Angiotensin-converting enzyme genotype affects the response of human skeletal muscle to functional overload

The response to strength training varies widely between individuals and is considerably influenced by genetic variables, which until now, have remained unidentified. The deletion (D), rather than the insertion (I), variant of the human angiotensin-converting enzyme (ACE) genotype is an important factor in the hypertrophic response of cardiac muscle to exercise and could also be involved in skeletal muscle hypertrophy - an important factor in the response to functional overload. Subjects were 33 healthy male volunteers with no experience of strength training. We examined the effect of ACE genotype upon changes in strength of quadriceps muscles in response to 9 weeks of specific strength training (isometric or dynamic). There was a significant interaction between ACE genotype and isometric training with greater strength gains shown by subjects with the D allele (mean +/- S.E.M.: II, 9.0+/-1.7 %; ID, 17.6 +/-2.2 %; DD, 14.9+/-1.3 %, ANOVA, P 0.05). A consistent genotype and training interaction (ID DD II) was observed across all of the strength measures, and both types of training. ACE genotype is the first genetic factor to be identified in the response of skeletal muscle to strength training. The association of the ACE I/D polymorphism with the responses of cardiac and skeletal muscle to functional overload indicates that they may share a common mechanism. These findings suggest a novel mechanism, involving the renin-angiotensin system, in the response of skeletal muscle to functional overload and may have implications for the management of conditions such as muscle wasting disorders, prolonged bed rest, ageing and rehabilitation, where muscle weakness may limit function.     

Polymorphism of the ACE Gene in dialysis patients: overexpression of DD genotype in type 2 diabetic end-stage renal failure patients

The angiotensin-converting enzyme (ACE) gene DD homozygote has been suggested to be a significant risk factor for the progression of diabetic nephropathy. We analyzed clinical parameters and ACE genotype distribution between type 2 diabetic patients at the extremes of renal risk, i.e. an end-stage renal failure (ESRF) group (n = 103, group 1) who were on dialysis therapy due to progression of diabetic nephropathy, and a no progression group (n = 88, group 2) who had maintained normal renal function and normoalbuminuria for more than 15 years. There were no significant differences in age, sex, body mass index, HbA1c level, or lipid profiles between the two groups (p > 0.05). Group 1 had a significantly higher prevalence of hypertension [group 1: 82.5% (85/103) vs. group 2: 50.0% (44/88), p < 0.05] and diabetic retinopathy [group 1: 103/103 (100%) vs. group 2: 28/88 (31.8%), p < 0.05] than group 2. Daily urinary albumin excretion was also higher in group 1 than in group 2 [group 1: 2873 +/- 2176 mg/day vs. 12 +/- 7 g/day, p < 0.05]. The frequencies of the DD, ID, and II genotypes of the ACE gene in group 1 and group 2 were 26.2%, 47.6%, and 26.2%, and 7.9%, 57.9%, and 34.2%, respectively. The ACE genotype frequencies between the two groups were significantly different according to a chi-square test with Bonferroni's correction (p = 0.004). The presence of the DD genotype increased the risk of ESRF 4.286-fold compared to the II genotype [odds ratio 4.286, 95% CI 1.60- 11.42, p = 0.005]. The frequency of the D-allele was higher in both male and female patients in group 1 compared to group 2, but reached statistical significance only in males [male, group 1: 50.8% vs. group 2: 35.0%, p = 0.018, female, group 1: 48.8% vs. group 2: 39.5%, p = 0.231]. This study, although limited by sample size, showed that type 2 diabetic ESRF patients more frequently expressed the DD genotype. These findings may substantiate the previously noted relationship between the ACE DD genotype and the progression of diabetic nephropathy in Korean type 2 diabetic patients.     

