Clustering of Lifestyle Factors and Its Association with Low Back Pain: A Cross-Sectional Study of Over 400,000 Japanese Adults

Purpose

Although many studies have indicated the association between low back pain (LBP) and lifestyle factors, the combined effect of lifestyle factors on LBP has not been adequately investigated. We aimed to investigate the association between a cluster of unhealthy lifestyle behaviors and LBP using a large cohort of Japanese adults.

Methods

We included 419,003 adults aged over 20 years who underwent an annual health checkup between April 2013 and March 2014 in Japan. Information on the following lifestyle factors was collected using the standardized questionnaire: smoking, alcohol intake, exercise, physical activity, walking speed, weight control, eating habits, and sleep. Each factor was evaluated as a dichotomous variable (1: health risk, 0: no health risk). A lifestyle risk score was calculated by summing the score of each lifestyle factor (range: 0–12) and was categorized into three groups (low, moderate, high). LBP was defined as self-reported LBP under treatment. Logistic regression analysis was conducted to calculate the odds ratio (OR) and 95% confidence interval (CI) for LBP.

Results

In multivariable logistic regression analysis, the OR for LBP was significantly higher in the moderate-risk score group (adjusted OR: 1.33 [95% CI: 1.23–1.44] in men; 1.40 [95% CI: 1.27–1.54] in women) and the high-risk score group (adjusted OR: 1.54 [95% CI: 1.43–1.67] in men; 1.83 [95% CI: 1.64–2.03] in women) than in the low-risk score group. A trend of higher risk of LBP associated with higher lifestyle risk score was observed in both sexes (p for trend < 0.001). These results were similar even in subgroup analysis by age and body mass index (BMI).

Conclusion

Clustering of unhealthy lifestyles was associated with increased risk of LBP regardless of age and BMI. These results may provide implications for better prevention and management of LBP, considering modifiable lifestyle factors.

Seven-day services in surgery and the "weekend effect" at a Japanese teaching hospital: a retrospective cohort study

Background

Hospitals deliver 24-h, 7-day care on a 5-day workweek model, as fewer resources are available on weekends. In prior studies, poorer outcomes have been observed with weekend admission or surgery. The purpose of this study was to investigate the effect of 7-day service at a hospital, including outpatient consultations, diagnostic examinations and elective surgeries, on the likelihood of the “weekend effect” in surgery.

Methods

This was a retrospective cohort study of patients who underwent surgery between April 2014 and October 2016 at an academic medical centre in Tokyo, Japan. The main outcome measure was 30-day in-hospital mortality from the index surgery. The characteristics of the participants were compared using the Mann–Whitney U test or the chi-squared test as appropriate. Logistic regression was used to test for differences in the mortality rate between the two groups, and propensity score adjustments were made.

Results

A total of 7442 surgeries were identified, of which, 1386 (19%) took place on the weekend. Of the 947 emergency surgeries, 25% (235) were performed on the weekend. The mortality following emergency weekday surgery was 21‰ (15/712), compared with 55‰ (13/235) following weekend surgery. Of the 6495 elective surgeries, 18% (1151) were performed on the weekend. The mortality following elective weekday surgery was 2.3‰ (12/5344), compared with 0.87‰ (1/1151) following weekend surgery. After adjustment, weekend surgeries were associated with an increased risk of death, especially in the emergency setting (emergency odds ratio: 2.7, 95% confidence interval: 1.2–6.5 vs. elective odds ratio: 0.4, 95% confidence interval: 0.05–3.2).

Conclusions

Patients undergoing emergency surgery on the weekend had higher 30-day mortality, but showed no difference in elective surgery mortality. These findings have potential implications for health administrators and policy makers who may try to restructure the hospital workweek or consider weekend elective surgery.

Correction to: Cross-sectional study of associations between normal body weight with central obesity and hyperuricemia in Japan

After publication of this article [1], it was brought to our attention that there is an error in the Table 5, which "Cases" should be revised to "HU" in Table 5. The original publication has been corrected.

Changes in overweight/obesity and central obesity status from preadolescence to adolescence: a longitudinal study among schoolchildren in Japan

Background

Little is known about changes in overweight/obesity and central obesity status among schoolchildren from preadolescence to adolescence in Japan, where waist circumference (WC) is generally not measured in annual health examinations at elementary and junior high schools. This study examined changes of overweight/obesity and central obesity status among schoolboys and schoolgirls from preadolescence to adolescence in Japan.

Methods

Study subjects were fourth-grade school children (9 or 10 years of age) from all four of Ina town’s elementary schools in Japan. Measurement of each participant’s height, weight, and WC were made at baseline and 3 years later. Childhood overweight/obesity was determined according to the age- and sex-specific body mass index cut-off points proposed by the International Obesity Task Force. Central obesity was defined as waist-to-height ratio ≥ 0.5. Kappa (κ) statistic was calculated to examine the tracking of overweight/obesity and central obesity.

Results

Data from 1436 participants (boys: n = 720, girls: n = 716) were analyzed. Overweight/obesity status tracked substantially from fourth grade to seventh grade in both boys (κ = 0.614, P value < 0.001) and girls (κ = 0.619, P value < 0.001). Among participants who were overweight/obese in fourth grade, 55.2% of boys and 63.2% of girls were still overweight/obese in seventh grade. Tracking of central obesity from fourth graders to seventh graders was substantial in boys (κ = 0.651, P value < 0.001) and moderate in girls (κ = 0.544, P value < 0.001). Among participants who had central obesity in fourth grade, 54.1% of boys and 52.6% of girls still had central obesity in seventh grade.

