Associations of household expenditure and marital status with cardiovascular risk factors in Japanese adults: analysis of nationally representative surveys

Trends and socioeconomic inequities in insomnia-related symptoms among Japanese adults from 1995 to 2013

BACKGROUND

Although insomnia prevalence is increasing in developed countries, little is known about trends in sleep problems among Japanese adults according to socioeconomic status. Therefore, we aimed to determine trends and socioeconomic inequalities in insomnia-related symptom (IRS) in Japan using nationally representative data.

METHODS

The IRSs were based on past subjective sleeping difficulty. Using data from the Comprehensive Survey of Living Conditions for every 3 years from 1995 to 2013, we built multivariable Poisson regression models, with IRS as an outcome and survey year and socioeconomic status variables as explanatory variables.

RESULTS

Data from 513,223 Japanese adults were analyzed. Age- and sex-adjusted IRS prevalence was the lowest in 1995, highest in 2007, and decreased from 2007 to 2013. The IRSs were more frequently reported in unemployed or self-employed individuals aged 20-64 years; those with the lowest household expenditure level, except among women aged ≥65 years; and those divorced, separated, or single, especially among women aged 20-64 years.

LIMITATIONS

First, the repeated cross-sectional study design prevented the exclusion of the possibility of reversal of causality between factors. Second, data on insomnia-related lifestyle behaviors were unavailable. Third, the IRSs examined did not meet established clinical criteria for clinical insomnia. Fourth and fifth, information and selection biases could exist because of self-reported data and a small sample size, respectively.

CONCLUSIONS

These results could aid in developing more effective prevention strategies for sleep problems and provide benchmarks for monitoring sleep health trends in Japan and other East Asian countries.

Associations of Socioeconomic Status and Healthy Lifestyle With Incidence of Dyslipidemia: A Prospective Chinese Governmental Employee Cohort Study

Objective

The purpose of the study was to test whether primary lifestyles mediate associations of SES with incidence of dyslipidemia and to explore interaction relations of lifestyles and SES with incidence of dyslipidemia.

Methods

We included 9,901 individuals at baseline from January 2018 to November 2019, and incidence data were updated to 31 December 2020. Dyslipidemia was defined as total cholesterol (TC) 6.2 mmol/L TC ≥ or triglycerides (TG) ≥2.3 mmol/L or low-density lipoprotein cholesterol (LDL-C) ≥4.1 mmol/L or high-density lipoprotein cholesterol (HDL-C) <1.0 mmol/L; or physician diagnosed dyslipidemia or lipid-lowering drugs use. Lifestyles, socioeconomic factors, and personal characteristics were collected by a questionnaire. A latent class analysis based on education, family income, and occupational position was used to assess the SES. Lifestyle score was calculated using cigarette smoking, alcohol consumption, physical activity, and diet. Cox proportional hazard models and multivariate analyses were used to explore the associations. The mediation effect was evaluated using bootstrap method.

Results

Participant mean age was 36.5 years (SD = 0.11). The cumulative incidence of dyslipidemia was 11.0% over a mean follow-up of 13.4 months. Compared with participants of high SES, those with low SES had higher risk of incidence of dyslipidemia [hazard ratio 1.32, 95% confidence interval (CI): 1.01–1.73], after adjusting for lifestyle scores and other covariates. The proportion mediated by lifestyles was 5.41% (95%CI: 4.17–7.11). A significant additive interaction was found between lifestyles and SES, whereas association between lifestyle and incidence of dyslipidemia was stronger among those of high SES. Additionally, individuals with low SES and no or one healthy lifestyle behavior had a higher risk of developing dyslipidemia than those with high SES and 3 or 4 healthy lifestyles.

Conclusion

Unhealthy lifestyles play a small moderating role in socioeconomic inequity in incidence of dyslipidemia among Chinese governmental employees, suggesting that promoting healthy lifestyles alone may not significantly reduce socioeconomic inequalities in health, and measures to address other social determinants of health should also be considered alongside.

A genetic sum score of effect alleles associated with serum lipid concentrations interacts with educational attainment

High-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and total cholesterol (TC) levels are influenced by both genes and the environment. The aim was to investigate whether education and income as indicators of socioeconomic position (SEP) interact with lipid-increasing genetic effect allele scores (GES) in a population-based cohort. Using baseline data of 4516 study participants, age- and sex-adjusted linear regression models were fitted to investigate associations between GES and lipids stratified by SEP as well as including GES×SEP interaction terms. In the highest education group compared to the lowest stronger effects per GES standard deviation were observed for HDL-C (2.96 mg/dl [95%-CI: 2.19, 3.83] vs. 2.45 mg/dl [95%-CI: 1.12, 3.72]), LDL-C (6.57 mg/dl [95%-CI: 4.73, 8.37] vs. 2.66 mg/dl [95%-CI: −0.50, 5.76]) and TC (8.06 mg/dl [95%-CI: 6.14, 9.98] vs. 4.37 mg/dl [95%-CI: 0.94, 7.80]). Using the highest education group as reference, interaction terms showed indication of GES by low education interaction for LDL-C (ß_{GES×Education}: −3.87; 95%-CI: −7.47, −0.32), which was slightly attenuated after controlling for GES_LDL-C×Diabetes interaction (ß_{GES×Education}: −3.42; 95%-CI: −6.98, 0.18). The present study showed stronger genetic effects on LDL-C in higher SEP groups and gave indication for a GES_LDL-C×Education interaction, demonstrating the relevance of SEP for the expression of genetic health risks.

