Lipid profile, plasma apolipoproteins, and risk of a first myocardial infarction among Asians: an analysis from the INTERHEART Study.

OBJECTIVES: This study sought to determine the prevalence of lipid and lipoprotein abnormalities and their association with the risk of a first acute myocardial infarction (AMI) among Asians. BACKGROUND: Patterns of lipid abnormalities among Asians and their relative impact on cardiovascular risk have not been well characterized. METHODS: In a case-control study, 65 centers in Asia recruited 5,731 cases of a first AMI and 6,459 control subjects. Plasma levels of lipids and apolipoproteins in the different Asian subgroups (South Asians, Chinese, Southeast Asians, and Japanese) were determined and correlated with the risk of AMI. RESULTS: Among both cases and controls, mean low-density lipoprotein cholesterol (LDL-C) levels were about 10 mg/dl lower in Asians compared with non-Asians. A greater proportion of Asian cases and controls had LDL-C

Tobacco use and risk of myocardial infarction in 52 countries in the INTERHEART study: a case-control study.

BACKGROUND: Tobacco use is one of the major avoidable causes of cardiovascular diseases. We aimed to assess the risks associated with tobacco use (both smoking and non-smoking) and second hand tobacco smoke (SHS) worldwide. METHODS: We did a standardised case-control study of acute myocardial infarction (AMI) with 27,089 participants in 52 countries (12,461 cases, 14,637 controls). We assessed relation between risk of AMI and current or former smoking, type of tobacco, amount smoked, effect of smokeless tobacco, and exposure to SHS. We controlled for confounders such as differences in lifestyles between smokers and non-smokers. FINDINGS: Current smoking was associated with a greater risk of non-fatal AMI (odds ratio [OR] 2.95, 95% CI 2.77-3.14, p<0.0001) compared with never smoking; risk increased by 5.6% for every additional cigarette smoked. The OR associated with former smoking fell to 1.87 (95% CI 1.55-2.24) within 3 years of quitting. A residual excess risk remained 20 or more years after quitting (1.22, 1.09-1.37). Exclusion of individuals exposed to SHS in the never smoker reference group raised the risk in former smokers by about 10%. Smoking beedies alone (indigenous to South Asia) was associated with increased risk (2.89, 2.11-3.96) similar to that associated with cigarette smoking. Chewing tobacco alone was associated with OR 2.23 (1.41-3.52), and smokers who also chewed tobacco had the highest increase in risk (4.09, 2.98-5.61). SHS was associated with a graded increase in risk related to exposure; OR was 1.24 (1.17-1.32) in individuals who were least exposed (1-7 h per week) and 1.62 (1.45-1.81) in people who were most exposed (>21 h per week). Young male current smokers had the highest population attributable risk (58.3%; 95% CI 55.0-61.6) and older women the lowest (6.2%, 4.1-9.2). Population attributable risk for exposure to SHS for more than 1 h per week in never smokers was 15.4% (12.1-19.3). CONCLUSION: Tobacco use is one of the most important causes of AMI globally, especially in men. All forms of tobacco use, including different types of smoking and chewing tobacco and inhalation of SHS, should be discouraged to prevent cardiovascular diseases.

Imaging the Indian subcontinent beneath the Himalaya.

The rocks of the Indian subcontinent are last seen south of the Ganges before they plunge beneath the Himalaya and the Tibetan plateau. They are next glimpsed in seismic reflection profiles deep beneath southern Tibet, yet the surface seen there has been modified by processes within the Himalaya that have consumed parts of the upper Indian crust and converted them into Himalayan rocks. The geometry of the partly dismantled Indian plate as it passes through the Himalayan process zone has hitherto eluded imaging. Here we report seismic images both of the decollement at the base of the Himalaya and of the Moho (the boundary between crust and mantle) at the base of the Indian crust. A significant finding is that strong seismic anisotropy develops above the decollement in response to shear processes that are taken up as slip in great earthquakes at shallower depths. North of the Himalaya, the lower Indian crust is characterized by a high-velocity region consistent with the formation of eclogite, a high-density material whose presence affects the dynamics of the Tibetan plateau.

Asthma and indoor environment in Nepal.

