Comparison of pulmonary function between children living in rural and urban areas in northern Nigeria

Children in northern Nigeria and elsewhere in the hot, arid western Sahel, are at risk of having their lung function compromised by a variety of factors, including undernutrition, environmental factors (e.g. airborne pollutants such as dust and smoke from wood fires), chronic upper-respiratory tract infections, and low socioeconomic class. We were interested in using spirometry to compare the pulmonary function of Nigerian children and adolescents aged 6-18 years who were living in urban and rural settings with the corresponding standards for African-American children. A total of 183 boys and girls in the rural village of Sabon Fobur on the Jos Plateau and another 128 boys and girls in the city of Jos were tested to determine their forced vital capacity (FVC), FVC at 1 s (FVC1), and peak expiratory flow (PEF). The nutritional status of the subjects was determined by measuring the body mass index (BMI), triceps skin-fold thickness, and mid-arm circumference, and fat-free mass (FFM) and fat mass (FM) by bioelectrical impedance analysis. According to the results of anthropometry, the subjects in Sabon Fobur and Jos were lean but generally adequately nourished. The mean FVC, FVC1 and PEF values for the rural males were 1.851,1.761, and 3.521, and for the urban males they were 1.971,1.791, and 3.471, respectively. The corresponding values for the rural females were 1.791,1.701, and 3.371, and for the urban females they were 1.761,1.671, and 3.091. These values were approximately 100 per cent of the corresponding values for African-American children. In general, strong correlations were found between each of the three lung function parameters and age, weight, height (only for the males), BMI, MAC, and FFM. These results show that: (1) the lung function of Nigerian children and adolescents living in either rural or urban areas were similar and compared favorably with African-American standards, and (2) weight was as important as height in determining pulmonary function. The inclusion of FFM as an explanatory variable did notfurther increase the accuracy of the prediction, even in a population where malnutrition may be prevalent. Therefore, we conclude that measurements of height and weight are all that are required for the assessment of lung function using spirometry in Nigerian children.     

Body composition and respiratory function in healthy non-obese children

BACKGROUND: The purpose of the present paper was to evaluate the role that body composition plays in lung function, among healthy children and adolescents. METHODS: Cross-sectional study was undertaken using sex- and age-stratified sampling among healthy children and adolescents aged 6-18 years. Spirometry was performed on every child who fulfilled inclusion criteria. Fat mass (FM) and fat-free mass (FFM) were calculated from triceps skinfold thickness and arm circumference. Multiple logistic regression was used to obtain adjusted prevalence odds ratios (OR) and 95% confidence intervals (95%CI) between low pulmonary function (PF) of schoolchildren and body composition expressed in FM and FFM. Calculations of OR imply that the outcome is dichotomous (low PF/normal PF), therefore those children who had parameters of pulmonary function below the 25th percentile were classed as cases and the rest of the subjects were considered as controls. RESULTS: A total of 2408 children were included; 1270 (53%) of them were male and 1138 (47%), female. Among boys the increase of FFM was associated with an increase of forced expiratory volume in 1 s (FEV1). Among girls the increase of FFM was associated with an increase of FEV1, forced vital capacity, and peak expiratory flow. The increase in FM was associated with a decrease of spirometric parameters in both genders, with a stronger effect among boys. CONCLUSIONS: The present study confirms the negative effect of body fat on the PF of children and adolescents, even though obese subjects were excluded. The effect is different between boys and girls.     

Impact of acute chest syndrome on lung function of children with sickle cell disease

OBJECTIVE: To test the hypothesis that children with sickle cell disease (SCD) who experienced an acute chest syndrome (ACS) hospitalization episode would have worse lung function than children with SCD without ACS episodes. STUDY DESIGN: Forced expiratory volume in 1 second (FEV(1)); forced vital capacity (FVC); FEV(1)/FVC ratio; peak expiratory flow (PEF); forced expiratory flow at 25% (FEF(25)), 50% (FEF(50)), and 75% (FEF(75)) of FVC; airway resistance (Raw); and lung volumes were compared in 20 children with ACS and 20 aged-matched children without ACS (median age, 11 years; range, 6 to 16 years). Fourteen age-matched pairs were assessed before and after bronchodilator use. RESULTS: The mean Raw (P = .03), TLC (P = .01), and RV (P = .003) were significantly higher in the group with ACS than in the group without ACS. There were no significant differences in the changes in lung function test results in response to bronchodilator administration between the 2 groups, but the children with ACS had a lower FEF(25) (P = .04) and FEF(75) (P = .03) pre-bronchodilator use and a lower mean FEV(1)/FVC ratio (P = .03) and FEF(75) (P = .03) post-bronchodilator use. CONCLUSIONS: Children with SCD who experienced an ACS hospitalization episode had significant differences in lung function compared with those who did not experience ACS episodes. Our results are compatible with the hypothesis that ACS episodes predispose children to increased airway obstruction.     