Conclusions

The present study showed that the tracking of overweight/obesity from preadolescence to adolescence was substantial in boys and girls. Moreover, more than half of those who had central obesity in preadolescence had central obesity in adolescence. This study suggests that it is important to implement a primary prevention program for overweight/obesity and central obesity in elementary schools before fourth grade.

Survey of a nutrition management method for very low birthweight infants: Status before wide use of breast milk banks in Japan

BACKGROUND

The importance of breast-feeding for very low birthweight (VLBW) infants has been pointed out. Some overseas studies suggested that the standardization of enteral nutrition (EN) leads to improved prognosis in VLBW infants. In Japan, however, physicians in charge of infants are responsible for making nutrition management decisions on an individual basis. We conducted an online survey to clarify the course of nutrition management of VLBW infants currently implemented in Japan.

METHODS

We mailed a notice to 300 representative neonatologists throughout Japan requesting their participation in the online survey. On the survey website, neonatologists responded to questions regarding the nutritional strategy for five birthweight groups (less than 500 g, 500-749 g, 750-999 g, 1,000-1,249 g and 1,250-1,499 g).

RESULTS

Responses were recieved from 137 neonatologists. The first choice for EN up to 1 week after birth was breast milk regardless of birthweight (92.0% for 1,250-1,499 g to 95.6% for 500-999 g). More than 30% of the respondents answered that they fast infants who weigh <750 g at birth or feed them with other mothers' breast milk until their own mother's milk becomes available. The lower the birthweight, the later EN is started, and the greater the number of days to establish EN.

CONCLUSION

The lower the birthweight, the more difficult it is to feed infants their own mother's milk and the later the EN is started. If donor milk is supplied in a stable manner, it takes fewer days to establish EN.

Cross-sectional study of associations between normal body weight with central obesity and hyperuricemia in Japan

BACKGROUND

Several studies have shown that normal weight with central obesity (NWCO) is associated with cardiovascular disease risk factors such as hypertension, dyslipidemia and diabetes. However, the relationship between NWCO and hyperuricemia has not been studied in detail.

METHODS

We investigated the association between NWCO and hyperuricemia among Japanese adults aged 40-64 years who had undergone periodic health examinations between April 2013 and March 2014. Obesity was defined as a body mass index (BMI) ≥25 kg/m² and central obesity was determined as a waist-to-height ratio (WHtR) ≥0.5. We classified the participants into the following groups based according to having obesity and central obesity: normal weight (BMI 18.5-24.9 kg/m²) without (NW; WHtR < 0.5) and with (NWCO) central obesity, and obesity without (OB) and with (OBCO) central obesity. Hyperuricemia was defined as serum uric acid > 7.0 and ≥ 6.0 mg/dL in men and women, respectively, or under medical treatment for hyperuricemia. Alcohol intake was classified as yes (daily and occasional consumption) and none (no alcohol consumption). Odds ratios (OR) and 95% confidence intervals (CI) for hyperuricemia were calculated using a logistic regression model.

RESULTS

We analyzed data derived from 96,863 participants (69,241 men and 27,622 women). The prevalences of hyperuricemia in men and women were respectively, 21.4 and 11.0%, and of participants with NWCO respectively 15.6 and 30.0%. The adjusted OR for hyperuricemia was significantly increased in OBCO compared with NW, regardless of sex (men: OR, 2.12; 95%CI; 2.03-2.21; women: OR, 3.54; 95%CI, 3.21-3.90) and were statistically significant in NWCO compared with NW (men: OR, 1.44; 95%CI, 1.36-1.52; women: OR, 1.41; 95%CI, 1.27-1.57). The results were similar regardless of alcohol consumption.

CONCLUSIONS

We found that NWCO and OBCO were associated with hyperuricemia in middle-aged Japanese men and women. Middle-aged Japanese adults with normal weight but having central obesity should be screened using a combination of BMI and WHtR and educated about how to prevent hyperuricemia.

Associations between normal weight central obesity and cardiovascular disease risk factors in Japanese middle-aged adults: a cross-sectional study

BACKGROUND

Several studies have shown that normal weight central obesity (NWCO) is associated with cardiovascular disease (CVD) risk factors. However, studies conducted in the Japanese population have been very limited. Thus, the relationships between normal weight central obesity, classified using body mass index (BMI), the waist-to-height ratio (WHtR), and CVD risk factors in middle-aged Japanese adults were investigated.

METHODS

The participants were Japanese adults aged 40-64 years who had undergone periodic health examinations in Japan during the period from April 2013 to March 2014. The participants were categorized into the following four groups: normal weight (BMI 18.5-24.9 kg/m²) and no central obesity (WHtR < 0.5) (NW); normal weight and central obesity (WHtR ≥ 0.5) (NWCO); obesity (BMI ≥ 25 kg/m²) and no central obesity (OB); and obesity and central obesity (OBCO). Hypertension was defined as systolic blood pressure ≥ 140 mmHg, diastolic blood pressure ≥ 90 mmHg, or taking medication for hypertension. Dyslipidemia was defined as LDL-C ≥ 140 mg/dl, HDL-C < 40 mg/dl, triglyceride ≥ 150 mg/dl, or taking medication for dyslipidemia. Diabetes was defined as fasting plasma glucose ≥ 126 mg/dl, random plasma glucose ≥ 200 mg/dl, HbA1c ≥ 6.5%, or receiving medical treatment for diabetes mellitus. A logistic regression model was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for hypertension, dyslipidemia, and diabetes.