Association of angiotensin-converting enzyme insertion/deletion polymorphism with obesity,cardiovascular risk factors and exercise-mediated changes in Korean women

This study examined whether the angiotensin-converting enzyme (ACE) insertion (I)/deletion (D) polymorphism is associated with obesity, cardiovascular risk factors and 12-week exercise-mediated changes in Korean women. A total of 105 subjects were divided into three groups as II, ID and DD genotype groups based upon ACE I/D genotypes. Body composition and cardiovascular risk factors were compared among the three groups, and the association of ACE I/D genotypes with obesity and hypertension was evaluated. Total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) levels were higher (P < 0.05) in the DD genotype than in II or ID genotypes. D allele frequency in ACE I/D gene had a higher (P = 0.063) trend in the hypertensive group than the normotensive group. The DD genotype had a trend to develop (odds ratio 4.032, P = 0.086) more hypertension than the II genotype. The II and ID genotypes showed a significant (P < 0.05) decrease in intima media thickness of the carotid artery after an exercise intervention, whereas the DD genotype showed an increase. In conclusion, there is a trend towards association of ACE I/D polymorphism with hypertension but not with obesity. Exercise-mediated changes did not differ significantly among genotypes except IMTCA.     

Effects of maximal effort strength training with different loads on dynamic strength, cross-sectional area, load-power and load-velocity relationships

The effects of maximal effort strength training with different loads on maximal strength, muscle cross-sectional area, the load-power and load-velocity relationship were investigated in the elbow flexors. Physical education students were matched into three groups; G90 (n?=?9) trained with a load of 90%, G35 (n?=?11) with 35%, and G15 (n?=?10) with 15% of 1RM (1 repetition maximum). Training consisted of three to five sets, performed three times a week for 9 weeks. Each set consisted of two, seven and ten repetitions in G90, G35 and G15, respectively. Training was performed with the nondominant arm, and the dominant arm served as control. The 1RM increased 15.2 (SD 4.5)% (P?P?P?P?P?P?r?=?0.93, P?r?=?0.73, P?相似文献   

Relationship between ace genotype and short duration aerobic performance development

We have previously demonstrated that, ACE D allele may be related with a better performance in short duration aerobic endurance in a homogeneous cohort with similar training backgrounds. We aimed to study the variation in the short-duration aerobic performance development amongst ACE genotypes in response to identical training programs in homogeneous populations. The study group consisted of 186 male Caucasian non-elite Turkish army recruits. All subjects had undergone an identical training program with double training session per day and 6 days a week for 6 months. Performances for middle distance runs (2,400 m) were evaluated on an athletics track before and after the training period. ACE gene polymorphisms were studied by PCR analysis. The distribution of genotypes in the whole group was 16.7% II, n = 31; 46.2% ID, n = 86; 37.1% DD, n = 69. Subjects with ACE DD genotype had significantly higher enhancement than the ID (P < 0.01) and II (P < 0.05) genotype groups. Around 2,400 m performance enhancement ratios showed a linear trend as ACE DD > ACE ID > ACE II (P value for Pearson χ² = 0.461 and P value for linear by linear association = 0.001). ACE DD genotype seems to have an advantage in development in short-duration aerobic performance. This data in unison with the data that we have obtained from homogenous cohorts previously is considered as an existence of threshold for initiation of ACE I allele effectiveness in endurance performance. This threshold may be anywhere between 10 and 30 min with lasting maximal exercises.     

The ACE deletion allele is associated with Israeli elite endurance athletes

An Alu insertion (I)/deletion (D) polymorphism in the angiotensin I converting enzyme (ACE) gene has been associated with ACE activity. Opposing effects on elite athletic performance have been proposed for the I and D alleles; while the D allele favours improved endurance ability, the I allele promotes more power-orientated events. We tested this hypothesis by determining the frequency of ACE ID alleles amongst 121 Israeli top-level athletes classified by their sporting discipline (marathon runners or sprinters). Genotyping for ACE ID was performed using polymerase chain reaction on DNA from leucocytes. The ACE genotype and allele frequencies were compared with those of 247 healthy individuals. Allele and genotype frequencies differed significantly between the groups. The frequency of the D allele was 0.77 in the marathon runners, 0.66 in the control subjects (P = 0.01) and 0.57 in the sprinters (P = 0.002). The ACE DD genotype was more prevalent among the endurance athletes (0.62) than among the control subjects (0.43, P = 0.004) and the power athletes (0.34, P = 0.004). In the group of elite athletes, the odds ratio of ACE DD genotype being an endurance athlete was 3.26 (95% confidence interval 1.49-7.11), and of ACE II genotype was 0.41 (95% confidence interval 0.14-1.19). We conclude that in Israeli elite marathon runners the frequency of the ACE D allele and ACE DD genotype seems to be higher than in sprinters, suggesting a positive association between the D allele and the likelihood of being an elite endurance athlete in some ethnic groups.     

