Effects of three tapering techniques on the performance, forces and psychometric measures of competitive swimmers

The 100-m and 400-m swim time, tethered swimming forces, mood states and self-ratings of well-being of 27 competitive swimmers were measured before and after 4 weeks of intense training and after 1 week and 2 weeks of tapering for major competition. The swimmers were divided into three groups. Each group completed one of three taper regimes similar to those currently performed by swimmers in preparation for competition: (a) reduced training frequency according to each athlete's daily ratings of well-being, (b) reduced training volume, and (c) reduced training volume and intensity. Significant improvements in the Profile of Mood States measures of tension, depression and anger (P < 0.05) were observed after 1 week of tapering, with significant improvements in total mood disturbance and fatigue (P < 0.05) and peak tethered swimming force (P < 0.01) after 2 weeks. Non-significant improvements in 100-m and 400-m swim time (P > 0.05) were observed and no significant differences were revealed among the three tapering techniques. These data highlighted the importance of providing sufficient recovery before competition, since 1 week of reduced training was not long enough to maximise the benefits of tapering. However, none of the three types of tapering currently used by competitive swimmers could be shown to be more beneficial than the others. Accepted: 9 February 1998     

Obesity Is Associated With Altered Lung Function Independently of Physical Activity and Fitness

Measures of obesity, especially central adiposity, have been associated with reduced lung function. However, previous studies may have been affected by confounding by physical activity and fitness. This study aimed to examine the relationship among body fatness, fat distribution, and lung function, adjusted for physical activity energy expenditure (PAEE) and aerobic fitness (VO₂max), in a cohort of British white adults with a family history of type 2 diabetes. A total of 320 adults (mean age 40.4 ± 6.0 years) attended for anthropometric and VO₂max testing, and had ambulatory heart rate monitoring for 4 days to determine PAEE. Spirometry was used to measure forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC). The tests were repeated 12 months later, and a cross‐sectional analysis using linear regression with repeated measures was performed. Measures of obesity (BMI, waist circumference (WC), fat mass (FM), body fat percentage (BF%)) were associated with lower lung function in men and women (P < 0.01), while waist‐to‐hip ratio (WHR) was associated with lower lung function in men only (P < 0.001). Associations remained after adjusting for age, smoking status, height, PAEE, and VO₂max. The estimated difference in mean FEV₁ and FVC per unit increase in the exposure measures were consistently stronger in men compared to women (P for interaction <0.001). Obesity is inversely associated with lung function in adults, but central fat distribution appears to have a stronger relationship with respiratory mechanics in men than in women. These associations were independent of the degree of physical activity and aerobic fitness in this cohort.     

Respiratory Function and Changes in Lung Epithelium Biomarkers after a Short-Training Intervention in Chlorinated vs. Ozone Indoor Pools

Background

Swimming in indoor pools treated with combined chemical treatments (e.g. ozone) may reduce direct exposure to disinfection byproducts and thus have less negative effects on respiratory function compared to chlorinated pools. The aim of this study is to analyze the effects of a short-term training intervention on respiratory function and lung epithelial damage in adults exercising in indoor swimming pool waters treated with different disinfection methods (chlorine vs. ozone with bromine).

Methods

Lung permeability biomakers [surfactant protein D (SP-D) and Clara cell secretory protein (CC16) in plasma] and forced expiratory volumes and flow (FEV1, FVC and FEF_25–75) were measured in 39 healthy adults. Thirteen participants swam during 20 sessions in a chlorinated pool (CP), 13 performed and equivolumic intervention in an ozone pool (OP) and 13 were included in a control group (CG) without exposition.

Results

Median plasma CC16 levels increased in CP swimmers (4.27±3.29 and 6.62±5.51 µg/L, p = 0.01, pre and post intervention respectively) while no significant changes in OP and CG participants were found. No significant changes in median plasma SP-D levels were found in any of the groups after the training period. FVC increased in OP (4.26±0.86 and 4.43±0.92 L, p<0.01) and CP swimmers (4.25±0.86 and 4.35±0.85 L, p<0.01). FEV1 only increased in OP swimmers (3.50±0.65 and 3.59±0.67, p = 0.02) and FEF_25–75 decreased in CP swimmers (3.70±0.87 and 3.37±0.67, p = 0.02).