RESULTS

A total of 117,163 participants (82,487 men and 34,676 women) were analyzed. The prevalence of NWCO was 15.6% in men and 30.2% in women. With reference to NW, the ORs for hypertension (adjusted OR 1.22, 95% CI 1.17-1.27 in men, 1.23, 1.16-1.31 in women), dyslipidemia (1.81, 1.74-1.89 in men, 1.60, 1.52-1.69 in women), and diabetes (1.35, 1.25-1.46 in men, 1.60, 1.35-1.90 in women) were significantly higher in NWCO.

CONCLUSIONS

Normal weight with central obesity was associated with CVD risk factors, such as hypertension, dyslipidemia, and diabetes, compared with normal weight without central obesity, regardless of sex. It is important to focus on normal weight with central obesity for the prevention of CVD in Japanese middle-aged adults.

Factors associated with disabling low back pain among nursing personnel at a medical centre in Japan: a comparative cross-sectional survey

OBJECTIVES

Low back pain (LBP) is a common cause of disability among nursing personnel. Although many studies regarding the risk factors for LBP among nursing staff have focused on the physical load at work, multidimensional assessments of risk factors are essential to identify appropriate preventive strategies. We aimed to investigate the association of multidimensional factors (individual, physical, psychological and occupational) with disabling LBP among nursing personnel in Japan.

DESIGN

Observational study with comparative cross-sectional design.

SETTING

Data were collected using the self-administered questionnaire at a tertiary medical centre.

PARTICIPANTS

After excluding participants with missing variables, 718 nursing personnel were included in the analysis.

OUTCOME MEASURES

A self-administered questionnaire assessed individual characteristics, rotating night shift data, severity of LBP, previous episode of LBP, sleep problem, kinesiophobia (Tampa Scale for Kinesiophobia), depressive condition (K6), physical flexibility and frequency of lifting at work. A logistic regression model was used to evaluate the factors associated with disabling LBP (LBP interfering with work) among nursing personnel.

RESULTS

Of all participants, 110 (15.3%) reported having disabling LBP. The multivariable logistic regression analysis after adjustment for several confounding factors showed that kinesiophobia (highest tertile, adjusted OR (aOR): 6.13, 95% CI : 3.34 to 11.27), previous episode of LBP (aOR: 4.31, 95% CI: 1.50 to 12.41) and insomnia (aOR: 1.66, 95% CI: 1.05 to 2.62) were significantly associated with disabling LBP.

CONCLUSIONS

The present study indicated that kinesiophobia, a previous episode of LBP, and sleep problems were associated with disabling LBP among nursing personnel. In the future, workplace interventions considering assessments of these factors may reduce the incidence of disabling LBP in nursing staff, although further prospective studies are needed.

Longevity-associated mitochondrial DNA 5178 C/A polymorphism modifies effect of aging on renal function in male Japanese health checkup examinees: an exploratory cross-sectional study

Background

Mitochondrial DNA 5178 (Mt5178) C/A polymorphism is reportedly associated with longevity in the Japanese population. The objective of this study was to investigate whether Mt5178 C/A polymorphism influences the effect of physiological aging on renal function in male Japanese health checkup examinees.

Methods

A total of 404 male subjects (mean age ± SD, 53.9 ± 7.8 years; range, 29–76 years) were selected from among individuals visiting the hospital for regular medical checkups. After Mt5178 C/A genotyping, a cross-sectional study assessing the joint effects of Mt5178 C/A polymorphism and aging on renal function was then conducted. Renal function was evaluated by estimated glomerular filtration rate (eGFR). Subjects were divided into three age groups (< 50, 50–59, ≥ 60 years).

Results

In simple linear regression analysis, a significant negative association between aging and eGFR was observed in both Mt5178C and Mt5178A genotypic men (P < 0.001 and P = 0.003, respectively). However, in multiple linear regression analysis, a significant effect of aging on reduced eGFR was observed only in Mt5178C genotypic men (P < 0.001). Logistic regression analysis showed that, in the case of reduced eGFR defined as < 75 mL/min/1.73 m², reduced eGFR was dependent on aging in both Mt5178C and Mt5178A genotypic men (P for trend < 0.001 and P for trend = 0.002, respectively). After adjusting for smoking status and alcohol consumption, reduced eGFR was also dependent on aging in both Mt5178C and Mt5178A genotypic men (P for trend < 0.001 and P for trend = 0.014, respectively). However, in reduced eGFR defined as < 90 mL/min/1.73 m², reduced eGFR was dependent on aging only in Mt5178C genotypic men (P for trend < 0.001).

Conclusions

This cross-sectional study suggests that Mt5178 C/A polymorphism modulates the effects of physiological aging on kidney function in Japanese men.

Sex differences in the association of metabolic syndrome with low back pain among middle-aged Japanese adults: a large-scale cross-sectional study

BACKGROUND

Although some recent studies have indicated an association between metabolic syndrome (MetS) and musculoskeletal disease, little is known about the association of MetS with low back pain (LBP). The present study aimed to investigate sex differences in the association of MetS and the clustering of MetS components with LBP among middle-aged Japanese individuals.

