Yoshihiro Miyamoto

Hypertension and lifetime risk of stroke

Background: The lifetime risk (LTR) articulates the probability of disease in the residual lifetime for an index age. These estimates can be useful for general audience-targeted knowledge translation activities against hypertension. There are only a few reports on lifetime of impact of hypertension on stroke events in Asians in whom stroke incidence is higher than Westerners. Methods: The Suita Study, a cohort study of cardiovascular diseases in Japan, was established in 1989. We included all participants who were stroke free at baseline. Age (in years) was used as the time scale. Age-specific incidence rates were calculated with person-year method within 10-year bands. We estimated the sex and index-age specific LTR of first-ever stroke with taking the competing risk of death into account. Results: We followed 5783 men and women during 1989–2007 for 74u200a933 person-years. During the follow-up period, 276 (149 men and 127 women) participants had incident stroke. Of them, majority were cerebral infarction; 166 (102 men and 64 women). The LTR of stroke, accounted for competing risk of death, at 45 years of age for men without hypertension was 17.21% and it was 32.79% for hypertensive men. Among the hypertensive patients, participants with stage 2 or greater hypertension had higher LTR of stroke than the participants with stage 1 hypertension. This increased LTR of stroke for hypertensive patients were also observed among women and across all index ages for stroke. Conclusion: In this urban community-based population, we observed that hypertension has significant effect on the residual LTR of stroke among both men and women of middle age, specifically for ischemic stroke.

Serum polyunsaturated fatty acid composition and serum high-sensitivity C-reactive protein levels in healthy Japanese residents: The KOBE study

Background/ObjectivesSerum polyunsaturated fatty acid (PUFA) composition reflects dietary intake and is related to risks for cardiovascular diseases. We hypothesized that serum n-3 PUFA composition, especially including long-chain n-3 PUFA such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), is associated with inflammatory status, which is related to increased risk for cardiovascular diseases.Subjects/MethodsWe investigated the relationship between serum PUFA composition and high-sensitivity C-reactive protein (hs-CRP) levels in a cross-sectional study among 1,102 healthy men and women aged 40–74 years who reside in Kobe City. Multiple linear regression models that predict hs-CRP level were prepared to confirm the contribution of serum total n-3 PUFA, long-chain n-3 PUFA, EPA and DHA compositions after adjusting for other PUFAs and atherosclerotic risk factors.ResultsThe serum n-3 PUFA, particularly long-chain n-3 PUFA, compositions were inversely associated with the hs-CRP levels. The standardized regression coefficient was −0.089 (p < 0.01) for total n-3 PUFA, −0.091 (p < 0.01) for long-chain n-3 PUFA, −0.071 (p = 0.03) for EPA, and −0.068 (p = 0.04) for DHA. The n-6 PUFA compositions were also inversely associated with the hs-CRP levels (−0.169 [p < 0.01] for total n-6 PUFA and −0.159 [p < 0.01] for linoleic acid).ConclusionsThe serum n-3 PUFA compositions were inversely related with the hs-CRP levels, similar associations were also observed in n-6 PUFA compositions. Our results suggest that dietary PUFA intake was inversely associated with attenuated inflammation in healthy Japanese population.

HOMA-IR Values are Associated With Glycemic Control in Japanese Subjects Without Diabetes or Obesity: The KOBE Study