Conclusion

Despite lung function being similar in both groups, a higher lung permeability in CP compared to OP swimmers was found after a short-term swimming program. Combined chemical treatments for swimming pools such as ozone seem to have less impact on lung epithelial of swimmers compared to chlorinated treated pools.     

Pulmonary function of a firemen-diver population: a longitudinal study

Non smoking, male professional firemen-divers (n = 20) underwent two pulmonary function tests (PFT) separated by 8–9 years. Measured data were compared to European Coal Steel Community recommended reference values to permit cross-sectional and then longitudinal studies. Higher vital capacity (VC) and forced expiratory volume in 1 s (FEV₁; bothP<0.001), and lower residual volume (P<0.01) were observed in both PFT. Longitudinal analysis showed a smaller VC reduction than FEV₁ reduction, leading to a FEV₁/VC percentage decrease with time. Maximal mid expiratory flow (MMEF) and MMEF/VC changes during this 9-year period showed an unusually pronounced decrease, suggesting possible chronic effects of diving on small airways. Thus, it is suggested from our observations that a hyperbaric stimulus compensates in part for the effects of aging on VC and that obstructive disease could occur in subjects with long diving experience.     

Effects of training on lipid metabolism in swimming muscles of sea trout (Salmo trutta)

We examined the effect of exercise intensity and endurance training on plasma free fatty acid (FFA) kinetics and lipid metabolism in swimming muscles of reared sea trout. In both training groups [water current velocities 1 and 2 body lengths per second (bl s⁻¹)] the plasma level of FFAs decreased significantly (P < 0.001) compared to the control group. Similar significant (P < 0.01) post-exercise decrease was observed also in the lipase-esterase activity in the red muscle, but not in white. Moreover, in the group swimming with higher intensity a significantly higher (P < 0.05) lipase-esterase activity in the red muscle was found compared with the group on moderate exercise. As with cytochrome c oxidase activity, a significant elevation in the enzyme activity was also observed after training in the 1 bl s⁻¹ group in red and white muscle (P < 0.05 and P < 0.01, respectively). No changes were observed in β hydroxyacyl CoA dehydrogenase activity. The lipid content was on average nine times higher in red compared to white muscle being 16.7, 21.1, and 24.9% in the red muscle of the control, 1 and 2 bl s⁻¹ groups, respectively, with a significant (P < 0.05) increase after training. We conclude that (1) unlike in mammals, plasma FFA kinetics and oxidation are not linearly related to exercise intensity in reared sea trout, (2) training enhances the capacity to uptake FFA from plasma, and (3) high intensity training shifts the proportion of energy derived from fat oxidation to carbohydrate-derived energy.     

Influence of training on the response to exercise of adrenocorticotropin and growth hormone plasma concentrations in human swimmers

The aim of the present study was to evaluate the response of adrenocorticotropin ([ACTH]) and growth hormone ([GH]) concentrations to a typical aerobic swimming set during a training season. Nine top-level male endurance swimmers (age range 17–23 years) were tested during three training sessions occurring 6, 12 and 18 weeks after the beginning of the season. During each session, after a standard warm-up, the swimmers performed a training set of 15 × 200-m freestyle, with 20 s of rest between repetitions, at a predetermined individual speed. Blood samples were collected before warm-up and at the end of the training set. A few days before each session, the individual swimming velocity corresponding to the 4 mmol · l⁻¹ blood lactate concentration (v ₄) was assessed as a standard of aerobic performance. Aerobic training affected v ₄ levels, which were highest 18 weeks after the beginning of the season; at the same time, while [ACTH] response was attenuated, [GH] response was enhanced. These results could be considered as adaptations to the exercise intensity. In our training programme, these adaptations seemed to have occurred between the 12th and 18th weeks of the training season. Accepted: 21 April 1998     

Fungal content of air samples from some asthmatic childrens’ homes in Mexico City

