| 1. |
- Ljung, Thomas, 1961-, et al.
(author)
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Inhibition of cortisol secretion by dexamethasone in relation to body fat distribution: a dose-response study
- 1996
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In: Obesity Research. - : Wiley. - 1071-7323 .- 1550-8528. ; 4:3, s. 277-282
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Journal article (peer-reviewed)abstract
- There is now evidence of a hypersensitive hypothalamo-pituitary-adrenal (RPA) axis in subjects with an elevated waist/hip circumference ratio (WHR), an indicator of the centralization of body fat stores. The activity of the HPA axis is regulated by central glucocorticoid receptors, whose activity can be tested by the administration of exogenous glucocorticoids, which normally inhibit cortisol secretion.In this study, dexamethasone (dex) was administered in random order in doses of 0.05, 0.125, 0.25 and 0.5 mg at 10 p.m. with measurements of serum cortisol in the morning (8 a.m.) of this and the following day. The test was performed on 22 apparently healthy men, 40 to 60 years of age, recruited from laboratory personnel, outpatient clinics or advertisements in a newspaper. Eight had a body mass index (BMI) (kg/m(2)) of <25 and 14 of >25. Twelve men had a waist hip ratio (WHR) of <1.0 and 10 men had a WHR of >1.0.Cortisol values at baseline were correlated inversely with WHR and were usually lower in men with a high (>1.0) rather than a low than low (<1.0) WHR after dex inhibition. There was apparently no inhibition by dex at 0.05 and 0.125 mg on average in men with a WHR of >1.0. In addition, the inhibition at 0.5 mg dex correlated negatively with the WHR and was significantly lower (p<0.05) in men with a WHR of >1.0 than in men with a WHR of <1.0. None of these differences or relationships was found to be dependent on BMI.It is concluded that men with an elevated WHR experience a decrease in the inhibition of cortisol secretion by dex. It is suggested that this could explain or contribute to the elevated sensitivity of their HPA axis. Furthermore, lower morning cortisol concentrations suggest a change in diurnal secretion patterns.
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| 2. |
- Oscarsson, Jan, 1960, et al.
(author)
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Low dose continuously infused growth hormone results in increased lipoprotein(a) and decreased low density lipoprotein cholesterol concentrations in middle-aged men.
- 1994
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In: Clinical endocrinology. - 0300-0664. ; 41:1, s. 109-16
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Journal article (peer-reviewed)abstract
- Animal studies have shown that slight increases in basal GH concentrations may result in changes in lipoprotein metabolism. Such changes in GH secretion have been observed in physiological and pathophysiological states such as fasting, uncontrolled diabetes and during oestrogen treatment. The aim of this study was to investigate the possible effects of increases in basal plasma GH concentrations on lipoprotein concentrations.Recombinant human growth hormone (rhGH) was given as a continuous subcutaneous infusion in a low dose (0.02 U/kg/day) in an open study.Eight middle-aged (42-59 years) overweight (body mass index: 26.1-33.8 kg/m2) but otherwise healthy men were studied over a period of 14 days.Blood samples were obtained after an over-night fast before and after 2, 7 and 14 days of treatment. Plasma and serum were separated and used for subsequent measurements of hormone and lipoprotein concentrations. On days 0, 7 and 14 of treatment, post-heparin plasma was also obtained for determinations of plasma lipoprotein lipase and hepatic lipase activities. In addition, a hyperinsulinaemic euglycaemic glucose clamp was performed on days 0 and 13 of the study. Fat biopsies from abdominal and gluteal fat depots were obtained for measurement of lipoprotein lipase activities on days 0 and 14 of the study.Serum GH concentrations increased to a steady level of 2-4 mU/l during treatment. Serum insulin-like growth factor-I (IGF-I) concentrations increased throughout the treatment period to twice the pretreatment levels. Plasma insulin and blood glucose concentrations increased on day 2 of treatment. After 7 and 14 days of treatment blood glucose concentrations were not different from pretreatment levels, but plasma insulin concentrations were still elevated. Serum cholesterol and low density lipoprotein (LDL) cholesterol concentrations had decreased after 7 and 14 days of treatment. High density lipoprotein (HDL) cholesterol concentrations were not affected, but very low density lipoprotein (VLDL) cholesterol and triglyceride concentrations increased transiently at day 2 of treatment. Serum apolipoprotein (apo) A-I, apoB and apoE concentrations were not significantly affected. Serum lipoprotein(a) concentrations had increased by days 7 and 14 to 147 and 142% of pretreatment concentrations, respectively. Lipoprotein lipase and hepatic lipase activities in post-heparin plasma, as well as abdominal and gluteal adipose tissue lipoprotein lipase activities, were not affected. There was no significant change in glucose disposal rate estimated from the glucose clamp studies.A low dose infusion of GH results in marked changes in lipoprotein concentrations with a transient increase in VLDL cholesterol and thereafter in a decrease in LDL cholesterol. In addition, this low dose of GH resulted in marked increases in lipoprotein(a) concentrations. The observed effects of GH may partly involve changes in IGF-I and insulin secretion.
