Cortisol secretory parameters in young exercisers in relation to LH secretion and bone parameters

Abstract

Objective-Amenorrhoea and low bone density are common in excessive exercisers, yet endocrine factors that differentiate adolescent amenorrhoeic exercisers (AE) from eumenorrhoeic exercisers (EE) are unclear. We have previously reported that high ghrelin and low leptin predict lower LH secretion in AE. Leptin and ghrelin impact cortisol secretion, and hypercortisolaemia can inhibit LH pulsatility. We hypothesized that higher cortisol secretion in young endurance weight-bearing AE compared with EE and non-exercisers predicts lower LH secretion, lower levels of a bone formation marker and higher levels of a bone resorption marker. Design-Cross-sectionalSubjects-We studied 21 AE, 18 EE and 20 non-exercisers 14-21 years (BMI 10th-90 th %iles).Measurements-Subjects underwent frequent sampling (11 p.m. to 7 a.m.) to assess cortisol, ghrelin, leptin and LH secretory dynamics. Fasting levels of a bone formation (P1NP) and bone resorption (CTX) marker were measured.Results-BMI did not differ among groups. Cortisol pulse amplitude, mass, half-life and area under the curve (AUC) were highest in AE (p=0.04, 0.007, 0.04 and 0.003) and were associated inversely with fat mass (r=−0.29, −0.28 and −0.35, p=0.03, 0.04 and 0.007). We observed inverse associations between cortisol and LH AUC (r= −0.36, p=0.008), which persisted after controlling for fat mass, leptin and ghrelin AUC. Cortisol correlated positively with CTX in EE and inversely with P1NP in non-exercisers.Conclusions-Higher cortisol secretion in AE compared with EE and non-exercisers is associated with lower LH secretion. Effects of leptin and ghrelin on LH secretion may be mediated by increased cortisol.

Exercise, Training, and the Hypothalamic-Pituitary-Gonadal Axis in Men and Women

“…Adipocytes are responsible for the secretion of leptin and adiponectin, which, as mentioned earlier, have opposing effects on the HPG axis [89][90][91][92] . There is consistent evidence that amenorrheic athletes with normal lean body mass and BMI have lower body fat and percent body fat than eumenorrheic athletes and nonathletes [93,94] . Leptin, an anorexigenic hormone, declines with low energy availability [95,96] and, as expected, is lower in amenorrheic athletes compared to eumenorrheic athletes and nonathletes [74,93] .…”

Body Composition, Hemodynamic, and Biochemical Parameters of Young Female Normal-Weight Oligo-Amenorrheic and Eumenorrheic Athletes and Nonathletes

“…Thus severe energy depletion (as in AN) that causes severe weight loss likely has a different effect on fat distribution than less severe energy depletion where weight is preserved (as in normal-weight OAA). In a previous study, we reported that OAA have higher cortisol than EA and non-athletes [23]. Because increased cortisol favors central adiposity [24, 25], it is possible that trunk fat redistribution in OAA is at least partially mediated by increased cortisol.…”

Reproductive dysfunction and associated pathology in women undergoing military training

“…Despite refutation of the exercise stress hypothesis (ie, that activation of the HPA axis solely leads to reproductive dysfunction) in favour of the energy availability hypothesis,41 the observation remains that FHA is associated with elevated central and peripheral levels of cortisol 36 56. Vulliémoz et al 57 demonstrated this in female rhesus monkeys, in whom negative energy balance and reproductive dysfunction had been induced by ghrelin infusion.…”

“…Subsequently, in a cross-sectional analysis of overnight hormone levels in adolescent amenorrhoeic endurance athletes, Ackerman et al 36 demonstrated cortisol levels were independently associated with reduced LH pulsatility after correcting for leptin, ghrelin and fat mass. These studies suggest that the action of gut peptides in the reduced energy availability state is mediated through activation of the HPA axis.…”