with serum GH (r = 0.450; P < 0.01) but showed no correlation with basal insulin concentrations. Serum HDL cholesterol increased on treatment (F= 4.29; P < 0.05). Tri glycerides were reduced only in the 12 patients without diabetes melli tus (F= 4.75; P < 0.05). No significant change in LDL cholesterol occu rred. Our findings suggest that apo(a) may constitute another cardiova scular risk factor in untreated acromegaly and that GH may be involved in the regulation of circulating apo(a) concentration.