c-peptide and androstane-3-17-diol-glucuronide

Studies specifically investigating the effects of single dietary components on plasma levels of dehydroepiandrosterone (DHEA) and its sulfate ester (DHEAS) are rare. Especially no data is available with regard to specific dietary fibers. Therefore, the impact of pectin (a representative fiber that affects the enterohepatic recirculation of bile acids) was studied in a randomized crossover trial consisting of three diet periods characterized by the same food supply and daily doses of 0 g, 15 g or 30 g pectin. Blood and 24-h-urine samples were collected at the end of each 4-day diet period from 6 healthy male volunteers. Plasma levels of DHEA, cortisol and the major binding protein of DHEAS albumin remained unchanged with the varying pectin supplements. Also, no changes were observed for several urinary analytes including urinary DHEAS. However, effects of pectin intake (30, 15 versus 0 g/d) were seen for plasma DHEAS (9.3 +/- 2.8, 9.2 +/- 2.6, 8.0 +/- 3.1 mumol/L, p < 0.01) and total plasma cholesterol (4.4 +/- 0.7, 4.5 +/- 0.7, 4.7 +/- 0.8 mmol/L, p = 0.1). Obviously, the altered intake of fiber in the form of pectin affects plasma concentrations of DHEAS and cholesterol in an opposite direction. The reason for this is not known but a dietetically induced modulation of the binding properties of plasma albumin for DHEAS appears possible. Our findings suggest that the target tissue-available, not protein-bound fraction of circulating DHEAS (as reflected by the renal DHEAS output) is not necessarily altered when total plasma concentrations of DHEAS vary.

Topics: Adult; Androstane-3,17-diol; C-Peptide; Cholesterol; Creatinine; Cross-Over Studies; Dehydroepiandrosterone; Dehydroepiandrosterone Sulfate; Dietary Fiber; Dose-Response Relationship, Drug; Food Additives; Humans; Hydrocortisone; Ketosteroids; Kidney; Male; Pectins; Serum Albumin

The aim of this study was to determine whether definite diet changes affect adrenocortical activity and/or adrenal androgen metabolism. A controlled experimental diet study with four consecutive diet periods (repeated measure design) was carried out in six healthy adult volunteers. Four nearly isoenergetic diets, two normal (N) moderately protein-rich, one protein-rich (P), and one low protein lactovegetarian (L), were fed. At the end of each 5-day diet period a blood sample and two 24-h urine specimens were obtained from each subject. Plasma levels of dehydroepiandrosterone sulfate (DHEAS) were elevated with diet L (6.5 +/- 1.4 vs. 5.3 +/- 1.1 mumol/L; P < 0.05) compared to diet N, whereas other plasma hormones, including cortisol and insulin-like growth factor I did not vary markedly. A marked increase of 60% was seen in the urinary 24-h output of 3 alpha-androstanediol glucuronide with diet P. Urinary 24-h excretion rates for C peptide, free cortisol, DHEAS, and total 17-ketosteroid sulfates were clearly reduced with diet L compared to those with diet N or P. Our results show that a lactovegetarian diet can reduce adrenocortical activity (at least after a short term diet change). In addition, this vegetarian nutrition leads to a particular metabolic situation (elevated plasma DHEAS and reduced urinary DHEAS output) that usually is characteristic of fasting. Peripheral androgen metabolism as reflected by urinary 3 alpha-androstanediol glucuronide appears to be influenced only by high protein intake (diet P). Further research (controlled dietary long term investigation) is required 1) to validate whether the effects of diet on adrenocortical activity represent sustained endocrine changes and 2) to elucidate the underlying mechanism.

Topics: 17-Ketosteroids; Adrenal Cortex; Adrenal Glands; Adult; Androgens; Androstane-3,17-diol; C-Peptide; Chorionic Gonadotropin; Dehydroepiandrosterone Sulfate; Diet, Vegetarian; Dietary Proteins; Energy Intake; Female; Humans; Hydrocortisone; Male; Middle Aged; Serum Albumin; Sex Characteristics; Sex Hormone-Binding Globulin