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| 3. |
- Ottosson, Malin, 1959, et al.
(author)
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Blockade of the glucocorticoid receptor with RU 486: effects in vitro and in vivo on human adipose tissue lipoprotein lipase activity.
- 1995
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In: Obesity research. - 1071-7323. ; 3:3, s. 233-40
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Journal article (peer-reviewed)abstract
- Cortisol is known to induce lipoprotein lipase (LPL) activity in human adipose tissue in vitro and in vivo such as in Cushing's syndrome. The significance of the glucocorticoid receptor (GR) for this induction was evaluated in the present study. The synthetic steroid molecule RU 486, a potent glucocorticoid antagonist, was used as a tool to block the GR, in vitro and in vivo. In addition to LPL activity, glucose tolerance, blood pressure and plasma lipids, all variables influenced by cortisol, were studied in order to evaluate the peripheral antiglucocorticoid activity of RU 486 in vivo, in man. Addition of both cortisol and RU 486 to incubations of human adipose tissue pieces significantly inhibited the increase in LPL activity that could be induced by cortisol alone (p < 0.01). In a ten-fold molarity excess RU 486 totally abolished cortisol action (p < 0.01). With cortisol and RU 486 in equimolar concentrations the RU 486 blockade was probably incomplete and LPL activity induced (p < 0.05). The results imply that the stimulating effect of cortisol on LPL activity in human adipose tissue is mediated via the GR. Administration of 400 mg RU 486 at 2200 hours on two consecutive days to healthy men caused a significant rise in serum cortisol levels measured at 0800 hours (p < 0.05). The mean LPL activity in the subcutaneous abdominal adipose tissue remained unchanged. The mean level of serum triglycerides decreased significantly (p < 0.01) and there was a negative correlation between change in LPL activity and change in triglyceride levels (r = -0.73, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
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| 4. |
- Andersson, B., et al.
(author)
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Testosterone concentrations in women and men with NIDDM
- 1994
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In: Diabetes Care. ; 17, s. 405-411
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Journal article (peer-reviewed)abstract
- Department of Medicine, Sahlgren's Hospital, University of Göteborg, Sweden. OBJECTIVE--To evaluate androgen concentrations in relation to insulin resistance in men and women with and without NIDDM. Recent studies have indicated the potential importance of the regulation of insulin sensitivity by androgens in both women and men. Low sex hormone binding globulin (SHBG) concentration is an independent risk factor for the development of non-insulin-dependent diabetes mellitus (NIDDM) in women and is strongly associated statistically with signs of insulin resistance. RESEARCH DESIGN AND METHODS--We compared measurements of anthropometric variables and SHBG, steroid hormone, and insulin concentrations of women and men who have NIDDM with those of control subjects. RESULTS--Women with NIDDM had somewhat higher plasma insulin concentrations, lower SHBG, and higher free testosterone values than did control subjects with similar body mass index (BMI). Women with NIDDM had marginally higher waist-to-hip ratios (WHR). Plasma insulin concentrations correlated positively with BMI, WHR, and free testosterone and negatively with SHBG. In multivariate analyses, insulin concentrations remained positively associated with BMI and free testosterone. Men with NIDDM had higher fasting plasma insulin concentrations than did the nondiabetic control subjects. Testosterone and SHBG were lower in the diabetic men than in both control groups. The derived value of free testosterone was not different between groups. Univariate correlation analyses revealed tight statistical couplings between plasma insulin on the one hand and SHBG and testosterone concentrations (negative) on the other. In multivariate analyses, only the insulin-testosterone association remained. CONCLUSIONS: Women with NIDDM have high levels of free testosterone and low levels of SHBG. Insulin resistance is closely correlated with these signs of hyperandrogenicity as well as with obesity. Men with NIDDM also have low levels of SHBG and, in contrast to women, low testosterone values. Insulin values correlate negatively with these hormonal factors. Based on the results of experimental work and intervention studies, we suggest that these androgen abnormalities might be causally related to insulin resistance in NIDDM. PMID: 8062607 [PubMed - indexed for MEDLINE]
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| 5. |
- Eriksson, Matts, et al.
