Body mass index, or BMI, is a numerical measurement calculated from height and weight. This number is intended to measure obesity, but people with a high muscle mass may also have a high BMI. A high body mass index may be a risk indicator for a number of health problems, including respiratory disorders such as asthma. Understanding the link between body mass and asthma may help sufferers faced with treatment and lifestyle decisions.
Significance
A number of studies have indicated that a higher body mass correlates directly with an increased risk of asthma and increased asthma severity. For example, according to the American Journal of Respiratory and Critical Care Medicine, young women with a higher BMI and early menstruation are more likely to suffer from severe asthma than women with a lower BMI or later menstruation. The American Academy of Pediatrics notes that children with a high BMI suffer from more severe asthma and more frequent asthma attacks.
Reporting Problems
Not all studies covering the link between body mass and asthma show the same results. The International Journal of Obesity suggests that part of this difference may be due to the way data is gathered. In studies for which people are allowed to report their own height and weight, body mass seems less closely connected to asthma than in studies in which the height and weight are measured by professionals.
Metabolic Imbalance
According to the website Modern Medicine, a study at the West Virginia University School of Medicine showed that children with problems metabolizing glucose and lipids---or fats---were more likely to suffer from asthma. These children had higher triglyceride levels and insulin resistance than non-asthmatic children, regardless of their body weight. Many children with these metabolic imbalances, however, also had high BMIs.
Considerations
A high BMI doesn't always mean a person is obese. It may also indicate high muscle mass or dense bones. High body mass correlates with some problems regardless of whether the person's mass is mostly fat or mostly muscle. For example, professional football players, who tend to have very high BMIs, suffer from an increased risk of heart disease and respiratory problems, including sleep apnea. This suggests that even very fit people with high a BMI may be at increased risk for asthma.
Prevention/Solution
The link between a high BMI and asthma shows reversibility, according to the National Institutes of Health. Reversibility is a concept that suggests lowering the patient's BMI should reduce asthma symptoms. A systematic review of the data on weight loss and asthma suggests that reducing the BMI decreases at least some symptoms in nearly all cases, regardless of the patient's age, gender or country of origin. Less information is available regarding weight loss and asthma in children.
Children should attempt to reduce body mass only under the supervision of a doctor.
References
- International Journal of Obesity: Body mass index and asthma among Mexican adults: the effect of using self-reported vs measured weight and height
- American Journal of Respiratory and Critical Care Medicine: Asthma Severity Is Associated with Body Mass Index and Early Menarche in Women
- American Academy of Pediatrics: Relationships Between BMI, Asthma Symptom Report & Activity Limitations: Findings from the Child Health Information Reporting Project (CHIRP)
- Modern Medicine: Metabolic Imbalance Linked With Asthma in Children
- USA Today: NFL linemen awaken to sleep apnea dangers
- National Institutes of Health: Weight loss and asthma: a systematic review
