Paid employment in subjects with and without chronic obstructive pulmonary disease in five Latin American cities: the PLATINO study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a costly condition that frequently causes permanent work disabilities. Little information exists regarding the impact of COPD on work force participation and the indirect costs of the disease in developing countries.

OBJECTIVE

To examine the frequency of paid employment and factors influencing it in a Latin-American population-based study.

METHODS

Post-bronchodilator FEV(1)/FVC < 0.70 (forced expiratory volume in 1 s/forced vital capacity) was used to define COPD. Information regarding paid work was assessed by the question 'At any time in the past year, have you worked for payment?'

RESULTS

Interviews were conducted with 5571 subjects; 5314 (759 COPD and 4554 non-COPD) subjects underwent spirometry. Among the COPD subjects, 41.8% reported having paid work vs. 57.1% of non-COPD (P < 0.0001). The number of months with paid work was reduced in COPD patients (10.5 ± 0.17 vs. 10.9 ± 0.06, P < 0.05). The main factors associated with having paid work in COPD patients were male sex (OR 0.33, 95%CI 0.23-0.47), higher education level (OR 1.05, 95%CI 1.01-1.09) and younger age (OR 0.90, 95%CI 0.88-0.92). COPD was not a significant contributor to employment (OR 0.83, 95%CI 0.69-1.00, P = 0.054) in the entire population.

CONCLUSIONS

Although the proportion of persons with paid work is lower in COPD, having COPD appears not to have a significant impact on obtaining paid employment in the overall population of developing countries.

The 6-min walk distance in healthy subjects: reference standards from seven countries

The 6-min walk distance (6MWD) predicted values have been derived from small cohorts mostly from single countries. The aim of the present study was to investigate differences between countries and identify new reference values to improve 6MWD interpretation. We studied 444 subjects (238 males) from seven countries (10 centres) ranging 40-80 yrs of age. We measured 6MWD, height, weight, spirometry, heart rate (HR), maximum HR (HR(max)) during the 6-min walk test/the predicted maximum HR (HR(max) % pred), Borg dyspnoea score and oxygen saturation. The mean ± sd 6MWD was 571 ± 90 m (range 380-782 m). Males walked 30 m more than females (p < 0.001). A multiple regression model for the 6MWD included age, sex, height, weight and HR(max) % pred (adjusted r² = 0.38; p < 0.001), but there was variability across centres (adjusted r² = 0.09-0.73) and its routine use is not recommended. Age had a great impact in 6MWD independent of the centres, declining significantly in the older population (p < 0.001). Age-specific reference standards of 6MWD were constructed for male and female adults. In healthy subjects, there were geographic variations in 6MWD and caution must be taken when using existing predictive equations. The present study provides new 6MWD standard curves that could be useful in the care of adult patients with chronic diseases.

Worldwide burden of COPD in high- and low-income countries. Part II. Burden of chronic obstructive lung disease in Latin America: the PLATINO study

SETTING

Five Latin American cities: São Paulo, Brazil; Mexico City, Mexico; Montevideo, Uruguay; Santiago, Chile; Caracas, Venezuela.

OBJECTIVE

To describe the burden of chronic obstructive pulmonary disease (COPD) in Latin America.

DESIGN

This is a multicentre study. Post-bronchodilator spirometry was used and the main outcome measure was FEV(1)/FVC < 0.7 (fixed ratio criterion). Global Obstructive Lung Disease (GOLD) stages were also analysed.

RESULTS

The combined population aged > or =40 years in the five countries included in the study was approximately 85.3 million. Of these, it was estimated that 12.2 million have airflow obstruction, which corresponds to our prevalence estimate of 14.3%. The proportion of subjects in Stages II-IV of the GOLD classification was 5.6%. Risk factors presenting the highest aetiological fractions for COPD were age, current smoking, indoor exposure to coal and exposure to dust in the workplace. Smoking, the modifiable factor with the strongest aetiological fraction for COPD, affects 29.2% of adults aged > or =40 years in these cities, corresponding to approximately 25 million smokers in this age group.

CONCLUSION

Prevention of smoking and exposure to pollutants, such as coal and dust, are the interventions most likely to succeed against COPD in Latin America. The information obtained by a collaborative study has been vast and encouraging for other similar studies.

