Effect of discontinuation of long-term growth hormone treatment on carbohydrate metabolism and risk factors for cardiovascular disease in girls with Turner syndrome.
GH treatment increases insulin levels in girls with Turner syndrome (TS), who are already predisposed to develop diabetes mellitus and other risk factors for developing cardiovascular disease. Therefore, in the present study, we investigated carbohydrate metabolism and several other risk factors that may predict development of cardiovascular disease in girls with TS after discontinuation of long-term GH treatment. Fifty-six girls, participating in a randomized dose-response study, were examined before, during, and 6 months after discontinuing long-term GH treatment with doses of 4 IU/m(2).d ( approximately 0.045 mg/kg.d), 6 IU/m(2).d, or 8 IU/m(2).d. After a minimum of 4 yr of GH treatment, low-dose micronized 17beta-estradiol was given orally. Mean (SD) age at 6 months after discontinuation of GH treatment was 15.8 (0.9) yr. Mean duration of GH treatment was 8.8 (1.7) yr. Six months after discontinuation of GH treatment, fasting glucose levels decreased and returned to pretreatment levels. The area under the curve for glucose decreased to levels even lower than pretreatment level (P < 0.001). Fasting insulin levels and the area under the curve for insulin decreased to levels just above pretreatment level (P < 0.001 for both), although being not significantly different from the control group. No dose-dependent differences among GH dosage groups were found. At 6 months after discontinuation, impaired glucose tolerance was present in 1 of 53 girls (2%), and none of the girls developed diabetes mellitus type 1 or 2. Compared with pretreatment, the body mass index SD-score had increased (P < 0.001), and the systolic and diastolic blood pressure SD-score had decreased significantly at 6 months after discontinuation of GH treatment (P < 0.001 for both) although remaining above zero (P < 0.001, P < 0.05, and P < 0.005, respectively). Compared with pretreatment, total cholesterol (TC) did not change after discontinuation of GH treatment, whereas the atherogenic index [AI = TC/high-density lipoprotein cholesterol (TC/HDL-c)] and low-density lipoprotein cholesterol (LDL-c) had decreased; and both HDL-c and triglyceride levels increased (P < 0.001 for AI, LDL-c, and HDL-c; P < 0.05 for triglyceride). Compared with the control group, AI, serum TC, and LDL-c levels were significantly lower (P < 0.001 for all), whereas HDL-c levels were significantly higher (P < 0.05). In conclusion, after discontinuation of long-term GH treatment in girls with TS, the GH-induced insulin resistance disappeared, blood pressure decreased but remained higher than in the normal population, and lipid levels and the AI changed to more cardio-protective values.
Van Pareren YK
,De Muinck Keizer-Schrama SM
,Stijnen T
,Sas TC
,Drop SL
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《JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM》
Body composition, blood pressure, and lipid metabolism before and during long-term growth hormone (GH) treatment in children with short stature born small for gestational age either with or without GH deficiency.
To assess the effects of long-term continuous GH treatment on body composition, blood pressure (BP), and lipid metabolism in children with short stature born small for gestational age (SGA), body mass index (BMI), skinfold thickness measurements, systemic BP measurements, and levels of blood lipids were evaluated in 79 children with a baseline age of 3-11 yr with short stature (height SD-score, < -1.88) born SGA (birth length SD-score, < -1.88). Twenty-two of the 79 children were GH deficient (GHD). All children participated in a randomized, double-blind, dose-response multicenter GH trial. Four- and 6-yr data were compared between two GH dosage groups (3 vs. 6 IU/m2 body surface/day). Untreated children with short stature born SGA are lean (mean BMI SD-score, -1.3; mean SD-score skinfolds, -0.8), have a higher systolic BP (SD-score, 0.7) but normal diastolic BP (SD-score, -0.1), and normal lipids (total cholesterol, 4.7 mmol/L; low-density lipoprotein, 2.9 mmol/L; high-density lipoprotein, 1.3 mmol/L) compared with healthy peers. During long-term continuous GH treatment, the BMI normalized without overall changes in sc fat compared with age-matched references, whereas the BP SD-score and the atherogenic index decreased significantly. Although the mean 6-yr increase in height SD-score was significantly higher in the children receiving GH treatment with 6 IU/m2 x day (2.7) than in those receiving treatment with 3 IU/m2 day (2.2), no differences in the changes in BMI, skinfold measurements, BP, and lipids were found between the GH dosage groups. The pretreatment SD-scores for BMI, skinfold, and BP, as well as the lipid levels, were not significantly different between GHD and non-GHD children, but after 6 yr of GH treatment the skinfold SD-score and BP SD-score had decreased significantly more in the GHD than in the non-GHD children. Our data indicate that GH treatment has at least up to 6 yr positive instead of negative effects on body composition, BP, and lipid metabolism. In view of the reported higher risk of cardiovascular diseases in later life in children born SGA, further research into adulthood remains warranted.
