Independent, additive and interactive effects of acute normobaric hypoxia and cold on submaximal and maximal endurance exercise

PURPOSE

To evaluate the independent and combined effects of hypoxia (FiO2 = 13.5%) and cold (- 20 °C) on physiological and perceptual responses to endurance exercise.

METHODS

14 trained male subjects ( V . O2max: 64 ± 5 mL/kg/min) randomly performed a discontinuous maximal incremental test to exhaustion on a motorized treadmill under four environmental conditions: Normothermic-Normoxia (N), Normothermic-Hypoxia (H), Cold-Normoxia (C) and Cold-Hypoxia (CH). Performance and physiological and perceptual responses throughout exercise were evaluated.

RESULTS

Maximal WorkLoad (WL) and WL at lactate threshold (LT) were reduced in C (- 2.3% and - 3.5%) and H (- 18.0% and - 21.7%) compared to N, with no interactive (p = 0.25 and 0.81) but additive effect in CH (- 21.5% and - 24.6%). Similarly, HRmax and Vemax were reduced in C (- 3.2% and - 14.6%) and H (- 5.0% and - 7%), showing additive effects in CH (- 7.7% and - 16.6%). At LT, additive effect of C (- 2.8%) and H (- 3.8%) on HR reduction in CH (- 5.7%) was maintained, whereas an interactive effect (p = 0.007) of the two stressors combined was noted on Ve (C: - 3.1%, H: + 5.5%, CH: - 10.9%). [La] curve shifted on the left in CH, displaying an interaction effect between the 2 stressors on this parameter. Finally, RPE at LT was exclusively reduced by hypoxia (p < 0.001), whereas TSmax is synergistically reduced by cold and hypoxia (interaction p = 0.047).

CONCLUSION

If compared to single stress exposure, exercise performance and physiological and perceptual variables undergo additive or synergistic effects when cold and hypoxia are combined. These results provide new insight into human physiological responses to extreme environments.

Analysis of Sprint Ski Mountaineering Performance

Ski mountaineering sprint competitions are short individual races involving 3 uphill sections (U), 3 transitions (T), and a final descent. To date, relatively little is known about this novel Olympic discipline, and here we examined (1) the contribution of the time spent on U, T, and final descent to overall finishing time and (2) the potential relationships with final ranking. During the different rounds of 2 International Ski Mountaineering Federation World Cup sprint competitions, male and female ski mountaineers were video recorded. Correlation and multiple linear regression analyses were used to investigate the impact of U, T, and final descent on the best overall finishing time. Linear-mixed model analysis was applied to explore potential interactions between section times, rounds, and final ranking. Overall, U (r = .90-.97) and T (r = .57-.89) were closely correlated with the best overall finishing time (all P < .05). U explained approximately 80% to 90% of the variation in the best finishing time for both sexes, with U + T explaining approximately 95% to 98% of this variation. In each successive round, the ski mountaineers eliminated were all slower on U than the Top 3 (all P < .05). The fastest skiers increased their performance on U in the later rounds of the competitions, while those eliminated showed a tendency toward a decrease. Our findings reveal that world-class sprint ski mountaineers conduct transitions optimally and perform effectively uphill. Training for such competitions should aim to improve short supramaximal uphill performance (∼1.5-2.5 min), ensuring that this does not decline with multiple efforts. These insights into ski mountaineering sprint performance are of considerable value in connection with training for the 2026 Winter Olympics.

The effects of a 6-hour ultra-endurance run on postexercise parasympathetic reactivation responses

BACKGROUND

Alterations in cardiac autonomic control reflecting depressed parasympathetic activity have been previously reported after ultra-endurance events at rest and during dynamic tasks assessing cardiac autonomic responsiveness. This study investigated the impact of a 6-hour ultra-endurance run on parasympathetic reactivation indices, using an exercise-recovery transition approach.

METHODS

Nine trained runners (VO<inf>2max</inf> 67±12 mL/kg/min) completed a 6-hour run (EXP) whilst other six runners (VO<inf>2max</inf> 66±10 mL/kg/min) served as a control (CON). Before (PRE) and after the run/control period (POST) participants completed standard cardiac autonomic activity assessments. Postexercise parasympathetic reactivation was assessed by means of heart rate recovery (HRR) and vagal-related time-domain HRV indices.

RESULTS

HR was increased at rest (P<0.001, ES=3.53), during exercise (P<0.05, ES=0.38) and recovery (all P<0.001, ES from 0.91 to 1.46) at POST in EXP and not in CON (all P>0.05). At POST vagal-related HRV indices were significantly decreased at rest (P<0.001, ES from -2.38 to -3.54) and during postexercise recovery (all P<0.001, ES from -0.97 to -1.58) only in EXP. HRR at 30 and 60 s were markedly reduced at POST in EXP both when expressed in bpm and normalized for the exercising HR (all P<0.001, ES from -1.21 to -1.74).

CONCLUSIONS

A 6-hour run markedly impacted upon postexercise parasympathetic reactivation responses causing a decrease in HRR and HRV recovery indices. For the first time, this study attested blunted postexercise parasympathetic reactivation responses following an acute bout of ultra-endurance exercise.

Participation and performance by women and men in ski-mountaineering sprint races during the past decade

BACKGROUND

The sprint is one of the two ski-mountaineering disciplines that will be held at the coming Milano Cortina 2026 Winter Olympics (Italy). To date little information exists on this novel Olympic discipline.

METHODS

We characterized retrospectively the participation and performance in international male and female ski mountaineering sprint races from November 2012 to April 2022. Potential associations between sex and season with participation, as well as between sex, period, round and final ranking with parameters of performance were examined with linear-mixed models.

RESULTS

The minimal performance time required for success (i.e., being eligible for the next round/winning a medal) decreased progressively from the qualifications (Qs) to the final (F). Finalists adopted a conservative strategy in the Qs, improving their performance in the quarter-finals (QFs) and semifinals (SFs). The best and second-best male skier and the best female skier improved their performances even further in the F, which appears to be a key feature for success. For women, the number of participants and level of competition increased over the decade, whereas male participation did not. During the last two seasons, male sprint winners performed relatively more slowly in the preliminary rounds leaving more room for improvement in the F, which could reflect increased specialization in this discipline.

CONCLUSIONS

Our findings provide novel insights into ski-mountaineering sprint races that can guide competition strategies and could be of considerable importance in connection with the Milano Cortina 2026 Winter Olympics (Italy).

Eager to set a record in a vertical race? Test your VO2max first!