Tuberculosis and airflow obstruction: evidence from the PLATINO study in Latin America

The aim of the present study was to evaluate the association between history of tuberculosis and airflow obstruction. A population-based, multicentre study was carried out and included 5,571 subjects aged > or =40 yrs living in one of five Latin American metropolitan areas: Sao Paulo (Brazil); Montevideo (Uruguay); Mexico City (Mexico); Santiago (Chile); and Caracas (Venezuela). Subjects performed pre- and post-bronchodilator spirometry and were asked whether they had ever been diagnosed with tuberculosis by a physician. The overall prevalence of airflow obstruction (forced expiratory volume in one second/forced vital capacity post-bronchodilator <0.7) was 30.7% among those with a history of tuberculosis, compared with 13.9% among those without a history. Males with a medical history of tuberculosis were 4.1 times more likely to present airflow obstruction than those without such a diagnosis. This remained unchanged after adjustment for confounding by age, sex, schooling, ethnicity, smoking, exposure to dust and smoke, respiratory morbidity in childhood and current morbidity. Among females, the unadjusted and adjusted odds ratios were 2.3 and 1.7, respectively. In conclusion, history of tuberculosis is associated with airflow obstruction in Latin American middle-aged and older adults.

Prevalence of oxygen desaturation and use of oxygen at home in adults at sea level and at moderate altitude

The aim of this study was to determine the prevalence of oxygen desaturation in adults aged>or=40 yrs as altitude above sea level increases. A population-based, cross-sectional study with a multistage cluster sampling of 1,063 subjects from metropolitan Mexico City (Mexico; 2,240 m above sea level), 1,357 from Caracas (Venezuela; 950 m) and 943 from Montevideo (Uruguay; 35 m). The mean of six measurements of arterial oxygen saturation (SP,O2) was estimated using a pulse oximeter. Mean SP,O2 decreased with altitude. No subject from Montevideo had a mean SP,O2<or=88%. Prevalence of subjects with SP,O2<or=88%, a common criterion used for oxygen prescription, was 1.0% in Caracas and 6.0% in Mexico City. Additional predicting factors for hypoxaemia in multiple regression models were age, body mass index and a low forced expiratory volume in one second as a percentage of the predicted value. In Mexico City and Caracas, <10% of the hypoxaemic subjects reported use of domiciliary oxygen, whereas at least half of the subjects reporting use of oxygen at home had a resting SP,O2>88%. In conclusion, the prevalence of hypoxaemia was closely related to altitude. Priorities for oxygen prescription must be defined in moderate altitudes because it is unfeasible to provide it to all subjects fulfilling the criteria commonly used.

Squash Yellow Leaf Curl Virus: A New Whitefly-Transmitted Poty-Like Virus

A severe yellow and leaf curl disease affecting field squash was found in the Batinah region of the Sultanate of Oman. The symptoms appear as small yellow spots, diffuse veinal yellowing, and leaf curling of young leaves. The inciting virus was easily transmitted by mechanical inoculation and by the whitefly Bemisia tabaci in a semi-persistent manner. The host range of the virus was restricted to two cucurbit species. Leaf dip preparations contained few flexuous particles about 700 to 750 nm long. Pinwheel-like inclusion bodies were observed in thin sections of diseased squash tissues. Serological tests by enzyme-linked immunosorbent assay showed that the virus is serologically related to watermelon mosaic virus-2, but not to zucchini yellow mosaic virus or papaya ring spot virus (watermelon strain). In view of these properties, this virus is considered to be a newly described virus and is tentatively named squash yellow leaf curl virus.

Sonographic aspects of pseudoxanthoma elasticum

We describe a case of pseudo-xanthoma elasticum (PE) in a child with distinctive skin lesions without other symptoms. Renal ultrasonography showed a characteristic pattern of dotted increased echogenicity in the corticomedullary junction. Pancreas and spleen had similar echographic findings. We point out the importance of ultrasonography in the diagnosis of this rare disorder.

Paroxysmal aphasias

Forty cases of paroxysmal aphasia were found in a sample of 4,000 patients with epilepsy. Twenty-five had structural brain damage demonstrated by CT scan. Except for two cases, the epileptic focus was located in the left hemisphere. Two patients had a paroxysmal alexia associated with the aphasic disorder. Though preliminary, our data suggest a correlation of dysphasic components with posterior lesions and phonatory components with anterior lesions.

Transcortical motor aphasia: one or two aphasias?

The name "transcortical motor aphasia" has been used to refer to two different types of language alterations: damage in the left supplementary motor area and Luria's dynamic aphasia. It is proposed that they represent two types of language disturbances different enough to be considered two different forms of aphasia.