Journal of Anesthesia (2018) 32:360–367
Association of body mass index with chronic pain prevalence: a large
population‑based cross‑sectional study in Japan
· Yasuhiko Kubota
· Hiroyasu Iso
· Hiroyuki Oka
· Junji Katsuhira
· Ko Matsudaira
Received: 30 November 2017 / Accepted: 16 March 2018 / Published online: 26 March 2018
© Japanese Society of Anesthesiologists 2018
Purpose The aim of this study was to examine the association between body mass index and chronic pain.
Methods The outcome was chronic pain prevalence by body mass index (BMI). BMIs of less than 18.5, 18.5–25.0, 25.0–30.0,
and 30.0 or over kg/m
were deﬁned as underweight, normal weight, overweight, and obese.
Subjects We used data from 4993 participants (2464 men and 2529 women aged 20–79 years) of the Pain Associated
Cross-sectional Epidemiological survey in Japan. Sex-stratiﬁed multivariable-adjusted odds ratios were calculated with
95% conﬁdence intervals using a logistic regression model including age, smoking, exercise, sleep time, monthly household
expenditure, and presence of severe depression. We analyzed all ages and age subgroups, 20–49 and 50–79 years.
Results The prevalence of chronic pain was higher among underweight, overweight, and obese male respondents than those
reporting normal weight, with multivariable odds ratios of 1.52 (1.03–2.25), 1.55 (1.26–1.91), and 1.71 (1.12–2.60). Accord-
ing to underweight, only older men showed higher prevalence of chronic pain than normal weight men with odd ratios, 2.19
(1.14–4.20). Being overweight and obese were also associated with chronic pain in women; multivariable odds ratios were
1.48 (1.14–1.93) and 2.09 (1.20–3.64). Being underweight was not associated with chronic pain.
Conclusion There was a U-shaped association between BMI and chronic pain prevalence among men ≥ 50 years, and a
dose–response association among women. Our ﬁnding suggests that underweight should be considered in older men suf-
fering chronic pain.
Keywords Chronic pain · Body mass index · Underweight · Overweight · Obese
The association between obesity and chronic pain has been
well-documented by researchers . We have the clinical
impression, however, that underweight people are also more
likely to report chronic pain. People with severe chronic pain
may lose their appetite for food and, therefore, lose weight.
Few studies, however, have examined whether being under-
weight is correlated with chronic pain. This study, therefore,
sought to investigate this issue.
Body mass index (BMI), calculated using the square of
the height in meters (kg/m
), is a simple index designed to
consider health risks by body proportions . The current
WHO classiﬁcation deﬁnes underweight as having a BMI
of less than 18.50 kg/m
. The proportion of underweight
people in Japan (4.4% of men and 11.0% of women aged 20
and over in 2009) is higher than other developed countries
. For example, the proportion of underweight adults was
1.0% of men and 2.6% of women aged 20 and over in the
Electronic supplementary material The online version of this
article (https ://doi.org/10.1007/s0054 0-018-2486-8) contains
supplementary material, which is available to authorized users.
* Keiko Yamada
Public Health, Department of Social Medicine, Osaka
University Graduate School of Medicine, 2-2 Yamadaoka,
Suita, Osaka 565-0871, Japan
Osaka Center for Cancer and Cardiovascular Disease
Prevention, Osaka, Japan
Department of Medical Research and Management
for Musculoskeletal Pain, 22nd Century Medical
and Research Center, Faculty of Medicine, The University
of Tokyo, Tokyo, Japan
Department of Prosthetics and Orthotics and Assistive
Technology, Faculty of Medical Technology, Niigata
University of Health and Welfare, Niigata, Japan
Japan Labour Health and Welfare Organization, Tokyo, Japan