Lung function in Canadian Inuit: a follow-up study.

To assess the impact of acculturation on lung function, the forced vital capacity (FVC) and the 1-second forced expiratory volume (FEV1) of 341 Inuit at Igloolik, NWT were measured. The same observers had used the same equipment to test 196 subjects in 1970-71. Cross-sectional analysis suggested that, relative to the previous decade, younger subjects had larger lung volumes (with gains of about 10% in FVC and 5% in FEV1), while the elderly had smaller volumes (with losses of about 22% in FVC and 25% in FEV1). Longitudinal analysis confirmed an accelerating loss of lung function in the older subjects: from age 25 to 35 years men and women had a loss in FVC of 13 and 11 mL/yr respectively, whereas from age 45 to 55 years the corresponding figures were 70 and 38 mL/yr. Cigarette smoking had increased substantially among the Inuit over the decade: the proportion of males and females smoking rose from 64% to 81% and from 85% to 93% respectively. Daily cigarette consumption per smoker increased from 11.8 to 20.2 and from 7.4 to 12.0 among men and women respectively. Nevertheless, the main explanation for the shape of the ageing curve is the survival of a small cohort of elderly Inuit with advanced tuberculosis. With control of this disease future cohorts of the elderly will have better lung function.     

Relationship between respiratory muscle function and age, sex, and other factors

To investigate the effects of gender and age on respiratory muscle function, 160 healthy volunteers (80 males, 80 females) were divided into four age groups. Twenty-eight of the male subjects were smokers. After the subjects were familiarized with the experimental procedure, respiratory muscle strength, inspiratory muscle endurance, and spirometric function, including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC, tidal volume, breathing rate, and duty cycle, were measured. The respiratory muscle strength was indicated by the maximal static inspiratory and expiratory pressures (PImmax and PEmmax). Inspiratory muscle endurance was determined by the time the subject was able to sustain breathing against an inspiratory pressure load on a modified Nickerson-Keens device. The results showed that 1) except for inspiratory muscle endurance and FEV1/FVC, men had greater respiratory muscle and pulmonary functions than women, 2) respiratory muscle function and pulmonary function decreased with age, 3) smoking tended to lower duty cycle and FEV1/FVC and to enhance PE,mmax, and 4) inspiratory muscle endurance was greater in men who were physically active than in those who were sedentary. Therefore we conclude that there are sexual and age differences in respiratory muscle strength and pulmonary function and that smoking or physical activity may affect respiratory muscle function.     

Respiratory effects of non-tobacco cigarettes.

Data from the Tucson epidemiological study of airways obstructive disease on smoking of non-tobacco cigarettes such as marijuana were analysed to determine the effect of such smoking on respiratory symptoms and pulmonary function. Among adults aged under 40, 14% had smoked non-tobacco cigarettes at some time and 9% were current users. The prevalence of respiratory symptoms was increased in smokers of non-tobacco cigarettes. After tobacco smoking had been controlled for men who smoked non-tobacco cigarettes showed significant decreases in expiratory flow rates at low lung volumes and in the ratio of the forced expiratory volume in one second to the vital capacity. This effect on pulmonary function in male non-tobacco cigarette smokers was greater than the effect of tobacco cigarette smoking. These data suggest that non-tobacco cigarette smoking may be an important risk factor in young adults with respiratory symptoms or evidence of airways obstruction.     