The association between informal caregiving and poor self-rated health among ever-married women in Japan: A nationally representative survey

Background

The number of people providing informal caregiving, including dual care, which is the combination of child and nursing care, is increasing. Due to the burden of multiple responsibility, dual care could negatively affect the health of informal caregivers. Previous research has not studied the effects of combining different types of informal caregiving. Therefore, we examined, among Japanese women, 1) the association between types of informal caregiving and self-rated health (SRH), and 2) difference in this association according to caregivers’ socio-economic conditions.

Methods

We analyzed the nationally representative 2013 Comprehensive Survey of Living Conditions data of 104,171 women aged 20–59 years. The odds ratios (ORs) for poor SRH by type of informal caregiving (no care, childcare, nursing care, and dual care) were estimated using logistic regression. We also conducted sub-group analyses by socio-economic conditions (equivalent monthly household expenditure and educational attainment).

Results

Compared to the no care group, the adjusted ORs for poor SRH of the childcare, nursing-care, and dual care groups were 0.92 (95% confidence interval [CI], 0.88–0.97), 1.33 (95% CI, 1.21–1.47), and 1.42 (95% CI, 1.23–1.64), respectively. There was no extra risk arisen from combining childcare and nursing care. The sub-group analyses indicated that neither household expenditure nor educational attainment affected the association between caregiving type and poor SRH.

Conclusion

Our study found that informal nursing care and dual care impose a health burden on female caregivers, regardless of their socio-economic conditions. This highlights the importance of addressing the effects of informal caregiving on the health of women.

Sex difference in the association of obesity with personal or social background among urban residents in Japan

The development of obesity is influenced by genetic and environmental factors and is associated with a variety of health problems. To gain insight into environmental factors that contribute to obesity, we analyzed the relation of personal or social background to obesity in men and women separately with the use of data from a community-based questionnaire survey of 5425 residents aged 20 to 64 years of Kobe, a representative large city in Japan. Obesity and normal weight were defined as a body mass index (BMI) of ≥25 and of ≥ 18.5 and < 25 kg/m2, respectively, according to the diagnostic criteria of the Japan Society for the Study of Obesity. The personal or social background factors examined included marital status, family structure, employment, household income, residence type, welfare enrollment, economic conditions of current life, educational level, extracurricular activity in school, living conditions at 15 years of age, and childhood adversity. We found that the prevalence of obesity was 27.2% and 10.6% in men and women, respectively. Among women, unmarried status, a low household income, welfare enrollment, difficult current economic conditions, a low educational level, and childhood adversity were associated with obesity, whereas none of the personal or social background factors examined were associated with obesity in men. Our results suggest that the development of obesity in women is strongly influenced by personal or social background, and such factors should be taken into consideration in the management of this condition in women.

Shift work, and particularly permanent night shifts, promote dyslipidaemia: A systematic review and meta-analysis

BACKGROUND AND AIMS

Shift work is common worldwide and linked to deleterious cardiovascular effects that might be underlined by dyslipidemia. The aim of this systematic review and meta-analysis is to determine the impact of shiftwork on dyslipidemia.

METHODS

Searching in PubMed, Cochrane Library, Science Direct and Embase databases without language restriction on 15 February 2020, included studies that describe blood lipids levels or a risk measure in shift workers compared with fixed-day workers (controls). Differences by study-level characteristics were estimated using stratified meta-analysis by type of shift work, and meta-regression to examine relations between dyslipidemia and demographic, lifestyle and work characteristics. Estimates were pooled using random-effect meta-analysis.

RESULTS

We included a total of 66 articles, representing 197,063 workers. Shift work globally increased the levels of triglycerides (overall SMD = 0.09; 95CI 0.05 to 0.13; p < 0.001), and globally decreased the levels of c-HDL (-0.08; 95CI -0.12 to -0.03; p = 0.001). Permanent night shift workers were an at-risk type of shift for dyslipidemia with significantly higher blood levels of total cholesterol (0.22; 95CI 0.01 to 0.42; p = 0.043) and triglycerides (0.18; 0.03 to 0.33; p = 0.017), and significantly lower blood levels of c-HDL (-0.16; 95CI -0.32 to 0.00; p = 0.05). Permanent night shift workers were more at-risk for total cholesterol than rotating 3 × 8 shift workers (Coefficient 0.22; 95CI 0.01 to 0.42; p = 0.038) and rotating 2 × 12 shift workers (0.24; 0.02 to 0.46; p = 0.037), and more at-risk for triglycerides than rotating day shift workers (0.21; 95CI 0.03 to 0.38; p = 0.023). Results were non-significant for c-LDL, nor depending on type of shifts.

CONCLUSIONS

Shift work, and particularly permanent night shift, is associated with dyslipidaemia via elevated total cholesterol and triglycerides, and reduced HDL-cholesterol. Our current study provides a practical and valuable strengthening of the evidence-base required for preventive health initiatives and workplace reform.

Concordance of hypertension, diabetes and dyslipidaemia in married couples: cross-sectional study using nationwide survey data in Japan

OBJECTIVE

Because married couples have many environmental influences in common, spouses may develop similar diseases. This study aimed to determine the concordance of hypertension, diabetes and dyslipidaemia, which are major risk factors for cardiovascular disease, among married couples in Japan.

RESEARCH DESIGN AND METHODS

We conducted a cross-sectional study of married couples who were both aged ≥40 years using the 2016 Comprehensive Survey of Living Conditions, which is a Japanese national survey. We first determined the proportions of wives and husbands who were receiving therapy for each of the diseases of interest. We then conducted logistic regression analyses using the wives undergoing therapy for each disease as outcomes and the husbands undergoing therapy for the same disease as the principal exposure, adjusting for covariates.

