The impact of anabolic androgenic steroids abuse and type of training on left ventricular remodeling and function in competitive athletes

Background/Aim. Long-term intensive training is associated with distinctive cardiac adaptations which are known as athlete’s heart. The aim of this study was to determine whether the use of anabolic androgenic steroids (AAS) could affect echocardiographic parameters of left ventricular (LV) morphology and function in elite strength and endurance athletes. Methods. A total of 20 elite strength athletes (10 AAS users and 10 non-users) were compared to 12 steroid-free endurance athletes. All the subjects underwent comprehensive standard echocardiography and tissue Doppler imaging. Results. After being indexed for body surface area, both left atrium (LA) and LV end-diastolic diameter (LVEDD) were significantly higher in the endurance than strength athletes, regardless of AAS use (p < 0.05, for both). A significant correlation was found between LA diameter and LVEDD in the steroid-free endurance athletes, showing that 75% of LA size variability depends on variability of LVEDD (p < 0.001). No significant differences in ejection fraction and cardiac output were observed among the groups, although mildly reduced LV ejection fraction was seen only in the AAS users. The AAS-using strength athletes had higher A-peak velocity when compared to steroidfree athletes, regardless of training type (p < 0.05 for both). Both AAS-using and AAS-free strength athletes had lower e’ peak velocity and higher E/e’ ratio than endurance athletes (p < 0.05, for all). Conclusions. There is no evidence that LV ejection fraction in elite athletes is altered by either type of training or AAS misuse. Long-term endurance training is associated with preferable effects on LV diastolic function compared to strength training, particularly when the latter is combined with AAS abuse.


Introduction
Long-term intensive training is associated with distinctive cardiac adaptations which are known as athlete's heart 1 . Although a certain relationship between the type of training (endurance versus strength exercise) and cardiac remodeling has been documented, the nature and magnitude of traininginduced changes are still the subject of debate.
Anabolic androgenic steroids (AAS) have been abused by both professional and recreational athletes to increase muscle mass and improve performance 2 . The use of AAS is particularly prevalent among powerlifters and bodybuildersas many as 55% of elite powerlifters admitted using these agents 3,4 . In contrast to numerous documented toxic and hormonal effects of AAS, their impact on left ventricular (LV) structure and function was not been yet completely understood. In animal model, AAS have been shown to induce cardiac renin-angiotensin system, increase cardiac collagen content and impair the beneficial effects of training 5 . In competitive athletes, self-administration of AAS has been linked to serious cardiac adverse events, including sudden cardiac death 6,7 , although reports on their impact on cardiac morphology and function varied 8 .
We hypothesized that there would be the differences in echocardiographic parameters of LV morphology and function between strength and endurance athletes and that the magnitude of these differences would be affected by AAS abuse. To test this hypothesis, we compared elite strength athletes using or not using AAS to steroid-free endurance athletes.

Methods
A total of 22 elite male athletes, aged 22-40 years, were recruited from the national power-lifting, bodybuilding, wrestling and running clubs. All the subjects gave written informed consent and were divided into three groups.
The group I consisted of 10 strength athletes (6 powerlifters and 4 bodybuilders) who reported both past and current self-administration of AAS. All the subjects used the combination of oral and injectable substances (methandienone, stanozolol, nandrolone decanoate and testosterone) for at least 3 years, in cycles lasting between 7 and 14 weeks. The group II consisted of 10 strength athletes (4 bodybuilders and 6 wrestlers) who denied taking AAS. They were all negative on several doping tests during and out of competition. The group III consisted of 12 endurance athletes (longdistance runners) who did not use AAS. They were also negative on doping tests performed during professional career. None of the subjects in either group had a history of cardiovascular or any other organic system disorder and were not taking any medications.

Anthropometric measurements
Body mass and height were measured using a balance beam scale and a height gauge, respectively. Lean body mass was calculated according to the formula provided by Hallynck et al. 9 , whereas body surface area was calculated using the Mosteller formula 10 .

Electrocardiography and blood pressure measurement
Twelve-channel electrocardiography (ECG) recording was done prior to blood pressure measurement and echocardiographic examination.
Blood pressure measurements were done in sitting position, using a cuff adjusted to upper arm circumference. The mean value of two measurements on both arms, 10 min apart, was recorded.