(author)
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No effect of the cortisol-synthesis inhibitor metyrapone on alcohol drinking: A pilot study
- 2001
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In: Alcohol. - 0741-8329. ; 25, s. 115-122
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Journal article (peer-reviewed)abstract
- Two bases for this study were the theory of stress as a provoking factor for high alcohol consumption in human being and findings that the stress hormones stimulate ethanol intake in rats. We therefore investigated whether the cortisol-synthesis inhibitor metyrapone could reduce high alcohol consumption in socially stable subjects who reported drinking mainly for relaxation purposes. Most of the investigated subjects were found to be alcohol dependent (81%), with moderately high levels of intake, yet they had not reported more severe life problems. All subjects reported their daily alcohol consumption during 2-week baseline, medication, and postmedication periods. Sixteen subjects were given 1 g of metyrapone orally daily for 14 days, and 15 subjects received placebo. Morning serum cortisol concentration was assessed four times in the course of the study period. Metyrapone treatment was not found to reduce alcohol consumption more than placebo. Serum cortisol concentrations remained within the laboratory reference interval during the study and did not differ between the study groups. In this study, we found that a cortisol-synthesis inhibitor had no effect on alcohol consumption. One reason may be that cortisol secretion has no role in the maintenance of high alcohol consumption. On the other hand, because this study is the first of its kind, further studies with the use of other doses of treatment and treatment schedules are suggested. © 2001 Elsevier Science Inc. All rights reserved.
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| 6. |
- Johannsson, Gudmundur, 1960, et al.
(author)
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Growth hormone treatment of abdominally obese men reduces abdominal fat mass, improves glucose and lipoprotein metabolism, and reduces diastolic blood pressure.
- 1997
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In: The Journal of clinical endocrinology and metabolism. - : The Endocrine Society. - 0021-972X. ; 82:3, s. 727-34
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Journal article (peer-reviewed)abstract
- The most central findings in both GH deficiency in adults and the metabolic syndrome are abdominal/visceral obesity and insulin resistance. Abdominal obesity is associated with blunted GH secretion and low serum insulin-like growth factor-I concentrations. GH treatment in GH-deficient adults has demonstrated favorable effects on most of the features of GH deficiency in adults, but it is not known whether GH can improve some of the metabolic aberrations observed in abdominal/visceral obesity. Thirty men, 48-66 yr old, with abdominal/visceral obesity were treated with recombinant human GH (rhGH) in a 9-month randomized, double-blind, placebo-controlled trial. The daily dose of rhGH was 9.5 micrograms/kg. Body fat was assessed from total body potassium, and abdominal sc and visceral adipose tissue was measured using computed tomography. The glucose disposal rate (GDR) was measured during an euglycemic, hyperinsulinemic glucose clamp. In response to the rhGH treatment, total body fat and abdominal sc and visceral adipose tissue decreased by 9.2 +/- 2.4%, 6.1 +/- 3.2%, and 18.1 +/- 7.6%, respectively. After an initial decrease in the GDR at 6 weeks, the GDR increased in the rhGH-treated group as compared with the placebo-treated one (P < 0.05). The mean serum concentrations of total cholesterol (P < 0.01) and triglyceride (P < 0.05) decreased, whereas blood glucose and serum insulin concentrations were unaffected by the rhGH treatment. Furthermore, diastolic blood pressure decreased and systolic blood pressure was unchanged in response to rhGH treatment. This trial has demonstrated that GH can favorably affect some of the multiple perturbations associated with abdominal/visceral obesity. This includes a reduction in abdominal/visceral obesity, an improved insulin sensitivity, and favorable effects on lipoprotein metabolism and diastolic blood pressure.
