Intense physical exercise increases systemic 11β-hydroxysteroid dehydrogenase type 1 activity in healthy adult subjects

Polyphenol Supplementation and Antioxidant Status in Athletes: A Narrative Review

Antioxidants in sports exercise training remain a debated research topic. Plant-derived polyphenol supplements are frequently used by athletes to reduce the negative effects of exercise-induced oxidative stress, accelerate the recovery of muscular function, and enhance performance. These processes can be efficiently modulated by antioxidant supplementation. The existing literature has failed to provide unequivocal evidence that dietary polyphenols should be promoted specifically among athletes. This narrative review summarizes the current knowledge regarding polyphenols' bioavailability, their role in exercise-induced oxidative stress, antioxidant status, and supplementation strategies in athletes. Overall, we draw attention to the paucity of available evidence suggesting that most antioxidant substances are beneficial to athletes. Additional research is necessary to reveal more fully their impact on exercise-induced oxidative stress and athletes' antioxidant status, as well as optimal dosing methods.

Mass spectrometry in the diagnosis of thyroid disease and in the study of thyroid hormone metabolism

The importance of thyroid hormones in the regulation of development, growth, and energy metabolism is well known. Over the last decades, mass spectrometry has been extensively used to investigate thyroid hormone metabolism and to discover and characterize new molecules involved in thyroid hormones production, such as thyrotropin-releasing hormone. In the earlier period, the quantification methods, usually based on gas chromatography-mass spectrometry, were complicated and time consuming. They were mainly focused on basic research, and were not suitable for clinical diagnostics on a routine basis. The development of the modern mass spectrometers, mainly coupled to liquid chromatography, enabled simpler sample preparation procedures, and the accurate quantification of thyroid hormones, of their precursors, and of their metabolites in biological fluids, tissues, and cells became feasible. Nowadays, molecules of physiological and pathological interest can be assayed also for diagnostic purposes on a routine basis, and mass spectrometry is slowly entering the clinical laboratory. This review takes stock of the advancements in the field of thyroid metabolism that were carried out with mass spectrometry, with special focus on the use of this technique for the quantification of molecules involved in thyroid diseases.

Cortisol metabolism in pregnancies with small for gestational age neonates

Small for gestational age (SGA) newborns are often born from hypertensive pregnancies. This study aimed to compare the systemic metabolism of cortisol (F) in pregnancies with SGA and appropriate for gestational age (AGA) infants, considering both the normotensive (NT) and hypertensive patients. We hypothesized that the disturbances in systemic metabolism of F in pre-eclampsia (PE) might be attributed not to hypertension only, but to SGA. The study included 117 pregnants in the third trimester, divided into groups: NT pregnancy and SGA neonate (SGA-NT); NT pregnancy and AGA neonate (AGA-NT; controls), and respective groups with PE: SGA-PE and AGA-PE. We assessed the glucocorticoid balance with the function of enzymes involved in systemic metabolism of F: 11β-hydroxysteroid dehydrogenase type 1 and 2 (11β-HSD1 and 11β-HSD2), 5α- and 5β-reductase. The enzymes' functions were estimated with the levels of F, cortisone (E), and their metabolites in plasma or urine, which we measured with HPLC-FLD and HPLC-MS/MS. The plasma F/E and urinary free F/E (UFF/UFE) ratios correlated significantly only in patients with the normal function of 5α- and 5β-reductase. The increased function of 11β-HSD2 was noted in all pre-eclamptic pregnancies. Increased function of 5α- and 5β-reductase was specific only for SGA-PE pregnancies, and the function of 5α-reductase was dependent on fetal sex. The SGA-NT pregnancies with male fetuses trended towards the higher function of renal 11β-HSD2 and 5β-reductase; SGA-NT pregnancies with female fetuses lacked any systemic glucocorticoid imbalance. In conclusion, systemic metabolism of F is the most intensive in pre-eclamptic pregnancies complicated by SGA with female fetuses. Our study supports the hypothesis about the different origins of PE and idiopathic intrauterine growth restriction and suggests the sex-specific mechanisms responsible for fetal growth restriction.

11β Hydroxysteroid dehydrogenase - 1 activity in type 2 diabetes mellitus: a comparative study

BACKGROUND

A comparative study of 11 β HSD 1 activity in type 2 diabetes mellitus subjects with respect to fasting blood glucose and other metabolic parameters was conducted.

