Trends in the prevalence of type 2 diabetes and prediabetes in a Japanese community, 1988-2012: the Hisayama Study

Risk and Population Attributable Fraction of Stroke Subtypes in Japan

BACKGROUND

Associations of major risk factors for stroke with total and each type of stroke, as well as subtypes of ischemic stroke, and their population attributable fractions had not been examined comprehensively.

METHODS

Participants of the Japan Public Health Center-based prospective (JPHC) Study Cohort II without histories of cardiovascular disease and cancer (n = 14,797) were followed from 1993 through 2012. Associations of current smoking, hypertension, diabetes, overweight (body mass index ≥25 kg/m2), non-high-density lipoprotein cholesterol (non-HDLC) categories, low HDLC (<40 mg/dL), urine protein, and history of arrhythmia were examined in a mutually-adjusted Cox regression model that included age and sex. Population attributable fractions (PAFs) were estimated using the hazard ratios and the prevalence of risk factors among cases.

RESULTS

Subjects with hypertension were 1.63 to 1.84 times more likely to develop any type of stroke. Diabetes, low HDLC, current smoking, overweight, urine protein, and arrhythmia were associated with risk of overall and ischemic stroke. Hypertension and urine protein were associated with risk of intracerebral hemorrhage, while current smoking, hypertension, and low non-HDLC were associated with subarachnoid hemorrhage. Hypertension alone accounted for more than a quarter of stroke incidence, followed by current smoking and diabetes. High non-HDLC, current smoking, low HDLC, and overweight contributed mostly to large-artery occlusive stroke. Arrhythmia explained 13.2% of embolic stroke. Combined PAFs of all the modifiable risk factors for total, ischemic, and large-artery occlusive strokes were 36.7%, 44.5%, and 61.5%, respectively.

CONCLUSION

Although there are differences according to subtypes, hypertension could be regarded as the most crucial target for preventing strokes in Japan.

Body mass index and characteristics of coronary plaque in younger patients with type 2 diabetes

BACKGROUND AND AIMS

The association between the body mass index (BMI) and the characteristics of coronary plaque in younger type 2 diabetes (T2D) patients with coronary artery disease (CAD) remains to be elucidated.

METHODS AND RESULTS

A total of 138 consecutive younger (<65 years) T2D patients with CAD, who underwent optical coherence tomography imaging of the culprit lesion were included. The patients were classified into either the higher BMI group (n = 68) or the lower BMI group (n = 70) according to the median of BMI (25.9 kg/m2). The prevalence of thin-cap fibroatheroma (TCFA) (35.3 vs. 17.1 %, p = 0.015) was significantly higher in the higher BMI group than in the lower BMI group. The prevalence of TCFA was significantly higher in patients with higher BMI than in those with lower BMI among patients with hemoglobin A1c (HbA1c) ≥7.0 % (odds ratio [OR] 5.40, 95 % confidence interval [CI] 1.72-17.0, p = 0.003) although the significant difference was not observed among patients with HbA1c <7.0 % (OR 0.89, 95 % CI 0.25-3.13, p = 0.851).

CONCLUSION

Higher BMI was associated with a higher prevalence of TCFA in younger T2D patients with CAD, particularly in patients with HbA1c ≥ 7.0 %.

Serum Mac-2 Binding Protein Glycosylation Isomer Concentrations Are Associated With Incidence of Type 2 Diabetes

CONTEXT

Serum Mac-2 binding protein glycosylation isomer (M2BPGi) concentrations are known to be an indicator of chronic liver injury and fibrosis.

OBJECTIVE

This study aimed to investigate the association between serum M2BPGi concentrations and the development of type 2 diabetes in a Japanese community.

METHODS

A total of 2143 community-dwelling Japanese individuals aged 40-79 years without diabetes at baseline were followed up for 7 years. Serum M2BPGi concentrations were divided into quintiles: Q1, ≤0.37 cutoff index (COI); Q2, 0.38-0.49 COI; Q3, 0.50-0.62 COI; Q4, 0.62-0.80 COI; and Q5, ≥0.81 COI. Cox proportional hazards models were used to estimate hazard ratios and 95% CIs for the development of type 2 diabetes.

