Clinical phenotypes of COPD: results of a Japanese epidemiological survey

OBJECTIVE: The Global Initiative for Obstructive Lung Disease characterizes COPD as airflow limitation caused by parenchymal destruction and/or small airway disease. This report characterizes the clinical features of these two phenotypes of COPD in Japan. METHODOLOGY: COPD was diagnosed by spirometric airflow limitation (FEV(1)/FVC < 70%), and all subjects underwent chest CT scanning. Patients with diffuse low attenuation areas (LAA) on CT scan were categorized as the emphysema-dominant phenotype; those with little LAA were categorized as the airway disease-dominant phenotype. The two groups were compared to identify significant clinical or demographic differences. RESULTS: Of the 1438 patients analysed, 1294 (90%) were classified as having an emphysema-dominant phenotype and 144 (10%) as having an airway disease-dominant phenotype. The airway disease-dominant phenotype was: more common than the emphysema-dominant phenotype in women (15%vs. 7%, P < 0.01) and in non-smokers (6%vs. 2%, P < 0.05); was more commonly complicated by asthmatic features (35%vs. 21%, P < 0.01); and had higher IgE and eosinophil levels (P < 0.05) and less lung function impairment. CONCLUSION: This analysis is the first to clinically define two phenotypes of COPD in a Japanese epidemiological survey. There appear to be striking differences as well as overlap between these two groups. Further research is warranted to determine the significance of COPD phenotypes.     

Geographic variations in the prevalence,awareness, treatment and control of hypertension in China

OBJECTIVE: To compare the prevalence, awareness, treatment and control of hypertension in north and south, and urban and rural residents of China. DESIGN: A cross-sectional survey conducted in 2000-2001. SETTING AND PARTICIPANTS: A multistage cluster sampling method was used to select a nationally representative sample of 15 540 men and women aged 35-74 years from the general Chinese population. MAIN OUTCOME MEASURES: Three blood pressure measurements were obtained by trained observers using a standardized mercury sphygmomanometer. Information on history of hypertension and use of antihypertensive medications was obtained by use of a standard questionnaire. Hypertension was defined as a mean systolic blood pressure >or= 140 mmHg and/or diastolic blood pressure >or= 90 mmHg and/or use of antihypertensive medications. RESULTS: The age-standardized prevalence of hypertension was significantly higher among residents living in north than in south China (33.8 versus 23.3%, P < 0.001), but similar in those living in urban and rural areas (29.0 versus 28.1%, P = 0.3). Average systolic and diastolic blood pressure levels were consistently higher in north than in south residents. Residents in north China had higher percentages of awareness but lower percentages of control compared with their counterparts in south China. Percentages of awareness, treatment and control of hypertension were significantly higher in urban than in rural residents. CONCLUSIONS: Our study documents a marked north-south gradient in the prevalence of hypertension in China. The previously reported urban-rural difference in the prevalence of hypertension was not noted, perhaps due to a rapid increase in the prevalence of hypertension in rural China.     

Chronic bronchitis among French adults: high prevalence and underdiagnosis.

The aims of this survey were to determine the prevalence of symptoms indicative of chronic bronchitis (CB) in the French adult population, to identify the role of risk factors for CB, and to assess rates of CB diagnosis and pulmonary function testing (PFT) in the presence of CB. A representative sample of 14,076 individuals aged > or = 25 yrs completed a self-administered questionnaire on symptoms, comorbidities, smoking history, sociodemographical data, and diagnosis and care by physicians. The prevalence of CB was 4.1% and the prevalence of chronic cough and/or expectoration was 11.7%. In individuals with comorbidity, these figures were 10.4% and 24.4%, respectively. Smoking was associated with an increased frequency of CB. In subjects with CB, 44.6% had PFT (spirometry or peak expiratory flow measurement), 24% were diagnosed as having CB, and 7.2% received care. Rates of diagnosis, PFT, and follow-up were lower in young individuals and in those without comorbidity. PFT and follow-up were less common in current smokers. Prevalence of chronic bronchitis in French adults is high and similar in magnitude to that of other industrialised countries. Comorbidities and tobacco smoking increase the frequency of chronic bronchitis symptoms. Chronic bronchitis is too infrequently diagnosed, investigated and cared for.     