METHODS

Study subjects were 45,192 adults (30,695 men, 14,497 women) aged 40-64 years who underwent annual health checkups conducted from April 2013 to March 2014. MetS was defined according to the criteria of the Examination Committee of Criteria for MetS in Japan as abdominal obesity plus at least two of dyslipidemia, high blood pressure, or high blood glucose. Information on LBP and health-related lifestyles were collected using a self-administered questionnaire. Logistic regression modeling was used to calculate the odds ratio (OR) and 95% confidence interval (CI) for LBP.

RESULTS

After adjusting for age and lifestyle factors, the OR of MetS for LBP was 1.15 (95% CI 0.95-1.40) in men and 2.16 (95% CI 1.32-3.53) in women. Compared to subjects without abdominal obesity, the presence of abdominal obesity significantly increased the OR for LBP among men (abdominal obesity only: OR 1.34, 95% CI 1.02-1.76; abdominal obesity plus one component: OR 1.24, 95% CI 1.01-1.52; abdominal obesity plus two or more components: OR 1.26, 95% CI 1.02-1.55). Among women, adding other components of MetS to abdominal obesity significantly increased ORs for LBP (abdominal obesity only: OR 1.70, 95% CI 0.94-3.08; abdominal obesity plus one component: OR 1.66, 95% CI 1.06-2.60; abdominal obesity plus two or more components: OR 2.30, 95% CI 1.41-3.78).

CONCLUSIONS

This large-scale cross-sectional study indicated that MetS was significantly associated with LBP among women only and that a sex-difference existed in the association between the clustering of MetS components and LBP. Clustering of MetS components by sex may need to be considered for the prevention of LBP, although further prospective studies are needed to clarify the causality.

Association of the combination of weight gain after 20 years of age and current obesity with chronic kidney disease in Japan: a cross-sectional study

OBJECTIVES

Weight gain after 20 years of age is associated with chronic kidney disease (CKD). However, the impact of weight gain on CKD might differ by current obesity status. We investigated the association of the combination of weight gain after 20 years of age and current obesity with CKD among adults in Japan.

DESIGN

A cross-sectional study.

SETTING AND PARTICIPANTS

We analysed data from 94 822 adults aged 40-64 years who had an annual health check-up in Japan from April 2013 to March 2014.

PRIMARY OUTCOME MEASURE

CKD was defined as an estimated glomerular filtration rate <60 mL/min/1.73 m² and/or proteinuria.

RESULTS

Both weight gain ≥10 kg after 20 years of age plus obesity (OR 2.21, 95% CI 2.07 to 2.36) and weight gain of ≥10 kg plus non-obesity (OR 1.31, 95% CI 1.21 to 1.42) significantly increased the OR for CKD when compared with weight gain <10 kg plus non-obesity in men. In women, weight gain ≥10 kg plus obesity (OR 2.04, 95% CI 1.84 to 2.25) and weight gain ≥10 kg plus non-obesity (OR 1.53, 95% CI 1.36 to 1.72) significantly increased the OR for CKD compared with weight gain <10 kg plus non-obesity. These results persisted even after adjustment for age, lifestyle factors, hypertension, dyslipidaemia and diabetes.

CONCLUSIONS

Weight gain ≥10 kg after 20 years of age was significantly associated with CKD in both obese and non-obese subjects. Moreover, the influence of weight gain ≥10 kg plus obesity on CKD was greater than that of weight gain ≥10 kg plus non-obesity on CKD. The present study results suggest that it is important to consider weight gain after maturity in both obese and non-obese subjects to prevent CKD among Japanese middle-aged adults.

The relationship between thyroid function and cerebral blood flow in mild cognitive impairment and Alzheimer's disease

The thyroid hormones have been reported to be associated with cognitive decline and Alzheimer’s disease. The relationship between thyroid function within the normal range and cerebral blood flow in Alzheimer’s disease patients has been shown in a recent study. Mild cognitive impairment is often the first stage of Alzheimer’s disease; thus, early diagnosis is important. The present study investigated the relationship between thyroid function and regional cerebral blood flow in patients with mild cognitive impairment and Alzheimer’s disease. A total of 122 memory clinic outpatients who underwent thyroid function testing and single photon emission computed tomography were divided into mild cognitive impairment, Alzheimer’s disease, and Normal groups. Regional cerebral blood flow was calculated using a three-dimensional stereotactic region of interest template in an automated cerebral perfusion single photon emission computed tomography analysis system. Multiple regression analysis adjusted for age and sex was conducted to examine the relationships between thyroid hormones and regional cerebral blood flow. Thyroid stimulating hormone was significantly associated with regional cerebral blood flow in the bilateral temporal, bilateral pericallosal, and bilateral hippocampal regions in the mild cognitive impairment group. In the Alzheimer’s disease group, free triiodothyronine was significantly associated with regional cerebral blood flow in the bilateral parietal, right temporal, and bilateral pericallosal regions. The present study showed the association of thyroid stimulating hormone with regional cerebral blood flow in the mild cognitive impairment group and the association of free triiodothyronine with regional cerebral blood flow in the Alzheimer’s disease group. These study findings could contribute to the early diagnosis of mild cognitive impairment at general memory clinics and the prevention of subsequent progression to Alzheimer’s disease.