Bioelectrical impedance analysis of the body composition of children and adolescents with sickle cell disease

OBJECTIVES: To examine the body composition of children and adolescents with sickle cell disease (SCD) using bioelectrical impedance analysis and to determine if the impedance parameters resistance, reactance, and phase angle are able to distinguish between subjects with SCD and age- and gender matched controls. STUDY DESIGN: Total body resistance and reactance were obtained for a total of 53 subjects with SCD (27 male and 26 female) between 10 and 18 years of age and 49 control subjects (23 male and 26 female). The fat-free mass, body cell mass, phase angle, and capacitance were also determined. Group comparisons were made using the 2-sample t test. RESULTS: Male subjects with SCD had significantly lower fat-free mass (37.5 +/- 8.8 vs 43.9 +/- 12.3 kg, P =.04), body cell mass (17.4 +/- 4.3 vs 21.7 +/- 5.8 kg,P =.005), and body fat (3.7 +/- 2.6 vs 6.6 +/- 4.7 kg, P =.008) compared with controls. No significant differences in any body composition components were found for the female subjects. Both male and female subjects had significantly lower phase angle measurements (P <.001 and.006, respectively) than their respective controls, indicating possible alterations in cell membrane properties because of an imbalance in membrane composition or function. CONCLUSIONS: Bioelectrical impedance analysis can be used to determine body composition differences in children with SCD. The phase angle may provide a useful method to monitor the efficacy of therapeutic interventions in patients with SCD.     

Changes in dynamic respiratory volumes in obese children and adolescents related to weight loss and sex]

Obesity is associated with various alterations in lung function in adults. These alterations appear to be proportional to the degree of EP and the beneficial effect of weight loss on respiratory function has been reported. Therefore, in 35 children and adolescents affected by essential obesity of medium-severe degree, we have evaluated the following parameters: FVC (forced vital capacity), PEF (peak expiratory flow), FEV1 (forced expiratory volume), FEV75, FEV50, FEV25, before and after six months of dieting. Twelve subjects (34%) showed at least a pathologic value of PEF and/or FEV50 before dieting. All the female patients normalized their parameters after six months of dieting, whilst 5 out of 7 males still showed pathologic respiratory indexes, although a similar weight loss was obtained in the two groups of patients. Our study enhances the presence of respiratory functions derangements in a significant percentage of children with medium-severe degree of obesity. A careful monitoring of these subjects is therefore necessary, in order to prevent further progression of the lung function damage. After dieting the pulmonary function improved in female patients only, suggesting that factors other than the EP are involved in the pathogenesis of the respiratory alterations.     

Long-term evaluation of effectiveness for selected chest physiotherapy methods used in the treatment of cystic fibrosis

The aim of this study was a long-term analysis of efficiency of selected chest physiotherapy methods used in the treatment of children with CF. We studied 80 CF children (39 male, 41 female), mean age ll.44yrs (range 6-18 yrs), with varying degree of severity. The study was carried out during 7 months. The subjects were assigned into four groups. Group had conventional postural drainage with clapping (33 patients, age x-11.12), group II- conventional postural drainage with clapping and vibration (16 patients, age x-11.25), group III - active cycle of breathing technique (18 patients, age x-10.5), group IV Flutter (13 patients, age x- 13.77). All patients had three physiotherapy sessions a day. We measured: FEV1 FVC, FEV1/FVC, MEF 25-7 %, PEF, before and after the study. In the group with postural drainage with clapping we observed statistically significant decrease of all studied parameters. The use of additional vibration improved FVC and FEV1/FVC values but the improvement was not statistically significant. FEV1, PEF and MEF 25 %, were significantly lower. Statistically significant increase of all studied parameters was observed in patients using ACBT. In the Flutter group we observed increase of FEV1 and FVC values. The other parameters were decreased without statistical significance. Analysis of variance of pulmonary function parameters between groups demonstrated significant differences in FEV1, PEF and MEF 50% between postural drainage with vibration and active cycle of breathing technique. Significant differences have also been shown in PEF between postural drainage with clapping and active cycle of breathing technique. We conclude that: 1) postural drainage with clapping is less effective compared with the other studied techniques.2) The use of additional vibration did not bring about improvement of drainage efficiency. Vibration increased airways resistance. 3) Flatter device may be less effective in peripheral airways clearance.     