BACKGROUND: The development of asthma seems to be influenced by the adoption of a Western lifestyle. A study was undertaken to assess the importance of indoor environmental factors in Nepal where the lifestyle and home environment differ from that in the West. METHODS: The home environment of 121 schoolchildren with asthma and 126 controls aged 11-17 years was studied. The homes of all participants were investigated and the children and their mothers were interviewed using a standardised questionnaire. Cases and controls were identified from an ISAAC (International Study of Asthma and Allergy in Childhood) based population study of 2330 schoolchildren in Kathmandu, Nepal. RESULTS: Keeping cattle inside the house during the night was related to a lower risk for having asthma (adjusted odds ratio (OR) 0.2 (95% CI 0.1 to 0.5)) while there was no association between asthma and cattle kept outside. Asthma was associated with cigarette smoking by two or more family members (OR 1.9 (95% CI 1.0 to 3.9)) and with the domestic use of smoky fuels (OR 2.2 (95% CI 1.0 to 4.5)). In analyses stratified by sex, passive smoking and the use of smoky fuels were significantly associated with asthma only in boys. CONCLUSIONS: The risk of asthma in Nepalese children was lower in subjects exposed to cattle kept inside the house and higher in subjects exposed to passive smoking and indoor use of smoky fuels. Childhood exposure to microorganisms or allergens from cattle may protect against the development of atopic disease.

Tobacco smoking and hypertension.

Coronary artery diseases is rapidly increasing in our part of the world. The South Asian ethnic groups are especially vulnerable to coronary artery disease. The two most striking features of coronary artery disease in the South Asian population are extreme prematurity and severity of the disease, both resulting from the malignant atherosclerosis that begins at an earlier age than in other population. Triple vessel disease and complicated lesions are not common even in young people and follow a malignant course. The most important aspect of prevention is to identify individuals with high risk of coronary artery disease at an early age and aggressive modification of risk factors. Tobacco smoking and hypertension are the two most important risk factors for coronary heart disease and stroke. Both of these risk factors have very high prevalence in India, Nepal and other countries of this region. There is a synergistic interaction of tobacco smoking with hypertension and high blood cholesterol which greatly increase coronary heart disease risk as well as sudden death and stroke.

Prevalence of rheumatic fever and rheumatic heart disease in school children of Kathmandu city.

To find out the prevalence of rheumatic fever/rheumatic heart disease in an urban area, a survey of school children aged between 5 to 16 years studying in randomly selected government schools in Kathmandu city was done. Out of 4984 students enrolled in the study 4736 were examined, the percentage of absentees being five. Revised Jones Criteria (1992) was used for the diagnosis of rheumatic fever. Diagnosis of rheumatic heart disease was confirmed only after Doppler echocardiography in suspected cases. A total of six cases of definite rheumatic heart disease (out of 13 suspected cases) were identified giving overall prevalence rate of 1.2 per 1000. Fifty percent rheumatic heart disease cases gave a history suggestive of rheumatic fever. No case of active rheumatic fever could be identified. The study gave lower result than that reported in most earlier studies from developing countries but it is similar to that reported from rural Kathmandu in 1991. It is concluded that there is some downward trend in rheumatic fever/rheumatic heart disease prevalence but the low prevalence is also due to the use of Doppler echocardiography which has prevented overdiagnosis in the present study. We feel that there is an urgent need to launch a National Programme for the control of rheumatic fever/rheumatic heart disease in Nepal with emphasis on primary and secondary prophylaxis of the disease.

Childhood mortality after a high dose of vitamin A in a high risk population.

OBJECTIVES: To determine whether a single high dose of vitamin A given to all children in communities with high mortality and malnutrition could affect mortality and to assess whether periodic community wide supplementation could be readily incorporated into an ongoing primary health programme. DESIGN: Opportunistic controlled trial. SETTING: Jumla district, Nepal. SUBJECTS: All children aged under 5 years; 3786 in eight subdistricts given single dose of vitamin A and 3411 in remaining eight subdistricts given no supplementation. MAIN OUTCOME MEASURES: Mortality and cause of death in the five months after supplementation. RESULTS: Risk of death for children aged 1-59 months in supplemented communities was 26% lower (relative risk 0.74, 95% confidence interval 0.55 to 0.99) than in unsupplemented communities. The reduction in mortality was greatest among children aged 6-11 months: death rate (deaths/1000 child years at risk) was 133.8 in supplemented children and 260.8 in unsupplemented children (relative risk 0.51, 0.30 to 0.89). The death rate from diarrhoea was also reduced (63.5 supplemented v 97.5 unsupplemented; relative risk 0.65, 0.44 to 0.95). The extra cost per death averted was about $11. CONCLUSION: The results support a role for Vitamin A in increasing child survival. The supplementation programme was readily integrated with the ongoing community health programme at little extra cost.