RESULTS

During the follow-up period, 219 individuals developed type 2 diabetes. The age- and sex-adjusted cumulative incidence of type 2 diabetes significantly increased with elevating serum M2BPGi levels (P for trend < .01). This association remained significant after adjustment for potential confounders (P for trend = .04). This significant association attenuated to a nonsignificant level after additionally adjusting for serum high-sensitivity C-reactive protein or homeostasis model assessment of insulin resistance.

CONCLUSION

The present study demonstrated that higher serum M2BPGi concentrations were significantly associated with higher risk of diabetes in a Japanese community. Moreover, inflammation and insulin resistance were suggested to contribute to the excess risk of diabetes in individuals with higher serum M2BPGi levels. These findings shed light on the importance of inflammation and insulin resistance when considering the pathogenesis of diabetes.

Secular trends in the prevalence, incidence, and progression of diabetic retinopathy: the Hisayama Study

PURPOSE

To examine the secular trends in the prevalence, incidence, and progression rates of diabetic retinopathy (DR) in a Japanese community.

METHODS

Community-dwelling Japanese residents aged ≥ 40 years with diabetes participated in comprehensive systemic and ophthalmological surveys, including an examination for DR, in 1998 (n = 220), 2007 (n = 511), 2012 (n = 515), and 2017 (n = 560). DR was assessed using colour fundus photographs after pupil dilation according to the modified Airlie House classification system. To compare the frequencies of newly developed or progressed DR between the studied decades, two eye cohorts were established (the 2000s cohort included 145 participants examined in 1998 and 2007; the 2010s cohort included 255 participants examined in 2007, 2012, and 2017). Trends in the prevalence, incidence, and progression rate of DR were tested by logistic regression analysis with a generalised estimating equation.

RESULTS

The age-adjusted prevalence of DR among individuals with diabetes decreased significantly with time from 1998 to 2017 (27.4% in 1998, 22.8% in 2007, 12.8% in 2012, and 6.4% in 2017; p for trend < 0.001). During this period, the prevalence of DR was decreasing in every haemoglobin A_1c category, but it remained constant in the high systolic blood pressure category. In addition, the rates of new-onset of DR were significantly lower in the 2010s compared to the 2000s (p < 0.001).

CONCLUSION

Our findings suggest that the prevalence and incidence of DR among diabetic people significantly decreased with time over the past two decades in a general Japanese population.

Trends in the incidence of renal replacement therapy by type of primary kidney disease in Japan, 2006-2020

AIM

Age-standardized incidence of end stage kidney disease requiring renal replacement therapy (RRT) has stabilized in men and declined in women in Japan since 1996. However, recent trends by primary kidney disease are unknown. The present study aimed to examine recent trends in incidence rates of RRT by primary kidney disease in Japan.

METHODS

Numbers of incident RRT patients aged ≥20 years by sex and primary kidney disease from 2006 to 2020 were extracted from the Japanese Society of Dialysis Therapy registry. Using the census population as the denominator, annual incidence rates of RRT were calculated and standardized to the WHO World Standard Population (2000-2025). Average annual percentage change (AAPC) and corresponding 95% confidence intervals (CIs) were calculated for trends using Joinpoint regression analysis.

RESULTS

From 2006 to 2020, the crude number of incident RRT patients due to nephrosclerosis increased by 132% for men and 62% for women. Age-standardized incidence rates of RRT due to nephrosclerosis increased significantly, by 3.3% (95% CI: 2.9-3.7) and 1.4% (95% CI: 0.8-1.9) per year for men and women, respectively. The AAPC of chronic glomerulonephritis (-4.4% [95% CI: -5.3 to -3.8] for men and -5.1% [95% CI: -5.5 to -4.6] for women) and diabetic nephropathy (-0.6% [95% CI: -0.9 to -0.3] for men and -2.8% [95% CI: -3.1 to -2.6] for women) significantly decreased from 2006 to 2020.

CONCLUSION

Incident RRT due to chronic glomerulonephritis and diabetic nephropathy decreased, while the number and incident rates of RRT due to nephrosclerosis increased, from 2006 to 2020 in Japan.

