PULMONARY FUNCTION OF HERDSMEN: DISCUSSION

spirometry

Findings resulted from our study of the relation of nutritional status and pulmonary function in rural Fulani males as compared to urban males. First, there was a significant difference in the nutritional status of the two study populations as assessed by weight, BMI, mid-arm circumference, and triceps skin-fold thickness measurements. Although the mean heights of both groups were identical (1.70 m), the Fulani men weighed, on average, about 9 kg less than their urban counterparts, which translated into a mean difference in BMI between the two study populations of 3.1 kg/m2. In light of the observed difference in BMI, it was not unexpected, therefore, to find that mid-arm circumference and triceps skinfold thickness were also decreased in the Fulani men, since mid-arm circumference and triceps skin-fold thickness are indices of muscle mass and subcutaneous fat, respectively. The anthropometric variations we observed between these two groups of subjects corresponded with observations made in previous studies of these same populations.

Second, despite differences in nutritional status, there were no significant differences in FVC, FEVi, FEF, or PEF between the two study populations. However, the percent of the predicted FVC for both groups, based on predicted values derived from equations for African Americans that were corrected for age and height, fell 15.5% below the expected values—a much greater decrease than the 6% observed by Gathuru and coworkers when they compared Nigerians and African Americans with no history of tobacco use; however, these values were still within the generally accepted normal range (i.e., 80-120% of predicted). Interestingly, the decrease we observed in percent of the predicted FEVi (corrected for age and height in African Americans) was consistent with the 8% difference that was reported between Nigerian and African-American adults. This finding is interesting, especially in light of the physically demanding nature of the work performed daily by the Fulani men, because high levels of physical activity tend to be associated with increased FVC relative to FEVb which would result in a lower than predicted FEVi to FVC ratio. However, the FEVi/FVC ratio, while it was the only index of pulmonary function that showed a statistically significant difference between the two study populations, was above the predicted value by about 2% in the urban males and by nearly 10% in the Fulani males. The FEVi/FVC ratio is often but not necessarily elevated in restrictive pulmonary conditions. While the generally accepted normal value for FEVi/FVC is in the range of 0.75-0.80, the elevated values we observed in the urban and Fulani men (0.85 versus 0.93, respectively) should not be cause for immediate concern due to the absence of other well-documented deficits in vital capacity and total lung capacity, which are necessary for positively identifying restrictive pulmonary patterns. kamagra oral jelly 100mg

However, coupled with the values we observed for FVC, which were only a few percent above the lower range of normal in the Fulani men, our results show a trend which may be indicative of borderline restrictive pulmonary disease (e.g., parenchymal disease, neuromuscular abnormalities, or chest wall deformities) and deserves further investigation. Unfortunately, due to the pastoral existence of the Fulani men and technical limitations where the study was performed, it was not possible for us to measure total lung capacity, which is required for diagnosing restrictive lung disease, or of diffusing capacity of carbon monoxide, which is commonly decreased in restrictive disease. Additionally, as our results did not point to the presence of gross alterations in pulmonary function, it was not reasonable to perform lung biopsies, which would have provided more definitive information.

Another pulmonary function parameter, FEF25-75%, while being suggestive of small airway obstruction, is not specific. However, in individuals with abnormally small lungs, the FEF25-75% must be interpreted cautiously, since the total lung capacity of these individuals is reduced. The values we observed for FEF2575% were increased for both the urban and rural Fulani men (102% and 117% predicted from equations corrected for age and height in African Americans). While these results are not specific, they lessen the likelihood that the subjects in both either study population were experiencing obstructive pulmonary disease. canadian pharmacy support net

The third observation we made related to the correlation of anthropometric parameters and pulmonary function indices. For the Fulani men, we saw small but significant correlations between pulmonary function parameters and age, height, and weight. However, the significant correlations we found for the urban males were between the pulmonary function parameters and weight, BMI, mid-arm circumference, and triceps skin-fold thickness. One possible reason for our not having found a significant correlation between pulmonary function and height in the urban subjects may be the small sample size (n=28) and relative lack of variability in the height of the subjects. The strongest correlations we observed were between pulmonary function (FEVi and PEF in particular) and weight and mid-arm circumference in the urban subjects, which is of interest because of the relationship that mid-arm circumference and weight have with muscle mass. Bearing in mind that Cotes and colleagues and Lazarus and associates found significant relationships between muscle mass, percent body fat, and fat-free mass index (fat-free mass/m2), as well as that FEVi and PEF are elevated with increased expiratory effort during the FVC maneuver, this might indicate that there is a threshold above which muscle mass or FFM significantly impact pulmonary function. However, further research would be needed to evaluate this hypothesis.

It is interesting that the diminished pulmonary function parameters which we documented in our previous study of Fulani children and adolescents appeared not to persist into adulthood. However, based on the data we gathered, there is insufficient information to ascertain the reason for the lack of significant differences in pulmonary function parameters between adult Fulani men and men from the urban center of Jos. There are several possibilities that could explain this, one being that children with impaired pulmonary function do not survive into adulthood, as was postulated in a previous study by Gathuru and colleagues to explain the low rates of obstructive pulmonary disease symptoms reported by Nigerians. Our study raises the question of whether better nutrition, resulting in increased FFM, would improve the measured pulmonary function parameters of the Fulani children we studied.

Category: Main

Tags: anthropometry, lung function, spirometry

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