METHODS

A case control experimental study was performed enrolling thirty type 2 diabetes mellitus patients and thirty age, gender and BMI matched controls using cortisone acetate test.

RESULTS

The rise of serum cortisol after oral 25 mg cortisone acetate from baseline (dexamethasone suppressed level) is higher in subjects with type 2 diabetes and is associated with exercise, BMI, SGOT but not daily calorie intake, lipid parameters and thyroid status. Fasting blood glucose after overnight 1 mg oral dexamethasone is a strong predictor of 11HSD1 activity, irrespective of presence of type 2 diabetes.

CONCLUSION

11β HSD 1 activity is higher in type 2 diabetes mellitus subjects, especially those who are lean. Future 11 β HSD 1 inhibitors targeting metabolic syndrome, will be most useful in those with increased fasting blood glucose. The role of DHEAS and vitamin D status needs to be explored.

Untargeted Metabolomics Profiling of an 80.5 km Simulated Treadmill Ultramarathon

Metabolomic profiling of nine trained ultramarathon runners completing an 80.5 km self-paced treadmill-based time trial was carried out. Plasma samples were obtained from venous whole blood, collected at rest and on completion of the distance (post-80.5 km). The samples were analyzed by using high-resolution mass spectrometry in combination with both hydrophilic interaction (HILIC) and reversed phase (RP) chromatography. The extracted putatively identified features were modeled using Simca P 14.1 software (Umetrics, Umea, Sweden). A large number of amino acids decreased post-80.5 km and fatty acid metabolism was affected with an increase in the formation of medium-chain unsaturated and partially oxidized fatty acids and conjugates of fatty acids with carnitines. A possible explanation for the complex pattern of medium-chain and oxidized fatty acids formed is that the prolonged exercise provoked the proliferation of peroxisomes. The peroxisomes may provide a readily utilizable form of energy through formation of acetyl carnitine and other acyl carnitines for export to mitochondria in the muscles; and secondly may serve to regulate the levels of oxidized metabolites of long-chain fatty acids. This is the first study to provide evidence of the metabolic profile in response to prolonged ultramarathon running using an untargeted approach. The findings provide an insight to the effects of ultramarathon running on the metabolic specificities and alterations that may demonstrate cardio-protective effects.

Enhanced Coupling Within Gonadotropic and Adrenocorticotropic Axes by Moderate Exercise in Healthy Men

CONTEXT

Exercise elicits incompletely defined adaptations of metabolic and endocrine milieu, including the gonadotropic and corticotropic axes.

OBJECTIVE

To quantify the impact of acute exercise on coordinate luteinizing hormone (LH) and testosterone (T) and adrenocorticotropic hormone (ACTH) and cortisol secretion in healthy men in relation to age.

PARTICIPANTS AND DESIGN

Prospectively randomized, within-subject crossover study in 23 men aged 19 to 77 years old. Subjects underwent rest and 30 minutes of mixed exercise at 65% of maximal aerobic capacity with 10-minute blood sampling between 7:00 am and 1:00 pm, 2 weeks apart.

MAIN OUTCOME MEASURES

Incremental changes in LH, T, ACTH, and cortisol concentrations, the feedforward and feedback strength between exercise and rest, quantified by approximate entropy (ApEn), and bihormonal synchrony, quantitated by cross-ApEn.

RESULTS

Mean hourly exercise-minus-rest LH and ACTH increments increased from -0.055 ± 0.187 to 0.755 ± 0.245 IU/L (P = 0.003) and from 2.9 ± 2.2 to 71.2 ± 16.1 ng/L (P < 0.0001), respectively, during exercise. T and cortisol increments increased concurrently from -9.6 ± 16.7 to 47.6 ± 17.1 ng/dL (P < 0.0001) and 0.45 ± 0.76 to 7.27 ± 0.64 µg/dL (P < 0.0001), respectively. During exercise, feedforward and feedback LH-T and ACTH-cortisol cross-ApEn decreased markedly quantifying enhanced hormonal coupling.

CONCLUSIONS

Acute moderate mixed exercise in healthy men rapidly enhances feedforward LH-T and ACTH-cortisol coordination and reciprocal feedback within the gonadotropic and corticotropic axes. In principle, enhancement of both LH-T and ACTH-cortisol secretory synchrony by exercise could reflect augmented coupling between brain-testicular and brain-adrenal neural outflow.