Effect of heavy strength training on muscle thickness, strength, jump performance, and endurance performance in well-trained Nordic Combined athletes

The purpose of the present study was to investigate the effect of supplemental heavy strength training on muscle thickness and determinants of performance in well-trained Nordic Combined athletes. Seventeen well-trained Nordic Combined athletes were assigned to either usual training supplemented with heavy strength training (STR; n = 8) or to usual training without heavy strength training (CON; n = 9). The strength training performed by STR consisted of one lower-body exercise and two upper-body exercises [3-5 repetition maximum (RM) sets of 3-8 repetitions], which were performed twice a week for 12 weeks. Architectural changes in m. vastus lateralis, 1RM in squat and seated pull-down, squat jump (SJ) height, maximal oxygen consumption (VO(2max)), work economy during submaximal treadmill skate rollerskiing, and performance in a 7.5-km rollerski time trial were measured before and after the intervention. STR increased 1RM in squat and seated pull-down, muscle thickness, and SJ performance more than CON (p < 0.05). There was no difference between groups in change in work economy. The two groups showed no changes in total body mass, VO(2max), or time-trial performance. In conclusion, 12 weeks of supplemental strength training improved determinants of performance in Nordic Combined by improving the athletes' strength and vertical jump ability without increasing total body mass or compromising the development of VO(2max).     

The angiotensin converting enzyme genetic polymorphism in acute coronary syndrome--ACE polymorphism as a risk factor of acute coronary syndrome.

The deletion polymorphism of angiotensin converting enzyme (ACE) genotype has been reported as an independent risk factor for the development of myocardial infarction (MI). However there are conflicting data showing no relationship between the ACE genotype and coronary artery disease. The present study was performed to investigate the correlation between ACE genetic polymorphism and acute coronary syndrome by comparing the distribution of ACE genotypes and ACE activities in patients with acute MI and unstable angina with those in control group. The frequency of genotype DD was significantly higher in patients with acute coronary syndrome than in controls. Logistic regression analysis showed that ACE polymorphism affected the development of acute coronary syndrome in recessive pattern of D allele. When we divided the patients into MI and unstable angina groups, the frequencies of genotype DD and D allele were significantly higher in unstable angina group than in MI or control groups. In the patients with MI, the frequency of D allele was significantly higher in patients without previous angina than in those with previous angina. There was no significant difference in ACE genotype or allelic frequency according to the severity of coronary lesions. The ACE genotype was associated with marked differences of ACE activity, but there was no difference between the patient and control groups for each genotype. In conclusion, the genotype DD of ACE gene associated with acute coronary syndrome, but not with the severity of coronary artery lesion. These results showed that the genotype DD of ACE gene might be associated with acute coronary syndrome by another mechanism rather than the coronary atherosclerosis.     

Maximal strength training improves work economy, rate of force development and maximal strength more than conventional strength training

This study compared maximal strength training (MST) with equal training volume (kg × sets × repetitions) of conventional strength training (CON) primarily with regard to work economy, and second one repetition maximum (1RM) and rate of force development (RFD) of single leg knee extension. In an intra-individual design, one leg was randomized to knee-extension MST (4 or 5RM) and the other leg to CON (3 × 10RM) three times per week for 8 weeks. MST was performed with maximal concentric mobilization of force while CON was performed with moderate velocity. Eight untrained or moderately trained men (26 ± 1 years) completed the study. The improvement in gross work economy was ?0.10 ± 0.08 L min^?1 larger after MST (P = 0.011, between groups). From pre- to post-test the MST and CON improved net work economy with 31 % (P < 0.001) and 18 % (P = 0.01), respectively. Compared with CON, the improvement in 1RM and dynamic RFD was 13.7 ± 8.4 kg (P = 0.002) and 587 ± 679 N s^?1 (P = 0.044) larger after MST, whereas isometric RFD was of borderline significance 3,028 ± 3,674 N s^?1 (P = 0.053). From pre- to post-test, MST improved 1RM and isometric RFD with 50 % (P < 0.001) and 155 % (P < 0.001), respectively whereas CON improved 1RM and isometric RFD with 35 % (P < 0.001) and 83 % (P = 0.028), respectively. Anthropometric measures of quadriceps femoris muscle mass and peak oxygen uptake did not change. In conclusion, 8 weeks of MST was more effective than CON for improving work economy, 1RM and RFD in untrained and moderately trained men. The advantageous effect of MST to improve work economy could be due to larger improvements in 1RM and RFD.     