Bioelectrical impedance analysis of the body composition of Nigerian children with sickle cell disease

We used bioelectrical impedance (BIA) to investigate the body composition of children with sickle cell disease (SCD) in northern Nigeria. A total of 48 children with SCD and 51 controls between 3 and 20 years of age were studied. A significant difference was found in the weights of male subjects over the age of 10 years compared to controls (p = 0.01), but not in height. Significant differences were also observed for SCD males in the 10-18-year-old age range in body mass index (p = 0.001), fat free mass (p = 0.001), per cent fat free mass, (p = 0.02), body fat (p = 0.02), and per cent body fat (p = 0.02). No significant differences in any of these parameters between SCD subjects and controls were obtained for males under the age of 10 years. There were no significant differences in the height, weight, body mass index, or fat free mass for female SCD subjects compared to controls over the age range we studied. However, there were significant differences in the per cent fat free mass (p = 0.006), body fat (p = 0.025), and per cent body fat (p = 0.01) for female SCD subjects over the age of 10 years compared to controls. In addition to documenting differences in the body composition of adolescent boys with sickle cell disease in Nigeria, this study also demonstrated the feasibility of using bioelectrical impedance to analyse the body composition of individuals under the hot, arid conditions which prevail in sub-Saharan Africa.     

节段性肺炎支原体肺炎患儿肺功能检测的临床意义

目的探讨节段性肺炎支原体肺炎(SMPP)患儿肺功能变化及临床意义。方法分别测定55例SMPP患儿急性期和恢复期的肺功能,包括FVC、FEV1、FEV1/FVC、PEF、FEF25%、FEF50%、FEF75%、FEF25%-75%。结果 55例SMPP患儿急性期FVC、FEV1、FEV1/FVC、PEF、FEF25%、FEF50%、FEF75%及FEF25%-75%均有不同程度降低,以FEF25%、FEF50%、FEF75%和FEF25%-75%降低较为明显。恢复期各项指标均有明显改善,两组比较差异有统计学意义(P<0.05)。多部位病变SMPP患儿急性期FVC和FEV1较单个叶段病变患儿下降明显(P<0.05)。结论 SMPP患儿急性期大、小气道功能均有不同程度损伤,多表现为限制性通气障碍,小气道功能受损更明显;恢复期肺功能明显好转。多叶段病变大气道功能受损较单个叶段病变严重。     

昆明市5~14岁儿童肺通气功能参数实测值与Zap

目的 研究昆明市5~14岁健康儿童肺通气功能主要参数实测值占Zapletal方程式预计值的百分比,为临床准确判断肺通气功能提供依据。方法 纳入昆明市5~14岁健康儿童702名,其中男352名,女350名。采用Jaeger肺功能仪测定用力肺活量（FVC）、第1秒用力呼气容积（FEV1）、1秒率（FEV1/FVC）、最大中期呼气流量（MMEF）、用力呼气25%肺活量时瞬时流量（FEF25）、用力呼气50%肺活量时瞬时流量（FEF50）、用力呼气75%肺活量时瞬时流量（FEF75）、最高呼气流量（PEF）、每分钟最大通气量（MVV）,共9项指标,以肺功能仪中提供的Zalpetal预计值公式得出的数值作为所选择儿童的预计值,计算其实测值占预计值的百分比。结果 在702名儿童中,肺通气功能主要参数PEF、FVC、FEV1、FEV1/FVC、MVV实测值占预计值百分比的均值分别波动于102%~114%、94%~108%、98%~113%、98%~107%、141%~183%。气道流速指标功能参数FEF25、FEF50、FEF75、MMEF实测值占预计值百分比分别波动于98%~116%、85%~102%、71%~98%、83%~100%。各参数PEF、FVC、FEV1、FEV1/FVC、MVV、FEF25、FEF50、FEF75、MMEF实测值占Zapletal方程式预计值百分比的下限分别为88.2%、88.4%、92.0%、94.4%、118.5%、82.9%、70.0%、62.1%、70.1%。结论 昆明地区5~14岁健康儿童肺通气功能参数水平与Zapletal方程式提供的正常值存在一定差异;该地区此年龄段的健康儿童肺通气功能参数PEF、FVC、FEV、FEV1/FVC、MVV、FEF25、FEF50、FEF75、MMEF实测值占预计值百分比的正常参考值下限可考虑分别设为88.2%、88.4%、92.0%、94.4%、118.5%、82.9%、70.0%、62.1%、70.1%。     