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| 7. |
- Karlsson, C, et al.
(author)
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Effects of growth hormone treatment on the leptin system and on energy expenditure in abdominally obese men.
- 1998
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In: European journal of endocrinology / European Federation of Endocrine Societies. - 0804-4643. ; 138:4, s. 408-14
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Journal article (peer-reviewed)abstract
- The present study has examined the short- and long-term effects of growth hormone (GH) treatment on the leptin system and energy expenditure. Thirty male individuals with abdominal obesity were randomised to GH or placebo treatment in a 9-month, double-blind study. The dose of GH was 9.5 microg/kg, administered subcutaneously every evening. Serum leptin concentrations were measured by a human leptin RIA. Total RNA was isolated from adipose tissue biopsies and leptin mRNA levels were determined by a semi-quantitative reverse transcriptase-PCR assay. Body composition was determined by potassium-40 and the basal metabolic rate (BMR) was measured by a computerised, ventilated, open-hood system. As compared with placebo, an overall decrease in serum leptin concentrations as assessed by the area under the curve (AUC) (P < 0.05) and an increase in BMR (AUC, P < 0.05) were observed during GH treatment. The overall GH-induced changes were due to marked changes in serum leptin concentrations and BMR after 6 weeks of treatment. After 9 months of GH treatment there was a significant reduction in body fat (BF) while serum leptin concentrations and BMR did not differ from baseline values. Leptin mRNA levels did not change over the study period. We speculate that long-term GH treatment induces a new energy balance steady state with decreased BF stores. The effects of GH on the leptin system is suggested to be of importance for the maintenance of a lower BF mass.
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| 8. |
- Mårin, Per, et al.
(author)
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Cortisol secretion in relation to body fat distribution in obese premenopausal women.
- 1992
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In: Metabolism: clinical and experimental. - : Elsevier BV. - 0026-0495. ; 41:8, s. 882-6
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Journal article (peer-reviewed)abstract
- Urinary cortisol output and serum cortisol concentrations were measured in the steady state, under "field" conditions, and during standardized inhibitory and stimulatory tests in premenopausal, obese women, and were analyzed in relation to adipose tissue distribution. Urinary cortisol output was increased under field conditions in women with an elevated waist to hip circumference ratio (WHR) and, in particular, in women with a large abdominal sagittal diameter, indicating visceral fat accumulation. However, dexamethasone inhibition of cortisol secretion was normal. Stimulation with corticotropin analogue and with physical (cold-pressor test) or mental (color-word or mathematic) stress tests also showed elevated responses of serum cortisol, but not of prolactin or growth hormone concentrations. It is suggested that women with visceral fat accumulation have elevated cortisol secretion due to an increased sensitivity along the hypothalamic-pituitary-adrenal axis, and that this may be causing their abnormal fat depot distribution.
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| 9. |
- Mårin, P, et al.
(author)
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The morphology and metabolism of intraabdominal adipose tissue in men.