Effects of pneumatic antishock garment inflation in normovolemic subjects

This study examines the effects of inflation of pneumatic antishock garments (PASG) in 10 normovolemic men (mean age 44 +/- 6 yr) undergoing diagnostic catheterization. Seven subjects had normal heart function and no evidence of coronary artery disease (CAD); three patients had CAD. High-fidelity multisensor catheters were employed to simultaneously record right and left heart pressures before PASG inflation and after inflation to 40, 70, and 100 mmHg. A thermal dilution catheter was used to obtain pulmonary capillary wedge pressure and cardiac output. Counterpressure increases greater than or equal to 40 mmHg were associated with significant changes in left and right heart pressures. Right and left ventricular end-diastolic pressures increased 100% (P less than 0.01); mean pulmonary arterial and aortic pressures increased 77 and 25%, respectively (P less than 0.01); systemic vascular resistance increased 22% (P less than 0.05) and pulmonary vascular resistance did not change in normal subjects at maximum PASG inflation. Heart rate, cardiac output, and aortic and pulmonary arterial pulse pressures did not change during inflation in either group. Right and left ventricular end-diastolic pressures and pulmonary capillary wedge pressure were greater (P less than 0.05) in the CAD group compared with the normal subjects during PASG inflation. The data suggest that the primary mechanism whereby PASG inflation induces changes in central hemodynamics in normovolemic subjects is through an acute increase in left ventricular afterload. PASG changes in afterload and pulmonary capillary wedge pressure imply that these devices should be used with caution in patients with compromised cardiac function.     

Elements in autopsy liver tissue samples from Greenlandic Inuit and Danes. II. Iron measured by X-ray fluorescence spectrometry.

The purpose of this study was to measure the content of iron (Fe) in liver tissue samples from urbanized Greenlandic Inuit using X-ray fluorescence spectrometry, and compare the results with those obtained in liver tissue samples from urbanized Danes. Normal liver tissue samples were obtained at autopsy from 50 Greenlandic Inuit (27 men, 23 women) with a median age of 61 years (range 23-83) and from 72 Danes (42 men, 30 women) with a median age of 62 years (range 15-87). In the entire series, there was no significant difference between liver iron in Inuit compared with Danes. Likewise, there was no significant gender difference concerning liver iron content, either in Inuit or in Danes. The median iron content (with 5-95 percentile) in Inuit was 17.23 mmol/kg dry liver (5.80-91.80) and in Danes 16.51 mmol/kg dry liver (7.83-39.05). However, when stratified according to age, a trend was revealed showing that Inuit men and women < or = 50 years had a lower liver iron content than Danes (p = 0.05 and p = 0.08) whereas Inuit men and women > 50 years had a higher liver iron content than Danes (p = 0.18 and p = 0.02). There was a significant correlation between liver iron content and age in both Inuit men (rs = 0.49, p = 0.01) and in women (rs = 0.64, p = 0.003), but not in Danes. In Inuit, the median hepatic iron index (liver iron content divided by age) was 0.33 in men and 0.32 in women. The median estimated iron content in the whole liver was 6.54 mmol (365 mg) in Inuit men and 5.41 mmol (302 mg) in Inuit women (p = 0.6). There was no correlation between hepatic iron index and age. In Danes, the median hepatic iron index was 0.46 in men and 0.29 in women (p = 0.01). There was a significant inverse correlation between hepatic iron index and age in the two genders and in the entire series (rs = -0.71, p = 0.0001). The results indicate that young and middle-aged urbanized Inuit have slightly smaller iron stores than urbanized Danes, whereas elderly Inuit have higher iron stores than Danes. In Danes, iron stores plateau at 30 to 40 years of age in men and some years after the menopause in women. In Inuit, iron stores continue to increase in old age, probably to due a lifelong dietary intake of haem iron.     

Elements in autopsy liver tissue samples from Greenlandic inuit and Danes. V. Selenium measured by X-ray fluorescence spectrometry

The content of selenium in normal liver tissue samples from Greenlandic Inuit was measured and the results compared with those obtained in normal liver tissue samples from Danes. Normal liver tissue samples were obtained at autopsy from 50 Greenlandic Inuit (27 men, 23 women) with a median age of 61 years (range 23–83) and from 74 Danes (44 men, 30 women) with a median age of 60 years (range 15–87). Total liver selenium content was measured by X-ray fluorescence spectrometry. The content of selenium (median) was in Inuit 26.6 mol/kg dry liver (5–95 percentile: 15.2–49.4) and in Danes 17.7 mol/kg dry liver (5–95 percentile: < 3.8–36.5) (p < 0.0001). Liver selenium content displayed no significant gender difference, either in Inuit or Danes. In Inuit men, there was a negative correlation between liver selenium content and age (r_s = −0.39, p < 0.05), whereas Danish men displayed a positive correlation between liver selenium content and age (r_s = 0.37, p = 0.02). There was no correlation in Inuit or Danish women. In Inuit, the median hepatic selenium index (liver selenium content divided by age) was 0.48 and in Danes 0.33 (p = 0.001). There was an inverse correlation between hepatic selenium index and age both in Inuit (r_s = −0.77, p < 0.0001) and in Danes (r_s = −0.47, p < 0.0001). In conclusion, Inuit had a higher liver content of selenium and a higher hepatic selenium index compared with Danes. The more favourable selenium status is due to a higher nutritional selenium intake with fish and meat from sea mammals.     