We investigated the relationship between maximal oxygen consumption (VO_2max) and performance in vertical races (VRs). In total, 270 performances, from 26 VRs, and cardiopulmonary data of 64 highly-trained mountain runners (53 M, V O_2max: 75.7±5.8 mL/min/kg; 11 F: 65.7±3.4 mL/min/kg), collected over a 11-year period (2012-2022), were analysed. The relationship between performance and VO_2max was modelled separately for national (NVRs), international (IVRs), and VRs of current pole-unassisted and pole-assisted vertical kilometre (VK) records (RVRs). Three different (p<0.001) exponential models described the relationship between performance and VO_2max in IVRs (R²=0.96, p<0.001), NRs (R²=0.91, p<0.001) and RVRs (R²=0.97, p<0.001). Estimated VO_2max requirements (with 95% CI) to win/set a record time in IVRs were 86.2(85.3-87.1)/89.4(88.2-90.5) and 74.0(73.6-74.4)/76.8(76.4-77.3) mL/min/kg, for males and females, respectively, 86.1(85.0-87.1)/90.4(89.0-91.8) and 74.8(74.2-75.3)/77.1(77.6-77.7) mL/min/kg in RVRs, decreasing to 83.7(82.5-84.9)/87.6(86.0-89.2) and 66.8(65.9-67.7)/70.7(70.1-71.4) mL/min/kg in NVRs. Our study also suggested a tendency towards a non-uniform variation in the metabolic demand of off-road running, likely attributable to the different features of the VRs (e.g., terrain, technical level, use of poles). These data provide mean VO_2max requirements for mountain runners to win and establish new records in VRs and stimulate new research on the energy cost of off-road running.

Effects of Low vs Moderate Dose of Recreational Football on Cardiovascular Risk Factors

This study aimed to compare the effectiveness of recreational football performed once (LOW) vs. twice (MOD) a week on cardiovascular risk factors in healthy, sedentary men. Body composition, resting blood pressure, blood lipid profile and maximal oxygen consumption (VO₂max) were measured at baseline, after a 12-week control and training period, using an interrupted time series study (study 1, n=18: n=8, LOW and n=10, MOD) nested in a randomised parallel trial (study 2, n=34: n=18 LOW and n=16 MOD). After the intervention in the study 1, LDL-Cholesterol (-12.3 mg•dL-¹ [-22.7 to -2.0]) and VO₂max (4.5 ml•kg-¹•min-¹ [1.2 to 7.8 ]) changed in LOW whereas differences were found in weight (-2.1 kg [-3.7 to -0.4]), BMI (-0.7 kg•m^-2 [-1.2 to -0.1]), total cholesterol (-22.2 mg•dL-¹ [-36.0 to -8.4]), no-HDL-cholesterol (-17.5 mg•dL-¹ [-30.5 to -4.5]), LDL-cholesterol (-14.9 mg•dL-¹ [-23.6 to -6.2]) and VO₂max (5.7 ml•kg-¹•min-¹ [2.8 to 8.6]) in MOD. Study 2 showed no evidence of differences between groups. Our results therefore, suggest positive health effects of recreational football even when performed at low frequency as it can happen in real context.

Exercising at the time of the COVID-19 pandemic: acute physiological, perceptual and performance responses of wearing face masks during sports activity

BACKGROUND

The COVID-19 pandemic requires the adoption of strict preventive measures, such as wearing a protective face mask , but few studies investigated its impact during exercise. We investigated the effects of wearing a protective face mask while exercising at different intensities and verified whether differences between two types of protective face masks exist.

METHODS

Twenty subjects performed 4-min running at 8 km•h-1 and at 10 km•h-1, 8 x 90-m Intermittent running bouts and the Yo-Yo Intermittent Recovery Test Level-1, while wearing either a surgical mask, a sports-reusable mask or no mask. Physiological responses (HR, [La], SpO2), overall and breathlessness perceived exertion and YYIRT1-distance were assessed.

RESULTS

Breathlessness RPE was greater with surgical than without mask at the end of the run at 8 km•h-1 (+7.18 [3.21, 11.50]) and with both surgical and sports-reusable mask than without mask at the end of the run at 10 km•h-1 (+8.09 [4.09, 12.60] and +8.21 [4.53, 12.70]) and intermittent exercise (+11.10 [6.41, 16.10] and +10.50 [6.18, 15.30]). Overall RPE was greater with surgical than without mask at the end of the run at 8 (+3.71 [1.15, 6.91]) and 10 km•h-1 (+5.29 [2.26, 8.85]). Furthermore, YYIRT1 performance was lower with surgical (-150 m [44, 240]) and sports-reusable mask (-201 m [108, 286]) than without mask.

CONCLUSIONS

Regardless of exercise intensity and mask type, wearing a protective face mask mostly affects perceptual responses, also causing a performance reduction during maximal exercise. These findings must be considered when prescribing/practicing exercise while wearing a protective face mask.

Assessment of bike handling during cycling individual time trials with a novel analytical technique adapted from motorcycle racing

A methodology to study bike handling of cyclists during individual time trials (ITT) is presented. Lateral and longitudinal accelerations were estimated from GPS data of professional cyclists (n=53) racing in two ITT of different length and technical content. Acceleration points were plotted on a plot (g-g diagram) and they were enclosed in an ellipse. A correlation analysis was conducted between the area of the ellipse and the final ITT ranking. It was hypothesized that a larger area was associated to a better performance. An analytical model for the bike-cyclist system dynamics was used to conduct a parametric analysis on the influence of riding position on the shape of the g-g diagram. A moderate (n=27, r=-0.40, p=0.038) and a very large (n=26, r=-0.83, p<0.0001) association were found between the area of the enclosing ellipse and the final ranking in the two ITT. Interestingly, this association was larger in the shorter race with higher technical content. The analytical model suggested that maximal decelerations are highly influenced by the cycling position, road slope and speed. This investigation, for the first time, explores a novel methodology that can provide insights into bike handling, a large unexplored area of cycling performance.

Acute exercise-induced changes in cardiac function relates to right ventricular remodeling following 12-wk hypoxic exercise training

Repeated ventricular exposure to alterations in workload may relate to subsequent cardiac remodeling. We examined whether baseline acute changes in right (RV) and left ventricular (LV) function relate to chronic cardiac adaptation to 12-wk exercise training. Twenty-one healthy individuals performed 12-wk high-intensity endurance running training under hypoxia (fraction of inspired oxygen: 14.5%). Resting transthoracic echocardiography was performed before and after the training program to assess ventricular structure, function, and mechanics (including strain-area/volume loops). In addition, we examined systolic cardiac function during recumbent exercise under hypoxia at baseline (heart rate of 110-120 beats/min, "stress echocardiography"). Fifteen individuals completed training (22.0 ± 2.4 yr, 10 males). Hypoxic exercise training increased RV size, including diameter and area (all P < 0.05). With exception of an increase in RV fractional area change (P = 0.03), RV function did not change post-training (all P > 0.05). Regarding the RV strain-area loop, lower systolic and diastolic slopes were found post-training (P < 0.05). No adaptation in LV structure, function, or mechanics was observed (all P > 0.05). To answer our primary aim, we found that a greater increase in RV fractional area change during baseline stress echocardiography (r = -0.67, P = 0.01) inversely correlated with adaptation in RV basal diameter following 12-wk training. In conclusion, 12-wk high-intensity running hypoxic exercise training induced right-sided structural remodeling, which was, in part, related to baseline increase in RV fractional area change to acute exercise. These data suggest that acute cardiac responses to exercise may relate to subsequent RV remodeling after exercise training in healthy individuals.NEW & NOTEWORTHY During exercise, the right ventricle is exposed to a disproportionally higher wall stress than the left ventricle, which is further exaggerated under hypoxia. In this study, we showed that 12-wk high-intensity running hypoxic exercise training induced right-sided structural remodeling, which was, in part, related to baseline cardiac increase in RV fractional area change to acute exercise. These data suggest that acute RV responses to exercise are related to subsequent right ventricular remodeling in healthy individuals upon hypoxic training.