BACKGROUNDnSeveral studies have reported that insulin resistance was a major risk factor for the onset of type 2 diabetes mellitus in individuals without diabetes or obesity. We aimed to clarify the association between insulin resistance and glycemic control in Japanese subjects without diabetes or obesity.nnnMETHODSnWe conducted a community-based cross-sectional study including 1083 healthy subjects (323 men and 760 women) in an urban area. We performed multivariate regression analyses to estimate the association between the homeostasis model assessment of insulin resistance (HOMA-IR) values and markers of glycemic control, including glycated haemoglobin (HbA1c), 1,5-anhydroglucitol (1,5-AG), and fasting plasma glucose (FPG) levels, after adjustment for potential confounders.nnnRESULTSnCompared with the lowest tertile of HOMA-IR values, the highest tertile was significantly associated with HbA1c and FPG levels after adjustment for potential confounders, both in men (HbA1c: β = 1.83, P = 0.001; FPG: β = 0.49, P < 0.001) and women (HbA1c: β = 0.82, P = 0.008; FPG: β = 0.39, P < 0.001). The highest tertile of HOMA-IR values was inversely associated with 1,5-AG levels compared with the lowest tertile (β = -18.42, P = 0.009) only in men.nnnCONCLUSIONSnHOMA-IR values were associated with markers of glycemic control in Japanese subjects without diabetes or obesity. Insulin resistance may influence glycemic control even in a lean, non-diabetic Asian population.Background Several studies have reported that insulin resistance was a major risk factor for the onset of type 2 diabetes mellitus in individuals without diabetes or obesity. We aimed to clarify the association between insulin resistance and glycemic control in Japanese subjects without diabetes or obesity. Methods We conducted a community-based cross-sectional study including 1083 healthy subjects (323 men and 760 women) in an urban area. We performed multivariate regression analyses to estimate the association between the homeostasis model assessment of insulin resistance (HOMA-IR) values and markers of glycemic control, including glycated haemoglobin (HbA1c), 1,5-anhydroglucitol (1,5-AG), and fasting plasma glucose (FPG) levels, after adjustment for potential confounders. Results Compared with the lowest tertile of HOMA-IR values, the highest tertile was significantly associated with HbA1c and FPG levels after adjustment for potential confounders, both in men (HbA1c: β = 1.83, P = 0.001; FPG: β = 0.49, P < 0.001) and women (HbA1c: β = 0.82, P = 0.008; FPG: β = 0.39, P < 0.001). The highest tertile of HOMA-IR values was inversely associated with 1,5-AG levels compared with the lowest tertile (β = −18.42, P = 0.009) only in men. Conclusions HOMA-IR values were associated with markers of glycemic control in Japanese subjects without diabetes or obesity. Insulin resistance may influence glycemic control even in a lean, non-diabetic Asian population.

Risk for metabolic diseases in normal weight individuals with visceral fat accumulation: a cross-sectional study in Japan

Objective To investigate the association between visceral fat area (VFA) and metabolic syndrome (Mets) among normal weight Japanese. Design A cross-sectional study. Setting The health check-up centre of the Takeda Hospital group in Kyoto, Japan. Methods This study involved 1674 men and 1448 women aged 30–74u2005years who underwent medical check-ups in 2012 in the health check-up centre. They were stratified by Body Mass Index (BMI cut-off for obesity is set at 23.0u2005kg/m2 for Asians): normal weight 18.5–22.9u2005kg/m2 or higher weight ≥23.0u2005kg/m2. The age-adjusted ORs of the 2nd to 4th groups of sex-specific VFA quartiles compared with the 1st quartile for a Mets component clustering were estimated. The clustering was having two or more of the following factors: high blood pressure, high fasting blood glucose (FBG), low high-density lipoprotein cholesterol (HDL-C) and high triglycerides. Statistical analyses were conducted in 2016. Results Participants in the 2nd to 4th VFA quartiles had significantly higher clustering risks; ORs were 3.4 (1.5 to 8.0), 6.3 (2.8 to 14.2) and 9.3 (4.2 to 20.7) for normal weight participants, and 1.7 (1.2 to 2.6), 2.6 (1.8 to 3.9) and 6.0 (4.1 to 8.8) for higher weight participants, respectively. The ORs of the 4th VFA quartile for Mets components were significantly higher; ORs for normal weight participants were 2.1 (1.5 to 3.0) (high blood pressure), 2.4 (1.4 to 4.2) (high FBG), 5.2 (2.1 to 12.9) (low HDL-C) and 12.0 (5.7 to 25.3) (high triglycerides), and higher weight participants were 3.9 (2.8 to 5.5), 4.1 (2.8 to 6.2), 3.9 (2.2 to 6.9) and 5.0 (3.4 to 7.4), respectively. Conclusions Among participants with normal weight, as well as those of higher weight, dose-dependent responses were observed between VFA and risk for Mets components and the clustering among Japanese adults. VFA may be useful information for interventions to improve metabolic risk factors in people with normal weight.

