Lung volumes (LV) in African Americans (AA) are purported to be 10-15% less than Caucasians (C) for identical height (ht). To test this, 42 nonsmoking AA and 12 C controls with no history of lung disease underwent pulmonary function testing.
Spirometry and total lung capacity (TLC) by plethymography were obtained. Miller (M),Knudson (Kn),and Crapo (C) prediction equation estimates (PEE) for spirometry were used by entering age,sex,ht,and weight (wt) into appropriate equations. Body mass index (BMI) was also calculated. Results are mean + S.D. An abnormal LV was < 80% predicted.
There were 20 female/22 male AA, mean age 35. There were 6 male/6 female C, average age 38. The average ht/wt/BMI were 68.2 + 3.6 inches/175.9 + 32.7 lbs/26.4 + 3.4 and 67.0 + 4.6 inches/153.9 + 35.2 lbs/23.5 for AA and C, respectively. The average FEV1, FVC and FEV1/FVC ratio were 3.23 + 0.68 liters, 3.90 + 0.84 liters, and 0.83 + 0.06 and 3.71 + 0.80 liters, 4.56 + 1.05 liters, and 0.82 + 0.06 for AA and Caucasian, respectively. There were significant difference in wt, BMI, FEV1, and FVC between AA and C (p < 0.05). The mean reductions in FEV1 and FVC were 12.9% and 14.5% in AA. TLC was 5.00 + 1.08 liters and 6.14 + 1.35 liters in AA/C, respectively. They were significantly different (p < 0.01) with an average reduction in TLC of 18.6% in AA. Using the C PEE on AA revealed abnormal FEV1 and/or FVC values in 16/42, 14/42, and 2/42 using the M, Kn, or C equations, respectively. When PEE were adjusted down by 15% for FVC and FEV1, all AA values were normalized. All C spirometric values were normal.
Healthy AA of similar ht compared to C have smaller LV. This explains the etiology for the reduced diffusion noted in healthy AA compared to C(Pesola, et.al. Respiration, in press).
Healthy AA can be defined as abnormal using PEE for LV derived from C unless adjustments are made.
G.R. Pesola, None.