Effects of three-exercise sessions in the heat on endurance cycling performance

PURPOSE

To investigate the effects of a very short-term acclimation protocol (VSTAP) on performance, physiological and perceptual responses to exercise in the heat.

METHODS

12 trained male cyclists (age 31.2 ± 7; weight 71.3 ± 7 kg, VO_2max: 58.4 ± 3.7 mL/kg/min) randomly performed two Time to Exhaustion Tests (TTE) at 75% of normothermic peak power output (PPO), one in normothermia (N,18°C-50% RH) and one in the heat (H,35°C-50% RH), before and after a VSTAP intervention, consisting of 3 days-90 min exercise (10min at 30% of PPO+80 min at 50% of PPO) in H (≈4.5h of heat exposure). Performance time of TTEs and physiological and perceptual variables of both TTEs and training sessions (T1, T2 and T3) were evaluated.

RESULTS

Magnitude Based Inferences (MBI) revealed 92/6/1% and 62/27/11% chances of positive/trivial/negative effects of VSTAP of improving performance in H (+17%) and in N (+9%), respectively. Heart Rate (HR) decreased from T1 to T3 (p < 0.001) and T2 to T3 (p < 0.001), whereas Tympanic Temperature (TyT) decreased from T1 to T2 (p = 0.047) and from T1 to T3 (p = 0.007). Furthermore, despite the increased tolerance to target Power Output (PO) throughout training sessions, RPE decreased from T1 to T3 (p = 0.032).

CONCLUSIONS

The VSTAP determined meaningful physiological (i.e. decreased HR and TyT) and perceptual (i.e. decreased RPE) adaptations to submaximal exercise. Furthermore, showing good chances to improve performance in the heat, it represents a valid acclimation strategy to be implemented when no longer acclimation period is possible. Finally, no cross-over effect of the VSTAP on performance in temperate conditions was detected.

Oxynet: A collective intelligence that detects ventilatory thresholds in cardiopulmonary exercise tests

The problem of the automatic determination of the first and second ventilatory thresholds (VT1 and VT2) from cardiopulmonary exercise test (CPET) still leads to controversy. The reliability of the gold standard methodology (i.e. expert visual inspection) feeds into the debate and several authors call for more objective automatic methods to be used in the clinical practice. In this study, we present a framework based on a collaborative approach, where a web-application was used to crowd-source a large number (1245) of CPET data of individuals with different aerobic fitness. The resulting database was used to train and test an artificial intelligence (i.e. a convolutional neural network) algorithm. This automatic classifier is currently implemented in another web-application and was used to detect the ventilatory thresholds in the available CPET. A total of 206 CPET were used to evaluate the accuracy of the estimations against the expert opinions. The neural network was able to detect the ventilatory thresholds with an average mean absolute error of 178 (198) mlO₂/min (11.1%, r = 0.97) and 144 (149) mlO₂/min (6.1%, r = 0.99), for VT1 and VT2 respectively. The performance of the neural network in detecting VT1 deteriorated in case of individuals with poor aerobic fitness. Our results suggest the potential for a collective intelligence system to outperform isolated experts in ventilatory thresholds detection. However, the inclusion of a larger number of VT1 examples certified by a community of experts will be likely needed before the abilities of this collective intelligence can be translated into the clinical use of CPET.

Talent Development in Young Cross-Country Skiers: Longitudinal Analysis of Anthropometric and Physiological Characteristics

Introduction: Very little is known about talent development and selection processes in young cross-country skiers.

Aim: (1) to analyze the effect of age on anthropometric and physiological parameters in medium-to-high level cross-country skiers during the late teenage period; (2) to describe parameters' trend in selected talents after the late teenage period; (3) to define which characteristics during the late teenage period could discriminate against further talent selection.

Method: We found 14 male (M) and nine (F) athletes in our database, identified as talents by regional teams during the late teenage period, who performed the same diagonal-stride roller-skiing incremental test to exhaustion at 17 and 18 years old. Of these, four M and three F teenagers performed four further evaluations, and were selected by the national team. Age effect during the late teenage period was verified on anthropometric and physiological parameters measured at maximal intensity (MAX), first (VT1), and second (VT2) ventilatory thresholds, and 3° and 6° of treadmill incline. An observational analysis allowed to evaluate parameters' trend after the late teenage period in selected athletes, and to determine possible characteristics early discriminating further selection.

Results: During the late teenage period, height, weight, and BMI was still raising in M as well as V'O₂ at VT2 and 6° of treadmill incline (all P > 0.05). In F, mass-scaled V'O₂ MAX increased while heart rate (HR) at MAX and VT2 decreased (all P > 0.05). Since the late teenage period, all selected males showed maximal ventilation volumes, absolute V'O₂ at MAX, VT1, and VT2 that were within or above the 75th percentile of their group; the same was found in selected females for mass-scaled V'O₂ MAX, VT1, and VT2 time. After the late teenage period, all selected athletes showed an increasing trend for VT2 time, while a decreasing trend for sub-maximal energetic cost, %V'O₂ and HR.

Discussion: During the late teenage period, males are still completing their maturation process. Since the late teenage period, some physiological parameters seem good indicators to early discriminate for further talents. A progressive increase in skiing efficiency was demonstrated in developing talents of both sexes after the late teenage period.

The acute and chronic effects of high-intensity exercise in hypoxia on blood pressure and post-exercise hypotension: A randomized cross-over trial

BACKGROUND

Acute exercise leads to an immediate drop in blood pressure (BP), also called post-exercise hypotension (PEH). Exercise in hypoxia is related to additional vasodilation, potentially contributing to more profound PEH. Therefore, we investigated the impact of hypoxia versus normoxia on the magnitude of PEH. Second, we examined whether these changes in PEH relate to the BP-lowering effects of 12-week exercise training under hypoxia.

METHODS

In this prospective study, 21 healthy individuals (age 22.2 ± 3.0 years, 14 male) performed a 45-minute high-intensity running exercise on 2 different days in a random order, under hypoxia (fraction of inspired oxygen 14.5%) and normoxia (fraction of inspired oxygen 20.9%). BP was examined pre-exercise (t = 0) and at t = 15, t = 30, t = 45, and t = 60 minutes post-exercise. Afterward, subjects took part in a 12-week hypoxic running exercise training program. Resting BP was measured before and after the 12-week training program.