PIP: The objective of this study was to determine whether a single high dose of Vitamin A given to all children in communities with high mortality and malnutrition could affect mortality and whether periodic community-wide supplementation could be readily incorporated into an ongoing primary health program. This opportunistic controlled trial was conducted in Jumla district, Nepal and subjects included all children under age 5--3786 in 8 subdistricts were given single doses of Vitamin A and 3411 in the remaining 8 subdistricts were given no supplementation. Mortality and cause of death in the 5 months after supplementation were the main outcome measures assessed. The risk of death for children ages 1-59 months in supplemented communities was 26% lower (relative risk 0.74, 95% confidence interval 0.55-0.99) than in unsupplemented communities. The reduction in mortality was greatest among children ages 6-11 months; the death rate (deaths/1000 child-years at risk) was 133.8 in supplemented children and 260.8 in unsupplemented children (relative risk 0.51, 0.30-0.89). The death rate from diarrhea was also reduced (63.5 supplemented vs. 97.5 unsupplemented; relative risk 0.65, 0.44-0.95). The extra cost/death averted was about $11.00. These results support a role for Vitamin A in increasing child survival. The supplementation program was readily integrated with the ongoing community health program at little extra cost.

Reduction in total under-five mortality in western Nepal through community-based antimicrobial treatment of pneumonia.

Pneumonia is a leading cause of death among children world wide but those at highest risk in developing countries have limited access to clinical services; effective and low-cost alternatives are a global public health priority. We have done a controlled intervention trial among 13,404 children under five in Jumla, Nepal, which relied exclusively on indigenous community health workers to detect and treat pneumonia according to the World Health Organisation decision strategy, with a five-day home-treatment course of oral co-trimoxazole. No other health services were provided, and referral of children to hospital was not practicable. During the three-year study, 2101 deaths were recorded. The programme led to a 28% reduction in the risk of death from all causes by the third year of services (relative risk 0.72, 95% confidence interval 0.63-0.82), with a significant trend (p less than 0.02) of lower mortality with greater duration of the programme. The greatest benefit was among infants. In addition to reduction in deaths due to pneumonia, there was a significant reduction in deaths due to diarrhoea and measles, indicating that reduction in pneumonia morbidity had considerable carry-over effect. Our findings show that indigenous community workers can effectively detect and treat pneumonia, and reduce overall child mortality, even without other primary care activities.

Efficacy of vitamin A in reducing preschool child mortality in Nepal.

Community trials of the efficacy of vitamin A supplementation in reducing preschool childhood mortality have produced conflicting results. To resolve the question, a randomised, double-masked, placebo-controlled community trial of 28,630 children aged 6-72 months was carried out in rural Nepal, an area representative of the Gangetic flood plain of South Asia. Randomisation was carried out by administrative ward; the vitamin-A-supplemented children received 60,000 retinol equivalents every 4 months and placebo-treated children received identical capsules containing 300 retinol equivalents. After 12 months, the relative risk of death in the vitamin-A-supplemented compared with the control group was 0.70 (95% confidence interval 0.56-0.88), equivalent to a 30% reduction in mortality. The trial, which had been planned to last 2 years, was discontinued. The reduction in mortality was present in both sexes (relative risk for boys 0.77; for girls 0.65), at all ages (range of relative risks 0.83-0.50), and throughout the year (0.76-0.67). The reduction in mortality risk was not affected by acute nutritional status, as measured by arm circumference. Thus, periodic vitamin A delivery in the community can greatly reduce child mortality in developing countries.

Prevalence of rheumatic fever and rheumatic heart disease in school children in a rural community of the hill region of Nepal.

A survey of school children aged 5 to 16 years living in a rural community of the hill region of Nepal, situated about 15-22 km outside Kathmandu city, was conducted to determine the prevalence of rheumatic fever (RF) and rheumatic heart disease (RHD). Of the 4,816 eligible children enrolled in the selected schools, 4,452 (92.4%) were examined. WHO expert committee criteria (1966) was used for the diagnosis and classification of rheumatic fever. Chest x-ray, electro-cardiography, echocardiography and Doppler study were done in all suspected cases of rheumatic heart disease. Six cases of RHD (1 pure mitral stenosis, 3 mitral regurgitation and 2 combined mitral stenosis and regurgitation) were identified giving overall prevalence rate of 1.35 per thousand. No case with active rheumatic fever could be identified. This is the first study on prevalence of RF/RHD in Nepal. The prevalence rate is lower than that reported from neighbouring countries.