Prognostic Value of Left Atrial Size and Functional Indices Measured by 3-Dimensional Speckle-Tracking Analysis

BACKGROUND

The prognostic value of indices for left atrial volumes (LAV) and reservoir function measured by 3D speckle-tracking analysis (3DSTA) has not been determined. Methods and Results: LA maximal and minimal volume indices (LAVImax, LAVImin), and LA emptying fraction (LAEmpF) were measured via 2D echocardiography (2DE) and 3DSTA in 514 patients (62% male, mean age: 66±15 years) with various cardiovascular diseases. Two cutoff values using normal±2SD (cutoff criterion 1) and receiver-operating characteristic analysis (cutoff criterion 2) were evaluated. During a mean follow-up of 720±383 days, MACE (cardiac death, nonfatal myocardial infarction, stroke and admission for heart failure) occurred in 98 patients. Kaplan-Meier survival analysis showed both cutoff criteria measured by 2DE and 3DSTA had significant predictive power for MACE (P<0.001). For cutoff criterion 1, 3DSTA measurements yielded higher hazard ratios than 2DE by Cox proportional hazard model. Cutoff criterion 2 using 3DSTA had higher average treatment effect values than 2DE by matching propensity scores on the outcome. Further, a regression model that included clinical variables, left ventricular ejection fraction and cutoff criterion 2 using 3DSTA-derived LAEmpF had significantly higher prognostic power than 2DE.

CONCLUSIONS

LA indices measured by 3DSTA had greater prognostic power for future MACE than 2DE. In particular, 3DSTA-derived LAEmpF has the potential to be a valuable prognostic tool in clinical settings.

Survey on chronic disabling low back pain among care workers at nursing care facilities: a multicenter collaborative cross-sectional study

Purpose: Care workers at nursing care facilities have a high rate of low back pain (LBP). Although increasing evidence has revealed the important role of psychosocial factors in chronic LBP, factors associated with chronic LBP interfering with work have not been fully investigated in Japanese workers at nursing care facilities. The present study aimed to determine the prevalence of chronic LBP interfering with work and related factors of chronic LBP including psychosocial factors, among workers at nursing care facilities.

Material and methods: Eligible participants in the present study were Japanese workers at 95 nursing care facilities in Ishikawa Prefecture (n=2,242). Of these, 1,345 participants completed a self-administered questionnaire that included the following items: individual characteristics, severity of LBP, sleep problem, fear-avoidance beliefs (Tampa Scale for Kinesiophobia: TSK), STarT Back Screening Tool (SBST), fatigue, somatizing tendency, and work-related stress such as job satisfaction, job demand, interpersonal stress at work, and social support. The logistic regression analysis was used to assess factors associated with chronic disabling LBP.

Results: Of participants who completed the questionnaires, 159 (11.8%) reported chronic LBP that interfered with their work. The multivariable analysis of related-factors of chronic disabling LBP found statistically significant associations with the following: high score of psychological subscale in SBST (adjusted odds ratio [aOR]: 5.83, 95% confidence interval [CI]: 3.55–9.59), high score of TSK (aOR: 1.08, 95% CI: 1.05–1.13), and high somatizing tendency (aOR: 2.07, 95% CI: 1.31–3.23).

Conclusion: Psychological factors, including fear-avoidance beliefs or somatizing tendency, showed significant association with chronic LBP that interfered with work, among workers at nursing care facilities. Our results suggest that these factors would need to be considered in addition to screening for the risk factors of LBP chronicity by SBST when evaluating workers with chronic disabling LBP.

Association between serum lipids and low back pain among a middle-aged Japanese population: a large-scale cross-sectional study

Background

Abnormal lipid levels have been suggested as a mechanism leading to atherosclerosis of the lumbar vessels, resulting in low back pain (LBP). This study examined whether abnormal lipid levels were associated with LBP among middle-aged adults in Japan.

Methods

The present study included adults between 40 and 64 years old who underwent an annual health checkup. A total of 258,367 eligible participants were analyzed to investigate associations of LBP with low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and LDL-C/HDL-C ratio. Participants were categorized into two groups according to each of LDL-C, HDL-C, and LDL-C/HDL-C ratio (LDL-C: ≥ 140 vs. < 140 mg/dL; HDL-C: ≥ 40 vs. < 40 mg/dL; LDL-C/HDL-C ratio: ≥ 2.5 vs. < 2.5). Information on LBP was obtained using a self-administered questionnaire. Logistic regression modeling was used to calculate the odds ratio (OR) and 95% confidence interval (CI) for LBP.

Results

The prevalence of LBP was 2.2% in men and 2.1% in women. Multivariable analysis adjusting for age, body mass index, and lifestyle factors found significant associations for HDL-C <  40 mg/dL (OR, 1.34; 95%CI, 1.20–1.48 in men; OR, 1.32; 95%CI, 1.02–1.72 in women) and LDL-C/HDL-C ratio ≥ 2.5 (OR, 1.17; 95%CI, 1.09–1.26 in men; OR, 1.15; 95%CI, 1.03–1.29 in women) with LBP.

Conclusions

Low HDL-C and high LDL-C/HDL-C ratio were significantly associated with LBP in a middle-aged Japanese population. These findings might support the atherosclerosis-LBP hypothesis.