RESULTS

The subjects of the analyses were 86 941 married couples. The wives of male patients were significantly more likely to be receiving therapy for the same disease. Logistic regression revealed that when husbands were undergoing therapy for these diseases their wives had ORs (95% CIs) of 1.79 (1.72-1.86) for hypertension, 1.45 (1.34-1.58) for diabetes, 2.58 (2.41-2.75) for dyslipidaemia and 1.87 (1.80-1.93) for any of these diseases.

CONCLUSIONS

If men have hypertension, diabetes or dyslipidaemia, their wives were also more susceptible to the same disease. Medical professionals and couples may need to recognise these results and consider couple-based interventions to help the prevention, early detection and treatment of these diseases.

Occupational Class and Risk of Cardiovascular Disease Incidence in Japan: Nationwide, Multicenter, Hospital-Based Case-Control Study

Background

In contemporary Western settings, higher occupational class is associated with lower risk for cardiovascular disease (CVD) incidence, including coronary heart disease (CHD) and stroke. However, in non‐Western settings (including Japan), the occupational class gradient for cardiovascular disease risk has not been characterized.

Methods and Results

Using a nationwide, multicenter hospital inpatient data set (1984–2016) in Japan, we conducted a matched hospital case‐control study with ≈1.1 million study subjects. Based on a standard national classification, we coded patients according to their longest‐held occupational class (blue‐collar, service, professional, manager) within each industrial sector (blue‐collar, service, white‐collar). Using blue‐collar workers in blue‐collar industries as the referent group, odds ratios and 95% CIs were estimated by conditional logistic regression with multiple imputation, matched for sex, age, admission date, and admitting hospital. Smoking and drinking were additionally controlled. Higher occupational class (professionals and managers) was associated with excess risk for CHD. Even after controlling for smoking and drinking, the excess odds across all industries remained significantly associated with CHD, being most pronounced among managers employed in service industries (odds ratio, 1.19; 95% CI, 1.08–1.31). On the other hand, the excess CHD risk in higher occupational class was offset by their lower risk for stroke (eg, odds ratio for professionals in blue‐collar industries, 0.77; 95% CI, 0.70–0.85).

Conclusions

The occupational “gradient” in cardiovascular disease (with lower risk observed in higher status occupations) may not be a universal phenomenon. In contemporary Japanese society, managers and professionals may experience higher risk for CHD.

Association between procrastination, white-collar work and obesity in Japanese male workers: a cross-sectional study

OBJECTIVE

To investigate the associations among procrastination (time inconsistency), work environment and obesity-related factors in Japanese male workers.

DESIGN

Cross-sectional study.

SETTING

Data were collected at two work sites of Japanese electronics manufacturing company in 2015.

PARTICIPANTS

795 full-time male workers in a Japanese electric company, aged 35-64 years, who underwent health checkups in 2015.

MAIN OUTCOME MEASURES

Body mass index (BMI), adult weight change, obesity (BMI ≥25 kg/m²), adult weight gain over 10 kg (AWG10) and metabolic syndrome (MetS). Multivariable linear and logistic regression analyses were performed to assess the associations of procrastination assessed by using a one-item questionnaire and white-collar and blue-collar work with obesity-related factors.

RESULTS

White-collar workers with high procrastination levels showed positive associations with BMI (B: 0.75, 95% CI 0.06 to 1.44) and adult weight change (B: 1.77, 95% CI 0.26 to 3.29), and had increased odds of AWG10 (OR: 1.85, 95% CI 1.04 to 3.29) and MetS (OR: 2.29 95% CI 1.18 to 4.44) after adjustment for age, education, work-related factors and lifestyle factors. However, such positive associations were not observed among blue-collar workers.

CONCLUSIONS

Procrastination and white-collar work might have a joint effect on weight gain during adulthood and consequential obesity.

High Blood Pressure Prevalence, Awareness, Control, and Associated Factors in a Low-Resource African Setting

Background and Objectives: Recent and contextualized data are needed to improve hypertension management known as a major cardiovascular disease risk factor regardless of the geographical area. This study aimed at assessing the prevalence of hypertension, awareness of hypertensive status, treatment, and control of hypertension as well as assessing the factors associated with risk of hypertension and awareness of hypertensive status in the population of Ngaoundere. Methods: This was a community based cross sectional study carried out from February to December 2016. A three-stage sampling method was used for recruitment of participants. Demographic, clinical, and biological data were collected and analyzed using Statistical Package for Social Sciences version 20.0. Statistical significance was set at P < 0.05. Results: In total, 948 participants were included in the study. The overall prevalence of hypertension was 46.94% (n = 445). Fraction of hypertensive participants who were aware of their status was 36.85% (n = 164). Among them, 39 (23.78%) were getting treatment and the control rate of treated hypertensives was 30.56%. Age, marital status, family history of hypertension, overweight, and high serum triglyceride level were identified as independent predicting factors of hypertension, whereas female gender, age, personal history of stroke or diabetes, family history of hypertension or heart failure, overweight, and abdominal obesity were those of hypertension awareness. Conclusion: The present study revealed high prevalence, extremely low awareness, treatment, and control rates of hypertension in Ngaoundere community setting.

