Association between objectively measured physical activity and body mass index with low back pain: a large-scale cross-sectional study of Japanese men

Abstract Background The relationship between the combination of physical activity (PA) and body mass index (BMI) with low back pain (LBP) is unclear. The present study offers a cross-sectional assessment of how combinations of PA and BMI are related to LBP in Japanese men. Methods Participants were 4022 Japanese men (mean age = 47) who underwent regular clinical examinations. PA was measured using a uniaxial accelerometer and divided into tertiles (PAhigh, PAmiddle, PAlow). A self-administered questionnaire was used to report on persistent LBP experience, drinking and smoking habits, and any existing lifestyle diseases. After covariance adjustment, a logistic regression model was used to assess how combinations of PA and BMI are related to persistent LBP. Results 428 of the participants had persistent LBP. A clear negative dose-response relationship was found between PA levels and persistent LBP (P for linearity = 0.012). Regarding BMI, odd ratios were shown to be higher in the overweight/obese category (BMI ≥ 25 kg/m2) than for the normal weight category (BMI < 25 kg/m2). When the PAhigh was taken as the reference in the normal weight category, odds ratios for PAlow and PAmiddle in the normal weight category were shown to be high. Moreover, in the overweight/obese category, odd ratios for every fitness level were also high as for the normal weight category. Conclusion The present study showed that both PA and BMI are related to persistent LBP. Also, the prevalence of persistent LBP became higher when PAlow and high BMI are combined rather than the group of PAhigh and low BMI combination

Long-term Impact of Cardiorespiratory Fitness on Type 2 Diabetes Incidence: A Cohort Study of Japanese Men

Background: We sought to examine the association between cardiorespiratory fitness (CRF) and incidence of type 2 diabetes considering the follow-up period in a cohort of Japanese men with a maximum follow-up period of 23 years. Methods: This study enrolled 7,804 male workers free of diabetes in 1986. CRF was measured using a cycle ergometer, and maximal oxygen uptake was estimated. During 1986–2009, participants were followed for development of type 2 diabetes, which was diagnosed using fasting blood tests, self-administered questionnaires, or oral glucose tolerance tests after urinary tests from annual health checkups. Hazard ratios for the incidence of type 2 diabetes were estimated using Cox proportional hazards models. Results: During the follow-up period, 1,047 men developed type 2 diabetes. In analyses by follow-up periods (1986–1993, 1994–2001, and 2002–2009), there was an inverse dose-response relationship between CRF and the development of type 2 diabetes for all three follow-up periods (P for trend 0.019, 20 years among men

Importance of Achieving a “Fit” Cardiorespiratory Fitness Level for Several Years on the Incidence of Type 2 Diabetes Mellitus: A Japanese Cohort Study

Background: The “Physical Activity Reference for Health Promotion 2013” provides “fit” reference values for cardiorespiratory fitness (CRF) for good health. The importance of achieving a fit CRF level for several years on the subsequent prevention of type 2 diabetes mellitus (T2DM) remains to be clarified. Methods: This cohort study was conducted in 2,235 nondiabetic males aged 21 to 59 years, enrolled in April 1986 through March 1987. We calculated the ratio of the area under the curve (AUCratio) for actual measured values and the AUC for the reference values of CRF in each individual during an 8-year measurement period before the baseline. According to whether they met a fit CRF level or not, participants were categorized into groups based on the AUCratio (FitAUC or UnfitAUC) and initial CRF (Fitinitial or Unfitinitial), respectively. T2DM was evaluated on health checkups until March 2010. Results: During the follow-up period, 400 men developed T2DM. After adjustment for confounders, as compared with those in the FitAUC group, the hazard ratio (HR) for those in the UnfitAUC group was 1.33 (95% confidence interval [CI], 1.06–1.65). A combined analysis with the categories of initial value and AUCratio showed that, compared with the Fitinitial and FitAUC group, the HRs of Fitinitial and UnfitAUC, Unfitinitial and FitAUC, and Unfitinitial and UnfitAUC groups were 1.41 (95% CI, 0.99–2.00), 1.18 (95% CI, 0.81–1.70), and 1.40 (95% CI, 1.08–1.83), respectively. Conclusion: Achievement of a fit CRF level established in the Japan physical activity guideline for several years was associated with lower subsequent risk of T2DM

Additional file 1 of Association between objectively measured physical activity and body mass index with low back pain: a large-scale cross-sectional study of Japanese men

Table S1-B: Sensitivity Analysis, Table S2-B: Sensitivity Analysis. Sensitivity analysis of the results of the combined “None/Sometime (intermittently)” and “All the time (Persistent)” group of LBP compared to the “All the time (Persistent)” group of LBP. (DOCX 24 kb