Association between the ACE I/D gene polymorphism and physical performance in a homogeneous non-elite cohort.

BACKGROUND: I/D polymorphism of the ACE gene may be associated with better endurance performance and a stronger response to exercise training. The aim of this study was to investigate the association between ACE gene polymorphism and athletic performance in a homogeneous cohort. METHODS: Eighty-eight male non-elite Caucasian Turkish athletes with similar training backgrounds for at least for 6 months were studied for ACE gene polymorphisms by PCR analysis. Performance on the 60-meter sprint and middle-distance running tests were evaluated. RESULTS: The distributions of the ACE I/D genotypes were 20.5%, 40.9%, and 38.6% for II, ID, and DD polymorphisms in the whole group (N = 88), respectively. The ACE DD genotype frequency was significantly higher in the superior group (56.7%) than in the poor (37.9%) and mediocre (20.7%) group in middle-distance running performance (chi2 = 11.778; p = 0.019). CONCLUSION: The ACE DD genotype may be related to better short-duration aerobic endurance performance. Larger homogeneous cohorts may help clarify the association between ACE I/D polymorphism and physical performance.     

Angiotensin-converting enzyme gene polymorphism in patients with systemic lupus

The renin-angiotensin-aldosterone system (RAAS) has been considered one of the probable pathophysiologic mechanisms involved in disease progression. Genetic polymorphism of the RAAS has been associated with the clinical course of renal disease. One of the genetic polymorphisms is a deletion or insertion of a 287 base pair fragment in intron 16 of the angiotensin-converting enzyme (ACE) gene. It is known that ACE gene polymorphism is present in humans and that it is associated with an increased risk of cardiovascular diseases, renal disease progression and sarcoidosis. In this study, the potential significance of ACE gene polymorphism in patients with systemic lupus erythematosus (SLE) was investigated. ACE gene polymorphism was determined in 18 patients with SLE and in 21 healthy volunteers as a control group. The mean age of patients was 38.5 years. All patients had a mean follow-up of 30.7 +/- 20.2 months (range 5-95 months). ACE genotypes were determined by the method of polymerase chain reaction. Proteinuria and creatinine were also followed. The frequency of DD, ID and II genotypes was 50%, 28% and 22% in SLE patients and 25%, 50% and 25% in healthy controls, respectively. DD genotype was more common in SLE patients than in the control group. The patients with II genotype had lower proteinuria and creatinine level than those with DD genotype (p < 0.05). The time to disease remission was shorter in patients with II genotype (p < 0.05). Study results indicated an increased frequency of D allele in SLE patients. The increased ACE activity in these patients pointed to the need of further studies of ACE gene polymorphism in SLE.     

Association of angiotensin converting enzyme gene polymorphism with tachycardia cardiomyopathy