Fungal particles can be considered a potential risk factor in children causing asthma, rhinitis, and allergy. However, a direct relationship between mold exposure and respiratory symptoms is difficult to establish, particularly if volumetric results are not well documented, as is often the case in Mexico. In order to assess mold exposure in some asthmatic childrens’ homes, eight asthmatic children were selected. For each child, lung function was measured by spirometry and the flow expiratory volume drop in the first second (FEV₁) as well as the CVF were estimated at 5, 10 and 15 min, after a running period on a treadmill. Exercise induced asthma (EIA) was defined as a FEV₁ drop <10% or FEV₁/CVF drop >10%. Atopy was estimated by skin testing of allergen extracts. Each room was volumetrically sampled using Burkard Personal samplers, every week for a month and with different degrees of activity. Fungal composition was mostly dominated by allergenic molds, spores smaller than 10 μm and non-seasonal molds. Concentrations ranged from 0 to 2087 CFU/m³ and 102 553–29 522 200 spores/m³, being significantly higher in indoor air, but the differences between rooms or weeks were not significant, either for CFUs (P>0.27) or for total particles (P>0.80). In general, mold counts were dominated byPenicillium spp. andCladosporium spp. especiallyP. aurantiogriseum andC. cladosporioides. We observed that the median concentration values were in general higher for children with exercise induced asthma (EIA). But the differences were significant only for EIA and degree, of asthma particularly for total (P=0.038), mycotoxin producers (P<0.009), seasonal molds (P<0.006) andPenicillium spp. (P=0.012). Total spore counts showed the highest median values in children without EIA, moderate asthma degree and no atopy. Significant differences were found for almost all spore, type groupings when comparing the presence of EIA (P<0.05) or asthma degree categories (P<0.030), but no differences were observed for atopy (P>0.21). We conclude that respiratory symptoms as described by EIA, asthma severity and atopy may give a good correlation with fungal concentrations and especially comparisons based on their physical and chemical properties.     

Effect of exercise-induced hyperventilation on airway resistance and cycling endurance

The purpose of the present study was to investigate the effect of exercise induced hyperventilation and hypocapnia on airway resistance (R _aw), and to try to answer the question whether a reduction of R _aw is a mechanism contributing to the increase of endurance time associated with a reduction of exercise induced hyperventilation as for example has been observed after respiratory training. Eight healthy volunteers of both sexes participated in the study. Cycling endurance tests (CET) at 223 (SD 47) W, i.e. at 74 (SD 5)% of the subject's peak exercise intensity, breathing endurance tests and body plethysmograph measurements of pre- and postexercise R _aw were carried out before and after a 4-week period of respiratory training. In one of the two CET before the respiratory training CO₂ was added to the inspired air to keep its end-tidal concentration at 5.4% to avoid hyperventilatory hypocapnia (CO₂-test); the other test was the control. The pre-exercise values of specific expiratory R _aw were 8.1 (SD 2.8), 6.8 (SD 2.6) and 8.0 (SD 2.1) cm H₂O · s and the postexercise values were 8.5 (SD 2.6), 7.4 (SD 1.9) and 8.0 (SD 2.7) cm H₂O · s for control CET, CO₂-CET and CET after respiratory training, respectively, all differences between these tests being nonsignificant. The respiratory training significantly increased the respiratory endurance time during breathing of 70% of maximal voluntary ventilation from 5.8 (SD 2.9) min to 26.7 (SD 12.5) min. Mean values of the cycling endurance time (t _cend) were 22.7 (SD 6.5) min in the control, 19.4 (SD 5.4) min in the CO₂-test and 18.4 (SD 6.0) min after respiratory training. Mean values of ventilation ( _E) during the last 3␣min of CET were 123 (SD 35.8) l · min⁻¹ in the control, 133.5 (SD 35.1) l · min⁻¹ in the CO₂-test and 130.9 (SD 29.1) l · min⁻¹ after respiratory training. In fact, six subjects ventilated more and cycled for a shorter time, whereas two subjects ventilated less and cycled for a longer time after the respiratory training than in the control CET. In general, the subjects cycled longer the lower the _E, if all three CET are compared. It is concluded that R _aw measured immediately after exercise is independent of exercise-induced hyperventilation and hypocapnia and is probably not involved in limiting t _cend, and that t _cend at a given exercise intensity is shorter when _E is higher, no matter whether the higher _E occurs before or after respiratory training or after CO₂ inhalation. Accepted: 11 September 1996     

