Indo-Caribbean population has lower vital capacities than Afro-Caribbean population in Trinidad and Tobago

Objective: Low forced vital capacity (FVC) is a good predictor of mortality and morbidity including cardiovascular disease, diabetes and chronic kidney disease in the general population. Objective of the current post-hoc analysis was to compare the FVCs among the major ethnic groups of Trinidad and Tobago. Design and Methodology: The Burden of Obstructive Lung Disease in Trinidad and Tobago (BOLD-TT) study was conducted to measure the COPD prevalence and its risk factors in the local population of 40 years and older by using questionnaires and quality assured spirometry. The participants were selected using two-stage stratified, cluster sampling to represent the national population in terms of gender, age and ethnic distributions. To avoid the influence of contentious international spirometry predictive values, FVC was used as a continuous variable after adjusting for age, gender, height and height square. Results: Among the 1,104 participants, 42% were Indo- Caribbeans, and 36% were Afro-Caribbeans. Indo- Caribbeans had a similar prevalence of abnormal waist circumference (57.0% vs. 58.7%; p=0.751), a lower prevalence of obesity (30.0% vs. 41.8%; p=0.008), but a higher prevalence of abnormal waist-hip ratio (74.1% vs. 57.5%; p<0.001) and diabetes (21% vs. 10%; p<0.001) than the Afro- Caribbeans. Multiple regression analysis indicated that FVC was independently associated with ethnicity and revealed lower volumes in Indo- Caribbean participants than Afro-Caribbeans (-180ml; 95%CI:-90ml,-269ml; p<0.001). Conclusions: The Indo-Caribbean population has a lower FVC than the Afro-Caribbean population which was independent of age, gender, and height. Healthrelated consequences of low FVC among local ethnic groups warrant further research using longitudinal studies.

Pulmonary function in Afro-Jamaicans: implications in screening

Pneometric parameters and closing volume were measured in 950 Afro-Jamaicans of both sexes. Prediction formulae relating each measurement to age and height were constructed. Based on these formulae it is concluded that differences in compartments of the lung exist in Afro-Jamaicans. Closing volume measurements yielded higher values for Afro-Jamaicans than is observed in white populations. It is suggested that in the absence of baseline values an erroneous diagnosis of small airway disease could result. The possibility that the observed differences may have been due to environmental rather than genetic factors is discussed. (AU)

Lung function of healthy boys and girls in Jamaica in relation to ethnic composition, test exercise performance, and habitual physical activity

The relationships of forced expiratory volume and forced vital capacity of height, age, sex, area of residence, and ethnic composition were assessed in 622 children in Jamaica. Rural children in hill-farming communities were judged to have a higher habitual physical activity than urban children. Allowing for differences in body size, forced vital capacity averaged 3 percent greater in rural children than in urban children, 7 percent less in girls than in boys, and 16 percent greater in children of European origin than in children of African descent. Lung volumes, indices of gas transfer, and sub-maximal-exercise responses were measured in a subgroup of 108 children of African descent believed to be of common genetic stock. Total lung capacity and vital capacity averaged respectively 6 percent greater and 7 percent greater in rural than in urban children of equal height but residual volume and transfer factor did not differ significantly between localities. Rural children had a lower average cardiac and respiratory components of the oxygen transport system, consonant with the demand for muscular work. Increased habitual physical capacity, total lung capacity, and transfer factor (AU)

Cigarette smoking and irreversible airways obstruction in the West Indies

Two communities, one in Jamaica and one in Guyana, have been surveyed in order to investigate the relationships between cigarette smoking and respiratory symptoms, and lung function in the West Indies. Cigarette consumption was less than that reported in the United Kingdom, particularly among women. Smoking was associated with cough, phleghm, increases in total lung capacity and residual volume, and reductions in FEV percent, transfer coeffecient (Kco), and aveolar capillary blood volume (Vc). Vital capacity (VC) and the diffusion capacity of the alveolar membranes (Dm) were normal. After allowing for differences in age and tobacco consumption, less cough, phleghm and airways obstruction occurred in the West Indies than has been reported in the United Kingdom. Forty-seven patients in Jamaica with chronic obstructive lung disease were followed for three years. All except six female asthmatics were either current smokers or ex-smokers. Smoking in patients was associated with a similiar but more severe pattern of lung disease to that found in survey subjects with, in addition, reductions in VC, and Dm. In the non-smoking asthmatics Kco, Dm, and Vc were normal. The lung function of these 47 patients was similiar to that reported for UK patients even though both chronic bronchitis and hypercapnia were considerably less common in Jamaica. Emphysema was present in all six patients who died and came to necropsy. It is suggested that in the West Indies emphysema contributes more than bronchitis to airways obstruction in smokers. There was also evidence that subjects of African origin were less susceptible to the emphysema-producing effect of cigarettes than were other ethnic groups (AU)

Variation in forced expiratory volume curves of asthmatic patients with increased water content

An experiment was designed to provide information on the "safe" level of humidifiction of inspired air in asthmatic patients. It was found that air at 25 degrees celcius and 70 percent relative humidity (RH) (16.11 gm/cu m WC) and 35 degrees celcius, 40 percent RH (17.80 gm/cu m) had no significant effect on forced expiratiory volume parameters. At 25 degrees celcius, 95 percent RH (21.88 gm/cu m WC) and above changes in VC/PVC, FEV 1 and FEV 3, MMF and MBC were significantly affected (P < 0.01). Approximately 21.88 gm/cu m Water content is considered the point at which humidification of inspired air ceases to be therapeutically useful.(AU)

Ethnic variation in forced expiratory volume and forced vital capacity of African and Indian adults in Guyana

In Guyana, forced expiratory volume in one second and forced vital capacity were measured in 96 African men, 109 African women, 129 Indian men, and 99 Indian women between 35 and 54 years old. No subject had evidence of any disorder that might have impaired ventilatory capacity. Indians of both sexes had significantly smaller values by approximately 4 percent to 7 percent than Africans, and both groups had smaller values than those quoted for white persons. These differences remained significant after standardization for age and body size. The forced expiratory volume and forced vital capacity values of the subjects are described as multiple regression equations on height and age.(Summary)