Pulmonary artery pressure and cardiac function in children and adolescents after rapid ascent to 3,450 m

High-altitude destinations are visited by increasing numbers of children and adolescents. High-altitude hypoxia triggers pulmonary hypertension that in turn may have adverse effects on cardiac function and may induce life-threatening high-altitude pulmonary edema (HAPE), but there are limited data in this young population. We, therefore, assessed in 118 nonacclimatized healthy children and adolescents (mean ± SD; age: 11 ± 2 yr) the effects of rapid ascent to high altitude on pulmonary artery pressure and right and left ventricular function by echocardiography. Pulmonary artery pressure was estimated by measuring the systolic right ventricular to right atrial pressure gradient. The echocardiography was performed at low altitude and 40 h after rapid ascent to 3,450 m. Pulmonary artery pressure was more than twofold higher at high than at low altitude (35 ± 11 vs. 16 ± 3 mmHg; P < 0.0001), and there existed a wide variability of pulmonary artery pressure at high altitude with an estimated upper 95% limit of 52 mmHg. Moreover, pulmonary artery pressure and its altitude-induced increase were inversely related to age, resulting in an almost twofold larger increase in the 6- to 9- than in the 14- to 16-yr-old participants (24 ± 12 vs. 13 ± 8 mmHg; P = 0.004). Even in children with the most severe altitude-induced pulmonary hypertension, right ventricular systolic function did not decrease, but increased, and none of the children developed HAPE. HAPE appears to be a rare event in this young population after rapid ascent to this altitude at which major tourist destinations are located.     

Pulmonary Impairment in Tuberculosis Survivors: The Korean National Health and Nutrition Examination Survey 2008-2012

Objectives

Pulmonary tuberculosis (TB) can affect lung function, but studies regarding long-term follow-up in patients with no sequelae on chest X-ray (CXR) have not been performed. We evaluated lung functional impairment and persistent respiratory symptoms in those with prior pulmonary TB and those with prior pulmonary TB with no residual sequelae on CXR, and determined risk factors for airflow obstruction.

Methods

We used data from adults aged ≥ 40 years from the annual Korean National Health and Nutrition Examination Surveys conducted between 2008 and 2012. P values for comparisons were adjusted for age, sex, and smoking status.

Results

In total of 14,967 adults, 822 subjects (5.5%) had diagnosed and treated pulmonary TB (mean 29.0 years ago). The FVC% (84.9 vs. 92.6), FEV₁% (83.4 vs. 92.4), and FEV₁/FVC% (73.4 vs. 77.9) were significantly decreased in subjects with prior pulmonary TB compared to those without (p < 0.001, each). In 12,885 subjects with no sequalae on CXR, those with prior pulmonary TB (296, 2.3%) had significantly lower FEV₁% (90.9 vs. 93.4, p = 0.001) and FEV₁/FVC% (76.6 vs. 78.4, p < 0.001) than those without. Subjects with prior pulmonary TB as well as subjects with no sequalae on CXR were more likely to experience cough and physical activity limitations due to pulmonary symptoms than those without prior pulmonary TB (p < 0.001, each). In total subjects, prior pulmonary TB (OR, 2.314; 95% CI, 1.922–2.785), along with age, male, asthma, and smoking mount was risk factor for airflow obstruction. In subjects with prior pulmonary tuberculosis, inactive TB lesion on chest x-ray (OR, 2.300; 95% CI, 1.606–3.294) were risk factors of airflow obstruction.

Conclusion

In addition to subjects with inactive TB lesion on CXR, subjects with no sequelae on CXR can show impaired pulmonary function and respiratory symptoms. Prior TB is a risk factor for airflow obstruction and that the risk is more important when they have inactive lesions on chest X-ray. Hence, the patients with treated TB should need to have regular follow-up of lung function and stop smoking for early detection and prevention of the chronic airway disease.     