Impact of hypertension on the lifetime risk of coronary heart disease

The lifetime risk estimate conveys the probability of disease in the remaining lifetime for an index age. These estimates may be useful for general audience-targeted knowledge translation activities against hypertension. There are only a few reports on the impact of hypertension on the lifetime risk of cardiovascular events. The Suita Study, a cohort study of urban residents, was established in 1989. We included all participants who were coronary heart disease (CHD) free at baseline. Age (in years) was used as the timescale. Age-specific incidence rates were calculated with the person-year method within 5-year bands. We estimated the sex- and index-age-specific lifetime risk of first-ever CHD, taking the competing risk of death into account. We followed 5834 participants from 1989 to 2007 for a total of 75u2009387.5 person-years. At age 45 years, the competing risk of death-adjusted lifetime risk for all CHD for men was 14.12% for normotensive men and 26.95% for hypertensive men. The competing risk of death-adjusted lifetime risk for all CHD at 45 years of age for women was 6.21% for normotensive women and 14.85% for hypertensive women. This increased lifetime risk of CHD for hypertensive patients was observed among both men and women across all index ages. Although the overall lifetime risk of CHD was lower than in the Western population, hypertension showed a significant effect on the residual lifetime risk of CHD among Japanese middle-aged men and women. This easy-to-understand knowledge may be used as an important index to assist public health education and planning.

Association between impairment of salty taste recognition and masked hypertension based on home blood pressure in Japanese residents: the KOBE study

Excessive salt intake is an established risk factor for hypertension. We conducted a cross-sectional study to examine the association between salty taste recognition and estimated salt intake and masked hypertension in a healthy Japanese normotensive population. The participants were 892 apparently healthy community residents (246 men and 646 women) aged between 40 and 74 years with blood pressure below 140/90u2009mmu2009Hg. Salty taste recognition was assessed using a salt-impregnated taste strip. Daily salt intake was calculated as estimated 24u2009h urinary sodium excretion using spot urine tests. Each participant performed home blood pressure measurements for a minimum of 5 days per week. The participants were classified into three groups according to their salty taste recognition threshold evaluated by the salt concentrations of the taste strips (0.6%, 0.8%, and ≥u20091.0%). In women, the multivariate odds ratio (95% confidence interval) for masked hypertension (u2009≥u2009135/85u2009mmu2009Hg) was 2.98 (1.16–7.64) in the ≥u20091.0% group compared with that in the 0.6% group. In men, the proportion of masked hypertension in the ≥u20091.0% group did not differ from that in the 0.6% group, and no correlation was identified between estimated daily salt intake and the salty taste recognition threshold. In conclusion, impairment of salty taste recognition was associated with masked hypertension in women even with normal blood pressure in the clinical setting.

Diabetes and lifetime risk of stroke and subtypes in an urban middle-aged population.

AIMSnLifetime risk (LTR) is defined as the cumulative probability of developing a disease in ones remaining lifetime from a given index age. The impact of diabetes on the LTR of stroke events in Asians, where stroke incidence is higher than for Westerners, has not been estimated yet. These estimates can be useful for diabetes knowledge translation activities.nnnMETHODSnAll participants who were stroke-free at baseline in the Suita Study, a cohort study of cardiovascular diseases in Japan, were included in the study sample. Age, in years, was used as the time-scale. Age-specific incidence rates were calculated using the person-years method within five-year bands. We estimated the sex- and index-age-specific LTR of first-ever stroke accounting for the competing risk of death.nnnRESULTSnIn this cohort study, we followed 5515 participants from 1989 to 2007 for 71,374.23 person-years. At age 40, the LTRs, adjusted for competing risk of death, for all strokes were 15.98% for men without diabetes and 26.64% for men with diabetes. The LTR for stroke was 10.66% higher for men with diabetes than men without diabetes. For women of same index age, the LTR of stroke was 17.29% and 30.72% with diabetes and without diabetes, respectively. The difference in LTR between persons with diabetes and without diabetes was 13.43%. This increased LTR of strokes for persons with diabetes was observed among both men and women across all index ages. Similar results were observed for cerebral infarction stroke subtype.nnnCONCLUSIONSnIn this urban community-based population we observed that diabetes has a significant effect on the residual LTR of stroke for both men and women of middle age. This knowledge can be used to inform public health education and planning.