RESULTS

Acute exercise induced a significant decrease in systolic BP (systolic blood pressure [SBP], P = .001), but not in diastolic BP (diastolic blood pressure [DBP], P = .113). No significant differences were observed in post-exercise BP between hypoxic and normoxic conditions (SBP, P = .324 and DBP, P = .204). Post-exercise changes in SBP, DBP, and mean arterial pressure significantly correlated to the 12-week exercise training-induced changes in SBP (r = 0.557, P = .001), DBP (r = 0.615, P < .001), and mean arterial pressure (r = 0.458, P = .011).

CONCLUSION

Our findings show that hypoxia does not alter the magnitude of PEH in healthy individuals, whilst PEH relates to the BP-lowering effects of exercise. These data highlight the strong link between acute and chronic changes in BP.

Shortening Work-Rest Durations Reduces Physiological and Perceptual Load During Uphill Walking in Simulated Cold High-Altitude Conditions

Fornasiero, Alessandro, Aldo Savoldelli, Federico Stella, Alexa Callovini, Lorenzo Bortolan, Andrea Zignoli, David A. Low, Laurent Mourot, Federico Schena, and Barbara Pellegrini. Shortening work-rest durations reduces physiological and perceptual load during uphill walking in simulated cold high-altitude conditions. High Alt Med Biol. 21:249-257, 2020. Background: We investigated the effects of two different work-rest durations on the physiological and perceptual responses to a simulated mountain hike in a cold hypoxic environment. Materials and Methods: Twelve healthy nonacclimatized active men (age 31.3 ± 5.3 years, body mass index 22.4 ± 1.5 kg/m²) completed a 80-minute work-matched intermittent exercise on a motorized treadmill (25% incline, fixed self-selected speed), in a simulated mountain environment (-25°C, FiO₂ = 11%, ≈5000 m a.s.l.), wearing extreme cold weather gear, once with short (20 × 3 minutes walking with 1 minute rest; SHORT) and once with long (10 × 6 minutes walking with 2 minutes rest; LONG) work-rest durations. Heart rate (HR), pulse oxygen saturation (SpO₂), rate of perceived exertion (RPE), and thermal sensation (TS) were assessed throughout the exercise protocols. Cardiac autonomic modulation was assessed before (PRE) and after exercise (POST) in supine position, as well as during standing resting periods by means of HR recovery (HRR) assessment. Results: SpO₂ and TS were similar (p > 0.05) in SHORT and LONG protocols. HR and RPE were increased, and HRR reduced during LONG compared to SHORT (p < 0.05). Parasympathetic activity indices were reduced at POST after both protocols (p < 0.05), but to a lesser extent after SHORT (p < 0.05). Conclusions: Reduced work-rest durations are associated with improved perceptual responses and less perturbation of cardiac autonomic balance, compared to longer work-rest durations. Shorter exercise periods from more frequent breaks during hikes at high altitude may represent a valid strategy to limit the impact of exercise under extreme environmental conditions.

Estimating an individual's oxygen uptake during cycling exercise with a recurrent neural network trained from easy-to-obtain inputs: A pilot study

Measurement of oxygen uptake during exercise ([Formula: see text]) is currently non-accessible to most individuals without expensive and invasive equipment. The goal of this pilot study was to estimate cycling [Formula: see text] from easy-to-obtain inputs, such as heart rate, mechanical power output, cadence and respiratory frequency. To this end, a recurrent neural network was trained from laboratory cycling data to predict [Formula: see text] values. Data were collected on 7 amateur cyclists during a graded exercise test, two arbitrary protocols (Prot-1 and -2) and an "all-out" Wingate test. In Trial-1, a neural network was trained with data from a graded exercise test, Prot-1 and Wingate, before being tested against Prot-2. In Trial-2, a neural network was trained using data from the graded exercise test, Prot-1 and 2, before being tested against the Wingate test. Two analytical models (Models 1 and 2) were used to compare the predictive performance of the neural network. Predictive performance of the neural network was high during both Trial-1 (MAE = 229(35) mlO2min-1, r = 0.94) and Trial-2 (MAE = 304(150) mlO2min-1, r = 0.89). As expected, the predictive ability of Models 1 and 2 deteriorated from Trial-1 to Trial-2. Results suggest that recurrent neural networks have the potential to predict the individual [Formula: see text] response from easy-to-obtain inputs across a wide range of cycling intensities.

Similar cardiovascular and autonomic responses in trained type 1 diabetes mellitus and healthy participants in response to half marathon

AIMS

This field experiment examined whether trained people with type 1 diabetes mellitus (T1D) have similar cardiovascular and baroreflex alterations after a 21-km running race when compared to healthy people.

METHODS

Nine T1D (39.0 ± 11.1 yr; 175.0 ± 10.2 cm; 70.8 ± 8.7 kg) were matched with 9 healthy participants (42.4 ± 5.8 yr; 175.7 ± 6.7 cm; 72.1 ± 8.5 kg) who ran an official half-marathon. Before and 1-hour after the race, cardiovascular variables, sympathetic activity (catecholamines), parasympathetic (heart rate variability analysis) modulation and cardiac baroreflex function (transfer function analysis) were assessed during supine rest and a squat stand test (forced blood pressure change).

RESULTS

Performance time and weight loss [104.0 ± 13.2 and 111.0 ± 18.7 min; -2.57 ± 1.05 kg (-1.88 ± 0.88%) and -2.29 ± 1.15 kg (-1.59 ± 0.59%)] for healthy and T1D participants, respectively) were similar. Before running, no significant differences in any cardiovascular or autonomic variables were noted between the groups. After 1 h of recovery, both groups exhibited post-exercise hypotension, accompanied by increased sympathetic activity, decreased parasympathetic modulation, and reduced cardiac baroreflex sensitivity.

CONCLUSIONS

Our results showed that the pattern of change in cardiovascular and autonomic nervous activity to strenuous exercise are well maintained in T1D participants with a training history of at least 5 years.

Disentangling the molecular mechanisms of multiple sclerosis: The contribution of twin studies

Twin studies of disease concordance are useful to weight the relative contribution of genetic and environmental factors to the cause of common complex disorders. In multiple sclerosis (MS) different twinning rates from geographic areas at different prevalence suggested that heritable and non-heritable factors contribute in different proportions and ways to MS risk in diverse populations. This concept prompted genome-wide association studies, and the implementation of the co-twin control design, that allows stringent experimental approaches in MS-discordant identical pairs, controlling for genetic influences and many other known and unknown factors. The co-twin control design provided important clues on MS molecular model. These studies will be reviewed, focusing on those showing significant differences between affected and healthy co-twins. In some cases, differences that emerged in non-twin patients compared to matched controls were not confirmed in identical MS-discordant pairs, suggesting an 'MS subclinical trait'. Early patterns of magnetic resonance imaging and predictive biomarkers that characterize 'healthy' co-twins may be useful for the identification of a prodromal reversible phase of the disease.