Effects of occupation on intracerebral hemorrhage-related deaths in Inner Mongolia

This study assessed the relationship between occupation and Intracerebral Hemorrhage-related deaths and compared the differences in ICH-related deaths rates between the eastern and midwestern regions of Inner Mongolia. We used the case-control method. Cases included Intracerebral Hemorrhage-related deaths that occurred from 2009 to 2012 in Inner Mongolia while controls included non-circulatory system disease deaths that occurred during the same period. Odds ratios (ORs) for Intracerebral Hemorrhage-related deaths were calculated using logistic regression analysis, estimated according to occupation, and adjusted for marital status and age. The Intracerebral Hemorrhage mortality rate in the eastern regions (125.19/100000) was nearly 3 times higher than that in the midwestern regions (45.31/100000). ORs for agriculture-livestock workers, service professionals and general workers, professional workers and senior officials were in descending order. The age-adjusted OR for Intracerebral Hemorrhage-related deaths was lowest in unmarried men senior officials (OR 0.37, 95% CI 0.14-0.99). The Intracerebral Hemorrhage mortality rate in the eastern regions was much higher than that of the midwestern regions, since about 90% of Intracerebral Hemorrhage-related deaths in the eastern regions were those of agriculture-livestock workers who has the largest labor intensity of any other occupation assessed.

The Association Between Education and Smoking Prevalence, Independent of Occupation: A Nationally Representative Survey in Japan

Background

Higher smoking prevalence in less educated persons and manual workers is well known. This study examines the independent relationship of education and occupation with tobacco use.

Methods

We used anonymized data from a nationwide population survey (30,617 men and 33,934 women). Education was divided into junior high school, high school, or university attainment. Occupation was grouped into upper non-manual, lower non-manual, and manual. Poisson regression models stratified by age and gender were used to estimate adjusted prevalence ratio (PR) and 95% confidence interval (CI) for current smoking.

Results

After adjustment for covariates, education, and occupation, education was significantly related to current smoking in both genders; compared to university graduates, PRs of junior high school graduates aged 20–39, 40–64, and ≥65 were 1.74 (95% CI, 1.53–1.98), 1.50 (95% CI, 1.36–1.65), and 1.28 (95% CI, 1.08–1.50) among men, and 3.54 (95% CI, 2.92–4.30), 2.72 (95% CI, 2.29–3.23), and 1.74 (95% CI, 1.14–2.66) among women, respectively. However, significantly higher smoking prevalence in manual than in upper non-manual was found only in men aged 20–64; compared to upper non-manual, the PRs of manual workers aged 20–39, 40–64, and ≥65 were 1.11 (95% CI, 1.02–1.22), 1.18 (95% CI, 1.10–1.27), and 1.10 (95% CI, 0.89–1.37) among men, and 0.95 (95% CI, 0.75–1.20), 0.92 (95% CI, 0.75–1.12), and 0.46 (95% CI, 0.22–0.95) among women, respectively.

Conclusions

Independent of occupation, educational disparities in smoking existed, regardless of age and gender. Occupation-smoking relationship varied with age and gender. Our study suggests that we should pay attention to social inequality in smoking as well as national smoking prevalence.

Socioeconomic Disparity in the Prevalence of Objectively Evaluated Diabetes Among Older Japanese Adults: JAGES Cross-Sectional Data in 2010

Background

Studies on sex-specific socioeconomic gradients in objectively evaluated diabetes among older adults are scarce.

Methods

We used cross-sectional data of 9,893 adults aged 65 years and older in Aichi Prefecture without long-term care insurance from the Japan Gerontological Evaluation Study (JAGES) in 2010 (Response rate: 66.3%). We collected demographic, socioeconomic (income, years of education, and longest occupation) and behavioral information using a mail-in self-reported survey. Blood samples for the objectively evaluated diabetes and self-reported medical history were collected at annual municipal health checkups. Poisson regression analysis stratified by sex with multiple imputations was conducted to calculate prevalence ratio and 95% confidence interval.

Results

A clear income gradient in diabetes prevalence was observed among women, from 11.7% in the lowest income quartile (Q1) to 7.8% in the highest (Q4). Among men, the findings were 17.6% in Q1 to 15.1% in Q4. The prevalence ratios for diabetes with incomes Q1 to Q4 were 1.43 (95% confidence interval [CI], 1.07–1.90) for women and 1.16 (95% CI, 0.90–1.50) for men after adjusting for age and other socioeconomic factors. Even after adjusting for marital status, body mass index, other metabolic risk factors, and lifestyle factors, the income-based gradient remained among women. Education and occupation were not significantly associated with diabetes in the study population.

Conclusions

Only women showed an income-based gradient in diabetes. Monitoring income gradient in diabetes is important in public health actions, even in older populations. Future longitudinal and intervention studies should evaluate the causal link of income to diabetes onset, determine the mechanisms of the potential sex differences in the income/diabetes association, and identify ways to mitigate the income-based inequality.

Associations of non-standard employment with cardiovascular risk factors: findings from nationwide cross-sectional studies in Japan

This study aimed to examine the cross-sectional association of non-standard employment with cardiovascular disease risk factors. Five yr of data from the Comprehensive Survey of Living Conditions and National Health and Nutritional Survey were combined. We used logistic regression to examine the association of employment contract (non-standard [part-time, dispatched, or contract] vs. standard [full-time and permanent]) with eight cardiovascular disease risk factors among 1,636 men and 2,067 women aged 40-60 yr. There were significant associations between non-standard employment and cardiovascular disease risk factors such as current smoking among men (odds ratio [OR] 1.39; 95% confidential interval [CI], 1.13-1.86) and diabetes among women (OR 1.83; 95% CI, 1.10-3.09). Non-standard employment was associated with a few cardiovascular disease risk factors in this middle-aged cohort in Japan.