Decreased pulmonary diffusing capacity of divers over a 6-year period

Non-smoking, male, professional firemen divers (n = 15) underwent two pulmonary function tests (PFT) separated by 6 years. Measured data were compared to European Coal Steel Community recommended reference values to permit cross-sectional and then longitudinal study. Higher vital capacity (VC; P < 0.01) and forced expiratory volume in 1 s (FEV₁; P < 0.05), and lower maximal mid-expiratory flow (MMEF) coefficient with VC (MMEF/VC; P < 0.05) were observed in both PFT. Diver's pulmonary diffusing capacity (DL_CO) and the coefficient with alveolar volume (DL_CO/V _A) showed significantly (P < 0.001) different evolution profiles than those expected from predicted values. In divers, DL_CO and DL_CO/V _A decreased from 104.0% to 91.4% and from 106.4% to 91.5% of predicted values respectively. Changes in DL_CO and DL_CO/V _A correlated positively with the initial measurement of DL_CO (r = 0.67, P < 0.01) and DL_CO/V _A (r = 0.74, P < 0.01) respectively, whereas no correlation between changes in pulmonary gas transfer function and age or diving history parameters was found. Thus, it is suggested from our observations that hyperbaric atmosphere exposure increases the effects of aging on pulmonary diffusing capacity and that pulmonary gas transfer function should be regularly tested in professional and recreational divers. Accepted: 22 February 1997     

Respiratory symptoms and lung function in taxi drivers and manual workers

The aim of this study, was to determine the prevalence of some respiratory symptoms and possible diseases among taxi drivers and manual workers. This prospective study was performed on 165 Pakistani male drivers, (mean age: 34.5±7.8 years) and 165 Pakistani male manual workers not exposed to dust or fumes, without occupational exposure to driving employed in the Water and Electricity Department and recruited as controls (mean age: 34.6±7.6 years and mean height and weight 169.8±6.0 cm and 71.9±10.9 kg). The data on chronic respiratory symptoms showed that taxi drivers had higher prevalence of symptoms than manual workers, being significantly greater for asthma (RR=1.72; 95% CI=1.00–2.88,P=0.037); allergic rhinitis (RR=2.41; 95% CI=1.46–3.94,P=0.0006); dyspnea (RR=2.13; 95% CI=1.22–3.71,P=0.009); and nasal catarrh (RR=2.19; 95% CI=1.22–3.91,P=0.0106). Thirty percent of taxi drivers and 27% of manual workers were smokers, there was no significant differences in the prevalence of chronic respiratory symptoms between smokers and non-smokers. Lung function parameters in the taxi drivers were significantly lower than in manual workers group (P<0.0001) except PEF parameter. When comparing the measured mean values of lung function parameters in the drivers among smokers and nonsmokers, there was no significant differences between smokers and nonsmokers. Also, a comparison of ventilatory capacity of paired predicted values with measured normal values showed statistically significant differences between predicted and measured values for taxi drivers and manual workers for FVC, FEV₁, FEF_25–75 and PEF parameters except for FEV₁/FVC test in manual workers. In conclusion, the results of the present study provide evidence regarding effects of such as carbon monoxide, nitrogen dioxide, sulfur dioxide and gases exposures on taxi drivers and long-term driving, which may be associated with the development of chronic respiratory symptoms and lung function impairment.     

Exercise performance and magnetic resonance imaging-determined thigh muscle volume in children