Cardiac Autonomic and Physiological Responses to Moderate- intensity Exercise in Hypoxia

Exercise physiological responses can be markedly affected by acute hypoxia. We investigated cardiac autonomic and physiological responses to different hypoxic training protocols. Thirteen men performed three exercise sessions (5×5-min; 1-min passive recovery): normoxic exercise at 80% of the power output (PO) at the first ventilatory threshold (N), hypoxic exercise (FiO₂=14.2%) with the same PO as N (HPO) and hypoxic exercise at the same heart rate (HR) as N (HHR). PO was lower in HHR (21.1±9.3%) compared to N and HPO. Mean HR was higher in HPO (154±11 bpm, p<0.01) than N and HHR (139±10 vs. 138±9 bpm; p=0.80). SpO₂ was reduced (p<0.01) to a similar extent (p>0.05) in HPO and HHR compared to N. HR recovery (HRR) and HR variability indices were similar in N and HHR (p>0.05) but reduced in HPO (p<0.05), mirroring a delayed parasympathetic reactivation. Blood lactate and ventilation were similar in N and HHR (p>0.05) and increased in HPO (p<0.001). During recovery oxygen consumption and ventilation were similar in N and HHR (p>0.05) and increased in HPO (p<0.01). Moderate HR-matched hypoxic exercise triggers similar cardiac autonomic and physiological responses to normoxic exercise with a reduced mechanical load. On the contrary, the same absolute intensity exercise in hypoxia is associated with increased exercise-induced metabolic stress and delayed cardiac autonomic recovery.

Delayed parasympathetic reactivation and sympathetic withdrawal following maximal cardiopulmonary exercise testing (CPET) in hypoxia

PURPOSE

This study investigated the effects of acute hypoxic exposure on post-exercise cardiac autonomic modulation following maximal cardiopulmonary exercise testing (CPET).

METHODS

Thirteen healthy men performed CPET and recovery in normoxia (N) and normobaric hypoxia (H) (FiO₂ = 13.4%, ≈ 3500 m). Post-exercise cardiac autonomic modulation was assessed during recovery (300 s) through the analysis of fast-phase and slow-phase heart rate recovery (HRR) and heart rate variability (HRV) indices.

RESULTS

Both short-term, T30 (mean difference (MD) 60.0 s, 95% CI 18.2-101.8, p = 0.009, ES 1.01), and long-term, HRRt (MD 21.7 s, 95% CI 4.1-39.3, p = 0.020, ES 0.64), time constants of HRR were higher in H. Fast-phase (30 and 60 s) and slow-phase (300 s) HRR indices were reduced in H either when expressed in bpm or in percentage of HR_peak (p < 0.05). Chronotropic reserve recovery was lower in H than in N at 30 s (MD - 3.77%, 95% CI - 7.06 to - 0.49, p = 0.028, ES - 0.80) and at 60 s (MD - 7.23%, 95% CI - 11.45 to - 3.01, p = 0.003, ES - 0.81), but not at 300 s (p = 0.436). Concurrently, Ln-RMSSD was reduced in H at 60 and 90 s (p < 0.01) but not at other time points during recovery (p > 0.05).

CONCLUSIONS

Affected fast-phase, slow-phase HRR and HRV indices suggested delayed parasympathetic reactivation and sympathetic withdrawal after maximal exercise in hypoxia. However, a similar cardiac autonomic recovery was re-established within 5 min after exercise cessation. These findings have several implications in cardiac autonomic recovery interpretation and in HR assessment in response to high-intensity hypoxic exercise.

Tamoxifen in Disseminated Breast Cancer

86 postmenopausal women with disseminated breast cancer have been treated orally with 30 mg of Tamoxifen per day (ICI 46474, Nolvadex) for periods of 2 months or more. The overall responders were 28/86 (32.5 %) with a median remission duration of 9 months. In 30 patients already shown to be resistant to cytotoxic chemotherapy, Tamoxifen was used as first hormonal agent; the remission rate in this group was 12/30 (40 %), while it was 28.5 % (16/56) in the others who had already received different hormonal treatments. In 6 early menopausal cases, the treatment had to be stopped for a dangerous « worsening syndrome ». Other side effects were trivial. In 28/35 cases (80%), we have found the reappearance of a pattern of estrogenic activity in vaginal smears during treatment. Hence a « simil-estrogen », more than an « anti-estrogen » mechanism of action is postulated and a selection of patients for treatment in the « mid postmenopausal age » is recommanded.

FAM2 Regimen in Disseminated Gastric Cancer

Forty-four previously untreated patients with advanced inoperable and/or disseminated gastric carcinoma were given an i.v. combination (FAM2) chemotherapy of 5-fluorouracil, 400 mg/m2 on days 1, 2 and 3, and 21, 22 and 23; adriamycin, 40 mg/m2 on days 2 and 22; and mitomycin C, 10 mg/m2 on day 1, with a recycle on day 42 (1 cycle = 41 days). Forty patients have completed 2 cycles and are evaluable (median number of cycles 5; range 3 to 8): 26 of these achieved a partial remission, with a response rate of 65 %; 4 (10 %) gained a stable situation for 3 to 6 months, and 10 (25 %) showed progression of disease. Median duration of partial remissions was 10 months, and median survival was 15 months for responders and 5 months for nonresponders. A fall in WBC (< 2500/μl) occurred in 7 % and of platelets (< 80,000/μl) in 4.5 %. Total alopecia occurred in 20 of 40 patients and nausea and or weakness were common findings. No drug-related infection, bleeding or death was observed. Patients with advanced gastric carcinoma can derive useful palliation from FAM2 chemotherapy.

Cisplatin plus Vindesine versus Cisplatin plus VP16 versus Doxorubicin plus Cytoxan in Non-Small-Cell Carcinoma of the Lung. A Randomized Study

From March 1981 to January 1984, 116 patienst with advanced non-small-cell carcinoma of the lung (NSCCL) were randomly assigned to 3 combinations as follows: CDDP + DVA, CDDP + VP16 and DXR + CTX. 94 patients were evaluable for response, 106 for toxicity and survival. Of 31 patients, 15 (48%; 3 CRs and 12 PRs) responded to CDDP + DVA; of 33 patients, 12 (36%, 2 CRs and 10 PRs) responded to CDDP + VP16; of 30 patients, 3 (10%) obtained a PR with DXR+CTX (CDDP+DVA vs DXR + CTX, P < 0.005; CDDP + VP16 vs DXR + CTX, P < 0.05; CDDP + DVA vs CDDP + VP16, P = NS). The median duration of response was 22 weeks in the CDDP-DVA group, 17 weeks in the CDDP-VP16 group, and 16 weeks in the DXR+CTX group. No significant difference in survival was observed among the 3 groups (median: 43, 47, 41 weeks, respectively). Hematologic and neurologic toxicities were significantly higher in the DVA-containing regimen. Despite the lack of improvement of overall survival with the CDDP-containing combinations over the DXR + CTX control group, the good response rate makes them suitable to be used in combined therapeutic strategies.