Echocardiographic examination
All examinations were done in supine left decubitus position using a Hewlett-Packard Sonos 2500 machine (Andover, MA, USA), with a 2.5 MHz transducer. Echocardiograms consisted of two-dimensional, M-mode, Doppler flow measurements and tissue Doppler imaging (TDI) from standard parasternal and apical positions. All measurements were made by a single experienced observer (VD) who was blinded to the subjects' data.
M-mode measurements were performed for the assessment of LV diastolic and systolic diameters, according to the most recent guidelines 11 and presented both as raw data and adjusted for body surface area (BSA) when appropriate. Measurements obtained with this method served for calculation of LV mass, using the Devereux et al. formula 12 . Relative wall thickness (RWT) was calculated when the sum of interventricular septal wall (IVS) thickness and posterior wall (PW) thickness was divided by LV end-diastolic diameter (LVEDD).
For the assessment of systolic function LV volumes were measured by tracing the endocardial border in apical four-and two-chamber view. The ejection fraction was estimated using the Simpson's biplanar method 11 . Cardiac output was determined by calculating the product of stroke volume and heart rate that was obtained from the final loop of each study.
Pulsed-Doppler LV inflow recordings were made in the apical four-chamber view, with the sample volume placed at the tips level of the mitral valve. Early (E) and atrial (A) peak velocities, E-wave deceleration time and isovolumetric relaxation time were measured. TDI recordings were performed in apical four-chamber view, with the pulse-wave Doppler sample volume placed at the septal and lateral side of mitral annulus. Longitudinal tissue Doppler velocities of a systolic wave (S) and 2 diastolic waves -early (e') and atrial (a') -were reported as the mean of 3 consecutive cardiac cycles. Most recent guidelines on the chamber quantification and the assessment of LV diastolic function were used to define a reference range for all echocardiographic parameters 11,13 .

Statistical analysis
Data are expressed as mean ± standard deviation. Comparison between the groups was performed using the analysis of variance or a Kruskal-Wallis test, with Bonferroni correction for multiple comparisons. The relations between selected measures were calculated by the linear regression analysis and correlation analysis using the Pearson or Spearman's method. A p-value of < 0.05 was considered significant.

Results
The athletes from the 3 groups were comparable for age, body mass, BSA, lean body mass and duration of training (Table1).
Resting heart rate and diastolic blood pressure were significantly lower in the endurance than the AAS-using strength athletes, with no significant difference between ASS-free athletes.

Standard echocardiographic parameters
The standard echocardiographic parameters are shown in Table 2. No significant differences in wall thickness were found among the 3 groups.
After being indexed for BSA, both left atrium (LA) dimension and LVEDD were higher in the endurance than AAS-using strength athletes. Further, a significant correlation between LA diameter and LVEDD was found, but only in the endurance athletes, in whom more than 75% of LA size variability (R 2 = 0.761) depended on variability of LVEDD ( Figure 1A). It was also shown for this group that each increase of 1 mm in LVEDD was associated with approximately 0.7 mm increase in LA diameter (95% confidence interval (CI) 0.44 to 1.01, p < 0.001). A trend towards a significant correlation between LVEDD and LA diameter was noted in the AAS-free strength athletes ( Figure 1B), while such correlation was not observed in the AAS-using strength athletes ( Figure 1C).

Left ventricular systolic function
No significant differences in ejection fraction, cardiac output and cardiac index were observed among the groups (Table 3). However, 3 of the 10 AAS users had LV ejection fraction below 55%, while all AAS-free athletes had normal LV ejection fraction (≥ 55%). Peak systolic velocity (S) at septal level was significantly higher in the endurance than AAS-free strength athletes.

Transmitral Doppler velocities and tissue Doppler Imaging data
The AAS-using strength athletes had higher peak Awave velocity when compared to both endurance and AASfree strength athletes (Table 3). Regardless of AAS misuse, the strength athletes had significantly lower e' peak velocity and higher E/e' ratio than the endurance athletes, when measurements were done at lateral wall level (Table 3). Peak e' velocities at lateral wall level were within reference range in all endurance athletes, while in 30% of AAS-using strength athletes laid outside the normal range.
The 95% confidence itervals (CI) for the peak lateral e' velocity in the endurance steroid-free and steroid-using strength afthletes, compared to the reference range for different age groups are shown in Figure 2.

Discussion
Our data indicate that both type of training and AAS abuse may affect LV diastolic function. Although paradoxically associated with increased LA size, it appears that a long-term AAS-free endurance training may have preferable effects on LV filling and relaxation parameters, compared to  strength training, particularly in the presence of AAS abuse. No significant differences between the elite strength and endurance athletes were found for systolic function indices, although mildly reduced LV ejection fraction was seen only in AAS users.

