Associations of androgens with physical activity and fitness in young black and white men: the CARDIA Male Hormone Study

Deterioration of Chronotropic Responses and Heart Rate Recovery Indices in Men With Erectile Dysfunction

Introduction

Erectile dysfunction (ED) and cardiovascular (CV) diseases share common risk factors and ED has been accepted as an early manifestation of CV disease. Exercise stress testing (EST) is used to evaluate CV functions in men with ED. Low exercise workload, a slower heart rate recovery (HRR) after exercise, and inability to increase heart rate during EST (chronotropic incompetence) are independent negative predictors of adverse CV outcomes.

Aim

To assess the association among EST parameters, ED, and testosterone levels.

Methods

The study population consisted of 41 patients with ED and 40 controls. All participants underwent treadmill EST to assess cardiac autonomic functions. HRR indices were calculated by subtracting 1st (HRR1), 2nd (HRR2), and 3rd (HRR3) minute heart rates during the recovery period from maximal heart rate. Total exercise duration, exercise capacity and chronotropic response, and plasma testosterone levels were evaluated. Erectile functions were evaluated with the Sexual Health Inventory for Men. Patients were divided into subgroups according to severity and duration of ED.

Main Outcome Measures

Mean HRR1 (30.6 ± 11.9 vs 36.9 ± 9.9; P = .01), HRR2 (44.9 ± 12.4 vs 54.9 ± 7.8; P < .001), and HRR3 (50.1 ± 11.7 vs 63.0 ± 7.9; P < .001) were significantly lower in the ED than in the control group. Total exercise duration (9.4 ± 1.9 vs 10.9 ± 1.7 minutes; P < .001), exercise capacity (12.5 ± 1.9 vs 13.6 ± 1.4 metabolic equivalents; P = .004), and chronotropic response (0.88 ± 0.1 vs 1.0 ± 0.1; P < .001) were worse in the ED group. However, we found no association between severity and duration of ED and EST parameters. In addition, serum testosterone levels were significantly correlated with HRR1 (r = 0.36, P = .02) in men with ED.

Conclusion

Our data suggested that cardiac autonomic functions are impaired in patients with ED. A weak correlation between cardiac autonomic dysfunction and low testosterone levels in patients with ED was noted. However, further studies are needed to elucidate the prognostic significance and clinical implications of impaired autonomic functions and testosterone replacement therapy in patients with ED.

Kucukdurmaz F, Agar G, Resim S. Deterioration of Chronotropic Responses and Heart Rate Recovery Indices in Men With Erectile Dysfunction. Sex Med 2018;6:8–14.

The effects of bed-rest and countermeasure exercise on the endocrine system in male adults: evidence for immobilization-induced reduction in sex hormone-binding globulin levels

BACKGROUND AND AIM

There is limited data on the effects of inactivity (prolonged bed-rest) on parameters of endocrine and metabolic function; we therefore aimed to examine changes in these systems during and after prolonged (56- day) bed-rest in male adults.

SUBJECTS AND METHODS

Twenty healthy male subjects underwent 8 weeks of strict bed-rest and 12 months of follow-up as part of the Berlin Bed Rest Study. Subjects were randomized to an inactive group or a group that performed resistive vibration exercise (RVE) during bed-rest. All outcome parameters were measured before, during and after bed-rest. These included body composition (by whole body dual X-ray absorptiometry), SHBG, testosterone (T), estradiol (E2), PRL, cortisol (C), TSH and free T3 (FT3).

RESULTS

Serum SHBG levels decreased in inactive subjects but remained unchanged in the RVE group (p<0.001). Serum T concentrations increased during the first 3 weeks of bed-rest in both groups (p<0.0001), while E2 levels sharply rose with re-mobilization (p<0.0001). Serum PRL decreased in the control group but increased in the RVE group (p=0.021). C levels did not change over time (p≥0.10). TSH increased whilst FT3 decreased during bed-rest (p all ≤0.0013).

CONCLUSIONS

Prolonged bed-rest has significant effects on parameters of endocrine and metabolic function, some of which are related to, or counteracted by physical activity.

The difference of heart rate recovery between males with and without erectile dysfunction

AIM

In this study, we aimed to investigate the relationship between heart rate recovery (HRR) time and Chronotropic Index (CHIND) parameters, which also reflect autonomic function, after exercise stress test (EST) in males with or without erectile dysfunction (ED), and we investigated the relationship between HRR and CHIND and serum steroid hormone levels.

MATERIAL AND METHODS

A total of 135 participants (mean age: 45.0 +/- 11.8 years) were enrolled into the study. Detailed biochemical and hormonal analyses, 12-lead electrocardiography and EST (Treadmill) were performed in all participants. Erectile function was assessed using the International Index of Erectile Function (IIEF) questionnaire form. Patients were categorized into two groups according to their IIEF scores as ED (+) (IIEF < 26) and ED (-) (IIEF > or = 26). Afterward, statistical analyses were performed to evaluate the correlations between ED and HRR and CHIND.