This study examined the relationships between thigh muscle volume (TMV) and aerobic and anaerobic performance in children. A total of 32 children, 16 boys and 16 girls, aged 9.9 (0.3) years completed a treadmill running test to exhaustion for the determination of peak oxygen uptake (peak V˙O₂) and a Wingate Anaerobic Test (WAnT) for the determination of peak power (PP) and mean power (MP). The volume of the right thigh muscle was determined using magnetic resonance imaging. TMV was not significantly different in boys and girls [2.39 (0.29) l vs 2.18 (0.38) l, P > 0.05]. Peak V˙O₂ and MP were significantly higher in boys than girls (P < 0.01) whether expressed in absolute, mass-related or allometrically scaled terms. Absolute PP was not significantly different in boys and girls but mass-related and allometrically scaled values were higher in boys (P < 0.01). TMV was correlated with absolute peak V˙O₂, PP and MP in both sexes (r = 0.52–0.89, P < 0.01). In boys, mass-related PP was correlated with TMV (r =0.53, P < 0.01), and in girls mass-related peak V˙O₂ was correlated with TMV (r = −0.61, P < 0.01). However, in neither sex were allometrically scaled peak V˙O₂, PP or MP correlated with TMV (P > 0.05). There were no significant differences between boys and girls in terms of peak V˙O₂, PP or MP when expressed in a ratio to TMV or allometrically scaled TMV. In conclusion, this study has demonstrated that, when body size is appropriately accounted for using allometric scaling, TMV is unrelated to indices of aerobic and anaerobic power in 10-year-old children. Furthermore, there appear to be no qualitative differences in the muscle function of boys and girls in respect of aerobic and anaerobic function. Accepted: 4 February 1997     

Sequential analysis of surfactant,lung function and inflammation in cystic fibrosis patients

Background

In a cross-sectional analysis of cystic fibrosis (CF) patients with mild lung disease, reduced surfactant activity was correlated to increased neutrophilic airway inflammation, but not to lung function. So far, longitudinal measurements of surfactant function in CF patients are lacking and it remains unclear how these alterations relate to the progression of airway inflammation as well as decline in pulmonary function over time.

Methods

As part of the BEAT trial, a longitudinal study to assess the course of airway inflammation in CF, we studied lung function, surfactant function and endobronchial inflammation using bronchoalveolar lavage fluid from 20 CF patients with normal pulmonary function (median FEV₁ 94% of predicted) at three times over a three year period.

Results

There was a progressive loss of surfactant function, assessed as minimal surface tension. The decline in surfactant function was negatively correlated to an increase in neutrophilic inflammation and a decrease in lung function, assessed by FEV₁, MEF_75/25%VC, and MEF_25%VC. The concentrations of the surfactant specific proteins A, C and D did not change, whereas SP-B increased during this time period.

Conclusion

Our findings suggest a link between loss of surfactant function driven by progressive airway inflammation and loss of small airway function in CF patients with limited lung disease.     

Lysophosphatidic acid and apolipoprotein A1 predict increased risk of developing World Trade Center-lung injury: a nested case-control study

Abstract

Rationale: Metabolic syndrome, inflammatory and vascular injury markers measured in serum after World Trade Center (WTC) exposures predict abnormal FEV₁. We hypothesized that elevated LPA levels predict FEV₁?<?LLN.

Methods: Nested case-control study of WTC-exposed firefighters. Cases had FEV₁?<?LLN. Controls derived from the baseline cohort. Demographics, pulmonary function, serum lipids, LPA and ApoA1 were measured.

Results: LPA and ApoA1 levels were higher in cases than controls and predictive of case status. LPA increased the odds by 13% while ApoA1 increased the odds by 29% of an FEV₁?<?LLN in a multivariable model.

Conclusions: Elevated LPA and ApoA1 are predictive of a significantly increased risk of developing an FEV₁?<?LLN.     