Despite incessant tachycardia, not all patients develop tachycardia-mediated cardiomyopathy. The cardiac renin-angiotensin system may be involved in cardiac remodelling and fibrosis. The level of angiotension-converting enzyme (ACE) in the serum is associated with a 287 bp insertion (I)/deletion (D) polymorphism in intron 16 of the ACE gene. The DD genotype is associated with increased serum ACE levels and a higher incidence of idiopathic dilated and ischemic cardiomyopathy. The objective of this study was to assess whether the ACE gene I/D polymorphism is responsible for development of tachycardia-mediated cardiomyopathy. We identified 20 consecutive patients with persistent tachycardia and cardiomyopathy who showed significant improvement in ejection fraction after rate control (group A, tachycardia cardiomyopathy group). We compared the I/D genotype frequency of group A with the gene frequency of a separate group of 20 patents who, despite rapid atrial arrhythmias had preserved left ventricular ejection fraction (group B, tachycardia without cardiomyopathy group). These two groups were then compared with 24 healthy normal volunteers (group C). After a mean follow-up of 30 months, group A patients showed improvement in ejection fraction from 20+/-7 to 43+/-9% (p<0.001). Group A had a significantly higher frequency of the DD genotype than groups B and C (p-value <0.035 and <0.009 respectively). The profile of group B patients was intermediate between normal and patients with tachycardia-mediated cardiomyopathy. I/D polymorphism of the ACE gene may account for cardiomyopathy secondary to tachycardia.     

Genetic variation in the renin-angiotensin system and athletic performance

The D allele at the angiotensin-I-converting enzyme (ACE)-insertion/deletion polymorphism has been associated with an increased risk of developing several pathological processes, such as coronary heart disease and ventricular hypertrophy. Individuals with the DD genotype show a significantly increased left-ventricular mass in response to physical training, compared to the II genotype (which would be associated with the lowest plasma ACE levels) and the ID genotype. The II genotype has been linked to a greater anabolic response. In accordance with a role for ACE in the response to rigorous physical training, a higher frequency of the I allele has been reported to exist among elite rowers and high-altitude mountaineers. Sixty elite (professional) athletes (25 cyclists, 20 long-distance runners, and 15 handball players), and 400 healthy controls were genotyped for the DNA polymorphisms of the ACE, angiotensinogen (Ang) and angiotensin receptor type 1 (AT1) genes. Plasma ACE levels showed a strong correlation with the I/D genotype in our population. The I-allele occurred at a significantly higher frequency in athletes compared to controls (P=0.0009). Gene and genotype frequencies for the Ang and AT1 polymorphisms did not differ between athletes and controls. Since the frequency of the ACE I allele was significantly increased among our elite athletes, we conclude that the ACE polymorphism represents a genetic factor that contributes to the development of an elite athlete. Accepted: 21 December 1999     

A study of the relationships between angiotensin- converting enzyme gene, chymase gene polymorphisms, pharmacological treatment with ACE inhibitor and regression of left ventricular hypertrophy in essential hypertension patients treated with benazepril

BACKGROUND: About 15-37% of the adult population worldwide suffers from hypertension. Hypertension is responsible for one-third of all global deaths. Left ventricular hypertrophy (LVH) is one of the most important characteristics of hypertension target organ damage and is also an independent risk factor for cardiovascular events. Therefore, effective regression of LVH is a main aim of hypertension treatment and also an important public health concern. However, few studies of the regression of LVH have been reported. In particular, little is known about the relationship between the genotypes of angiotensin-converting enzyme (ACE) and chymase (CMA) genes, and the effectiveness of antihypertensive drugs in regression of LVH. AIM: The study investigated whether the insertion/deletion (I/D) polymorphism of ACE gene and the A/B polymorphism of the CMA gene are related to the regression of LVH in essential hypertension patients who were participants in a long-term trial of therapy with benazepril. SUBJECTS AND METHODS: Data from 157 patients was collected and used in the analysis. The genotypes of ACE and CMA genes were identified by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). Left ventricular mass (LVM) was measured by echocardiography, and left ventricular mass index (LVMI) was calculated. RESULTS: Blood pressure was markedly reduced and heart rate was unchanged by long-term treatment with benazepril. Regression of LVH was observed. The mean reduction in LVMI was 41.50+/-28.48 g m-2. Reduction of LVM, LVMI and percentage reduction of LVMI were more in the DD group than in the II and ID groups (P<0.05). No significant difference in other indices was found in the different genotype groups of ACE (P>0.05). No significant difference in all indices was found among the different genotype groups of CMA (P>0.05). No interaction was found between the genotypes of ACE and CMA. CONCLUSION: Hypertension patients with the DD genotype are more likely to have regression of LVH when treated with benazepril than patients with other genotypes of ACE. No evidence was found to support an association between CMA genotype and regression of LVH in patients or to support the interaction between the two genes in regression of LVH.     