Associations between Socioeconomic Status and the Prevalence and Treatment of Hypercholesterolemia in a General Japanese Population: NIPPON DATA2010

AIM

To investigate associations between socioeconomic status (SES) and the prevalence and treatment status of hypercholesterolemia in a general Japanese population.

METHODS

In 2010, we established a cohort study of 2417 adults (age 20-91 yr) from 300 randomly selected areas across Japan who participated in the National Health and Nutrition Survey of Japan. We cross-sectionally examined an association between SES and (1) prevalence of hypercholesterolemia in 2417 participants (999 men and 1418 women) and (2) not receiving medication for hypercholesterolemia in 654 participants (215 men and 439 women). SES included employment status, marital status, length of education, and household expenditures. Hypercholesterolemia was defined as a total serum cholesterol level of ≥6.21 mmol/L (240 mg/dL) or the use of lipid-lowering medications.

RESULTS

The overall prevalence of hypercholesterolemia was 21.5% in men and 31.0% in women. In men, the lowest quintile of household expenditures was associated with a higher prevalence of hypercholesterolemia (28.3%) compared with the upper 4 quintiles (19.9%) (multivariable-adjusted odds ratio 1.66; 95% confidence interval [CI] 1.16-2.38). Among participants with hypercholesterolemia, 55.4% of men and 55.1% of women were not receiving medication. Unmarried men were more likely to be untreated (75.0%) than married men (50.9%) (multivariable-adjusted odds ratio 2.53;95%CI 1.05-6.08). SES had no significant effects in women.

CONCLUSION

In a general population of Japanese men, low household expenditures were associated with a higher prevalence of hypercholesterolemia, and unmarried men with hypercholesterolemia were less likely to receive medication.

Differences in Lifestyle Improvements With the Intention to Prevent Cardiovascular Diseases by Socioeconomic Status in a Representative Japanese Population: NIPPON DATA2010

BACKGROUND

The relationships among socioeconomic status and lifestyle improvements have not yet been examined in a representative Japanese population.

METHODS

We analyzed data from 2,647 participants (1,087 men and 1,560 women) who participated in NIPPON DATA2010. This survey inquired about lifestyle improvements and socioeconomic status. Education was categorized as low (≤9 years), middle (10-12 years), and high (≥13 years). Marital status was categorized as married, divorced, widowed, and never married/other. A multivariable logistic regression model was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) of lifestyle improvements with the intention of preventing cardiovascular diseases for educational attainment and marital status, with adjustments for age and awareness of cardiovascular disease risk factors.

RESULTS

Overall, 1,507 (56.9%) participants practiced prevention and improvements in hypertension, diabetes, elevated cholesterol, and metabolic syndrome, and the OR of lifestyle improvements was significantly higher with a high education than with a low education in men (OR 2.86; 95% CI, 1.96-4.17) and women (OR 2.36; 95% CI, 1.67-3.33). The number of participants who practiced prevention and improvements in hypertension, diabetes, elevated cholesterol, and metabolic syndrome was significantly lower in divorced than in married men (OR 0.46; 95% CI, 0.22-0.95) and women (OR 0.53; 95% CI, 0.33-0.86).

CONCLUSIONS

Specific differences caused by educational attainment and marital status may exist in lifestyle improvements.

Relationships among Socioeconomic Factors and Self-rated Health in Japanese Adults: NIPPON DATA2010

BACKGROUND

The distributions of socioeconomic status (SES) factors have been changing in Japan. We examined the relationships among SES and self-rated health (SRH) in Japanese adults.

METHODS

We analyzed 1,178 men and 1,555 women. We showed the distribution of SRH by sex and age and examined cross-sectional relationships among educational attainment, marital/living statuses, working status, household income and expenditure, and fine SRH (defined as excellent, very good, or good). We adjusted for age, subjective symptoms, visiting doctors, monthly equivalent household expenditure (EHE), and living in their own house.

RESULTS

The age-standardized prevalence of fine SRH was 79% and 73% among men and women, respectively. Among men, graduating from high school (adjusted odds ratio [aOR] 1.53; 95% confidence interval [CI], 1.07-2.19, relative to graduating from elementary or junior high school) and university or junior college (aOR 1.74; 95% CI, 1.15-2.62) was associated with fine SRH. Among women, graduating from university or junior college was associated with fine SRH (aOR 1.65; 95% CI, 1.12-2.46). Neither marital/living status nor working status was associated with SRH after adjustments for age in either sex. Among women, high EHE and income were associated with fine SRH (the highest expenditure group: aOR 1.80; 95% CI, 1.22-2.65; the highest income group: aOR 2.15; 95% CI, 1.34-3.46, relative to the corresponding lowest group). These simple relationships were not observed for men.

CONCLUSIONS

High educational attainment was associated with fine SRH. Relationships among household income, EHE, and fine SRH differed by sex.

Relationship Between Socioeconomic Status and the Prevalence of Underweight, Overweight or Obesity in a General Japanese Population: NIPPON DATA2010

BACKGROUND

Socioeconomic status (SES) imbalances in developed and developing countries may result in individuals being overweight and obese. However, few studies have investigated this issue in Japan. We herein examined the relationship between SES and being underweight, overweight or obese according to sex and age groups (20-64 or ≥65 years) in Japan.

METHODS

In 2010, we established a cohort of participants in the National Health and Nutrition Survey of Japan. We divided 2,491 participants (1,081 men and 1,410 women) according to the WHO definitions of underweight, overweight or obesity and performed multinomial logistic analyses using BMI <18.5 kg/m2 (underweight), BMI 25.0-29.9 kg/m2 (overweight), and BMI ≥30.0 kg/m2 (obese) versus BMI 18.5-24.9 kg/m2 (normal) as the outcome, with SES groups as the main explanatory variables.