Metabolomic Profiling of Submaximal Exercise at a Standardised Relative Intensity in Healthy Adults

Ten physically active subjects underwent two cycling exercise trials. In the first, aerobic capacity (VO2max) was determined and the second was a 45 min submaximal exercise test. Urine samples were collected separately the day before (day 1) , the day of (day 2), and the day after (day 3) the submaximal exercise test (12 samples per subject). Metabolomic profiling of the samples was carried out using hydrophilic interaction chromatography (HILIC) coupled to an Orbitrap Exactive mass spectrometer. Data were extracted, database searched and then subjected to principle components (PCA) and orthogonal partial least squares (OPLSDA) modelling. The best results were obtained from pre-treating the data by normalising the metabolites to their mean output on days 1 and 2 of the trial. This allowed PCA to separate the day 2 first void samples (D2S1) from the day 2 post-exercise samples (D2S3) PCA also separated the equivalent samples obtained on day 1 (D1S1 and D1S3). OPLSDA modelling separated both the D2S1 and D2S3 samples and D1S1 and D1S3 samples. The metabolites affected by the exercise samples included a range of purine metabolites and several acyl carnitines. Some metabolites were subject to diurnal variation these included bile acids and several amino acids, the variation of these metabolites was similar on day 1 and day 2 despite the exercise intervention on day 2. Using OPLS modelling it proved possible to identify a single abundant urinary metabolite provisionally identified as oxo-aminohexanoic acid (OHA) as being strongly correlated with VO2max when the levels in the D2S3 samples were considered.

A study of the effects of exercise on the urinary metabolome using normalisation to individual metabolic output

Aerobic exercise, in spite of its multi-organ benefit and potent effect on the metabolome, has yet to be investigated comprehensively via an untargeted metabolomics technology. We conducted an exploratory untargeted liquid chromatography mass spectrometry study to investigate the effects of a one-h aerobic exercise session in the urine of three physically active males. Individual urine samples were collected over a 37-h protocol (two pre-exercise and eight post-exercise). Raw data were subjected to a variety of normalization techniques, with the most effective measure dividing each metabolite by the sum response of that metabolite for each individual across the 37-h protocol expressed as a percentage. This allowed the metabolite responses to be plotted on a normalised scale. Our results highlight significant metabolites located in the following systems: purine pathway, tryptophan metabolism, carnitine metabolism, cortisol metabolism, androgen metabolism, amino acid oxidation, as well as metabolites from the gastrointestinal microbiome. Many of the significant changes observed in our pilot investigation mirror previous research studies, of various methodological designs, published within the last 15 years, although they have never been reported at the same time in a single study.

Salivary and serum cortisol levels during recovery from intense exercise and prolonged, moderate exercise

The aim of this study was to compare serum (SERc) and salivary cortisol (SALc) responses during recovery from two different exhaustive exercises to determine peak cortisol sampling time and the agreement between SERc and SALc levels. Twelve healthy men underwent a maximal treadmill graded exercise to exhaustion (MEx) and a prolonged, submaximal cycle exercise in the heat for 90 min (PEx) while SERc and SALc samples were taken in parallel at baseline, end of exercise, and 15 min intervals over one hour of recovery. MEx and PEx significantly increased SERc and SALc levels (p < 0.01) while absolute SERc levels were approximately 7-10 folds higher than SALc. SERc and SALc showed highly positive correlation (R = 0.667-0.910, p < 0.05) at most sampling times and only a few individual values were out of 95% limit of agreement when analyzed by Bland-Altman plots. However, peak SERc levels (MEx: 784.0±147, PEx: 705.5±212.0 nmol · L(-1)) occurred at 15 min of recovery, whereas peak SALc levels (MEx: 102.7±46.4, PEx: 95.7±40.9 nmol · L(-1)) were achieved at the end of exercise in MEx and PEx. The recovery trend of SERc and SALc also differed following MEx and PEx. Activity of 11β-hydroxysteroid dehydrogenase type 2 enzymes may be suppressed following MEx compared to PEx. In conclusion, sampling for peak SERc and SALc levels should take into account their evolution and clearance characteristics as well as type of exercise performed, whereas SALc appeared to be a more sensitive marker than SERc for the measurement of cortisol responses during exercise recovery.