The Trail as Home: Inuit and Their Pan-Arctic Network of Routes

This paper provides ethnographic and historical evidence for the existence, in time and space, of a network of well-established trails connecting most Inuit settlements and significant places across the Canadian Arctic. The geographic and environmental knowledge relating to trails (and place names associated with the trails) has been orally transmitted through many generations of Inuit. I use historical documents, ethnographic research, and new geographic tools such as GPS, GIS and Google Earth, to show the geographic extent of the network and its historical continuity. I particularly draw on a trip following Inuit along a traditional trail connecting the communities of Iglulik and Naujaat (Repulse Bay). Inuit have made systematic use of the Arctic environment as a whole and trails are, and have been, significant channels of communication and exchange across the Arctic. There are some types of oral history and knowledge that can be accurately transmitted through generations, and I propose that some aspects of Inuit culture are better understood in terms of moving as a way of living.

The Physical Status of Men in the Lowest Income Group in the Sixth Decade of Life

Forty-one men between the ages of 50 and 60 from the indigent population in Montreal have been studied during two winters. Clinical evaluation, completion of a respiratory questionnaire, electrocardiograms, plain chest radiographs and full chest tomograms, and a battery of pulmonary function tests were completed on each.No difference in pulmonary function could be demonstrated among nine men who gave no history of chronic bronchitis and 14 who gave positive answers to the same questionnaire.Five who had had dusty occupations in the past had more evidence of function impairment than men not exposed to this hazard.Thirteen were found to have complicating disease; two had active tuberculosis, one a mediastinal tumour, and the remaining 10 various forms of heart disease.Considering the group as a whole, only 18 (44%) had no objective evidence of any organic disease.     

右心导管法测大鼠肺动脉压力的改良

目的:目前常用的测量大鼠肺动脉压力的右心导管法存在一定的缺陷,且很难得到典型的压力曲线图。本实验对大鼠经颈外静脉插管与测压的方法进行改良,同时与已有报道的实验结果进行比较,并提供正常SD大鼠右心房、右心室及肺动脉的压力参考值及典型的压力曲线图,以协助研究人员判断导管位置,及时调整导管的深度和方向,快速测出肺动脉压力。方法:雌雄不分的清洁级SD大鼠共30只,体重180~230 g,6~7周龄。应用自制的末端呈一弧形的PE-10管,采用改良后的右心导管法,经颈外静脉插入大鼠心腔及肺动脉,检测并计算大鼠右心房、右心室和肺动脉的收缩压、舒张压及肺动脉平均压。结果:右心房压力波动较平缓,呈小波浪形;右心室压力曲线波动大,骤升骤降;肺动脉压力曲线有重搏波。正常SD大鼠右心房舒张压为(2.03±2.56)mmHg,收缩压为(2.82±1.85)mmHg;右心室舒张压为(5.72±3.99)mmHg,收缩压为(18.73±4.80)mmHg;肺动脉舒张压为(15.27±2.64)mmHg,收缩压为(18.49±2.53)mmHg,肺动脉平均压为(16.34±2.32)mmHg。右心室收缩压与肺动脉收缩压无明显差异(P0.05)。结论:改良后的方法可准确到达大鼠肺动脉,提供的压力参考值及曲线图有助于研究人员顺利完成测压实验。     

Elements in autopsy liver tissue samples from Greenlandic Inuit and Danes. III. zinc measured by X-ray fluorescence spectrometry