慢性阻塞性肺疾病不同表型患者CAT评分与肺功能及预后的相关性分析

摘要 目的：探讨慢性阻塞性肺疾病（chronic obstructive pulmonary disease,COPD）不同表型评估测试问卷（COPD assessment test,CAT）评分与肺功能及预后的关系。方法：收集361例COPD患者临床资料、CAT评分、肺功能检查结果及肺外合并症、肺内并发症等情况,按临床表型分为肺气肿组（n=200）和支气管炎组（n=161）,分析肺气肿组200例和支气管炎组161例COPD患者CAT评分与肺功能及预后的关系。结果：肺气肿组CAT评分高于支气管炎组（P<0.05）,一秒用力呼气容积（FEV₁）占预计值百分比（FEV₁%）、FEV₁/用力肺活量（FVC）低于支气管炎组（P<0.05）,吸气分数（IC/TLC）低于支气管炎组,残总比（RV/TLC）高于支气管炎组（P<0.05）;肺气肿组肺间质性病变、肺动脉高压发生率均高于支气管炎组（P<0.05）;支气管炎、肺气肿组CAT评分均与FEV₁%、FEV₁/FVC、IC/TLC呈负相关（P<0.05）,与RV/TLC呈正相关（P<0.05）,肺气肿各参数相关度更高（P<0.05）;肺气肿组不同CAT评分患者肺间质性病变、肺动脉高压发生率比较差异有统计学意义（P<0.05）,支气管炎组不同CAT评分肺动脉高压发生率比较差异有统计学意义（P<0.05）,随CAT评分的升高,肺气肿组肺间质性病变、肺动脉高压发生率上升,支气管炎组肺动脉高压发生率上升。结论： COPD肺气肿表型CAT评分较支气管炎表型高,肺功能降低更明显,呈现肺过度通气,气流受限特点,更易并发肺间质纤维化、肺动脉高压,且与CAT评分变化密切相关。     

KINEMATIC VARIABLES AND BLOOD ACID-BASE STATUS IN THE ANALYSIS OF COLLEGIATE SWIMMERS’ ANAEROBIC CAPACITY

Short duration repeated maximal efforts are often used in swimming training to improve lactate tolerance, which gives swimmers the ability to maintain a high work rate for a longer period of time. The aim of the study was to examine the kinematics of swimming and its relation to the changes in blood acid-base status and potassium level. Seven collegiate swimmers, with at least 6 years of training experience, volunteered to participate in the study. The test consisted of 8 x 25 m front crawl performed with maximum effort. The rest period between repetitions was set to five seconds. Blood samples were taken from the fingertip at rest, after warm-up and in the 3rd minute after completion of the test. The swimming was recorded with a video recorder, for later analysis of time, velocity and technique (stroke index). Based on the swimming velocity results, the obtained curve can be divided into rapid decrease of velocity and relatively stable velocities. The breaking point of repetition in swimming velocity was assumed as the swimming velocity threshold and it was highly correlated with the decrease of the blood acid-base status (pH r=0.82, BE r=0.87, HCO₃ ^- r=0.76; p<0.05 in all cases). There was no correlation between stroke index or fatigue index and blood acid-base status. Analysis of the swimming speed in the 8 x 25 m test seems to be helpful in evaluation of lactate tolerance (anaerobic capacity) in collegiate swimmers.     

Enhancement of exercise endurance capacity by fermented deer antler in BALB/c mice

To investigate the activity of fermented deer antler on exercise endurance capacity, we evaluated endurance capacity in five-week-old male BALB/c mice by administering the fermented deer antler extract (FA) or the non-fermented deer antler extract (NFA) and then subjected the mice to exercise in the form of swimming. The mice administered 500?mg/kg/day of FA showed a significant increase in swimming time compared with mice administered placebo (16.55?min vs. 21.64?min, P?<?0.05). Serum lactate dehydrogenase (LDH), the marker of the liver and muscle damage, was significantly lower in FA groups. However, NFA groups did not show significantly different swimming time or serum LDH from that of the control group. Moreover, the FA-500 group had significantly higher hepatic superoxide dismutase (SOD) activity after forced swimming than the control and NFA groups (P?<?0.05). These findings suggest that fermentation may increase the exercise endurance capacity of the deer antler.     

Genome-Wide Joint Meta-Analysis of SNP and SNP-by-Smoking Interaction Identifies Novel Loci for Pulmonary Function