Acute effects of physical exercise and phosphodiesterase's type 5 inhibition on serum 11β-hydroxysteroid dehydrogenases related glucocorticoids metabolites: a pilot study

Endogenous glucocorticoids (GC) rapidly increase after acute exercise, and the phosphodiesterase's type 5 inhibitor (PDE5i) tadalafil influences this physiological adaptation. No data exist on acute effects of both acute exercise and PDE5i administration on 11β-hydroxysteroid dehydrogenases (11β-HSDs)-related GC metabolites. We aimed to investigate the rapid effects of exercise on serum GC metabolites, with and without tadalafil administration. A double blind crossover study was performed in eleven healthy male volunteers. After the volunteers randomly received a short-term administration of placebo or tadalafil (20 mg/die for 2 days), a maximal exercise test to exhaustion on cycle ergometer was performed. Then, after a 2-week washout period, the volunteers were crossed over. Blood samples were collected before starting exercise and at 5 and 30 min of recovery (+5-Rec, +30-Rec). Serum ACTH, corticosterone (Cn), cortisol (F), cortisone (E), tetrahydrocortisol (THF), tetrahydrocortisone (THE), cortols, cortolones and respective ratios were evaluated. Pre-Ex THF was higher after tadalafil. Exercise increased ACTH, Cn, F, E, THE, cortols and cortolones after both placebo and tadalafil, and THF after placebo. The F/E ratio increased at +5-Rec and decreased at +30-Rec after placebo. Compared to placebo, after tadalafil lower ACTH, F and Cn, higher THF/F and THE/E, and not E (at +5-Rec) and F/E modifications were observed. Acute exercise rapidly influences serum GC metabolites concentrations. Tadalafil influences both GC adaptation and 11β-HSDs activity during acute exercise. Additional researches on the effects of both exercise and PDE5i on tissue-specific 11β-HSDs activity at rest and during physiological adaptation are warranted.

Oral contraception but not menstrual cycle phase is associated with increased free cortisol levels and low hypothalamo-pituitary-adrenal axis reactivity

BACKGROUND

In females, estrogen is a potential modulator of cortisol response to stressors. The aim of this study was to determine the influence of menstrual cycle phase, oral contraception (OC) use and exercise training on hypothalamo-pituitary-adrenal (HPA) axis activity and reactivity after physical stress.

AIM

We investigated the effects of the menstrual cycle and OC use on exhaustive exerciseinduced changes in free salivary cortisol concentrations and free urinary cortisol/cortisone excretion in healthy young women.

MATERIALS AND SUBJECTS

Twenty-eight women were allocated to an untrained group (no.=16) or a trained group (no.=12), depending on their physical training background. The untrained group was composed of nine OC users (UNTOC+) and seven eumenorrheic women (UNT-OC-) tested in the follicular and luteal phases, while the trained group was entirely composed of OC+ subjects (T-OC+).

METHODS

Three laboratory sessions were conducted in a randomised order: a prolonged exercise test, a short-term exercise test, and a control session. For each session, urine and saliva specimens were collected at rest (09:00 h) and then, 30, 60 and 90 min later.

RESULTS

Estradiol fluctuation during the menstrual cycle phase did not alter free cortisol baseline values and responses to exercise. OC use was associated with increased free resting salivary concentrations and urinary cortisol excretion with blunted salivary cortisol response to prolonged exercise stimulation. No training effect was noted.

CONCLUSIONS

OC but not menstrual cycle phase is associated with increased free cortisol levels and low HPA axis reactivity.

11beta-Hydroxysteroid dehydrogenase type 1 inhibitors: novel agents for the treatment of metabolic syndrome and obesity-related disorders?

OBJECTIVE

Metabolic syndrome (MetS) and Cushing's syndrome share common features. It has been proposed that increased glucocorticoid activity at peripheral tissues may play a role in the pathogenesis of MetS and obesity-related disorders. It is well-known that intracellular cortisol concentrations are determined not only by plasma levels but also by the activity of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) which catalyzes the conversion of inactive cortisone to active cortisol, especially in the liver and adipose tissue. Another isoenzyme exists, the 11β-hydroxysteroid dehydrogenase type 2, which acts in the opposite direction inactivating cortisol to cortisone in the kidney. This review considers the significance of the 11β-HSD1 inhibition in the treatment of several features of MetS and provides current data about the development of 11β-HSD1 inhibitors, as new agents for this purpose.