Active commuting, commuting modes, and the risk of diabetes: 14-year follow-up data from the Hisayama Study

Aims/Introduction

We aimed to investigate the association of active commuting (cycling or walking to work), as well as the association of the individual commuting modes, with the risk of diabetes in a prospective cohort of community‐dwelling adults in Japan.

Material and Methods

A total of 1,270 residents aged 40–79 years were followed up for a median of 14 years. Active commuting was defined as either cycling or walking to work. A Cox proportional hazards model was used to examine the association of active commuting with the risk of diabetes. Associations for different forms of active commuting (cycling, walking and mixed modes of cycling or walking with non‐active components) were also examined.

Results

During the follow‐up period, 191 participants developed diabetes. Active commuting was associated with a lower risk of diabetes than non‐active commuting after adjustment for potential confounders (hazard ratio [HR] 0.54, 95% confidence interval [CI] 0.31–0.92). With regard to the commuting modes, the risk of diabetes was significantly lower in individuals who commuted by cycling alone (HR 0.46, 95% CI 0.22–0.98), and tended to be lower in individuals who commuted by walking alone (HR 0.14, 95% CI 0.02–1.02) compared with that in individuals with non‐active commuting. Meanwhile, no significant associations were observed for the mixed mode of walking and non‐active commuting (HR 1.69, 95% CI 0.77–3.71).

Conclusions

Active commuting, particularly that consisting exclusively of cycling or walking, was associated with a reduced risk of diabetes. Our findings support a public health policy that promotes the choice of active commuting for the prevention of diabetes.

Current utilization patterns for long-acting insulin analogues including biosimilars among selected Asian countries and the implications for the future

INTRODUCTION

Prevalence rates for diabetes mellitus continue to rise, which, coupled with increasing costs of complications, has appreciably increased expenditure in recent years. Poor glycaemic control including hypoglycaemia enhances complication rates and associated morbidity, mortality and costs. Consequently, this needs to be addressed. Whilst the majority of patients with diabetes have type-2 diabetes, a considerable number of patients with diabetes require insulin to help control their diabetes. Long-acting insulin analogues were developed to reduce hypoglycaemia associated with insulin and help improve adherence, which can be a concern. However, their considerably higher costs have impacted on their funding and use, especially in countries with affordability issues. Biosimilars can help reduce the costs of long-acting insulin analogues thereby increasing available choices. However, the availability and use of long-acting insulin analogues can be affected by limited price reductions versus originators and limited demand-side initiatives to encourage their use. Consequently, we wanted to assess current utilisation rates for long-acting insulin analogues, especially biosimilars, and the rationale for patterns seen, across multiple Asian countries ranging from Japan (high-income) to Pakistan (lower-income) to inform future strategies.

METHODOLOGY

Multiple approaches including assessing utilization and prices of insulins including biosimilars among six Asian countries and comparing the findings especially with other middle-income countries.

RESULTS

Typically, there was increasing use of long-acting insulin analogues among the selected Asian countries. This was especially the case enhanced by biosimilars in Bangladesh, India, and Malaysia reflecting their perceived benefits. However, there was limited use in Pakistan due to issues of affordability similar to a number of African countries. The high use of biosimilars in Bangladesh, India and Malaysia was helped by issues of affordability and local production. The limited use of biosimilars in Japan and Korea reflects limited price reductions and demand-side initiatives similar to a number of European countries.

CONCLUSIONS

Increasing use of long-acting insulin analogues across countries is welcomed, adding to the range of insulins available, which increasingly includes biosimilars. A number of activities are needed to enhance the use of long-acting insulin analogue biosimilars in Japan, Korea and Pakistan.

10-year trend of tooth loss and associated factors in a Japanese population-based longitudinal study

OBJECTIVES

We examined the trend in the number of missing teeth in a Japanese community over a 10-year period and the potential associated explanatory factors.

DESIGN

Prospective cohort study.

SETTING

A population-based study conducted in 2007, 2012 and 2017 in Japan (Hisayama Study).

PARTICIPANTS

Residents of a Japanese community aged 40-79 years undergoing dental examination in 2007 (n=2665), 2012 (n=2325) and 2017 (n=2285).