Genome-wide association studies have identified numerous genetic loci for spirometic measures of pulmonary function, forced expiratory volume in one second (FEV₁), and its ratio to forced vital capacity (FEV₁/FVC). Given that cigarette smoking adversely affects pulmonary function, we conducted genome-wide joint meta-analyses (JMA) of single nucleotide polymorphism (SNP) and SNP-by-smoking (ever-smoking or pack-years) associations on FEV₁ and FEV₁/FVC across 19 studies (total N = 50,047). We identified three novel loci not previously associated with pulmonary function. SNPs in or near DNER (smallest P _JMA =5.00×10⁻¹¹), HLA-DQB1 and HLA-DQA2 (smallest P _JMA =4.35×10⁻⁹), and KCNJ2 and SOX9 (smallest P _JMA =1.28×10⁻⁸) were associated with FEV₁/FVC or FEV₁ in meta-analysis models including SNP main effects, smoking main effects, and SNP-by-smoking (ever-smoking or pack-years) interaction. The HLA region has been widely implicated for autoimmune and lung phenotypes, unlike the other novel loci, which have not been widely implicated. We evaluated DNER, KCNJ2, and SOX9 and found them to be expressed in human lung tissue. DNER and SOX9 further showed evidence of differential expression in human airway epithelium in smokers compared to non-smokers. Our findings demonstrated that joint testing of SNP and SNP-by-environment interaction identified novel loci associated with complex traits that are missed when considering only the genetic main effects.     

胸部肿瘤患者放疗中肺功能指标的变化及放射性肺炎的影响因素分析

目的:研究胸部肿瘤患者放疗中肺功能指标的变化并分析放射性肺炎的影响因素。方法:将2018年3月至2019年3月于我院接受放疗的胸部肿瘤患者100例记为观察对象,按照是否发生放射性肺炎分为肺炎组28例与无肺炎组72例。分别比较两组的临床资料、放疗前后肺功能及放疗参数,并采用多因素Logistic回归分析放射性肺炎的影响因素。结果:放疗后两组第1秒用力呼气容积(FEV_1)、FEV_1/用力肺活量(FVC)、一氧化碳弥散量(DLCO)均高于放疗前,且肺炎组放疗前、后FEV_1、FEV_1/FVC、DLCO均低于无肺炎组(均P0.05)。两组年龄、肿瘤类型、化疗史、美国东部肿瘤合作组(ECOG)评分、放疗靶区比较差异有统计学意义(均P0.05)。肺炎组计划靶区(PTV)、受到一定剂量以上照射的肺体积占全肺总体积的百分数(V_(dose))、平均肺计量(MLD)、正常组织并发症概率(NTCP)、总射野数高于无肺炎组(均P0.05)。经多因素Logistic回归分析可得:胸部肿瘤放疗患者放射性肺炎的独立危险因素有肺癌、化疗史、ECOG评分为2分、放疗靶区以肺野为主、PTV、MLD、V_(dose)、NTCP、总射野数、FEV_1、FEV_1/FVC(均P0.05)。结论:放疗可有效改善胸部肿瘤患者的肺功能,其中肺癌、化疗史、ECOG评分为2分、放疗靶区以肺野为主以及PTV、MLD、V_(dose)、NTCP、总射野数、FEV_1、FEV_1/FVC是放射性肺炎的影响因素。     

Gene promoter methylation is associated with lung function in the elderly: The normative aging study

Lung function is a strong predictor of mortality. While inflammatory markers have been associated with lung function decrease, pathways are still poorly understood and epigenetic changes may participate in lung function decline mechanisms. We studied the cross-sectional association between DNA methylation in nine inflammatory genes and lung function in a cohort of 756 elderly men living in the metropolitan area of Boston. Participants donated a blood sample for DNA methylation analysis and underwent spirometry at each visit every 3 to 5 y from 1999–2006. We used separate multivariate mixed effects regression models to study the association between each lung function measurement and DNA methylation within each gene. Decreased CRAT, F3 and TLR2 methylation was significantly associated with lower lung function. One interquartile range (IQR) decrease in DNA methylation was associated with lower forced vital capacity (FVC) and forced expiratory volume in one second (FEV₁), respectively by 2.94% (p < 10^?4) and 2.47% (p < 10^?3) for F3, and by 2.10% (p < 10^?2) and 2.42% (p < 10^?3) for TLR2. Decreased IFNγ and IL6 methylation was significantly associated with better lung function. One IQR decrease in DNA methylation was associated with higher FEV₁ by 1.75% (p = 0.02) and 1.67% (p = 0.05) for IFNγ and IL6, respectively. These data demonstrate that DNA methylation may be part of the biological processes underlying the lung function decline and that IFNγ and IL6 may have ambivalent roles through activation of negative feedback.