昆明市5~14岁儿童肺通气功能参数实测值与Zap

目的 研究昆明市5~14岁健康儿童肺通气功能主要参数实测值占Zapletal方程式预计值的百分比,为临床准确判断肺通气功能提供依据。方法 纳入昆明市5~14岁健康儿童702名,其中男352名,女350名。采用Jaeger肺功能仪测定用力肺活量（FVC）、第1秒用力呼气容积（FEV1）、1秒率（FEV1/FVC）、最大中期呼气流量（MMEF）、用力呼气25%肺活量时瞬时流量（FEF25）、用力呼气50%肺活量时瞬时流量（FEF50）、用力呼气75%肺活量时瞬时流量（FEF75）、最高呼气流量（PEF）、每分钟最大通气量（MVV）,共9项指标,以肺功能仪中提供的Zalpetal预计值公式得出的数值作为所选择儿童的预计值,计算其实测值占预计值的百分比。结果 在702名儿童中,肺通气功能主要参数PEF、FVC、FEV1、FEV1/FVC、MVV实测值占预计值百分比的均值分别波动于102%~114%、94%~108%、98%~113%、98%~107%、141%~183%。气道流速指标功能参数FEF25、FEF50、FEF75、MMEF实测值占预计值百分比分别波动于98%~116%、85%~102%、71%~98%、83%~100%。各参数PEF、FVC、FEV1、FEV1/FVC、MVV、FEF25、FEF50、FEF75、MMEF实测值占Zapletal方程式预计值百分比的下限分别为88.2%、88.4%、92.0%、94.4%、118.5%、82.9%、70.0%、62.1%、70.1%。结论 昆明地区5~14岁健康儿童肺通气功能参数水平与Zapletal方程式提供的正常值存在一定差异;该地区此年龄段的健康儿童肺通气功能参数PEF、FVC、FEV、FEV1/FVC、MVV、FEF25、FEF50、FEF75、MMEF实测值占预计值百分比的正常参考值下限可考虑分别设为88.2%、88.4%、92.0%、94.4%、118.5%、82.9%、70.0%、62.1%、70.1%。     

Pulmonary function test in transfusion-dependent β-thalassemia major patients: a pilot study

Lung involvement is one of known complications of thalassemia. The aim of this study was to determine predominant type of pulmonary dysfunction and its relationship to iron overload in β-thalassemia children. Fifty thalassemia major children with treatment of regular blood transfusion and desferrioxamine participated in the study. Thirty-three boys and 17 girls (median age 12.5 years) with β-thalassemia enrolled in the study. Other information including body mass index, hematocrit, and the number of years of blood transfusion were recorded. Serum ferritin level and hematocrit were 3346 ± 1667 mg/dL and 27.7 ± 2, respectively. Pulmonary function tests were performed in all subjects for detecting pulmonary dysfunction. Thirty-five patients (70%) with thalassemia had abnormal result of spirometry. Obstructive airway disease based on reduced forced expiratory volume in 1 second (FEV(1)) and FEV(1)/forced vital capacity (FVC) ratio <80% was detected in 4 patients (8%). Six patients (12%) showed restrictive pattern, as defined by a reduction FVC <80% and FEV(1)/FVC ratio ≥80%. In this study, small airway involvement based on presence of forced expiratory flow (FEF(25%-75%)) <60%, FEV(1)/FVC ratio >70%, and FVC >80% was detected in 25 subjects (50%). Decreased values of peak expiratory flow rate (PEF) were detected in 23 (46%) and low FEV(1) in 10 (20%) subjects. There was no significant correlation between abnormal pulmonary function test and serum ferritin level in children with thalassemia. This study showed small airway disease was predominant abnormality in thalassemia patients, although additional larger studies are needed to evaluate underlying mechanisms and validate these findings.     