OUTCOME MEASURES

The number of missing teeth, periodontal condition, dental caries experience, dental plaque index and oral health behaviours were evaluated each year. The longitudinal analysis of variation in these factors were assessed using mixed models.

RESULTS

The age-adjusted and sex-adjusted mean number of missing teeth decreased with time (6.80 in 2007, 6.01 in 2012 and 4.99 in 2017). The mean clinical attachment level (CAL), prevalence of periodontitis and dental plaque index decreased over the study period, while dental caries experience slightly increased. The level of oral health behaviour increased over time. Poisson mixed models showed that changes in mean CAL and dental caries experience were positively associated with the change in the number of missing teeth over time. Linear mixed models showed that changes in dental plaque index and no regular dental visit were positively associated with changes in mean CAL.

CONCLUSIONS

These findings suggest that a decreasing trend regarding the number of missing teeth in Japan might be associated with improvements in the periodontal condition due to changes in oral hygiene level and oral health behaviour.

Serum High-Sensitivity C-Reactive Protein Levels and the Development of Atrial Fibrillation in a General Japanese Population - The Hisayama Study

BACKGROUND

Atrial fibrillation (AF) is a common arrhythmia in the elderly, and causes complications such as cardioembolic stroke. Serum high-sensitivity C-reactive protein (hs-CRP), a marker of systemic inflammation, has been reported to be a risk factor for developing AF in Western countries. However, few community-based studies have examined this issue in general Asian populations.Methods and Results:A total of 2,510 community-dwelling Japanese participants aged ≥40 years without a history of AF were divided into 4 groups according to the sex-specific quartiles of serum hs-CRP concentrations (Q1, lowest and Q4, highest) and followed up for 24 years. The hazard ratios and their 95% confidence intervals for the development of AF were estimated using a Cox proportional hazards model. During the follow up, 234 subjects developed AF. The risk of AF increased significantly with elevating serum hs-CRP levels after adjustment for potential confounding factors (hazard ratio [95% confidence interval], Q1, 1.00 [reference]; Q2, 1.26 [0.83-1.92]; Q3, 1.77 [1.18-2.66]; and Q4, 1.89 [1.24-2.86]; P for trend <0.001).

CONCLUSIONS

The study findings suggest that elevated serum hs-CRP levels are an independent risk factor for the development of AF in a general Japanese population.

An Age-Period-Cohort Analysis of Biomarkers of Lifestyle-Related Diseases Using the National Health and Nutrition Survey in Japan, 1973-2018

Studies of biomarkers of lifestyle-related diseases in Japanese cohorts are scarce. This study aimed to analyze trends in risk markers of lifestyle-related diseases using age-period-cohort (APC) analysis. Data on systolic blood pressure and BMI from 1973 to 2018 and serum glucose, triglyceride, and high-density lipoprotein cholesterol levels from 1989 to 2018 available from the National Health and Nutrition Survey were used. Values for each of the risk markers for each age, period, and cohort were estimated using APC analysis. For women, a decrease in all the risk markers of lifestyle-related diseases was observed in individuals born between the 1930s and approximately 1970. Therefore, female individuals born in approximately 1970 were considered to have the lowest risk of developing lifestyle-related and cardiovascular diseases. Meanwhile, the cohort effect on all the risk markers deteriorated for the younger cohorts, and changes in lifestyle behavior are needed for cohorts born more recently. For men, the trends in risk markers across the cohorts differed, and the relative risk of lifestyle-related diseases for each cohort differed according to disease. These results could help understand cohort-specific risks for lifestyle-related disease and enable identification of high-risk populations who could benefit from preventive measures.