RESULTS

In adult men, a lower education level relative to a higher education level was inversely associated with obesity after adjustments for other SESs (odds ratio [OR] 0.41; 95% confidence interval [CI], 0.18-0.96). However, in adult women, lower education level was positively associated with being overweight and obese (OR 1.67; 95% CI, 1.07-2.49 for overweight and OR 2.66; 95% CI, 1.01-7.01 for obese). In adult women, a lower household income was positively associated with being overweight and obese (obese: OR 4.84; 95% CI, 1.36-17.18 for those with a household income <2 million JPY relative to those with ≥6 million JPY).

CONCLUSIONS

In adult women, a lower education level and lower household income were positively associated with being overweight or obese. In contrast, in adult men, a lower education level was inversely associated with obesity. Gender and age differences in SESs affect the prevalence of being overweight or obese.

Socioeconomic Status and Knowledge of Cardiovascular Risk Factors: NIPPON DATA2010

BACKGROUND

The relationship between socioeconomic status (SES) and knowledge of cardiovascular risk factors remains unknown in a general Japanese population.

METHODS

Of 8,815 participants from 300 randomly selected areas throughout Japan, 2,467 participants who were free of cardiovascular disease and who provided information on SES in the National Health and Nutrition Survey of Japan 2010 were enrolled in this cross-sectional analysis. SES was classified according to the employment status, length of education, marital and living statuses, and equivalent household expenditure (EHE). Outcomes were ignorance of each cardiovascular risk factor (hypertension, diabetes, hypercholesterolemia, low high-density lipoprotein [HDL] cholesterol, arrhythmia, and smoking) and insufficient knowledge (number of correct answers <4 out of 6).

RESULTS

A short education and low EHE were significantly associated with a greater ignorance of most cardiovascular risk factors. A short education (<10 years) was also associated with insufficient knowledge of overall cardiovascular risk factors: age- and sex-adjusted odds ratios (OR) were 1.92 (95% confidence interval [CI], 1.51-2.45) relative to participants with ≥13 years of education. Low EHE was also associated with insufficient knowledge (age- and sex-adjusted OR 1.24; 95% CI, 1.01-1.51 for the lowest quintile vs the upper 4 quintiles). These relationships remained significant, even after further adjustments for regular exercise, smoking, weekly alcohol consumption, body mass index, hypertension, diabetes mellitus, hypercholesterolemia, and low HDL cholesterol.

CONCLUSION

Participants with a short education and low EHE were more likely to have less knowledge of cardiovascular risk factors.

Effect of Genetic Information Regarding Salt-Sensitive Hypertension on the Intent to Maintain a Reduced Salt Diet: Implications for Health Communication in Japan

The authors investigated the relationship between the awareness of dietary salt and genetics and the intent to maintain a low-salt diet. In particular, they assessed whether hypothetical genetic information regarding salt-sensitive hypertension motivates the intent to reduce dietary salt for communicating the health benefits of lower salt consumption to citizens. A self-administered questionnaire survey was conducted with 2500 randomly sampled residents aged 30 to 69 years living in Nagahama, Japan. Genetic information regarding higher salt sensitivity increased motivation to reduce salt intake for both those who agreed that genes cause hypertension and those who did not. Less than 50% of those who agreed that genes cause hypertension lost their intention to lower their salt consumption when they found they did not possess the susceptibility gene. Communicating genetic information positively affected motivation to reduce salt intake. The present study clarifies the difficulty in changing the behavioral intent of those who have significantly less incentive to reduce salt intake. Therefore, a multidimensional approach is crucial to reduce salt consumption.

Serum Albumin Levels and Economic Status in Japanese Older Adults

BACKGROUND

Low serum albumin levels are associated with aging and medical conditions such as cancer, liver dysfunction, inflammation, and malnutrition and might be an independent predictor of long-term mortality in healthy older populations. We tested the hypothesis that economic status is associated with serum albumin levels and explained by nutritional and health status in Japanese older adults.

DESIGN

We performed a cross-sectional analysis using data from the Japan Gerontological Evaluation study (JAGES). The study participants were 6528 functionally independent residents (3189 men and 3339 women) aged ≥65 years living in four municipalities in Aichi prefecture. We used household income as an indicator of economic status. Multiple linear regression was used to compare serum albumin levels in relation to household income, which was classified as low, middle, and high. Additionally, mediation by nutritional and health-related factors was analyzed in multivariable models.

RESULTS

With the middle-income group as reference, participants with low incomes had a significantly lower serum albumin level, even after adjustment for sex, age, residential area, education, marital status, and household structure. The estimated mean difference was -0.17 g/L (95% confidence interval, -0.33 to -0.01 g/L). The relation between serum albumin level and low income became statistically insignificant when "body mass index", "consumption of meat or fish", "self-rated health", "presence of medical conditions", "hyperlipidemia", or "respiratory disease "was included in the model.

CONCLUSION

Serum albumin levels were lower in Japanese older adults with low economic status. The decrease in albumin levels appears to be mediated by nutrition and health-related factors with low household incomes. Future studies are needed to reveal the existence of other pathways.