- 1992
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In: Metabolism: clinical and experimental. - 0026-0495. ; 41:11, s. 1242-8
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Journal article (peer-reviewed)abstract
- Mass, morphology, and metabolism of total adipose tissue and its subcutaneous, visceral, and retroperitoneal subcompartments were examined in 16 men with a wide variation of total body fat. Computerized tomography (CT) scans showed that the intraabdominal fat mass comprised approximately 20% of total fat mass. Visceral and retroperitoneal fat masses were approximately 80% and 20% of total intraabdominal fat mass, respectively. Enlargement of intraabdominal fat depots was due to a parallel adipocyte enlargement only. Direct significant correlations were found between these adipose tissue masses and blood glucose and plasma insulin levels, blood pressure, and liver function tests, while glucose disposal rate during euglycemic glucose clamp measurements at submaximal insulin concentrations (GDR), plasma testosterone, and sex hormone-binding globulin concentrations correlated negatively. The correlations for glucose, insulin, and GDR were strongest with visceral fat mass. Adipose tissue lipid uptake, measured after oral administration of labeled oleic acid in triglyceride, was approximately 50% higher in omental than in subcutaneous adipose tissues. Adipocytes from omental fat also showed a higher lipolytic sensitivity and responsiveness to catecholamines. Furthermore, these adipocytes were less sensitive to the antilipolytic effects of insulin. Both lipid uptake and lipolytic sensitivity and responsiveness showed strong correlations (r = 0.8 to 0.9) to blood glucose and plasma insulin concentrations and also to the GDR (negative), while no such correlations were found with lipid uptake in subcutaneous or retroperitoneal abdominal adipose tissues. Taken together, these results suggest a higher turnover of lipids in visceral than in the other fat depots, which is closely correlated to systemic insulin resistance and glucose metabolism in men.
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| 10. |
- Oscarsson, Jan, 1960, et al.
(author)
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Two weeks of daily injections and continuous infusion of recombinant human growth hormone (GH) in GH-deficient adults. II. Effects on serum lipoproteins and lipoprotein and hepatic lipase activity.
- 1996
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In: Metabolism: clinical and experimental. - 0026-0495. ; 45:3, s. 370-7
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Journal article (peer-reviewed)abstract
- Recombinant human growth hormone (GH) administered as daily subcutaneous (SC) injections has been shown to affect serum lipoproteins in GH-deficient subjects. However, the effects of continuous infusion of GH on serum lipoproteins have not been investigated in GH-deficient adults. The aim of the present study was to compare effects of daily injections and continuous infusion of GH on lipoprotein metabolism. Recombinant human GH (0.25 U/kg/wk) was administered to nine GH-deficient adult men during a period of 14 days in two different ways, ie, as a daily SC injection at 8:00 PM and as a continuous SC infusion, with 1 month of washout between the treatments. Blood samples and tests were performed in the morning after an overnight fast before the start of GH treatment (day 0) and on day 2 and day 14 of treatment. Abdominal SC adipose tissue lipoprotein lipase (LPL), postheparin plasma LPL, and hepatic lipase (HL) activity were measured 120 minutes after the intake of 100 g glucose. Adipose tissue LPL activity decreased and postheparin plasma HL activity increased after 14 days of GH treatment irrespective of the mode of GH administration, whereas GH treatment had no effect on postheparin plasma LPL activity. Serum triglyceride and very-low-density lipoprotein (VLDL) triglyceride concentrations increased during GH treatment. However, VLDL triglyceride concentrations increased to a greater degree during treatment with daily GH injections than during continuous infusion of GH. Serum apolipoprotein (apo) B and low-density lipoprotein (LDL) cholesterol concentrations decreased during treatment with daily GH injections, but were not significantly affected by continuous GH infusion. Thus, apo B and LDL cholesterol concentrations were lower after daily GH injections versus continuous GH infusion. Serum lipoprotein(a) [Lp(a)] and apo E concentrations increased during both modes of GH treatment. However, continuous infusion of GH resulted in a more marked increase in Lp(a) and apo E concentrations than daily GH injections. Minor effects were observed on serum apo A-I concentrations but high-density lipoprotein (HDL) cholesterol concentrations were not affected. In conclusion, GH treatment of GH-deficient men influenced adipose tissue LPL and postheparin plasma HL activity, as well as serum lipoprotein concentrations. Moreover, continuous GH infusion and daily GH injections differed with respect to the magnitude of effects on several lipoprotein fractions including VLDL triglycerides, LDL cholesterol, apo B, apo E, and Lp(a) concentrations.
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