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UB study finds large abdomen can reduce men's lung function by 15 percent
By LOIS BAKER
Contributing Editor
Accumulating fat around one's middle can significantly impair lung function, new findings show, in addition to increasing the risk of heart disease.
The research, conducted by UB scientists, found that men in their study with the most abdominal fat experienced a 15.5 percent decrease in pulmonary function compared with men with the least fat. Women in the highest abdominal fat group showed a nearly 8 percent decrease in lung performance.
Results of the study were highlighted at the American Thoracic Society's 100th International Conference held recently in Orlando.
"There is a lot we don't know about lung function," said Heather Ochs-Balcom, doctoral candidate in the Department of Social and Preventive Medicine in the School of Public Health and Health Professions and first author on the study. "But we do know that reduced pulmonary function is associated with cardiovascular and all-cause mortality.
"Abdominal fat is associated with insulin resistance, a low-grade, system-wide inflammatory condition that may adversely impact pulmonary function," said Ochs-Balcom. "Therefore, we hypothesized that insulin resistance and abdominal obesity may be an important link between reduced lung function and mortality.
"This study has shown that the adverse association between abdominal obesity and pulmonary function is not limited to the severely obese. It also was seen in participants who were overweight and moderately obese. However, we need more work to identify the specific mechanism at work and to analyze how changes in weight are related to pulmonary function, which will tell us whether the negative effects on pulmonary function are reversible."
The study involved 2,153 men and women between the ages of 35 and 79 selected randomly from Erie and Niagara counties in Western New York. Persons with asthma or existing lung problems were excluded from the study.
Researchers collected measurements of weight, body-mass index, waist circumference, waist-to-hip ratio and abdominal height from all participants, as well as data on age, race and smoking history. Abdominal height was measured with a caliper while the participants lay flat on their back.
Readings of both forced expiratory volume in one second (FEV1) and forced vital capacity (FVC)—the maximum volume that can be forcefully and rapidly exhaled after a maximal inhale—were taken as well.
Results showed that of all the measures of obesity, abdominal height was associated most significantly with impaired lung function. The association was stronger in men than in women.
Abdominal height showed the strongest adverse association with FVC, with reductions of 7.9 percent among women and 15.5 percent in men, compared to those with the lowest abdominal height. The highest abdominal measures were associated with reduced FEV1 of 4.5 percent among women and 11.9 percent in men, results showed.
Additional researchers were Paula Muti, Jo Freudenheim and Maurizo Trevisan, all from the Department of Social and Preventive Medicine; Brydon Grant from the VA Medical Center and UB Department of Social and Preventive Medicine, and Holger Schünemann from the UB departments of Medicine and Social and Preventive Medicine.
The research was supported by grants from the American Lung Association and the National Institutes of Health.