Cross-sectional association between sedentary time and body mass index in Japanese population: the NIPPON DATA 2010

Ohashi, Mizuki

Cross-sectional association between sedentary time and body mass index in Japanese population: the NIPPON DATA 2010

Tuesday, 19 August 2014

Exhibit hall (Dena'ina Center)

Mizuki Ohashi, BS , Shiga University of Medical Science, Otsu, Japan

Naoko Miyagawa, MS , Shiga University of Medical Science, Otsu, Japan

Yosikazu Nakamura, PhD , JICHI MEDICAL UNIVERSITY, TOCHIGI, Japan

Masato Nagai, PhD , Shiga University of Medical Science, Otsu, Japan

Masahiko Yanagita, PhD , Doshisha University, Kyotanabe, Japan

Yoshihiro Miyamoto, MD , National Cerebral and Cardiovascular Center, Suita, Japan

Nagako Okuda, MD , National Institute of Health and Nutrition, Tokyo, Japan

Hirotsugu Ueshima, MD , Shiga University of Medical Science, Otsu, Japan

Akira Okayama, MD , Japan Anti-Tuberculosis Association, Tokyo, Japan

Katsuyuki Miura, MD , Shiga University of Medical Science, Otsu, Japan

INTRODUCTION: Recent studies show the association between sedentary time and obesity; however, few studies have examined the association in Japanese population where obesity is less prevalent compared with Western populations. The purpose of this study is to examine the association between sedentary time and body mass index (BMI) in a representative Japanese population who participated in a national survey.

METHODS: This is a cross-sectional study of 2,829 general populations (1,201 men, 1,628 women, aged 20 years and older) (the NIPPON DATA2010), who participated in the National Health and Nutrition Survey of Japan conducted in 2010 by the Ministry of Health, Labour and Welfare. Participants were collected from 300 randomly selected districts from all over Japan. Total sedentary time including TV-viewing and sitting time per day was measured by self-report and the following interview by trained interviewers. We examined the association between sedentary time and BMI using multiple linear regression. Since age has an interaction with the association between sedentary time and BMI, we examined the association in participants aged less than 50 years and 50 years or over, separately.

RESULTS: The average sedentary time was longer in men (5.8 hours/day) than in women (5.2 hours/day). Mean BMI was 23.9 in men and 22.7 in women. Sedentary time was significantly and positively associated with BMI in women after adjustment for age, education, total energy intake, hours of heavy or moderate physical activity, smoking status, and drinking status. The association was significant both in women aged less than 50 years (ß=0.184, p=0.001) and in those aged 50 years or over (ß=0.117, p=0.002). Meanwhile, the association between sedentary time and BMI was not significant in younger and older men.

CONCLUSIONS: Sedentary time was independently and positively associated with BMI in Japanese women. Reducing sedentary behavior may have health benefits by lowering BMI.