Phase II Evaluation of 4'EPI-Doxorubicin in Patients with Metastatic Colorectal Carcinoma

Thirty-four evaluable patients with metastatic colorectal carcinoma (13 rectal primary and 21 colonic primary, 4 pretreated and 30 untreated) received 4'epi-doxorubicin at the dose of 75 mg/m2 i.v. once every 21 days, for a minimum of 2 courses. Symptomatic toxicity (mainly confined to gastrointestinal complaints) was short-lived and easily managed. Hematologic toxicity was mild. Transient electrocardiographic abnormalities were found in 50 % of patients, without signs of significant cumulative cardiotoxicity. Three previously untreated patients achieved a partial response (lasting 16, 12 and 12 weeks, respectively) with a response rate of 9 % (3 % - 23 %, 95 % confidence interval). More interestingly, all responsive patients had rectal cancer: further studies of 4'epi-doxorubicin confined to the rectal localization seem warranted.

Tamoxifen Treatment for Advanced Renal Cell Cancer

Twelve patients with metastatic clear cell renal cancer received a course of tamoxifen. Three showed stable disease for a period from 2 to 12 months and 1 a mixed response for a short time. It does not appear that tamoxifen may be a useful agent in the treatment of metastatic renal cell carcinoma.

Alpha-2 Interferon and 5-Fluorouracil in Advanced Colorectal Cancer

A total of 21 untreated patients (5 males, 16 females; median age, 55 years; range, 28-72) with advanced measurable colorectal carcinoma were treated with an association of 5-fluorouracil (1000 mg/weekly) and alpha-2 interferon (three times a week s.c.: 6 x 10(6) U in the 1st month, 9 x 10(6) U in the 2nd month, 12 x 10(6) U in the 3rd month and then 18 x 10(6) U) until maximum response or progression of disease. Sites of disease involved liver in 10 patients, lung in 6, supraclavicular lymph nodes in 3, skin in 1, abdomen in 4, and vagina in 1 patient. Nine responses (42.8%) were documented (4 complete and 5 partial) with metastases confined to the liver, lung, nodes and skin. Median duration of response was 11 months (range, 4-17+) and median survival was 10 months (range, 2-17+). Side effects (fever, flu-like syndrome and leukopenia) required a dose reduction of 5-fluorouracil in 8 patients and interferon in 2 patients.

Tossicità della Bleomicina Somministrata in Infusione Continua ad Alte Dosi

Sono stati trattati 15 pazienti affetti da carcinoma non seminomatoso del testicolo con un regime polichemioterapico mensile comprendente cis-platino, vinblastina e bleomicina: questo ultimo farmaco veniva somministrato per infusione continua per 5 giorni, alla dose totale di 100 mg/m2 per ciclo. 12 su 15 pazienti hanno raggiunto remissione (10 CR e 2 PR); abbiamo studiato la tossicità di tale farmaco somministrato a dosi relativamente alte con una dose Medicina di 675 mg (range tra 450 e 1050 mg). La tossicità cutanea si è osservata in 2 pazienti su 15. La tossicità polmonare è praticamente nulla; questa è stata controllata con Rxgrafia, indice di Tiffeneau (valore mediano 84) Pa O2 (valore mediano 78). 2 su 15 pazienti hanno evidenziato grave ma reversibile tossicità alla mucosa orofaringea. Alopecia si è evidenziata in tutti i pazienti.

Intestinal Permeability in Relapsing-Remitting Multiple Sclerosis

Changes of intestinal permeability (IP) have been extensively investigated in inflammatory bowel diseases (IBD) and celiac disease (CD), underpinned by a known unbalance between microbiota, IP and immune responses in the gut. Recently the influence of IP on brain function has greatly been appreciated. Previous works showed an increased IP that preceded experimental autoimmune encephalomyelitis development and worsened during disease with disruption of TJ. Moreover, studying co-morbidity between Crohn's disease and MS, a report described increased IP in a minority of cases with MS. In a recent work we found that an alteration of IP is a relatively frequent event in relapsing-remitting MS, with a possible genetic influence on the determinants of IP changes (as inferable from data on twins); IP changes included a deficit of the active mechanism of absorption from intestinal lumen. The results led us to hypothesize that gut may contribute to the development of MS, as suggested by another previous work of our group: a population of CD8+CD161high T cells, belonging to the mucosal-associated invariant T (MAIT) cells, a gut- and liver-homing subset, proved to be of relevance for MS pathogenesis. We eventually suggest future lines of research on IP in MS: studies on IP changes in patients under first-line oral drugs may result useful to improve their therapeutic index; correlating IP and microbiota changes, or IP and blood-brain barrier changes may help clarify disease pathogenesis; exploiting the IP data to disclose co-morbidities in MS, especially with CD and IBD, may be important for patient care.

The Energetics during the World's Most Challenging Mountain Ultra-Marathon-A Case Study at the Tor des Geants®

Purpose: To provide insights into the energy requirements as well as the physiological adaptations of an experienced 50-year-old ultra-marathon male athlete during the world's most challenging mountain ultra-marathon (MUM).

Methods: The international race supporting the study was the Tor des Geants®, characterized by 330 km with +24,000 m D+ to be covered within 150 h. Before the MUM, we assessed the peak oxygen uptake (V˙O2peak) by means of an incremental graded running test. During the MUM we monitored six ascents (once per race day) with a portable gas analyzer, a GPS and a finger pulse oximeter. We then calculated the net metabolic cost per unit of distance (C), the vertical metabolic cost (C_vert) and the mechanical efficiency of locomotion (Eff_mech) throughout the six uphills monitored. We further monitored the distance covered, speed, altimetry and D+ from the GPS data as well as the pulse oxygen saturation with the finger pulse oximeter.

Results: Subject's V˙O2peak was 48.1 mL·kg⁻¹·min⁻¹. Throughout the six uphills investigated the mean exercise intensity was 57.3 ± 6.0% V˙O2peak and 68.0 ± 8.7% HR_peak. C, C_vert and Eff_mech were 11.4 ± 1.9 J·kg⁻¹·m⁻¹, 57.9 ± 15.2 J·kg⁻¹·mvert−1, and 17.7 ± 4.8%, respectively. The exercise intensity, as well as C, C_vert, and Eff_mech did not consistently increase during the MUM.

Conclusions: For the first time, we described the feasibility of assessing the energy requirements as well as the physiological adaptations of a MUM in ecologically valid environment settings. The present case study shows that, despite the distance performed during the MUM, our participant did not experience a metabolic fatigue state. This is likely due to improvements in locomotor efficiency as the race progressed.