The aim of the study was to measure the content of zinc (Zn) in liver tissue samples from Greenlandic Inuit using X-ray fluorescence spectrometry, and compare the results with those obtained in liver samples from Danes. Normal liver tissue samples was obtained at autopsy from 50 Greenlandic Inuit (27 men) with a median age of 61 years (range 23–83) and from 74 Danes (44 men) with a median age of 60 years (range 15–87). In the entire series, liver zinc content in Inuit was not significantly different compared with Danes. There was no significant gender difference in liver zinc content either in Inuit or in Danes. The content of zinc given as median (5–95 percentile) was in Inuit 3.809 mmol/kg dry liver (2.355–7.406), and in Danes 3.992 mmol/kg dry liver (2.499–8.645). There was a significant, positive correlation between liver zinc content and age in Danish women (r_s = 0.43, p = 0.02), which could not be demonstrated in Danish men or in Inuit. Median hepatic zinc index (zinc content in mmol/kg dry weight divided by age in years) in Inuit was 0.073, and in Danes 0.080 (p = 0.3) without any significant difference between the two genders. In Inuit and Danes there was an inverse correlation between hepatic zinc index and age both in the two genders and in the entire series: Inuit: r_s = −0.62, p < 0.0001; Danes: r_s = −0.70, p < 0.0001. The results indicate that Inuit have liver zinc levels, which are similar to those found in Danes.     

Cardiorespiratory Studies in Patients with Pulmonary Tuberculosis

Cardiorespiratory studies in 13 young females and 11 middle-aged men with localized acute pulmonary tuberculosis revealed evidence of significant resting hyperventilation and reduction in the dynamics of ventilation indicative of restrictive lung disease. Indices of intrapulmonary mixing and pulmonary diffusing capacities were normal, as were alveolar-arterial pCO₂ gradients.The ventilation/perfusion ratios were slightly elevated in both groups, while pulmonary artery pressure and total pulmonary vascular resistance (TPVR) showed a rise in the males only.Both groups showed an increase in actual QBF flows and a resultant significant decrease in arterial pO₂, which suggests that the areas of tuberculous infection are metabolically active.     

可逆性肺动脉高压的治疗在心脏移植围术期的应用

目的：通过早期判断并治疗心脏移植围术期可逆性肺动脉高压,降低移植手术后右心功能衰竭的发生率。方法：20例接受心脏移植手术的病人,术前放置肺动脉导管,测定肺动脉压、肺循环阻力。对肺动脉高压的病人在肺动脉端泵入硝酸甘油、前列腺素E1以确定可逆性。并在术后早期抗排异治疗的基础上应用增强心肌收缩力、降低肺动脉压力、强化氧疗和呼吸管理等综合措施。结果：20例病人中6例出现急性右心功能衰竭,其中4例经治疗后症状改善、出院,2例死亡。结论：术前早期判断并治疗可逆性肺动脉高压,可以有效预防并减少心脏移植术后右心功能衰竭的发生,提高手术成功率。     

Chest radiography findings in primary pulmonary tuberculosis in children

Plain chest radiography plays a major role in the diagnosis and follow-up of pulmonary tuberculosis in childhood. The aim of our study was to investigate the distribution of characteristic chest radiographic findings at diagnosis in children with pulmonary tuberculosis. The age of the patients and the type and localization of radiographic changes at admission were retrospectively analyzed. We reviewed chest radiographs in 204 children admitted from January 1, 1991 until June 30, 1994 for newly diagnosed pulmonary tuberculosis. Mean age +/- SD was 6.4 +/- 4.2 years (range 0-14). The most common lesion was lymphadenopathy (found in 172 children, 84.3%). It was significantly more common in the youngest age group (0-4 years) and was more significantly present in the right hilo-mediastinal region. Parenchymal changes were found in 125 children (61.3%). They were also significantly more common in the young age group and in the right lung. Other less common lesions included pleuritis, atelectasis, destructive-cavitary lesions and miliary dissemination. In conclusion, the leading radiographic finding in pulmonary tuberculosis in childhood remains hilar lymphadenopathy, but parenchymal changes are clearly strongly present, and should be sought and appreciated in the diagnostic work-up for pulmonary tuberculosis in childhood.     

Incidence of active tuberculosis in the native population of Canada.

We analysed the incidence rates of active tuberculosis reported between 1970 and 1981 in three groups of people born in Canada: Inuit, registered Indians and others (mainly of European origin). While the rates of tuberculosis were quite low in the last group, which constitutes about 82% of the population of Canada, they were 16 times higher among Indians and 24 times higher among Inuit. Some 20 to 30 years ago the Inuit had the highest recorded rate of tuberculosis in the world; with an intensive program the rate decreased sharply. Such a program has not been implemented among the Indian population, and the incidence rate has not decreased as rapidly. A major effort is required to satisfactorily control tuberculosis among Indians. In addition, we must not allow our efforts to slacken in the control of tuberculosis among the Inuit.     