The prevalence of asthma and COPD in Italy: a practice-based study

We conducted a population-based cross-sectional epidemiologic survey of asthma and COPD in an adult representative national sample using information obtained from the Health Search Database owned by the Italian College of General Practitioners. General Practitioners who had a list of patient population of 909,638 individuals (429,962 men and 479,676 women; man/woman ratio [M/WR]: 0.89) ≥ 14 years old at the end of December 2009 were selected to be representatives of the whole Italian population. Cases of asthma and COPD were identified on the basis of the ICD-9 codes. The total sample included 55,500 (6.10% of the entire population; 5.49% of men and 6.64% of women; M/WR: 0.74) subjects suffering from asthma and 25,762 (2.83% of the entire population; 3.51% of men and 2.23% of women; M/WR: 1.41) subjects suffering from COPD. The asthma/COPD ratio in general population was 2.16. The odds ratio (OR) was chosen because asthma and COPD had a prevalence less than 10%. The OR of developing asthma decreased with age both in men and women, but in the first group of age (15-34 years) it was higher in men vs. women (1.69 vs. 1.00) although it became lower than 1 from 35 years old and up in men and from 75 years old and up in women. On the contrary, the OR of developing COPD became higher than 1 from 55 years old and up both in men and in women and progressively increased with age (in the group 75-84 years, it was 6.16 in men and 4.07 in women, respectively).     

COPD prevalence in 12 Asia-Pacific countries and regions: projections based on the COPD prevalence estimation model

Objective:   COPD is a leading cause of mortality and morbidity worldwide. Despite the high rates of cigarette smoking, and the wide use of biomass fuels, there is very little objective data on the prevalence of COPD in Asia.
Methodology:   We used a COPD prevalence model to estimate the prevalence of COPD in 12 Asian countries. This model is a validated, computerized tool that uses epidemiological relationships and risk factor prevalence to project the prevalence of COPD within a given population aged 30 years and older.
Results:   The total number of moderate to severe COPD cases in the 12 countries of this region, as projected by the model, is 56.6 million with an overall prevalence rate of 6.3%. The COPD prevalence rates for the individual countries range from 3.5% (Hong Kong and Singapore) to 6.7% (Vietnam).
Conclusions:   The COPD prevalence rates projected by the model reflect the high prevalence of the risk factors for the disease in Asia. The combined prevalence of 6.3% for these countries is considerably higher than the overall rate of 3.8% as extrapolated from WHO data for this region. These estimates highlight the need for further epidemiological studies to support appropriate allocation of resources for the prevention and management of COPD.     

Depression, anxiety and health status after hospitalisation for COPD: a multicentre study in the Nordic countries

Patients with chronic obstructive pulmonary disease (COPD) often report anxiety, depression and poor health status, not least if they experience repeated hospitalisations due to acute exacerbations. The aim of this study was to analyse the interrelationships between health status, anxiety, depression and physical status in COPD patients being discharged after hospitalisation. This was a prospective study of 416 patients in five university hospitals in each of the Nordic countries. Data included demographic information, lung function and co-morbidity. The Hospital Anxiety and Depression Scale and St. George's Respiratory Questionnaire (SGRQ) were applied to all patients. Both anxiety and depression were common among these patients. Anxiety was more common in women than in men (47% vs. 34%, P=0.009) and current smokers had a higher prevalence of both anxiety (54% vs. 37%) and depression (43% vs. 23%) than non-smokers (P<0.01). In general, the studied COPD patients had poor health status, especially those with anxiety, depression or both. Psychological status was independently related to all dimensions of SGRQ. Higher GOLD stages were significantly associated with increasing impairment in health status. In conclusion this multicentre study showed that anxiety and depression are common in patients with COPD, and, furthermore, that patients with psychological disorders have poor health status. Screening for depression and anxiety may help to identify patients with poor quality of life and an urgent need for intervention in order to improve their health status.     