Secondary Data Analysis of National Surveys in Japan Toward Improving Population Health

Secondary data analysis of national health surveys of the general population is a standard methodology for health metrics and evaluation; it is used to monitor trends in population health over time and benchmark the performance of health systems. In Japan, the government has established electronic databases of individual records from national surveys of the population’s health. However, the number of publications based on these datasets is small considering the scale and coverage of the surveys. There appear to be two major obstacles to the secondary use of Japanese national health survey data: strict data access control under the Statistics Act and an inadequate interdisciplinary research environment for resolving methodological difficulties encountered when dealing with secondary data. The usefulness of secondary analysis of survey data is evident with examples from the author’s previous studies based on vital records and the National Health and Nutrition Surveys, which showed that (i) tobacco smoking and high blood pressure are the major risk factors for adult mortality from non-communicable diseases in Japan; (ii) the decrease in mean blood pressure in Japan from the late 1980s to the early 2000s was partly attributable to the increased use of antihypertensive medication and reduced dietary salt intake; and (iii) progress in treatment coverage and control of high blood pressure is slower in Japan than in the United States and Britain. National health surveys in Japan are an invaluable asset, and findings from secondary analyses of these surveys would provide important suggestions for improving health in people around the world.

Association of household income and education with eating behaviors in Japanese adults: a cross-sectional study

BACKGROUND

Socioeconomic inequalities as social determinants of health are important issues in public health and health promotion. However, the association between socioeconomic status and eating behaviors has been investigated poorly in Japanese adults. To fill this gap, the present study examines the association of eating behaviors with household income and education.

METHODS

The sample comprised 3,137 Japanese adults (1,580 men and 1,557 women) aged 30 to 59 years who responded to an Internet-based cross-sectional survey in 2014. Data on the following eating behaviors were collected via self-report: "taking care of one's diet for health," "eating vegetables," "frequency of eating breakfast," "frequency of family breakfasts," "frequency of family dinners," "using the information on nutrition labels," and "conversations with family or friends during meals." Self-reported data on socioeconomic status (household income and education) and demographic variables (gender, age, district of residence, marital status, residence status, and employment status) were also collected. The associations between eating behaviors and household income or education were tested using binomial logistic regression analysis with eating behaviors as dependent variables and household income and education as independent variables. A trend P -value was calculated for three categories of household income (less than 3,000,000 JPY, 3,000,000-7,000,000 JPY, and over 7,000,000 JPY) and education (junior high/high school, 2-year college, and 4-year college/graduate school).

RESULTS

Higher household income and education were significantly associated with higher rates of eating vegetables, using the information on nutrition labels, and conversation with family or friends during meals in Japanese men and women. Higher household incomes were significantly associated with lower rates of frequency of family breakfasts in Japanese men and lower rates of frequency of family dinners in Japanese men and women.

CONCLUSIONS

Higher socioeconomic status as indicated by household income or education was associated with eating more vegetables and conversation with family or friends during meals in Japanese men and women. Socioeconomic status should be considered in health promotion and diet improvement.

Tobacco Price Increase and Smoking Cessation in Japan, a Developed Country With Affordable Tobacco: A National Population-Based Observational Study

Background

Longitudinal assessment of the impact of tobacco price on smoking cessation is scarce. Our objective was to investigate the effect of a price increase in October 2010 on cessation rates according to gender, age, socioeconomic status, and level of tobacco dependence in Japan.

Methods

We used longitudinal data linkage of two nationally representative studies and followed 2702 smokers for assessment of their cessation status. The odds ratios (ORs) for cessation were calculated using logistic regression. To estimate the impact of the 2010 tobacco price increase on cessation, data from 2007 were used as a reference category.

Results

Overall cessation rates significantly increased from 2007 to 2010, from 3.7% to 10.7% for men and from 9.9% to 16.3% for women. Cessation rates were 9.3% for men who smoked 1–10 cigarettes per day, 2.7% for men who smoked 11–20 cigarettes per day, and 2.0% for men who smoked more than 20 cigarettes per day in 2007. These rates increased to 15.5%, 10.0%, and 8.0%, respectively, in 2010. The impact was stronger among subjects who smoked more than 11 cigarettes per day than those who smoked 1–10 cigarettes per day in both sexes: ORs for 2010 were 4.04 for those smoking 11–20 cigarettes per day, 4.26 for those smoking more than 20 cigarettes per day, and 1.80 for those smoking 1–10 cigarettes per day in the main model in men. There were no obvious differences in the relationship between tobacco price increase and smoking cessation across age and household expenditure groups.

Conclusions

The tobacco price increase in Japan had a significant impact on smoking cessation in both sexes, especially among heavy smokers, with no clear difference in effect by socio-demographic status.

Socioeconomic Status and Overweight: A Population-Based Cross-Sectional Study of Japanese Children and Adolescents

BACKGROUND

Socioeconomic status (SES) as a determinant of obesity has received scant attention in Japan. This study examined the association between SES and overweight among Japanese children and adolescents.

METHODS

Cross-sectional analyses of a representative sample of Japanese children (6-11 years: n = 397) and adolescents (12-18 years: n = 397) were performed, with measured heights and weights from the 2010 National Health and Nutrition Examination Survey and the 2010 Comprehensive Survey of Living Conditions. Overweight, including obesity, was defined by International Obesity Task Force cut-offs. SES indicators included household income, equivalent household expenditure, parental educational attainment, and parental occupational class.

RESULTS

Overweight prevalence was 12.3% in children and 9.1% in adolescents. Adolescents living in middle-income households were more likely to be overweight than those living in high-income households (OR 2.26, 95% CI, 1.01-5.67) after adjustment for age, sex, and parental weight status. Similarly, adolescents living in households with low expenditure levels were more likely to be overweight than those living in households with high expenditure levels (OR 3.40, 95% CI, 1.20-9.60). In contrast, no significant association was observed among children.