脑卒中患者血管紧张素转换酶基因多态性与心率变异性的关联研究

目的　探讨脑卒中患者血管紧张素转换酶 (angiotensin- converting enzyme,ACE)基因多态性和心脏心率变异性的关系。方法　应用聚合酶链反应方法检测 4 3名正常人、4 6例脑梗塞患者、4 0例脑出血患者 ACE基因的插入 /缺失多态性 (insertion/deletion,I/D) ,并用心率变异性 (heart rate variability,HRV)分析方法观察其 HRV的时域、频域和混沌参数。结果　缺血性、出血性脑卒中患者的 ACE基因缺失型 (DD)及 D等位基因频率明显高于正常对照组 (P<0 .0 1) ,DD型患者的 HRV的参数值升高 ,即相邻心搏间期的均方根值、相邻心搏间期差大于 10 ms的心搏间期数占心搏间期总数的百分比、总功率谱、高功率谱、低频功率谱、混沌参数 ,明显高于 ACE基因插入型 (II)、ACE基因插入 /缺失混合型 (ID)患者 ,差异有显著性 (P<0 .0 5 )。结论　 HRV的相关参数和遗传相关 ,提示脑卒中患者有 ACE DD基因型的人 ,有脑源性心脏自主神经功能紊乱发生的危险性。     

Association of the ACE gene polymorphism with the progression of autosomal dominant polycystic kidney disease

Renin-angiotensin system is considered important in the genesis of hypertension and development of end-stage renal disease (ESRD) in autosomal dominant polycystic kidney disease (ADPKD). The angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism has been associated with susceptibility to the development of some renal diseases. We investigated the association of ACE gene polymorphism with the progression to hypertension and ESRD in 108 patients with ADPKD. The ACE I/D polymorphism was amplified with the flanking primers by polymerase chain reaction. In patients genotyped for ACE gene polymorphism, the frequencies of DD (15%), ID (51%) and II (34%) genotypes were similar to those of the general population. Of the 108 patients, 64 (59%) developed hypertension and 24 (22%) reached ESRD at the time of study. The prevalence of hypertension was not significantly different among the three genotypes. The mean renal survival time was 53-6 yr in II genotype, 55+/-10 yr in ID genotype and 52+/-9 yr in DD genotype which was not significantly different among them. Cumulative renal survival was not significantly different either. There was no association of ACE gene polymorphism with the prevalence of hypertension and renal survival in ADPKD. We suggest that ACE I/D polymorphism is not an important modifying gene in the progression of ADPKD.     

ACE/DD基因型和MYH7突变与原发性高血压左室肥厚的关系

 目的 探讨ACE/DD基因型与MYH7突变联合作用和高血压左室肥厚（LVH）的关系。方法 对102例高血压LVH患者与101例高血压非LVH患者以及100例正常对照进行病例-对照研究。超声心动图测量和计算左室重量指数（LVMI）。用聚合酶链反应（PCR）、限制性片段长度多态性（RFLP）检测ACE/ID多态性,双脱氧末端测序方法检测MYH7基因突变。结果 高血压LVH组ACE基因DD基因型频率显著高于高血压非LVH组和正常对照组（P<0.01）;MYH7基因未发现突变。结论 ACE基因多态性与高血压LVH形成有关,DD基因型易发生左心室肥厚。MYH7基因突变与高血压LVH无明显关系,ACE基因DD基因型与MYH7基因间不存在联合作用。     

Effect of concurrent strength and endurance training on skeletal muscle properties and hormone concentrations in humans