COPD and lung cancer: epidemiological and biological links

Lung cancer and chronic obstructive lung disease (COPD) are two common fatal diseases. Apart from their common link to tobacco, these two diseases are usually considered to be the result of separate distinct mechanisms. In the past 15 years, numerous studies have produced arguments in favour of a relationship between these two pathologies that goes beyond a simple addition of risk factors. At the epidemiological level, there are data that demonstrate an increased incidence of bronchial carcinoma in patients with COPD. The links between these two pathologies are still unexplained but there are numerous arguments supporting a common physiopathology. Common genetic and epigenetic abnormalities, mechanical factors and signalisation pathways have been quoted. COPD and lung cancer appear to be two diseases possessing a genetic basis that creates a predisposition to environmental or toxic assaults, resulting in a different clinical manifestation in each disease. Consequently, improvements in the management of these two diseases will involve a more intensive investigation of their physiopathology, and require a closer collaboration between research centres and clinical units.     

COPD in the general population: prevalence, incidence and survival

Worldwide, COPD is a leading cause of chronic morbidity and mortality. Although its prevalence is already well documented, very few studies have measured its incidence. We therefore investigated the prevalence, incidence and lifetime risk of COPD in the general population. In a population-based study including subjects ≥ 40, with 12 months of history available in the Dutch IPCI database, we identified COPD cases by a two-step validation algorithm. Among 185,325 participants with 601,283 years of follow-up, 7308 subjects with COPD were identified, and 1713 had incident COPD. The overall IR of physician-diagnosed COPD was 2.92/1000PY (95%CI 2.78-3.06). The incidence of COPD was higher in men (3.54; 95%CI 3.33-3.77) than in women (2.34; 95%CI 2.17-2.52), and the overall baseline prevalence of COPD was 3.02% (95%CI 2.94-3.10). For people who had entered the study free of COPD at the age of 40, the risk of developing COPD within the next 40 years was 12.7% for men and 8.3% for women. In patients with very severe COPD, 26% died after 1 year of follow-up, whereas 2.8% died among the non-COPD subjects. In the general population in the Netherlands, three on 1000 subjects were diagnosed with COPD per year. The incidence increased rapidly with age and was higher in men than in women. One in eight men and one in 12 women, being COPD free at the age of 40, will develop COPD during their further life. Mortality rates differed substantially between COPD patients and non-COPD subjects of the same age, underlining the burden of this disease.     

COPD in Japan: the Nippon COPD Epidemiology study

OBJECTIVES: Despite high smoking rates, few prevalence studies of COPD have been performed in Asia. The Nippon COPD Epidemiology (NICE) Study used spirometry to measure prevalence of airflow limitation in Japanese adults. METHODOLOGY: Clinical, spirometric, and risk factor exposure data were collected on 2343 subjects aged > or = 40 years who were demographically similar to the Japanese population. Airflow limitation was defined according to Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria (FEV1/FVC < 70%). RESULTS: Prevalence of airflow limitation was 10.9%. Based upon GOLD severity criteria, 56% of these cases were found to be mild, 38% moderate, 5% severe, and 1% very severe. Airflow limitation was significantly more prevalent in males than females (16.4% vs. 5.0%; P < 0.001), in male ever-smokers than female ever-smokers (17.1% vs. 7.5%; P < 0.001), and in older subjects (3.5% in 40-49 years olds vs. 24.4% in those > 70 years; P < 0.001). Of note, airflow limitation was also found in 5.8% of non-smokers and 4.6% of those younger than age 60 years. Only 9.4% of cases with airflow limitation reported a previous diagnosis of COPD. CONCLUSIONS: Prevalence of airflow limitation in Japan is higher than previously reported, suggesting a high degree of under-recognition of COPD. The high prevalence of smoking coupled with an aging population threatens to further increase the burden of COPD, highlighting the need for enhanced screening efforts and interventions of prevention and treatment.     

