While many environmental exposures have valid and reliable biomarkers (e.g., ionizing radiation, persistent organochlorine pollutants), others have no available 'biomarkers' requiring proxy exposure assessments (e.g., poverty, physical activity), which may be subject to measurement error.
The causes of obesity are complex (lifestyle, physical activity, poverty, food insecurity, genetics and obesogenic chemicals all play a role).
Except for few variables (gender, poverty status, metro status, physical activity, and pain) all subgroup differences were significant at p <0.05.
The study controlled for poverty, urbanization, aging, obesity and physical activity.
Poverty, [ 10] lack of physical activity, [ 11, 12] poor diet, [ 13, 14] high rates of smoking, [ 13, 15] and side effects of antipsychotic medication, such as weight gain, [ 16, 17] likely contribute to the increased prevalence of medical comorbidities and premature mortality among persons with schizophrenia.
Moreover, for complex diseases, such as diabetes, the cumulative effect of multiple environmental insults (e.g., poverty, lack of opportunities for physical activity, and greater exposure to inexpensive, unhealthy foods) may dramatically heighten the risk of disease in genetically susceptible individuals (18, 19, 32).
Multiple models with various degrees of covariate adjustment are presented to provide clarity regarding confounding by design variables (age, sex, and race), socioeconomic status (education and poverty index), health behaviors (smoking status, physical activity, and diet), general vascular health status (hypertension and total cholesterol), and/or obesity (BMI and skinfold).
For example, approximately 32% of the population below 100% of the poverty level met the guidelines from the federal 2008 Physical Activity Guidelines for Americans, compared to 53% of the population at or above 200% of the poverty level [ 11, 12].
Age, sex, race/ethnicity, income-to-poverty ratio, education years, smoking history, drinking habits, physical activity, and frequency of regular dental visits were derived from interview data.
Disparate lifestyles currently coexist within and between countries of the region – undernutrition with overweight, dietary changes and physical activity associated with subsistence farming and poverty, with those associated with sedentary lifestyles and wealth.
Several lines of evidence are reviewed that suggest that the decline in physical activity of children, particularly those living in poverty in the United States, could have contributed to the rise in asthma.