CONCLUSIONS

Our results indicated that low household economic status was associated with being overweight, independent of parental weight status, among Japanese adolescents.

Individual- and community-level social gradients of edentulousness

Background

Community-level factors as well as individual-level factors affect individual health. To date, no studies have examined the association between community-level social gradient and edentulousness. The aim of this study was to investigate individual- and community-level social inequalities in edentulousness and to determine any explanatory factors in this association.

Methods

We analyzed the data from the Japan Gerontological Evaluation Study (JAGES). In 2010-2012, 112,123 subjects aged 65 or older responded to the questionnaire survey (response rate = 66.3%). Multilevel logistic regression analysis was applied to determine the association between community-level income and edentulousness after accounting for individual-level income and demographic covariates. Then, we estimated the probability of edentulousness by individual- and community-level incomes after adjusted for covariates.

Results

Of 79,563 valid participants, the prevalence of edentulousness among 39,550 men (49.7%) and 40,013 women (50.3%) were both 13.8%. Living in communities with higher mean incomes and having higher individual-level incomes were significantly associated with a lower risk of edentulousness (odds ratios [ORs] by 10,000 USD increments were 0.37 (95% confidence interval [CI] [0.22-0.63]) for community-level and 0.85 (95% CI [0.84-0.86]) for individual-level income). Individual- and community-level social factors, including density of dental clinics, partially explained the social gradients. However, in the fully adjusted model, both community- and individual-level social gradients of edentulousness remained significant (ORs = 0.43 (95% CI [0.27-0.67]) and 0.90 (95% CI [0.88-0.91]), respectively). One standard deviation changes in community- and individual-level incomes were associated with 0.78 and 0.84 times lower odds of edentulousness, respectively. In addition, compared to men, women living in communities with higher average incomes had a significantly lower risk of edentulousness (p-value for interaction < 0.001).

Conclusions

Individual- and community-level social inequalities in dental health were observed. Public health policies should account for social determinants of oral health when reducing oral health inequalities.

Socioeconomic Status and the Trajectory of Body Mass Index Among Older Japanese: A Nationwide Cohort Study of 1987-2006

OBJECTIVES

This research analyzed the body mass index (BMI) level and rate of change, and their association with socioeconomic status among older Japanese adults.

METHODS

Data came from a national sample of over 4,800 Japanese adults aged 60 and older at baseline, with up to 7 repeated observations over a period of 19 years (1987-2006). Hierarchical linear modeling was used to analyze the intrapersonal and interpersonal differences in BMI.

RESULTS

Average BMI among older Japanese was 22.26 at baseline and decreased with an accelerating rate over time. Relative to those with less education, BMI among older Japanese with more education was lower and it declined linearly at a faster rate over time. In contrast, higher household income at baseline was associated with a higher level of BMI but similar rates of decline over time. Furthermore, we found no evidence for age variations in the SES-BMI linkage as predicted by prior investigators.

DISCUSSION

These findings provide new insights into the complex relationship between socioeconomic factors and BMI, and help to inform the design of health policies and interventions related to weight control among older adults with diverse socioeconomic backgrounds.

Gender differences in childhood food preference: evaluation using a subjective picture choice method

BACKGROUND

A preference for calorie-dense food in men seems to be closely linked with a considerably higher incidence of obesity in adulthood for men than women, but it is not clear in which life stage the gender differences in food preference begin to appear. In order to clarify this, a picture choice method has been developed that is designed to evaluate food preferences or interests in children based on their subjective choices.

METHODS

In total, 486 children aged 6-12 years were enrolled. To evaluate food interest, children were instructed to choose any 10 from 36 pictures in the panel showing 10 different foods and 26 other things. The number of foods chosen was set as the food interest score. For food preference, they were also instructed to choose any 10 from 36 pictures in the other panel depicting 36 different foods. For the 10 foods chosen, Japanese food score, energy density, fat energy content, and saturated fatty acid score were calculated. These indices were compared for sex, age group and body mass index.

RESULTS

Indices reflecting food interest or fat preference were significantly higher in boys than girls both in the 7-9- and 10-12-year-old age groups. Positive correlations were found between food interest score and energy density, fat energy content, and saturated fatty acid score.

CONCLUSIONS

Using the picture choice method, definite gender differences in food preference were identified in early elementary school children. This information could be useful for dietary therapy in childhood obesity.

Socioeconomic status and dyslipidemia in Korean adults: the 2008-2010 Korea National Health and Nutrition Examination Survey

OBJECTIVE

This study investigated the relationship between socioeconomic status (SES) and dyslipidemia and various parameters of dyslipidemia among Korean adults.

METHODS

Data from the 2008-2010 Korea National Health and Nutrition Examination Survey were used in this study. A total of 19,041 Korean adults greater than 19years old participated in the study. The SES was assessed by monthly household income and education level. The relationship of SES to the risk of dyslipidemia was assessed with multivariate logistic regression analysis after adjusting for potential confounders.

RESULTS

The prevalence of dyslipidemia was 37.4% among Korean adults. In men, household income level was positively associated with prevalence and risks of several parameters of dyslipidemia, and education level had positive associations with the risks of dyslipidemia and parameters of dyslipidemia. However, low SES was linked to increased prevalence and risks of dyslipidemia (P for trend<0.05) and parameters of dyslipidemia in women.

CONCLUSIONS

Socioeconomic disparities in dyslipidemia were found in the Korean population. Also, there were gender differences in the relationship between SES and dyslipidemia. These disparities should be considered when performing risk calculations and screening for dyslipidemia, which will ultimately help prevent cardiovascular disease.