Indoor air pollution in developing countries.

Of the four principal categories of indoor pollution (combustion products, chemicals, radon and biologicals), research in developing countries has focused on combustion-generated pollutants, and principally those from solid-fuel-fired cooking and heating stoves. Such stoves are used in more than half the world's households and have been shown in many locations to produce high indoor concentrations of particulates, carbon monoxide and other combustion-related pollutants. Although the proportion of all such household stoves that are used in poorly ventilated situations is uncertain, the total population exposed to excessive concentrations is potentially high, probably several hundred million. A number of studies were carried out in the 1980s to discover the health effects of such stove exposures. The majority of such studies were done in South Asia in homes burning biomass fuels or in China with coal-burning homes, although a sprinkling of studies examining biomass-burning have been done in Oceania, Latin America and Africa. Of the health effects that might be expected from such exposures, little, if any, work seems to have been done on low birthweight and eye problems, although there are anecdotal accounts making the connection. Decreased lung function has been noted in Nepali women reporting more time spent near the stove as it has for Chinese women using coal stoves as compared to those using gas stoves. Respiratory distress symptoms have been associated with use of smoky fuels in West India, Ladakh and in several Chinese studies among different age groups, some with large population samples. Acute respiratory infection in children, one of the chief causes of infant and childhood mortality, has been associated with Nepali household-smoke exposures. Studies of chronic disease endpoints are difficult because of the need to construct exposure histories over long periods. Nevertheless, chronic obstructive lung disease has been associated with the daily time spent near the stove for Nepali women and found to be elevated among coal-stove users compared to gas-stove users in Shanghai. In contrast to early reports, there seems to be little or no risk of nasopharyngeal cancer from cookstove smoke. Several studies in China, however, have found smoke to be a strong risk factor for lung cancer among non-smoking women. In addition, severe fluorosis has been observed in several parts of China where coal fluoride levels are high.(ABSTRACT TRUNCATED AT 250 WORDS)

Impact of a pilot acute respiratory infection (ARI) control programme in a rural community of the hill region of Nepal.

A prospective study was conducted to determine the magnitude of morbidity and mortality caused by acute respiratory infections (ARI) among children under 5 years of age and to assess the feasibility of reducing mortality owing to ARI by the use of community health workers. Villages selected for this study were situated on the south-west edge of Kathmandu Valley, about 24 km from the city centre. The study group consisted of 1019 children under the age of 5 years at the beginning of the study and followed for 3 years. During the 1st year, baseline information was collected. During the 2nd and 3rd years, intervention measures (health education, immunization and antibiotics for children with signs suggesting pneumonia) were taken and their effect assessed. There was a 59% reduction in the ARI-specific death rate among study children between surveillance year and intervention year I and a further 25% reduction in the ARI-specific death rate between intervention years I and II. Despite a substantial reduction in ARI mortality with the interventions, there was still an unacceptably high mortality from chronic diarrhoea, malnutrition and other factors. This implies that the programme to control ARI, diarrhoea, malnutrition and immunizable diseases should be integrated into one, within the framework of a primary health care strategy.

Indoor air pollution in developing countries and acute respiratory infection in children.