Bioelectrical impedance analysis of the body composition of Nigerian children with calcium-deficiency rickets

Children with calcium-deficiency rickets experience increased urinary excretion of both essential and non-essential amino acids compared to non-rachitic children of the same age. Chronic wastage of amino acids into the urine could lead to a deficit in fat-free mass (FFM) in rachitic children. We therefore determined the FFM of children with calcium-deficiency rickets in northern Nigeria using bioelectrical impedance analysis. Because of the leg deformities present in the rachitic subjects, we calculated a 'corrected' height for each rachitic subject using the relationship between arm length and height in non-rachitic subjects over the same age range (r = 0.94). A total of 28 children (4 male and 24 female), 2-9 years of age with calcium-deficiency rickets and an equal number of age- and gender-matched controls were recruited into the study. Resistance and reactance measurements were obtained for all subjects and the total body water was calculated using age-specific equations. FFM was then calculated using age- and gender-specific hydration constants. No significant differences were found in the weights or FFM between the rachitic subjects and the controls (8.41 kg +/- 2.19 vs. 8.85 kg +/- 1.90, respectively). We conclude that chronic urinary wastage of amino acids by rachitic children does not result in a deficit in FFM.     

儿童右肺中叶综合征的肺功能变化及其意义

目的：探讨右肺中叶综合征患儿治疗前后的肺功能变化及其临床意义。方法：将30例儿童右肺中叶综合征住院患儿分成两组,≤4岁组患儿20例选用2600型肺功能仪,>4岁组患儿10例选用MIR型肺功能仪,分别在治疗前和治疗后做肺功能测定,比较其治疗前后的肺功能参数的变化。2600型肺功能仪测定的主要参数取75%潮气量与最高呼气流速之比(25/PF)和潮气量与最高潮气呼气流速之比(%V-PF)2个参数来反映0~4岁组患儿的肺功能变化,MIR型肺功能仪测定的主要参数取最大肺活量(FVC)、1秒率(FEV1)和最高呼气流速(PEF)共3个参数来反映>4岁组患儿的肺功能变化。结果：≤4岁组治疗前肺功能参数的测定值分别为25/PF=0.42±0.08,%V-PF=0.28±0.03;治疗后的肺功能参数的测定值为25/PF=0.58±0.12,%V-PF=0.39±0.06。两者治疗前后比较差异有显著性,t=4.21,3.82;均P<0.05。>4岁组治疗前肺功能参数的测定值分别为FVC=1.75±0.32,FEV1=1.36±0.52, PEF=2.56±0.78;治疗后的肺功能参数的测定值分别为FVC=2.37±0.78,FEV1=2.08±0.65, PEF=3.68±0.80。治疗前后比较,分别t=3.05, 2.98,3.12;均P<0.05。结论：右肺中叶综合征患儿治疗前后的肺功能变化是明显的,治疗后肺功能可恢复正常。［中国当代儿科杂志,2009,11（8）：669-671］     

重庆地区3～12岁儿童肺通气功能预计方程式的初步建立

目的　建立学龄前期及小学阶段学龄期儿童的肺通气功能参数预计方程式。方法　采用德国JAEGER公司MasterScreen Pead肺功能仪,于2017年4月至2018年9月对重庆地区主城两所幼儿园及小学的458名3～12岁儿童进行肺通气功能测定。采用SAS9.4统计软件包,通过单因素线性回归模型分析各已知及潜在的影响因素与各肺功能参数的相关性,以各肺功能指标实测值为因变量,以性别、年龄、身高、体重为自变量,通过多元逐步回归建立线性回归方程。将构建的方程式与文献中相应年龄段的肺功能预计方程式进行比较,采用相对预测误差平均值评价各公式的适用性。结果　对于学龄前期儿童,肺功能各指标［剩余25%肺活量时的用力呼气流量（MEF25）除外］均与月龄、身高、体重相关,性别与用力肺活量（FVC）、第0.5秒用力呼气容积（FEV0.5）、第1秒用力呼气容积（FEV1）、呼气峰流速（PEF）、MEF75、MEF50和最大通气量（MVV）相关。对于学龄期儿童,年龄、身高、体重与除呼气中段流速（MMEF）外的各肺功能指标均有显著相关性,性别与FVC、FEV1、FEV0.5/FVC、MEF50、MVV显著相关。预计公式模型比较后显示,该次构建的模型对该研究群体有较好的适用性。结论　年龄、身高和体重为影响学龄前期和学龄期儿童肺通气功能参数的主要变量,性别对学龄前期儿童肺功能参数的影响多于学龄期儿童,应根据不同年龄段建立各项肺通气功能指标的预计公式。该模型的构建可为3～12岁儿童肺通气功能相关参数的预测提供帮助。     