Parameters of LV diastolic function
Reflecting the LA-LV pressure gradient during late diastole, mitral A-wave velocity is affected by LV compliance and LA contractile function 13 . In line with this, a significantly higher peak A-velocity in AAS abusers, regardless the type of training, might indicate a relationship between AAS misuse and decreased LV compliance.
On the other hand, peak e' velocity, a parameter of LV relaxation, did not significantly differ between strength athletes with respect to AAS abuse. However, abnormally low values of this parameter were observed only in the AAS abusers -in 30% of AAS-using strength athletes (aged 27-31 years), e' velocities values were as low as they were measured in individuals aged between 41-60 years ( Figure 2).
Although all the AAS-free athletes had normal e' velocity and E/e' ratio values, significant differences related to the type of training were observed. The peak e' velocity was higher and E/e' ratio lower in the endurance than the strength athletes, suggesting that strength training may not produce equally favorable effects on diastolic function as endurance exercise.
Mechanisms responsible for the possible alterations of LV diastolic function with AAS abuse are poorly understood. The transient increase in blood pressure, also observed among the AAS users in this study, may negatively alter LV diastolic function, but it is usually mild and its clinical significance remains most likely modest 14 .
On the other hand, since no increase in LV wall thickness was found, AAS-mediated changes in myocardial intrinsic properties might be responsible for the differences in LV diastolic function.
Hence, in vitro and histological studies have shown that an increase in myocardial collagen content might occur as a repair mechanism against AAS-induced myocardial damage 15 , and also that chronic administration of 17amethyltestosterone, frequently used anabolic steroid, may reduce LV compliance 16 .
Data from previous (small-scale) studies are widely inconsistent, showing either negative [17][18][19][20] or no effect 21-23 of AAS on LV diastolic function. The inconsistency could be explained by methodological differences (pulsed-wave vs tissue Doppler imaging) and by the lack of power to detect true affects of AAS.

Relationship between LA remodeling and LV diastolic function
In non-athletic population, dilatation of LA reflects the cumulative effects of LV filling pressures and is an independent predictor of death, heart failure, atrial fibrillation and stroke 24 . Our data support the belief that LA enlargement in athletes should be regarded as a physiological adaptation to exercise conditioning 25 , particularly in endurance athletes. We demonstrated that the variability of LA size was predominantly influenced by LV dimension, but only in the absence of AAS misuse. The correlation between the LVEDD and LA dimension was statistically significant in AAS-free endurance athletes and borderline significant in the group of AAS-free strength athletes. A lack of correlation between LA size and LVEDD in AAS-using strength athletes may therefore be reflective of detrimental effects of AAS on LV diastolic function, regardless of training type. In line with this, the endurance athletes had the largest LA dimension but the lowest E/e' ratio, suggesting that LA enlargement should not be considered pathological in these athletes. Conversely, when LA enlargement occurs in strength athletes, particularly in the presence of AAS abuse, it should not be entirely ascribed to a long-term strength training, as it could also reflect the disturbances of LV diastolic function.

Left ventricular remodeling, type of training and AAS abuse
LV end-diastolic dimensions and LV mass, after being indexed for BSA, were higher in the endurance than in the AAS-using athletes, with no differences between the strength athletes with respect to AAS abuse. Our data are consistent with previous echocardiographic and magnetic resonance imaging studies showing that long-term endurance training has the strongest impact on LV cavity size, mass and thickness while strength training does not necessarily induce wall thickening 18,26,27 .
A significant increase in LV mass related to AAS administration was observed in some studies 20 , but not confirmed by others [21][22][23] .

Left verticular systolic function
Even though we did not observe a significant difference in LVEF among the 3 groups, a mild reduction of LVEF was detected only in the AAS users. Results from recent studies suggest that systolic dysfunction associated with AAS abuse might be subclinical and advanced echo techniques are needed for its detection 28,29 . It has been shown that chronic misuse of AAS is associated with reduced peak systolic strain, and strongly correlated with mean dosage and duration of AAS use 28 . However, it has been recently reported that, on top of reduced peak strain values, long-term AAS use might even be associated with a clinically relevant reduction in LV ejection fraction 29 .

Study limitations
Our study has some important limitations. First, like most previous studies, we did not perform plasma or urine assessment for drug levels and the history of AAS use was self-reported by the athletes included in the study. Although the results should be interpreted cautiously, we believe that the observed differences in athletes' clinical characteristic support the accuracy of athletes' statements regarding AAS use.
Both resting heart rate and diastolic blood pressure, which increase had been previously linked to AAS abuse 30 , were highest in the AAS-using athletes, with no difference between the AAS-denying endurance and strength athletes. The elevation of blood pressure is usually transient, returning to basal levels several weeks or months after drug discontinuation 31 which might explain why the AAS users had not been diagnosed of having hypertension during regular physical examinations.
Second, since AAS abuse is a very sensitive matter in professional sports, particularly among elite athletes, we recruited a small number of subjects. However, this limitation is more likely to produce type II errors (false-negative results) than type I errors (false-positive results) due to a reduced statistical power. On the other hand, type II errors might explain why several nonsignificant trends were ob-served -there were striking differences in mean values among the 3 groups for several clinical and echocardiographic variables, but with large variance. Therefore, further studies with adequate power are required.

Conclusion
There is no evidence that LV ejection fraction in elite athletes is altered by either type of training or AAS misuse. Long-term endurance training is associated with preferable effects on LV diastolic function compared to strength training, particularly when the latter is combined with AAS abuse.