[Relationship between low back pain and physical activity and sitting time among community-dwelling older adults: A cross-sectional study].

Objectives　Japan has a high prevalence of low back pain among older adults requiring long-term care, which results in increasing expenses; therefore, prevention measures are necessary. This study aimed to examine the relationship between low back pain and physical activity and sitting time according to sex and age (65-74 years [young-old adults]; ≥75 years [old-old adults]) who had not received long-term care certification.Methods　A self-administered survey was mailed to 7,080 adults >65 years of age residing in Tsuru City (Yamanashi Prefecture, Japan) from January to February 2018, and had not received long-term care certification. Demographic information, health status (body mass index and medical history), lifestyle (dietary habits, alcohol consumption, and smoking), presence of low back pain, physical activity, sitting time, and social participation were measured. Low back pain was evaluated by asking, "Did you experience pain in parts of the body other than the knees for the past month?" Those who answered, "experienced low back pain" were categorized as "with low back pain". The short form of the International Physical Activity Questionnaire was used to assess physical activity, which was categorized into three groups: <150, 150-299, and ≥300 min/week. Sitting time was divided into two groups: <480 and ≥480 min/day. Multiple logistic regression analysis was used to determine the association between low back pain and physical activity and sitting time, according to sex and age.Results　Of the 7,080 individuals surveyed, 4,877 responded (2,217 male, 2,660 female), corresponding to a response rate of 68.9%. The number of older adults with low back pain was 1,542 (31.6%) including 673 (30.4%) males and 869 (32.7%) females. The rate of low back pain in young-old adults was 29.8% and 33.6% in old-old adults. There was no significant relationship between lower back pain and physical activity among the young-old adults. In the old-old adults, there was a significant relationship in the male ≥300 min group (odds ratio [OR] 0.66 [95%CI 0.48-0.89]), and in both female 150-299 (OR 0.69 [95%CI 0.48-0.99]) and ≥300 (OR 0.59 [95%CI 0.44-0.80]) min/week groups.Conclusion　The complaint rate for low back pain was approximately 30%, regardless of sex or age. These results suggest that interventions to prevent low back pain are necessary. Moreover, physical activity, but not sitting time, was associated with low back pain in both males and females among the old-old adults.