The effect of growth hormone administration in growth hormone deficient adults on bone, protein, carbohydrate and lipid homeostasis, as well as on body composition

OBJECTIVE

The effect on bone, protein, carbohydrate and lipid homeostasis as well as body composition of the administration of growth hormone to adult patients with growth hormone deficiency was studied.

DESIGN

Growth hormone was administered at a dose of 25 micrograms/kg/day with a maximum of 1.48 mg (4 IU) a day, for 6 months in eight adults. Studies were done before the start and at 1, 3 and 6 months during therapy, as well as 3 months after treatment had been stopped.

RESULTS

Subjective well-being as assessed by a short psychological tests showed an improvement in six and no change in two patients. Body composition, as assessed by body impedance assessment and D2O dilution, both showed an increase in lean body mass of 4 kg (5% of body weight), accompanied by a decrease in mean fat mass of 3 kg. Nitrogen turnover studies showed a transient increase in fed state nitrogen balance due to an increase in the rate of protein synthesis, which exceeded a smaller increase in the protein degradation rate. Growth hormone treatment did not affect the circulating levels of 25(OH)-vitD or PTH 1-84, while 1,25(OH)2-vitD had significantly increased after 6 months, as well as 3 months after treatment ended. Osteocalcin, procollagen I levels, as well as 24-hour urinary excretion of hydroxyproline and calcium rose during growth hormone administration but subsequently decreased rapidly after administration had been stopped, while the increase in alkaline phosphatase persisted. This increase in markers of both bone resorption and bone formation indicates an activation of bone remodelling, but this was not reflected by an increase in bone density. Glucose levels, measured before and during a normal breakfast, increased during growth hormone treatment, but serum insulin levels did not. Total cholesterol levels decreased by 0.5 mmol/l. Levels of T4 and free T4 as well as rT3 decreased, while T3 increased during growth hormone treatment.

CONCLUSION

Therapy with growth hormone for 6 months in a dose varying between 6 and 25 micrograms/kg/day increased lean body mass and decreased fat mass. The sense of general well-being improved in most patients. Furthermore, growth hormone treatment increased bone turnover without a measurable increase in bone density, caused some minor changes in lipid and carbohydrate metabolism, and increased the metabolism of thyroxine to T3.

Patients with combined hypercholesterolemia-hypertriglyceridemia show an increased monocyte-endothelial cell adhesion in vitro: triglyceride level as a major determinant

Hypercholesterolemia (HC) is one of the primary risk factors for atherosclerosis. Patients with familial hypercholesterolemia (FH) or combined hypercholesterolemia-hypertriglycerinemia (CHH) are at risk to develop premature atherosclerosis. Animal models have revealed that diet-induced HC in vivo leads to an increased adhesion of monocytes to the endothelium of the vessel wall. Changes in the monocytes, endothelial cells, or serum components may lead to the increased monocyte adhesion that results in atherosclerotic plaque formation. In the present study, we investigated the binding of the monocyte in an in vitro system. Incubation of freshly isolated monocytes from CHH patients with cultured human umbilical vein endothelial cells (HUVEC) gave a significant 60% increase in monocyte adhesion when compared with monocytes from healthy subjects. No such increase was observed using monocytes from nontreated FH patients. These data suggest that CHH results in in vivo alterations of the monocytes that lead to an increased in vitro adhesion to HUVEC, and that an increased level of plasma triglycerides is the major determinant, since HC alone does not induce this alteration.

The efficacy and safety of pravastatin, compared to and in combination with bile acid binding resins, in familial hypercholesterolaemia

Forty patients with familial hypercholesterolaemia (FH) were treated with 40 mg pravastatin once daily. Pravastatin decreased serum total and low density lipoprotein cholesterol (LDL) after 8 weeks of treatment by 28% and 33%, respectively, while high density lipoprotein cholesterol increased by 8% and triglycerides decreased by 14%. In 30 patients LDL cholesterol had not decreased below 5.0 mmol l-1 after 8 weeks of treatment, and in these patients resins were added to pravastatin, resulting in an additional decrease in total and LDL cholesterol of 8% and 12%, respectively. A control group of 22 FH patients was treated with placebo for 10 weeks, after which time resins were added, and they induced a decrease in total and LDL-cholesterol of 17% and 22%, respectively. Our results over a 24-week treatment period indicate that 40 mg pravastatin is more effective than 3 packets of resins in lowering LDL cholesterol, whereas the combination is most effective of all and can be used safely.