Sas T
,Mulder P
,Hokken-Koelega A
《JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM》
Final height data, body composition and glucose metabolism in growth hormone-treated short children born small for gestational age.
Low birth weight has been associated with impaired insulin sensitivity, type 2 diabetes mellitus, hypertension and cardiovascular disease in later life. GH therapy is known to increase fasting and postprandial insulin levels. For this reason concern has been expressed regarding the possible detrimental effects of GH therapy in children born small for gestational age (SGA). To assess the effects of GH therapy on body composition, carbohydrate metabolism and final height in short SGA children, 165 prepubertal short children born SGA were enrolled in either a multicentre, double-blind, randomized, dose-response GH trial (n = 75) or in a GH controlled trial (n = 90). The inclusion criteria were: (1) birth length standard deviation score (SDS) below -2; (2) age 3-8 years; (3) height SDS below -2. The children's mean (SD) age was 7.3 (2.1) years (GH dose-response trial) and 6.0 (1.5) years (GH controlled trial), birth length SDS was -3.6 and height SDS was -3.0 (0.7). In the GH dose-response trial, children were randomly assigned to either 1 mg GH/m(2) per day (group A, n = 41) or 2 mg GH/m(2) per day (group B, n = 38) ( approximately 0.033 or 0.067 mg/kg per day, respectively). In the GH controlled trial, children were randomly assigned to 1 mg GH/m(2) per day (n = 60) or served as controls (n = 30). Subjects underwent standard oral glucose tolerance tests and measurement of body mass index, systolic and diastolic blood pressure and serum lipids at baseline and after 1 and 6 years of GH therapy and again 6 months after discontinuation of GH. Body composition was measured by dual energy x-ray absorptiometry at baseline and again after 3 years in the GH controlled trial. Mean (SD) final height SDS was not significantly different between the two GH dosage groups: -1.2 (0.7) in group A and -0.8 (0.7) in group B. At the start of GH therapy, 8% of children had impaired glucose tolerance (IGT). Systolic blood pressure was significantly higher in comparison with healthy peers. GH therapy induced considerably higher fasting and glucose-stimulated insulin levels after 1 and 6 years, regardless of GH dosage. After 6 years, 4% of children had IGT. Six months after discontinuation of GH, glucose levels remained normal, whereas fasting and glucose-stimulated insulin returned to levels comparable to those of healthy peers. None of the children developed diabetes. During 6 years of GH therapy both systolic and diastolic blood pressure decreased significantly and remained so after discontinuation of GH therapy. At baseline all children had reduced bone mineral content and lean body mass. Fat mass was not significantly lower than normal. Treatment with 1 mg GH/m(2) per day resulted in a significant increase in (and normalization of) bone mineral content and lean body mass in comparison with untreated short SGA controls. Fat mass decreased during the first year of GH but returned to values comparable to those at baseline in the following 2 years of GH therapy. We found that long-term, continuous GH therapy in short children born SGA leads to a normalization of height during childhood and to a normal final height in most children, regardless of GH dosage. Only very short or relatively older children may need a dosage of 2 mg GH/m(2) per day. Long-term GH therapy had no adverse effects on glucose levels and serum lipids and had a positive effect on blood pressure, even with GH dosages of up to 2 mg/m(2) per day. However, as has been reported in other patient groups, GH induced higher fasting and glucose-stimulated insulin levels, indicating insulin resistance. After discontinuation of GH serum insulin levels returned to normal age-reference levels. Short SGA children have a reduction in bone mineral content and lean body mass when compared with healthy controls, which significantly improved (normalized) with GH therapy at a dose of 1 mg/m(2) per day.
Hokken-Koelega AC
,van Pareren Y
,Sas T
,Arends N
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《hormone research》