Physiological intensity profile, exercise load and performance predictors of a 65-km mountain ultra-marathon

The aims of the study were to describe the physiological profile of a 65-km (4000-m cumulative elevation gain) running mountain ultra-marathon (MUM) and to identify predictors of MUM performance. Twenty-three amateur trail-runners performed anthropometric evaluations and an uphill graded exercise test (GXT) for VO_2max, ventilatory thresholds (VTs), power outputs (PMax, PVTs) and heart rate response (HRmax, HR@VTs). Heart rate (HR) was monitored during the race and intensity was expressed as: Zone I (<VT1), Zone II (VT1-VT2), Zone III (>VT2) for exercise load calculation (training impulse, TRIMP). Mean race intensity was 77.1%±4.4% of HRmax distributed as: 85.7%±19.4% Zone I, 13.9%±18.6% Zone II, 0.4%±0.9% Zone III. Exercise load was 766±110 TRIMP units. Race time (11.8±1.6h) was negatively correlated with VO_2max (r = -0.66, P <0.001) and PMax (r = -0.73, P <0.001), resulting these variables determinant in predicting MUM performance, whereas exercise thresholds did not improve performance prediction. Laboratory variables explained only 59% of race time variance, underlining the multi-factorial character of MUM performance. Our results support the idea that VT1 represents a boundary of tolerable intensity in this kind of events, where exercise load is extremely high. This information can be helpful in identifying optimal pacing strategies to complete such extremely demanding MUMs.

Physiological and anthropometric characteristics of top-level youth cross-country cyclists

In the literature there is a lack of data about the development of top level athletes in cross-country mountain biking (XCO). The purpose of this study was to analyze anthropometric and physiological characteristics of some of the best XCO bikers aged between 13 and 16. The study involved 45 bikers (26 males and 19 females) belonging to a youth national team. The evaluations, consisting of anthropometric measures, incremental cycling tests (VO_2max, PPO, P@RCP), and 30 s Wingate Tests (PMax, PMean), were conducted over a lapse of 4 years. Our findings showed in bikers, already at young age, a specific athletic profile advantageous for XCO performance. At the age of 16, just before entering the junior category and competing at international level, male and female bikers showed physiological values normalized to the body mass comparable to those reported in literature for high level athletes (VO_2max>70 and >60 ml/kg/min, PPO >6.5 and >5.5 W/kg, respectively in males and females). The production of high power-to-weight ratios and high peaks of anaerobic power attests the presence of highly developed aerobic and anaerobic systems in young XCO cyclists reflecting the high physiological demand of this sport.

IFN-β and multiple sclerosis: from etiology to therapy and back

Several immunomodulatory treatments are currently available for relapsing-remitting forms of multiple sclerosis (RRMS). Interferon beta (IFN) was the first therapeutic intervention able to modify the course of the disease and it is still the most used first-line treatment in RRMS. Though two decades have passed since IFN-β was introduced in the management of MS, it remains a valid approach because of its good benefit/risk profile. This is witnessed by new efforts of pharmaceutical industry to improve this line: a PEGylated form of subcutaneous IFN-β 1a, (Plegridy(®)) with a longer half-life, has been recently approved in RRMS. This review will survey the various stages of the use of type I IFN in MS, with special attention to the effect of the treatment on the supposed viral etiologic factors associated to the disease. The antiviral activities of IFN (that initially prompted its use as immunomodulatory agent in MS), and the mounting evidences in favor of a viral etiology in MS, allowed us to outline a re-appraisal from etiology to therapy and back.

Early prediction of response by ¹⁸F-FDG PET/CT during preoperative therapy in locally advanced rectal cancer: a systematic review

AIM

To assess the predictive value of fluorine-18-fluorodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) in early assessing response during neo-adjuvant chemoradiotherapy (CRT) in patients with locally advanced rectal cancer.

MATERIALS AND METHODS

A systematic review was performed by search of MEDLINE Library for the following terms: "rectal carcinoma OR rectal cancer", "predictive OR prediction OR response assessment OR response OR assessment", "early OR ad interim", "therapy", "FDG OR (18)F-FDG", "PET OR PET/CT". Articles performed by the use of stand-alone PET scanners were excluded.

RESULTS

10 studies met the inclusion criteria, including 302 patients. PET/CT demonstrated a good early predictive value in the global cohort (mean sensitivity = 79%; mean specificity = 78%). SUV and its percentage decrease (response index = RI) were calculated in all studies. A higher accuracy was demonstrated for RI (mean sensitivity = 82%; pooled specificity = 85%) with a mean cut-off of 42%. The mean time point to perform PET scan during CRT resulted to be at 1.85 weeks. Some PET parameters resulted to be both predictive and not statistical predictive of response, maybe due to the small population and few studies bias.

CONCLUSION

PET showed high accuracy in early prediction response during preoperative CRT, increased with the use of RI as parameter. In the era of tailored treatment, the precocious assessment of non-responder patients allows modification of the subsequent strategy especially the timing and the type of surgical approach.

Ifosfamide in Thymic Neoplasms

The role of systemic chemotherapy and optimal regimen in thymic neoplasms remains uncertain, because they are rare mediastinal tumors, frequently encapsulated or noninvasive at the time of presentation and surgical excision is adequate treatment. Chemotherapy is an essential treatment modality in advanced or recurrent disease and an increased number of publications on this aspect of management has appeared in the last 10 years. Both single-agent and combination chemotherapy have demonstrated activity in the adjuvant and neoadjuvant settings. There are little data concerning the activity of ifosfamide in thymoma and further investigation of the role of this drug in combination chemotherapy regimens, particularly as an alternative to the inclusion of cyclophosphamide, is warranted.

Neoadjuvant Moderately High-Dose Chemotherapy with rh-G-CSF in Locally Advanced Breast Carcinoma

Aims and Background

The poor results of local treatment for locally advanced breast carcinoma (LABC) justify the use of chemotherapy as primary treatment. Retrospective studies have shown a positive correlation between dose and response rate in advanced breast cancer. G-CSF has shown efficacy in achieving optimal dose intensity and ameliorating chemotherapy-induced myelosuppression. The aim of the present study was to assess the efficacy of a moderately high-dose chemotherapy regimen in terms of response rate, disease-free and overall survival and to assess the role of G-CSF in induced neutropenia.

Methods

Inclusion criteria were the following: age <65 years, WHO performance status <2, histologically proven breast carcinoma, adequate hematologic, renal and hepatic function, stage IIIA or IIIB disease, and no metastatic disease. No prior chemotherapy or radiotherapy was allowed. Three cycles of the following chemotherapy were used preoperatively: epirubicin (100 mg/m2 on day 1), cyclophosphamide (400 mg/m2 for 3 consecutive days) and rh-G-CSF (5 μg/kg/die from day 4 to day 12 every 14 days). After mastectomy or quadrantectomy plus radiotherapy, all patients were treated with 4 courses of adjuvant chemotherapy according to the CMF 1-8 schedule (methotrexate, 40 mg/m2; cyclophosphamide, 600 mg/m2; fluorouracil, 600 mg/m2; all on days 1 and 8, with recycle every 4 weeks).