东北地区学龄期儿童肺通气功能预计方程式建立的前瞻性研究

目的 建立东北地区6~<16岁儿童肺通气功能参数的预计方程式。 方法 前瞻性选择辽宁、吉林和黑龙江三省健康儿童504名,其中男242名,女262名,采用德国耶格MasterScreen Pneumo肺功能仪测定其肺通气功能。以用力肺活量（forced vital capacity,FVC）、第１秒用力呼气容积（forced expiratory volume in one second,FEV₁）、一秒率（FEV₁/FVC）、外推容积（back-extrapolated volume,BEV）等10项参数实测值为因变量,以年龄、身高和体重为自变量,通过多元逐步回归建立不同性别儿童的回归方程。采用相对预测误差平均值评价预计方程式的适用性。 结果 9~<10岁和15~<16岁男童的身高、FVC和FEV₁高于女童,9~<10、10~<11、11~<12和13~<14岁男童的FEV₁/FVC低于女童（P<0.05）。相关性分析显示,除FEV₁/FVC和BEV/FVC外,其他参数均与年龄、身高和体重呈显著正相关（P<0.001）。进一步回归分析显示,年龄和身高是大部分参数的影响因素,而体重较少被纳入回归方程。与不同研究的预计方程式比较,该次构建的回归方程对该研究群体有较好的适用性。 结论 该研究建立了东北地区6~<16岁儿童肺通气功能主要参数的预计方程式,为临床上准确判定肺功能异常奠定基础。 引用格式:     

不同胸部影像学表现的肺炎支原体肺炎儿童的肺功能变化特征

目的 探讨不同胸部影像学改变的肺炎支原体肺炎（MPP）患儿肺功能异常的特点。方法 根据胸部影像学结果将确诊为MPP 的215 名患儿分为支气管肺炎组（125 例）、大叶性肺炎组（69 例）和间质性肺炎组（21 例）,比较3 组间肺功能检测指标用力肺活量（FVC）、第1 秒时间用力呼出气体容量（FEV1）、最高呼气流速（PEF）和最大呼气中段流速（MMEF 25%~75%）的差异。结果 支气管肺炎组患儿急性期PEF（实测值和实测值/ 预计值）明显低于其他两组患儿;大叶性肺炎组患儿急性期MMEF 25%~75% 显著低于其他两组;间质性肺炎组患儿急性期FVC 明显低于其他两组患儿。3 组患儿恢复期肺功能与急性期比较,除大叶性肺炎组患儿FEV1 无明显好转外,其他指标均明显改善。结论 胸部影像学为支气管肺炎改变的MPP 患儿主要表现为大气道功能受损;大叶性肺炎改变者以小气道功能受损更为明显;间质性肺炎改变患儿既有阻塞性通气功能障碍,又有限制性通气功能障碍。     

The effect of shoulder-girdle loading by a school bag on lung volumes in Chinese primary school children

BACKGROUND: Heavy loading of the spine may induce musculoskeletal problems in children. Local surveys reported frequent overloading of school bags carried by primary school children. The effect of an overweight school bag on the child's lung function has not been reported. AIMS: To investigate the effect of shoulder-girdle loading on forced expiratory lung volumes in primary school children and to compare this effect with that of an assumed kyphotic posture. STUDY DESIGN AND SUBJECTS: Forty-three primary school children, mean age 9.6 years underwent spirometry lung-function measurements, while adopting the following five conditions in random order: free standing; kyphotic standing; standing wearing a backpack weighing 10%, 20% and 30% of their body weight. OUTCOMES MEASURES: Forced expiratory volume in the first second (FEV1), forced vital capacity (FVC) and peak expiratory flow rate (PEF). RESULTS: There were no significant differences in FEV1 and FVC between free standing and the 10% body weight load. However, both FEV1 and FVC decreased significantly when the student adopted the kyphotic posture and when the load in the backpack was increased to 20% and 30% of body weight. CONCLUSIONS: This study demonstrates a restrictive effect on lung volumes when a school-bag load is heavier than 10% of a child's body weight. Our results also confirm the detrimental effect of a kyphotic posture on pulmonary mechanics and the necessity for health-care professionals to advocate proper postural advice to school children, teachers and parents.     