Added and Free Sugars Intake and Metabolic Biomarkers in Japanese Adolescents

Reduction in the intakes of added and free sugars is a recommendation to lower cardiometabolic risks. Sugars intake is considered lowest in the Asian-Pacific region, particularly Japan. We examined the association between sugars intake and cardiometabolic risks in Japanese adolescents. We included 3242 students (mean age, 13.56 years) living in Shunan City, Japan, between 2006 and 2010. Sugars intake was estimated using the brief-type self-administered diet history questionnaire. Anthropometrics, serum lipids, fasting plasma glucose, and blood pressure were measured. Metabolic syndrome was determined by the combination of overweight and other risks. Intakes of added and free sugars were 7.6–7.9%E and 8.4–8.8%E of the total energy intake (%E), respectively. Categories based on quintiles of added or free sugars intakes were associated with fasting glucose, systolic blood pressure, and the z-score of metabolic syndrome (P_trend ≤ 0.025). Other than the association between added sugars ≥10%E and high glucose (odds ratio 1.51, 95% confidence interval 1.04–2.19, p = 0.031), non-significantly high intakes of added or free sugars for risks occurred. Association was observed between added or free sugars intake and cardiometabolic biomarkers in Japanese adolescents, and added sugars intake <10%E could prevent glucose intolerance but not metabolic syndrome.

Trends in prediabetes and diabetes prevalence and associated risk factors in Vietnamese adults

OBJECTIVES

The prevalence of diabetes mellitus is rapidly increasing in Vietnam, particularly among adults aged over 45 years. This study estimated trends in diabetes and prediabetes prevalence and determined risk factors in Vietnamese adults (over 45 years).

METHODS

A cross-sectional study was conducted based on data from an annual diabetes screening program among people aged 45-69 years in an urban city in central Vietnam (Da Nang). Joinpoint regression analyses were performed to calculate the annual percentage change and p_trend-values. Multinomial logistic regression analysis was used to determine risk factors.

RESULTS

In total, 3,765 men and 9,149 women were included in this analysis. The age-adjusted prevalence of diabetes and prediabetes in 2017 was 11.4% and 52.9%, respectively. The prevalence of diabetes was higher in men (15.1%) than in women (10.3%), but that of prediabetes was similar in both genders (53.4% vs. 52.8%). The prevalence of prediabetes significantly increased during the study period, whereas no upward or downward trend for diabetes was observed. The prevalence of obesity, abdominal obesity, hypertension, and dyslipidemia showed no obvious trend. Obesity, a high waist-to-hip ratio, hypertension, more severe abdominal obesity, and dyslipidemia were significantly associated with a higher risk of diabetes and prediabetes.

CONCLUSIONS

Diabetes and prediabetes were more prevalent among people aged over 45 years than in the general population. Da Nang has experienced a marked increase in the prevalence of prediabetes. These findings have significant implications regarding the need for nationwide public health interventions and management aiming at diabetes prevention and control.

Serum Ethylamine Levels as an Indicator of l-Theanine Consumption and the Risk of Type 2 Diabetes in a General Japanese Population: The Hisayama Study

OBJECTIVE

This study investigated the association between serum ethylamine levels as an indicator of l-theanine consumption and the development of type 2 diabetes in a Japanese community.

RESEARCH DESIGN AND METHODS

A total of 2,253 community-dwelling Japanese individuals aged 40-79 years without diabetes were monitored for 7 years. Serum ethylamine levels were divided into quartiles: ≤0.86, 0.87-2.10, 2.11-5.28, and ≥5.29 ng/mL. Kinetic analysis of serum ethylamine concentrations was performed after ingestion of l-theanine-rich green tea products containing 8 mg of l-theanine by 12 healthy volunteers.

RESULTS

During follow-up, 282 subjects developed type 2 diabetes. The age- and sex-adjusted cumulative incidence of type 2 diabetes decreased significantly with elevating levels of serum ethylamine (P for trend = 0.04). This association remained unchanged after adjusting for potential confounding factors. The multivariable-adjusted hazard ratio (HR) for type 2 diabetes was significantly lower in the fourth quartile of serum ethylamine than in the first quartile (HR 0.69, 95% CI 0.49-0.98). This trend of decrease in diabetic risk across serum ethylamine levels was more prominent in middle-aged subjects and in subjects with prediabetes, obesity, or insulin resistance. Kinetic analysis estimated that the minimum concentration at the steady state was >5.90 ng/mL in the case of twice-daily ingestion with an interval of 12 h.

CONCLUSIONS

Higher serum ethylamine was significantly associated with lower risk of the development of type 2 diabetes in a general Japanese population. The measurement of serum ethylamine concentration would be a useful biomarker for the objective estimation of l-theanine consumption.