RESULTS

A total of 65 patients were ED (+) (mean age 44.9 +/- 6.4 years), while 70 patients (mean age 43.7 +/- 7.7 years) had normal erectile status. There were statistically significant differences in CHIND (P = 0.015) and HRR time (P = 0.037) between ED (+) and ED (-) patients. In correlation analysis, IIEF score was found positively correlated with HRR and metabolic equivalent (MET) values (r(HRR)= 0.293, P = 0.037; r(METs)= 0.388, P = 0.011, respectively). Linear regression analysis revealed that METs value and total exercise time had a more linear relationship with IIEF score compared to the other EST parameters (p(METs)= 0.002 and p(TET)= 0.015, respectively).

CONCLUSION

Chronotropic incompetence and dynamic postexercise autonomic dysfunction are present in ED patients. This condition may reflect decreased functional capacity and exercise intolerance in these patients.

Testosterone, physical activity, and somatic outcomes among Filipino males

Testosterone (T) facilitates male investment in reproduction in part through its anabolic effects on skeletal muscle. Traits like muscle and strength are energetically costly but are believed to enhance competitive ability in humans and other mammals. However, there are limited data on relationships between T and somatic outcomes in lean, non-western populations. We evaluate relationships between waking and pre-bed salivary T and adiposity, fat-free mass (FFM), arm muscle area (AMA), and grip strength (GS) in a large, population-based birth cohort of young adult Filipino males (20.8-22.6 years, n = 872). Data were collected as part of the Cebu Longitudinal Health and Nutrition Survey. Neither waking nor evening T predicted FFM, AMA, or GS. However, there were borderline or significant interactions between T and basketball playing (the most common team sport) and weight lifting as predictors of outcomes: higher waking T predicted higher FFM (activity x T interaction P < 0.01), AMA (interaction P < 0.1), and GS (interaction P < 0.02) among frequent basketball players, and GS (interaction P < 0.09) among the smaller sample of weight lifters. In contrast to clinical studies, but consistent with findings in several subsistence-level populations, T was positively related to adiposity in these lean young males, suggesting that energy status might regulate circulating T. Our findings support a role of the prewaking rise in T as a determinant of energetic allocation to lean mass and strength in the context of repeated muscular use and support the hypothesized role of T as a mediator of investment in costly somatic traits in human males.

Physical activity and PDE5 inhibitors in the treatment of erectile dysfunction: results of a randomized controlled study

INTRODUCTION

Physical activity (PhA) has proven to be a protective factor for normal erectile function in numerous epidemiological studies.

AIM

The aim of this study was to establish if PhA could have a therapeutic role in the treatment of erectile dysfunction (ED).

METHODS

This was a randomized, open-label study. A total of 60 patients complaining of ED were studied. Patients were assessed at baseline and after 3 months of study treatment. At baseline, patients were randomized to receive phosphodiesterase type 5 inhibitor (PDE5i) alone (group A) or PDE5i plus regular (≥3 hours/week), aerobic, non-agonistic PhA (group B).

MAIN OUTCOME MEASURES

All subjects completed the International Index of Erectile Function (IIEF-15) questionnaire and performed total testosterone (TT).

RESULTS

Mean PhA was 3.4 hours/week in group B vs. 0.43 in group A; mean energy expenditure in group B was 1,868 kcal/ week or 22.8 metabolic equivalent (MET)/week. IIEF restoration of ED occurred in 77.8% (intervention group) vs. 39.3% (control) (P < 0.004). The IIEF-15 score resulted in statistical improvement in intervention group in all the domains but one (orgasm): erectile function 24.7 vs. 26.8 (P = 0.003); confidence (Q15) 3.53 vs. 4.07 (P = 0.006); sexual desire 6.46 vs. 7.18 (P = 0.028); intercourse satisfaction 9.85 vs. 11.25 (P = 0.001); total satisfaction 7.17 vs. 8.07 (P = 0.009); total score 56.2 vs. 61.07 (P = 0.007). TT was statistically similar in the two groups; separate analysis in each group showed statistical increase in group B 4.24 vs. 4.55 (P = 0.012). At multivariate logistic regression analysis, PhA was the only independent variable for normal erection (P = 0.010) (95% confidence interval [CI] 0.036-0.643), higher sexual satisfaction (P = 0.022) (95% CI 0.084-0.821) and normal total IIEF-15 score (P = 0.023) (95% CI 0.85-0.837).

CONCLUSION

In this randomized controlled pilot study, PDE5i plus PhA was more effective than PDE5i alone in the treatment of ED.