MATERIALS/METHODS

Using PubMed, we searched for publications during the last 20years regarding the development of 11β-HSD1 inhibitors.

RESULTS

Emerging data from animal and human studies indicate an association of 11β-HSD1 over-expression with obesity and disorders in glucose and lipid metabolism. This has led to the hypothesis that selective inhibition of 11β-HSD1 could be used to treat MetS and diabetes. Indeed, natural products and older agents such as thiazolidinediones and fibrates seem to exert an inhibitory effect on 11β-HSD1, ameliorating the cardiometabolic profile. In view of this concept, novel compounds, such as adamantyltriazoles, arylsulfonamidothiazoles, anilinothiazolones, BVT2733, INCB-13739, MK-0916 and MK-0736, are currently under investigation and the preliminary findings from both experimental and human studies show a favourable effect on glucose and lipid metabolism, weight reduction and adipokine levels.

CONCLUSIONS

Many compounds inhibiting 11β-ΗSD1 are under development and preliminary data about their impact on glucose metabolism and obesity-related disorders are encouraging.

Stress and Its Effects on Glucose Metabolism and 11β-HSD Activities in Rats Fed on a Combination of High-Fat and High-Sucrose Diet with Glycyrrhizic Acid

Chronic stress has been shown to have a strong link towards metabolic syndrome (MetS). Glycyrrhizic acid (GA) meanwhile has been shown to improve MetS symptoms caused by an unhealthy diet by inhibiting 11 β -HSD 1. This experiment aimed to determine the effects of continuous, moderate-intensity stress on rats with and without GA intake on systolic blood pressure (SBP) across a 28-day period, as well as glucose metabolism, and 11 β -HSD 1 and 2 activities at the end of the 28-day period. Adaptation to the stressor (as shown by SBP) resulted in no significant defects in glucose metabolism by the end of the experimental duration. However, a weakly significant increase in renal 11 β -HSD 1 and a significant increase in subcutaneous adipose tissue 11 β -HSD 1 activities were observed. GA intake did not elicit any significant benefit in glucose metabolism, indicating that the stress response may block its effects. However, GA-induced improvements in 11 β -HSD activities in certain tissues were observed, although it is uncertain if these effects are manifested after adaptation due to the withdrawal of the stress response. Hence the ability of GA to improve stress-induced disturbances in the absence of adaptation needs to be investigated further.

The ACTN3 genotype in soccer players in response to acute eccentric training

Genetic factors can interfere with sporting performance. The identification of genetic predisposition of soccer players brings important information to trainers and coaches for individual training loads adjustment. Different responses to eccentric training could be observed by the genotype referred to as α-actinin-3 (ACTN3) in biomarkers of muscle damage, hormones and inflammatory responses. The aim of this study was to compare acute inflammatory responses, muscle damage and hormonal variations according to the eccentric training in soccer professional athletes with different genetic profiles of ACTN3 (XX, RX and RR). 37 soccer professional athletes (9 XX, 13 RX, 15 RR) were randomly divided into five stations associated to eccentric muscle contraction and plyometrics. Blood samples were taken from athletes pre-eccentric training, immediately after (post), 2- and 4-h post-eccentric training to determine hormone responses (cortisol and testosterone), muscle damage (CK and α-actin), and inflammatory responses (IL-6). After eccentric training, athletes XX presented higher levels for CK (4-h post), α-actin (post and 2-h post) and cortisol (post) compared to RR and RX athletes. However, RR and RX athletes presented higher levels of testosterone (post) and IL-6 (2 h post and 4 h post) compared to athletes XX. The main conclusion of this study is that professional soccer athletes homozygous to ACTN3XX gene are more susceptible to eccentric damage and present a higher catabolic state, demonstrated by metabolic, hormonal and immune responses post an eccentric training, in comparison to ACTN3RR and ACTN3RX groups.

Is metabolic syndrome a mild form of Cushing's syndrome?

The Metabolic Syndrome is a diagnosis of increasing prevalence that is noted to share multiple clinical features with Cushing's syndrome. Several studies suggest abnormalities in the Hypothalamic-Pituitary-Adrenal axis to be associated with this disease and tissue-specific hypercortisolemia is being investigated as a possible contributing factor. More research is needed to explore the relation between cortisol and the metabolic syndrome which, if confirmed, will have major therapeutic and public health implications.