NADH Dehydrogenase Subunit-2 237 Leu/Met Polymorphism Influences the Association of Coffee Consumption with Serum Chloride Levels in Male Japanese Health Checkup Examinees: An Exploratory Cross-Sectional Analysis

Background: Nicotinamide adenine dinucleotide (NADH) dehydrogenase subunit-2 237 leucine/methionine (ND2-237 Leu/Met) polymorphism has been shown to modify the association of coffee consumption with the risk of hypertension, dyslipidemia, and abnormal glucose tolerance, and low serum chloride levels have been shown to be associated with all-cause and cardiovascular disease mortality. Therefore, the purpose of the present study was to investigate whether ND2-237 Leu/Met polymorphism influences the association of coffee consumption with serum chloride levels in male Japanese health checkup examinees. Methods: From among individuals visiting the hospital for a regular medical checkup, 402 men (mean age ± standard deviation, 53.9 ± 7.8 years) were selected for inclusion in the study. After ND2-237 Leu/Met genotyping, we conducted an exploratory cross-sectional study to examine the combined association of ND2-237 Leu/Met polymorphism and coffee consumption with serum electrolyte levels. Results: After adjusting for age, body mass index, habitual smoking, alcohol consumption, green tea consumption, and antihypertensive medication, coffee consumption significantly increased serum chloride levels (p for trend = 0.001) in men with the ND2-237Leu genotype. After these adjustments, the odds ratios (ORs) for low levels of serum chloride, defined as <100 mEq/L, were found to be dependent on coffee consumption (p for trend = 0.001). In addition, the OR for low levels of serum chloride was significantly lower in men with the ND2-237Leu genotype who consumed ≥4 compared with <1 cup of coffee per day (OR = 0.096, 95% confidence interval = 0.010–0.934; p = 0.044). However, neither serum chloride levels nor risk of low levels of serum chloride appeared to be dependent on coffee consumption. Conclusions: The results suggest that ND2-237 Leu/Met polymorphism modifies the association of coffee consumption with serum chloride levels in middle-aged Japanese men.

Relationship between Eating Quickly and Overweight : A Cohort Study of Schoolchildren in Japan

Several cross-sectional studies have shown that eating quickly is associated with overweight in children and adolescents. However, few cohort studies have examined this relationship. Here we investigated the relationship between eating quickly and overweight in a cohort study of fourth-grade schoolchildren (aged 9 or 10 years) who attended elementary schools in Ina-town, Japan. The children were followed for 3 years from 2001-2004 (at baseline) to 2004-2007. A questionnaire survey including information about eating speed (fast, medium, or slow) was administered, and height and weight measurements were obtained at baseline and follow-up. Overweight was defined according to the body mass index cutoff points proposed by the International Obesity Task Force. We used a Poisson regression model to examine the association between eating quickly at baseline and being overweight 3 years later. Data from 934 non-overweight children (465 boys, 469 girls) were analyzed. Eating quickly was not significantly associated with being overweight in the boys, whereas it was significantly associated with being overweight in the girls. Our analysis indicates that among girls, eating quickly leads to overweight, and that the modification of eating quickly could help prevent overweight in adolescents.

Effects of eating dinner alone on overweight in Japanese adolescents: a cross-sectional survey

Background

The decrease in the frequency of family meals among Asian youth is often lamented. In Japan, adolescents who eat breakfast alone might have an unhealthy diet, which increases the risk of overweight or obese. However, there are few studies on the relationship between eating dinner alone and overweight in Japanese adolescents. Here, we investigated if eating dinner alone is associated with being overweight in Japanese adolescents of each sex.

Methods

The participants consisted of 890 seventh graders (12–13 years of age) from the junior high schools of Ina, Japan who were recruited from 2011 to 2012. Information about eating dinner alone was obtained using a self-reported questionnaire, which was given to each participant. The participants were classified into the following three groups: does not eat alone, eats alone 1–2 times/week, or eats alone ≥3 times/week. A logistic regression model was used to examine the relationship between eating dinner alone and being overweight. The height and weight of each participant were measured. Childhood overweight status was defined using the body mass index cutoff points proposed by the International Obesity Task Force.

Results

When compared with girls who did not eat dinner alone, a significantly increased odds ratio (OR) was observed among girls who ate dinner alone ≥1 time/week (adjusted OR = 2.78; 95% confidence interval = 1.21–6.38). In contrast, there was no statistically significant difference between eating dinner alone and being overweight among boys.

Conclusion

The present study found that eating dinner alone is associated with being overweight among adolescent girls in this community in Japan. Therefore, reducing the frequency of eating dinner alone might contribute to decreasing the risk for becoming overweight or obese among adolescent girls.

Influence of eating quickly and eating until full on anthropometric gains in girls: A population-based, longitudinal study

BACKGROUND

In examining childhood overweight/obesity, there is a need to consider both eating quickly and eating until full. This longitudinal study investigated the influence of eating quickly and/or eating until full on anthropometric variables and becoming overweight/obese among Japanese schoolgirls.

METHODS

Study participants were fourth-grade schoolgirls (aged 9 or 10 years) in Ina Town, Japan. Physical examinations and a questionnaire survey were performed at baseline (fourth grade) and after 3 years (seventh grade). Height, weight, and waist circumference were measured in the physical examinations, while the data on eating quickly and eating until full were collected in the questionnaire survey. Analysis of variance and analysis of covariance were used to compare the differences in each anthropometric variable between fourth and seventh grade among groups.