The purpose of this study was to investigate the effect of concurrent strength and endurance training on strength, endurance, endocrine status and muscle fibre properties. A total of 45 male and female subjects were randomly assigned to one of four groups; strength training only (S), endurance training only (E), concurrent strength and endurance training (SE), or a control group (C). Groups S and E trained 3 days a week and the SE group trained 6 days a week for 12 weeks. Tests were made before and after 6 and 12 weeks of training. There was a similar increase in maximal oxygen consumption (V˙O_{2 max}) in both groups E and SE (P < 0.05). Leg press and knee extension one repetition maximum (1 RM) was increased in groups S and SE (P < 0.05) but the gains in knee extension 1 RM were greater for group S compared to all other groups (P < 0.05). Types I and II muscle fibre area increased after 6 and 12 weeks of strength training and after 12 weeks of combined training in type II fibres only (P < 0.05). Groups SE and E had an increase in succinate dehydrogenase activity and group E had a decrease in adenosine triphosphatase after 12 weeks of training (P < 0.05). A significant increase in capillary per fibre ratio was noted after 12 weeks of training in group SE. No changes were observed in testosterone, human growth hormone or sex hormone binding globulin concentrations for any group but there was a greater urinary cortisol concentration in the women of group SE and decrease in the men of group E after 12 weeks of training (P < 0.05). These findings would support the contention that combined strength and endurance training can suppress some of the adaptations to strength training and augment some aspects of capillarization in skeletal muscle. Accepted: 10 November 1998     

Linkage of angiotensin I-converting enzyme gene insertion/deletion polymorphism to the progression of human prostate cancer

Angiotensin-converting enzyme (ACE) degrades vasodilator kinins and generates angiotensin II (Ang II). It has been reported that ACE is synthesized by the prostate and that the AT-1 receptor subtype is the predominant prostatic Ang II receptor. A polymorphism in the human ACE gene has been described and the highest levels of circulating and tissue ACE activity are found in carriers of the DD genotype. In the present study, ACE genotypes were determined in 170 patients with prostate cancer and their association with disease progression was analysed. It was found that the DD genotype was present in 31 of 78 (39.8%) patients with advanced disease and in 19 of 82 (23.2%) with localized disease: this difference was statistically significant (OR = 2.18, 95% CI = 1.11-4.03; p = 0.024). Step-wise logistic regression analysis was used to identify predictive parameters of advanced disease and it was observed that the DD genotype (p = 0.002, OR = 5.4, 95% CI = 1.84-16.06), high-grade tumour (p < 0.001, OR = 8.04, 95% CI = 3.03-21.33), and high serum PSA (p < 0.001, OR = 10.87, 95% CI = 4.06-29.13) were significantly associated with advanced disease. The results of this study support the hypothesis that genetic factors related to ACE may influence the behaviour of human prostate cancer.     

Neuromuscular adaptations during combined strength and endurance training in endurance runners: maximal versus explosive strength training or a mix of both

This study compared the effects of mixed maximal strength and explosive strength training with maximal strength training and explosive strength training combined with endurance training over an 8-week training intervention. Male subjects (age 21–45 years) were divided into three strength training groups, maximal (MAX, n = 11), explosive (EXP, 10) and mixed maximal and explosive (MIX, 9), and a circuit training control group, (CON, 7). Strength training one to two times a week was performed concurrently with endurance training three to four times a week. Significant increases in maximal dynamic strength (1RM), countermovement jump (CMJ), maximal muscle activation during 1RM in MAX and during CMJ in EXP, peak running speed (S _peak) and running speed at respiratory compensation threshold (RCT_speed) were observed in MAX, EXP and MIX. Maximal isometric strength and muscle activation, rate of force development (RFD), maximal oxygen uptake $ \left( {\dot{V}{\text{O}}_{2\max } } \right) $ and running economy (RE) at 10 and 12 km hr^?1 did not change significantly. No significant changes were observed in CON in maximal isometric strength, RFD, CMJ or muscle activation, and a significant decrease in 1RM was observed in the final 4 weeks of training. RE in CON did not change significantly, but significant increases were observed in S _peak, RCT_speed and $ \left( {\dot{V}{\text{O}}_{2\max } } \right). $ Low volume MAX, EXP and MIX strength training combined with higher volume endurance training over an 8-week intervention produced significant gains in strength, power and endurance performance measures of S _peak and RCT_speed, but no significant changes were observed between groups.