Category Archives: Pulmonary

Clinical Diagnosis of COPD in Asia

chronic emphysemaIn Asian countries, patients with COPD are mostly under the care of primary care physicians. Synonyms for COPD, which include chronic bronchitis and chronic emphysema, complicate the diagnostic labeling. Doctors who practice alternative/traditional medicine do not differentiate asthma from COPD, resulting in the underdiagnosis of COPD. The diagnosis is usually based on a clinical history of persistent respiratory symptoms in a cigarette smoker, as spirometric documentation of fixed airflow limitation is not routine. In tertiary care practice, a spiromet-ric determination is often included. In Japan, COPD is underdiagnosed in the population, where a large epidemiologic study found that 90% of people with COPD, based on spirometry findings, did not have a prior diagnosis of the condition, which is comparable to a corresponding 63% reported in the National Health and Nutrition Examination Study in the United States. In Japan, in a primary care setting of smokers followed up for nonrespiratory conditions, 31% were found to have COPD based on screening spirometry findings, which is within the range of 14 to 46% reported in the United States.

Pulmonary tuberculosis is a major confounder in the diagnosis of COPD as the sequelae from healed tuberculosis include restrictive, obstructive, or mixed restrictive-obstructive pulmonary dysfunction, which could modify the interpretation of the spirometric evaluation. In addition, pulmonary tuberculosis often coexists with COPD, as regions with high prevalence rates of pulmonary tuberculosis, such as Indonesia, China, and Vietnam, also experience high cigarette smoking rates.


COPD in Asia Explained by Canadian Health&Care Mall: Associated Risk Factors

airway hyperresponsivenessThe pathogenesis of COPD is due to an interaction between host factors (ie, genes, airway hyperresponsiveness, and lung growth) and exposure to environmental pollutants (ie, tobacco smoke, occupational dust and fumes, respiratory infection, outdoor air pollution, and indoor air pollution caused by biomass or traditional fuels and coal) and socioeconomic status.

Genetic Factors

It is believed that many genetic factors may influence an individual likelihood of COPD developing. Studies have demonstrated an increased risk of COPD within families with COPD probands. Some of this risk may be due to shared environmental factors, but several studies in diverse populations have also suggested a shared genetic risk. To date, a1-antitrypsin (a1-AT) deficiency, a major circulating serine protease inhibitor, is the only genetic factor that is definitely linked to the development of emphysema or COPD, independent of tobacco exposure. Affected individuals have a 40-fold increase in the risk of the development of COPD compared to unaffected people. This rare hereditary deficiency is a recessive trait most commonly seen in individuals of Northern European origin and is extremely rare among Asians. Limited data have failed to link COPD with a1-AT deficiency in Chinese either by determining the levels in the serum or by genotyp-ing and electrophoretic phenotyping for cases of PiZ and PiS.’ Although variants of a1-AT deficiency have been reported such as variant Siiyama in Japan, and METokyo an Mpirare among Chinese, they have not been linked to COPD. COPD is effectively cured with remedies of Canadian Health&Care Mall

A number of candidate genes in whites have been implicated in an increased risk for COPD, including ABH nonsecretor status, microsomal epoxide hydrolase level, glutathione S-transferase level, a1-antichymotrypsin level, the complement component GcG level, cytokine tumor necrosis factor-a level, and microsatellite instability. The results are often inconsistent but could be related to the potential pathogenic mechanisms of COPD. In Asians, studies on putative candidate genes found in whites have not yielded consistent results in Chinese, Thais, Koreans, or Japanese.