RESULTS

Data on 425 non-overweight/obese schoolgirls in fourth grade were analyzed. Gains in anthropometric variables (body mass index, waist circumference, and waist-to-height ratio) from fourth to seventh grade were significantly larger in the "eating quickly and eating until full" group than in the "not eating quickly and not eating until full" group. In contrast, there were no significant differences in the gains between the "eating quickly or eating until full" group and the "not eating quickly and not eating until full" group. The proportion of overweight/obese girls in seventh grade was higher in the "eating quickly and eating until full" group than in the other groups.

CONCLUSIONS

Eating quickly and eating until full had a substantial impact on excess gains in anthropometric variables among schoolgirls, suggesting that modifying these eating behaviors may help prevent non-overweight/obese girls from the excess gains. Accordingly, school health programs need to focus on not eating quickly and/or not eating until full to prevent overweight/obesity; it is necessary to emphasize "the risk of overweight/obesity associated with these eating behaviors" in schools.

Lifestyle factors associated with underweight among Japanese adolescents: a cross-sectional study

Background

Because underweight in adolescents poses several health problems, it is important to prevent it in adolescence. For the prevention of underweight, it is necessary to investigate risk factors, especially lifestyles, because these can be modified. However, a limited number of studies exist regarding lifestyle factors associated with underweight among adolescents. The present study aimed to investigate the relationship between lifestyle factors and underweight among Japanese adolescents.

Methods

Study subjects comprised 2641 seventh-grade school children (age 12 or 13 years) from the town of Ina, Saitama Prefecture, Japan. Measurements of height and weight were made for each subject, while information regarding lifestyles of each subject was obtained using a self-administered questionnaire. Underweight was determined by the age- and sex-specific body mass index cut-off points. A logistic regression model was used to estimate the odds ratio (OR) and 95% confidence interval (95% CI) for underweight.

Results

Adolescents who ate slowly were more likely to be underweight than those who did not eat slowly; the OR (95% CI) was 2.78 (1.77–4.39) in boys and 2.69 (1.81–3.98) in girls. Girls who did not exercise were more likely than those who exercised to be underweight (OR: 1.64, 95% CI: 1.07–2.51).

Conclusions

The present study showed that eating slowly and exercise were associated with underweight among Japanese adolescents. These results suggest that eating speed and exercise need to be considered in school health programs for healthy body weight.

Rapid weight gain during infancy and early childhood is related to higher anthropometric measurements in preadolescence

BACKGROUND

This study examined the relationship between rapid weight gain during infancy and/or early childhood and anthropometric measurements [body mass index (BMI), percent body fat (%BF), waist circumference (WC) and waist-to-height ratio (WHtR)] in preadolescence by sex.

METHODS

Subjects were fourth-grade school children (aged 9 to 10 years) from elementary schools in Ina-town, Japan, in 2010. Measurements of height, weight, %BF and WC were conducted for each subject. We obtained data on height and weight of subjects at birth, age 1.5 years and age 3 years from the Maternal and Child Health handbook. Rapid weight gain was defined as a change in weight-for-age standard deviation score greater than 0.67 from birth to age 1.5 years (infancy) or from age 1.5 to 3 years (early childhood).

RESULTS

All anthropometric variables (BMI, %BF, WC and WHtR) at age 9 to 10 years were significantly higher in the rapid weight gain during both infancy and early childhood period group than in the no rapid weight gain group, regardless of sex. When compared with the no rapid weight gain group, rapid weight gain during early childhood period had significantly higher BMI and WC in boys and BMI, %BF and WC in girls. Compared with the no rapid weight gain group, the rapid weight gain during infancy group had a significantly higher WC in boys and significantly higher BMI and WC in girls.

CONCLUSION

Rapid weight gain during both infancy and early childhood was related to higher anthropometric measurements, including WHtR, among Japanese preadolescents, regardless of sex. This study suggests that rapid weight gain during infancy and early childhood may be a risk factor for general/abdominal obesity later in life.

High bone turnover elevates the risk of denosumab-induced hypocalcemia in women with postmenopausal osteoporosis

Hypocalcemia is the most common major adverse event in patients with osteoporosis receiving the bone resorption inhibitor denosumab; however, limited information is available regarding risk factors of hypocalcemia. Therefore, this study aimed to identify the risk factors of hypocalcemia induced by denosumab treatment for osteoporosis. We retrospectively reviewed the records of patients who had received initial denosumab supplemented with activated vitamin D for osteoporosis. Serum levels of the following bone turnover markers (BTMs) were measured at baseline: bone-specific alkaline phosphatase (BAP), total N-terminal propeptide of type 1 procollagen (P1NP), tartrate-resistant acid phosphatase 5b (TRACP-5b), and urinary cross-linked N-telopeptide of type 1 collagen (NTX). Of the 85 denosumab-treated patients with osteoporosis studied, 22 (25.9%) developed hypocalcemia. Baseline serum total P1NP, TRACP-5b, and urinary NTX were significantly higher in patients with hypocalcemia than in those with normocalcemia following denosumab administration (all P<0.01). Multivariate logistic regression analysis revealed that patients with total P1NP >76.5 μg/L, TRACP-5b >474 mU/dL, or urinary NTX >49.5 nmol bone collagen equivalent/mmol creatinine had a higher risk of hypocalcemia (P<0.01). Our study suggests that denosumab may have a greater impact on serum calcium levels in patients with postmenopausal osteoporosis with higher baseline bone turnover than in patients with postmenopausal osteoporosis with normal baseline bone turnover, because maintenance of normal serum calcium in this subgroup is more dependent on bone resorption. Close monitoring of serum calcium levels is strongly recommended for denosumab-treated patients with high bone turnover, despite supplementation with activated vitamin D and oral calcium.