Results

From May 1992 to June 1996, 57 patients with histologically proven LABC were preoperatively treated. Forty-four patients were premenopausal and 13 postmenopausal; the median age was 45 years (range, 29-64). Thirty-five patients had stage IIIA and 22 patients stage IIIB disease (7 with inflammatory disease). Forty-seven patients underwent radical mastectomy and 10 conservative surgery. A clinical response was noted in 93% (95% confidence interval, 83-98%) of patients (12% complete responses and 81% partial responses); 2 pathological complete remissions (3.5%) were obtained. No toxic deaths were observed. All patients had a follow-up of at least 42 months. The overall 5-year survival rate was 76% (standard error - SE), 6%) and the 5-year disease-free survival rate was 68% (SE, 6.3%).

Conclusions

The 14-day regimen was well tolerated and effective in LABC patients, although not superior to standard-dose chemotherapy. To improve results the use of new drugs in controlled clinical trials seems warranted.

Preoperative combined radiotherapy and chemotherapy for middle and lower rectal cancer: preliminary results

BACKGROUND

Adjuvant treatment for rectal cancer is still controversial. This study reports on overall survival and disease-free survival, toxicity, downstaging, and surgical morbidity in rectal cancer patients who received combined chemoradiation therapy followed by curative surgery.

METHODS

Between 1993 and 1998, 51 patients (31 males and 20 females; median age, 60 years; range, 33-73 years) underwent chemoradiation therapy followed by radical surgery for middle and lower rectal adenocarcinoma. Criteria for giving preoperative radiotherapy (total 45 Gy in 25 fractions of 1.8 Gy/day for 5 weeks) and chemotherapy (5-fluorouracil 350 mg/m2/day and leucovorin 10 mg/m2/day, bolus on days 1-5 and 29-33) were an age younger than 75 years; an Eastern Cooperative Oncology Group performance status score of 0 to 2; and clinical preoperative stage II-III. Forty-three low anterior and eight abdominoperineal resections were performed. Median follow-up time was 29 (range, 3-63) months.

RESULTS

Although grade 3 to 4 toxicity occurred in 14 cases (27.4%), all patients completed the planned adjuvant therapy. At pathology, a complete response was found in eight (15.7%) cases. Of the remaining 43 cases, 22 were stage I, 12 were stage II, and 9 were stage III. Five-year actuarial disease-free survival and overall survival rates were 86.4% and 85.5%, respectively. Whereas no local recurrences were found, 4 patients had distant metastases. Three patients died (1 of cancer-related causes), 45 are alive and disease free, and 3 are alive with disease.

CONCLUSIONS

The combined preoperative chemoradiation approach used by us seems to improve the disease-free survival and overall survival of selected patients with rectal cancer. However, a longer follow-up time is required to confirm these preliminary results.

Preoperative combined radiotherapy and chemotherapy for rectal cancer does not affect early postoperative morbidity and mortality in low anterior resection

PURPOSE

It is not yet known whether preoperative combined radiotherapy and chemotherapy for rectal cancer affects postoperative mortality and morbidity. We therefore evaluated early postoperative complications in patients given adjuvant radiotherapy and chemotherapy before surgery for middle and lower rectal adenocarcinoma.

METHODS

Between 1994 and 1998, 41 patients underwent combined preoperative pelvic radiotherapy and chemotherapy at our institution. Most of the patients had 45 Gy (1.8 Gy/day/25 fractions) during five weeks plus 5-fluorouracil (350 mg/m2/day) and low-dose leucovorin (10 mg/m2/day) bolus on Days 1 to 5 and 29 to 33. Surgery was performed four to six weeks after completion of adjuvant therapy. The 41 patients (Group A) were retrospectively compared with 30 patients (Group B) who, in the same period, underwent surgery without preoperative adjuvant therapy. The groups were homogeneous for age, gender, preoperative risk factors, operating surgeon, and pathologic stage. Mean distance of the tumor from the anal verge was shorter in Group A patients (P = 0.031).

RESULTS

There were seven major postoperative complications in each group. No significant differences were found between the groups for morbidity and mortality rates. Considering all patients, more postoperative complications were found in patients scored as American Society of Anesthesiologists 3, in those with a preoperative hemoglobin value < 10 g/dl, and in those without a diverting stoma (P = 0.0048, P = 0.0453, and P = 0.0033, respectively). At multivariate analysis, independent predictors of major complications were American Society of Anesthesiologists score (relative risk, 343; P = 0.022), diverting stoma (relative risk, 159; P = 0.010), type of surgical procedure (relative risk, 38.9; P = 0.048), preoperative hemoglobin value (relative risk, 9.72; P = 0.061), and intraoperative blood loss (relative risk, 1; P = 0.027). In Group A patients, the absence of diverting stomas was associated with major postoperative complications (P = 0.0307), and independent predictors of major complications were American Society of Anesthesiologists score (relative risk, 56; P = 0.111) and absence of a diverting stoma (relative risk, 22.42; P = 0.222).

CONCLUSION

Early postoperative complications after resection for middle and lower rectal adenocarcinoma are affected by intraoperative and preoperative risk factors and absence diverting stomas, but not by preoperative adjuvant therapy.

Letrozole, a new oral aromatase inhibitor for advanced breast cancer: double-blind randomized trial showing a dose effect and improved efficacy and tolerability compared with megestrol acetate

PURPOSE

To compare two doses of letrozole and megestrol acetate (MA) as second-line therapy in postmenopausal women with advanced breast cancer previously treated with antiestrogens.

PATIENTS AND METHODS

Five hundred fifty-one patients with locally advanced, locoregionally recurrent or metastatic breast cancer were randomly assigned to receive letrozole 2.5 mg (n = 174), letrozole 0.5 mg (n = 188), or MA 160 mg (n = 189) once daily in a double-blind, multicenter trial. Data were analyzed for tumor response and safety variables up to 33 months of follow-up evaluation and for survival up to 45 months.

RESULTS

Letrozole 2.5 mg produced a significantly higher overall objective response rate (24%) compared with MA (16%; logistic regression, P = .04) or letrozole 0.5 mg (13%; P = .004). Duration of objective response was significantly longer for letrozole 2.5 mg compared with MA (Cox regression, P = .02). Letrozole 2.5 mg was significantly superior to MA and letrozole 0.5 mg in time to treatment failure (P = .04 and P = .002, respectively). For time to progression, letrozole 2.5 mg was superior to letrozole 0.5 mg (P = .02), but not to MA (P = .07). There was a significant dose effect in overall survival in favor of letrozole 2.5 mg (P = .03) compared with letrozole 0.5 mg. Letrozole was significantly better tolerated than MA with respect to serious adverse experiences, discontinuation due to poor tolerability, cardiovascular side effects, and weight gain.

CONCLUSION

The data show letrozole 2.5 mg once daily to be more effective and better tolerated than MA in the treatment of postmenopausal women with advanced breast cancer previously treated with antiestrogens.