COPD prevalence in Salzburg, Austria: results from the Burden of Obstructive Lung Disease (BOLD) Study

BACKGROUND: COPD is projected to be the third leading cause of death worldwide by 2020. The Burden of Obstructive Lung Disease initiative was started to measure the prevalence of COPD in a standardized way and to provide estimates of the social and economic burden of disease. METHODS: We surveyed a gender-stratified, population-based sample of 2,200 adults >or= 40 years of age. The findings of prebronchodilator and postbronchodilator spirometry, as well as information on smoking and reported respiratory disease was recorded. Irreversible airflow obstruction was defined as a postbronchodilator FEV(1)/FVC ratio of < 0.70. RESULTS: For 1,258 participants with good-quality postbronchodilator spirometry findings, the overall prevalence of COPD at stage I or higher was 26.1%, and was equal in men and women. The prevalence of COPD stage II or higher (FEV(1)/FVC ratio, < 0.7; FEV(1), < 80% predicted) was 10.7%. The prevalence of COPD stage I+, and COPD stage II+, increased with age and cigarette smoking. A doctor diagnosis of COPD was reported by only 5.6% of participants. CONCLUSION: One quarter of residents of Salzburg County (Austria) who were >or= 40 years of age had at least mild irreversible airflow obstruction. The high prevalence of COPD highlights the impending health-care crisis that will affect many countries as a result of this greatly underappreciated condition.     

Foot pain in rheumatoid arthritis prevalence, risk factors and management: an epidemiological study

Foot involvement is a major feature of rheumatoid arthritis (RA). Most epidemiological studies of the RA foot report radiological changes and results of clinical examination. This study aimed to determine the prevalence of foot symptoms, frequency of foot assessment and access to foot care from the perspective of people with RA. A questionnaire was sent to 1,040 people with RA throughout the UK enquiring about foot symptoms, their anatomical distribution (via validated mannequins) availability of podiatry services and perceived usefulness of interventions for alleviating foot symptoms. Altogether 585 useable replies were received; 93.5% of respondents reported having experienced foot pain, and 35.4% reported current foot pain as the presenting symptom. Most (68.2%) reported moderate or severe foot pain daily. Pain was most prevalent in the forefoot and/or ankle. The main predictive factors for reporting current foot pain were longer disease duration (mean 13 vs 10.3 years, p = 0.009), higher BMI (25.6 vs 24.1 p = 0.001) and the prevalent foot symptoms foot stiffness and numbness (both p < 0.0001). Age, gender and current treatment were not significantly associated. Most (82%) had discussed foot symptoms with their rheumatologist, and only 64% had seen a podiatrist. Reported current adherence to prescribed orthoses was 55.8% and to prescribed shoes was 29.5%. Foot symptoms are ubiquitous in RA and frequently severe. Most patients had discussed their symptoms with their rheumatologist, and only 64% had specifically seen a podiatrist. Despite the remarkable progress in development of new treatment modalities for RA, foot pain remains a common and disabling symptom. Our findings support the need for wider access to specific foot care services and evidence-based, patient-centred interventions.     

The aetiology of chronic hepatitis in Italy: results from a multicentre national study

BACKGROUND: No recent national-level data on the aetiology of chronic hepatitis are available in Italy. AIM: To evaluate the current aetiology of chronic hepatitis in Italy. PATIENTS: A total of 6210 chronic hepatitis patients (both prevalence and incident cases) consecutively admitted to 79 hospitals located throughout Italy were enrolled over a 6-month period in 2001. The hospitals were randomly selected through systematic cluster sampling. RESULTS: The main agent associated with chronic hepatitis was hepatitis C virus, which was found in 76.5% of the patients (in 62.6% it was the only aetiologic factor). Hepatitis B surface antigen was present in the serum of 12.2% of the cases (in 9.2% it was the only aetiologic factor). Hepatitis B e antigen and hepatitis Delta were detected in 16.6% and 7.0%, respectively, of hepatitis B surface antigen-positive patients. A history of alcohol abuse was found in 19.2% of the cases (5.5% without viral infection). Autoimmune hepatitis and inborn metabolic disorders were extremely rare. The prevalence of hepatitis C virus-related cases was significantly lower in incident cases, compared to prevalent cases (55.1% versus 65.0%; p < 0.01). The mean alanine aminotransferase level was significantly higher in hepatitis B surface antigen-positive patients, compared to hepatitis B surface antigen-negative patients. The histology was less severe in non-viral-related cases. CONCLUSIONS: Hepatitis C virus is the most important pathogenic factor for chronic hepatitis in Italy; however, the comparison between prevalent and incident cases suggests that this infection will play a less important role in the future. A comparison with previous reports shows that both hepatitis B virus-related and hepatitis Delta virus-related cases are decreasing.