PIP: Indoor air pollution emerges as an important risk factor for acute respiratory infections (ARI) in developing countries. In many developing countries, in addition to an increasing amount of tobacco smoke, many homes contain high levels of smoke from the combustion of biofuels such as wood, crop residues, and animal dung for cooking or heating. In about half the world's households, such fuels are used for cooking daily, usually without a flue or chimney and with poor ventilation. Results of investigations in 6 developing nations have shown the range of indoor pollution in such circumstances. The best single indicator for comparison of toxic noncarcinogenic effects is most likely respirable particulates, similar to tar reported for cigarette emissions. Results of studies in animals suggest any difference in respiratory-system toxicity according to mass is not likely to be large. On the basis of the small amount of evidence available, peak and daily exposures to indoor particulate levels in villages in developing countries seem to be about 20 times greater than in developed nations. The results of a semi-quantitative epidemiological study conducted in Nepal showed a direct relation between reported hours/day spent near the stove by infants and children aged under 2 years and episodes of life threatening acute respiratory infections. If one discounts the many possible confounding factors, extrapolation shows that by moving all children into the lowest smoke exposure groups as much as 25% of moderate and severe infections would be eliminated. Extrapolation from studies of both ARI and environmental tobacco smoke also indicates indirectly the potential effect of indoor smoke from biofuels. Some environmental tobacco smoke studies have reported a dose-response relation between the number of cigarettes smoked in the home and respiratory symptoms in children. In sum, biofuel smoke is likely to be a factor in ARI, but its importance in relation to other risk factors is difficult to establish. It may be that prevention of acute respiratory infections could be best realized by initially addressing other risk factors or by addressing smoke solely in the context of broad based programs for several risk factors.^ieng

Epidemiological study of tobacco smoking behaviour among adults in a rural community of the hill region of Nepal with special reference to attitude and beliefs.

This study, designed to examine adult smoking behaviour, attitudes and norms was carried out in the hill villages of Alapot and Bhadrabas, Nepal, using the WHO standardized survey questionnaire. Some 1506 adults were interviewed. The overall prevalence of daily smokers is 73.7%. The majority of people, though aware of hazards of smoking, are not concerned with its possible effects on their own or other people's health. More males than females endorse public action against smoking. Both the endorsement of public action against smoking and awareness of social norms discouraging smoking increase with educational attainment. The motives for not smoking and endorsement of public actions against smoking have been ranked. Based on these findings strategies for a national smoking control programme have been recommended.

Domestic smoke pollution and respiratory function in rural Nepal.

A study was conducted to see the effect of domestic smoke pollution on respiratory function by using vitalograph Model 20.400 S-type dry portable spirometer in 150 randomly selected female subjects aged 30-44 years from a rural area situated in the outskirts of Kathmandu valley at an altitude of 4,800 ft. above sea level. The area is totally free from industrial and atmospheric pollution. Women spend considerable time near the fireplace, which serves both cooking and heating purposes and emits smoke from wood and other biomass fuel. Domestic smoke pollution is considerable because dwellings are ill-ventilated and without chimnies. The selected sample comprised of 6 groups-25 subjects each of 3 exposure levels to domestic smoke pollution amongst smokers and non-smokers. All the spirometric tests (FVO, FEV1 and FMEF 25-75) were performed in a standard way as recommended by American Thoracic Society in Snowbird Meeting in 1979. Variation of age, height, arm-span and weight between the three different levels of exposure to domestic smoke in both the smokers and non-smokers were compared and results revealed no significant variation in all the variables mentioned above. There was a fall of mean FVC, FEV1 and FMEF 25-75 as duration of exposure increased. This decline was found to be statistically significant amongst the smokers but not amongst the non-smokers. Similar results was found even after adjusting for age & height.

Prevalence of chronic bronchitis in a rural community of the Hill Region of Nepal.

A house to house survey of everyone aged 20 years and above living in a rural community in the Hill Region of Nepal, situated about 16 km outside Kathmandu city, was conducted to determine the prevalence of chronic bronchitis and cor pulmonale. Of the total eligible population, 2826 (95.5%) were interviewed. Chronic bronchitis was diagnosed according to the British Medical Research Council criteria, and emphysema and cor pulmonale according to the World Health Organisation expert committee criteria. The crude prevalence of chronic bronchitis was found to be 18.3%. The prevalence rate of chronic bronchitis was similar in men and women, whereas in most parts of the world much lower rates have been recorded in women. Study of a random sample of 85 individuals with chronic bronchitis showed that 57.4% had evidence of airways obstruction, whereas 15.8% of a representative sample (n = 111) of the surveyed population (excluding those with chronic bronchitis) showed evidence of airway obstruction. Of 516 subjects diagnosed as having chronic bronchitis, 382 were subsequently investigated in hospital, 134 having declined further investigation. The diagnosis was confirmed in most of the patients (93.2%) who were investigated. Other diseases played an insignificant part in the production of the observed high prevalence rates of chronic bronchitis. Of the 382 patients studied in hospital, 87 had emphysema and 42 had cor pulmonale, yielding overall prevalence rates for these two conditions of at least 3.1% and at least 1.5% respectively.