Changes in the Composition of Adiponectin Fractions over a 3-Year Period in Children: A Population-Based Cohort Study

BACKGROUND

Little information is available regarding changes in adiponectin fractions. The objective of this study was to examine changes in the composition of differing adiponectin fractions using a population-based, prospective pediatric cohort.

METHODS

A total of 358 fourth graders (9-10 years old) from Ina town in Saitama, Japan, were followed up for 3 years. BMI and total adiponectin (TAD), high-molecular weight adiponectin (HAD), medium-molecular weight adiponectin, and low-molecular weight adiponectin levels were measured in these subjects at baseline and at the end of the follow-up.

RESULTS

Of the fourth graders participating in the study, 326 (172 boys and 154 girls; follow-up rate, 91.1%) became available for follow-up. No significant changes were observed in TAD values after 3 years. HAD values were significantly decreased in both the boys (2.4 to 2.2 μg/mL: p < 0.001) and girls (3.1 to 2.7 μg/mL: p = 0.005). All values in the parameters examined at baseline and after 3 years were significantly correlated. A negative correlation was found between the ratios of follow-up compared to baseline values for BMI and those for TAD (boys, r = -0.322, p < 0.001; girls, r = -0.433, p < 0.001) as well as those for HAD (boys, r = -0.353, p < 0.001; girls, r = -0.351, p < 0.001).

CONCLUSIONS

HAD had the most robust correlation between its values at baseline and those after 3 years in both boys and girls. The changes in HAD also had the most robust correlation between the changes in BMI in 3 years.

Association between distorted body image and changes in weight status among normal weight preadolescents in Japan: a population-based cohort study

BACKGROUND

Distorted body image may be important risk factors for being underweight and overweight. The objective of this study was to investigate the association between having a distorted body image and being overweight or underweight among normal weight preadolescents in a population-based cohort study in Japan for each sex.

METHODS

The study participants were 1431 normal weight fourth-grade students (age range: 9-10 years) in Ina town, Japan from 2002 to 2007. The height and weight of each student were measured while they were in the fourth grade (at baseline) and seventh grade (3 years later). Childhood underweight and overweight were defined using the body mass index cut-off points proposed by the International Obesity Task Force. Information regarding the self-perceived weight status of each student at baseline was collected using a self-administered questionnaire. Children who were normal weight but perceived themselves as heavy or thin were regarded as having a distorted body images. A logistic regression model was used to calculate the odds ratios (ORs) and 95 % confidence interval (95 % CI) for being overweight or underweight 3 years later among those having a distorted body image at baseline.

RESULTS

Both boys and girls who perceived themselves to be heavy at baseline were at a statistically significantly greater risk of being overweight 3 years later as compared to boys and girls, respectively, who identified as being at a normal weight at baseline (boys: adjusted OR: 4.66, 95 % CI: 1.01-21.48; girls: 3.88, 1.56-9.65). Both boys and girls who perceived oneself to be thin at baseline were at a statistically significantly greater risk of bring underweight 3 years later as compared to boys and girls, respectively, who identified as being at a normal weight at baseline (boys: 5.51, 2.20-13.80; girls: 2.93, 1.40-6.11).

CONCLUSION

The results of the present study suggest that having a distorted body image in preadolescence is associated with being overweight or underweight in adolescence, among boys and girls, separately. Therefore, education regarding self-perceived weight could be important to help prevent underweight and overweight/obesity among preadolescent boys and girls in Japan.

Mitochondrial DNA 5178 C/A polymorphism modulates the effects of coffee consumption on elevated levels of serum liver enzymes in male Japanese health check-up examinees: an exploratory cross-sectional study

Background

Longevity-associated mitochondrial DNA 5178 cytosine/adenine (Mt5178 C/A) polymorphism modulates the effects of coffee consumption on the risk of hypertension, dyslipidemia, and abnormal glucose tolerance. The objective of this study was to investigate whether Mt5178 C/A polymorphism modifies the effects of coffee consumption on abnormally elevated levels of serum liver enzymes in male Japanese health check-up examinees.

Methods

A total of 421 male subjects (mean age ± SD, 54.1 ± 7.7 years) were selected from among individuals visiting the hospital for regular medical check-ups. After Mt5178 C/A genotyping, a cross-sectional study assessing the joint effects of Mt5178 C/A polymorphism and coffee consumption on elevated levels of serum aspartate aminotransferase (AST), serum alanine aminotransferase (ALT), and serum gamma-glutamyl transpeptidase (GGT) was then conducted.

Results

For men with Mt5178C, after adjustment for age, body mass index, alcohol consumption, habitual smoking, green tea consumption, antihypertensive treatment, and antidiabetic treatment, elevated levels of serum AST, as defined as ≥30 U/L; those of serum ALT, as defined as ≥25 U/L; or those of serum GGT, as defined as ≥60 or >51 U/L, may depend on coffee consumption (P for trend = 0.013, P for trend <0.001, P for trend = 0.002, and P for trend <0.001, respectively). On the other hand, no significant joint effects of Mt5178A genotype and coffee consumption on elevated levels of serum liver enzymes were observed.

Conclusions

The present results suggest that Mt5178 C/A polymorphism modifies the effects of coffee consumption on abnormally elevated levels of serum liver enzymes in male Japanese health check-up examinees.