Effects of long-term nutritional rehabilitation on body composition and clinical status in malnourished children and adolescents with cystic fibrosis

Fourteen patients aged 4.9 to 21.5 years with cystic fibrosis and moderate to severe lung disease, malnutrition, or growth failure were given nocturnal supplemental feeding by gastrostomy tube. Mean follow-up was for 1.1 years (range 0.8 to 2.78 years). Patients were studied to observe the effect of nutritional support on body composition, growth, pulmonary function, and quality of life. A contemporary group of patients with CF was retrospectively pair matched to the study group. The supplemental feeding resulted in positive changes in body composition and in growth velocity. Weight, as a percentage of standard in the control group, declined by 3% over 1 year, whereas it increased by 2% in the treatment group (P less than 0.05). Pulmonary function, assessed as a percent of predicted FVC and FEV1, did not change significantly in the treatment group over 1.1 years, whereas FVC declined by 12% (P less than 0.01) and FEV1 declined by 13% (P less than 0.01) in the control group. There was a marked increase in patient ability to participate in activities of daily living, even in those patients in whom pulmonary function deteriorated during the study.     

Pulmonary function tests in beta thalassemia

To study pulmonary function tests (PFT) in multiple transfusion recipient thalassemics, PFTs were done for 30 thalassemics and 20 matched controls. Confirmed cases of thalassemia on regular transfusion therapy were the subject of study. Apart from history and physical examination of the thalassemics, serum ferritin estimation and spirometry were done. Parameters studied included lung volumes—functional residual capacity (FRC), forced vital capacity (FVC), residual volume (RV) and total lung capacity (TLC); and flow rates —forced expiratory volume in one second (FEV,), forced expiratory volume in 1 second/forced vital capacity (FEV,/FVC), peak expiratory flow 25–75 (PEF 25–75%) and peak expiratory flow rate (PEFR). Single breath carbon monoxide diffusing capacity (DLco) and arterial blood gas (ABG) were also analysed. The mean height and weight of thalassemics were below that of age matched controls. A restrictive abnormality in PFT was found in 86.6% cases. These patients were found to have a decrease in all the lung volumes namely FVC, FRC, RV and TLC with a proportional decrease in the flow rates, FEV1, PEF 25–75% and PEF with a normal (> 0.75) FEV1/FVC ratio. DLco was decreased in all the patients with restrictive lung disease and fall in DLco showed a good correlation (r = 0.7, P <. 001) with the severity of restrictive disease suggesting that some intrapulmonary pathology is likely to be responsible for the restrictive pattern. None of the cases had an obstructive or mixed pattern of pulmonary dysfunction. No correlation was found between severity of restrictive disease and the serum ferritin levels. A negative correlation with degree of hepatosplenomegaly was found. No correlation was found between severity of the defect and age, number of blood transfusions received and hemoglobin at the time of doing the test. To conclude, restrictive lung disease is the predominant abnormality in multi-transfused thalassemics, which is probably due to pulmonary parenchymal pathology. The abnormality of PFTs is not directly related to iron overload.     

A mathematical procedure for estimating the spatial relationships between lung function, somatic growth, and maturation

A mathematical procedure is described for examining growth velocity rates of lung function (FEV1) in relationship to somatic growth and maturation. This procedure uses a polynomial smoothing spline model to yield a fitted curve through the data and to estimate the process first derivatives (i.e. growth velocity curves). We demonstrate this technique using data from children and adolescents enrolled in the Tucson Epidemiological Study of Airway Obstructive Diseases. The study group consisted of 772 healthy normal subjects, aged 3 to 25 y. The results for the normal subjects (male and female) indicate that the growth velocity peak (GVP) of somatic growth leads the GVP of functional growth (FEV1) by approximately 7 and 11 mo for females and male subjects, respectively, and that the GVP of maturation lags behind that of functional growth (FEV1) by approximately 1 y (male and female subjects). In addition, the normal subjects' growth velocity curves for FVC and FEV1/FVC were examined. The FEV1/FVC ratio was consistently high, and its growth velocity was not significantly different than 0 over the age range studied. This suggests that in normal children, the GVP seen in FEV1 is primarily due to a GVP in vital capacity or lung vol, rather than to a direct effect on expiratory flow rates alone. From this study we concluded that the polynomial smoothing spline procedure can adequately model the inherently noisy pulmonary function data and additionally yield an accurate estimate of the process first derivative.