The Chilliwack Respiratory Survey, 1963: Part IV. The Effect of Tobacco Smoking on the Prevalence of Respiratory Disease

Chronic non-specific respiratory disease was found by a survey at Chilliwack, B.C., to affect 29.3% of men and 18.0% of women between the ages of 25 and 74. The habit of current cigarette smoking was found to be the most important single factor associated with respiratory disease, and was found to be related to changes in simple measures of lung function. The authors were unable to confirm the existence of a threshold in lifetime cigarette smoking before respiratory disease occurred.Comparisons were made with a population previously studied at Berlin, New Hampshire, U.S.A., in 1961. At Berlin, where pollution by SO₂ and dust-fall had been thoroughly documented, the comparable prevalence rates for respiratory disease were 40.0% for men and 21.6% for women. When differences between the two populations as to age and number of cigarettes smoked daily were taken into account, the disease rates in these two communities were found to be quite similar. The Chilliwack sample did, however, have significantly higher values for the lung function tests.     

Spatio-temporal variations and age effect on Toxoplasma gondii seroprevalence in seals from the Canadian Arctic

Toxoplasmosis is a significant public health threat for Inuit in the Canadian Arctic. This study aimed to investigate arctic seals as a possible food-borne source of infection. Blood samples collected from 828 seals in 7 Canadian Arctic communities from 1999 to 2006 were tested for Toxoplasma gondii antibodies using a direct agglutination test. Polymerase chain reaction (PCR) was used to detect T. gondii DNA in tissues of a subsample of seals. Associations between seal age, sex, species, diet, community and year of capture, and serological test results were investigated by logistic regression. Overall seroprevalence was 10·4% (86/828). All tissues tested were negative by PCR. In ringed seals, seroprevalence was significantly higher in juveniles than in adults (odds ratio=2·44). Overall, seroprevalence varied amongst communities (P=0·0119) and by capture year (P=0·0001). Our study supports the hypothesis that consumption of raw seal meat is a significant source of infection for Inuit. This work raises many questions about the mechanism of transfer of this terrestrial parasite to the marine environment, the preponderance of infection in younger animals and the natural course of infection in seals. Further studies to address these questions are essential to fully understand the health risks for Inuit communities.     

Body weight and mortality in middle aged British men: impact of smoking.

OBJECTIVE--To assess the relation between body mass index and mortality in middle aged British men. DESIGN--Men who were recruited for the British Regional Heart Study were followed up for a mean of nine years. SETTING--General practices in 24 British towns. SUBJECTS--7735 Men aged 40-59 years selected from the age-sex registers of one group practice in each of the 24 towns. MAIN OUTCOME MEASURE--Mortality from cardiovascular and non-cardiovascular causes. RESULTS--660 Of the men died. There was a U-shaped relation between body mass index and total mortality. Very lean men (less than 20 kg/m2) had by far the highest mortality followed by lean men (20-22 kg/m2) and obese men (greater than or equal to 28 kg/m2). The high mortality in lean and very lean men was due largely to non-cardiovascular causes, particularly lung cancer and respiratory disease, which are associated with cigarette smoking. In obese men deaths were more likely to be due to cardiovascular causes. There was a strong inverse association between body weight and cigarette smoking. When the pattern of mortality was examined by age, smoking habits, and pre-existing smoking related disease both very lean men and obese men consistently had an increased mortality. The U-shaped relation was most prominent in men in the oldest age group (55-59). Current smokers had a higher mortality than former smokers at virtually all values of body mass index. An increased mortality in lean men was seen only in current smokers and in men with smoking related disease. Among men who had never smoked, lean men had the lowest total mortality, thereafter mortality increased with increasing body mass index (p less than 0.01). CONCLUSIONS--This study provides strong evidence of the impact of cigarette smoking on body weight and mortality and strongly suggests that the benefits of giving up smoking are far greater than the problems associated with the increase in weight that may occur.