Obesity and pain are associated in the United States

Recent small-scale studies have shown a positive association between central obesity and self-reported pain levels. This study attempts to replicate the finding in a survey of over 1,000,000 individuals in the United States. The Gallup Organization conducted a proprietary survey between 2008 through 2010 where 1,062,271 randomly selected individuals in the United States participated in a telephone interview. Survey questions included height and weight, from which BMI was computed, questions about pain conditions in the past year, and a question about pain experience yesterday. Only 36.8% [corrected] of the sample was classified as Low-Normal BMI, 38.6 [corrected] were classified as Overweight, and the remainder was in the three categories of Obese. BMI and pain yesterday were reliably associated when demographic variables were controlled: the overweight group reported 20% higher rates of pain than Low-Normal group, 68% higher for Obese I group, 136% higher for Obese II group, and 254% higher for Obese III group. The association held for both men and women and it became stronger in older age groups. Controlling the associations for other pain-related medical conditions substantially reduced the associations, but they remained substantial for the Obese groups. We conclude that BMI and daily pain are positively correlated in the United States: people who are obese are considerably more prone to having daily pain. The association is robust and holds after controlling for several pain conditions and across gender and age. The increasing BMI-pain association with older ages suggests a developmental process that, along with metabolic hypotheses, calls out for investigation.