Arterial stiffness is established as an independent predictor of cardiovascular morbidity and mortality. The objective was to prospectively evaluate association of aortic calcification burden with progression of arterial stiffness in population-based samples of healthy middle-aged men from ERA JUMP cohort. Men (n=635) aged 40–49 (207 White American, 45 African American, 142 Japanese American and 241 Japanese in Japan) were examined at baseline and 4–7 years later. Aortic calcification was evaluated from level of aortic arch to iliac bifurcation. Arterial stiffness progression was measured as annual change in brachial-ankle pulse wave velocity. Multivariable-adjusted general linear models were applied to investigate associations of longitudinal change in aortic calcification with arterial stiffness progression in participants overall, as well as in subgroups without or with prevalent aortic calcification at baseline. Annual change in aortic calcification was positively and significantly associated with arterial stiffness progression. In participants with annual changes in aortic calcium score of <=0, 1–10, 11–100, and > 100, the adjusted mean (standard deviation) for the annual change in baPWV was 3.8 (2.2), 7.2 (2.2), 12.2 (1.8) and 15.6 (2.6) cm/sec, respectively (P for trend < 0.01) adjusted for baseline aortic calcification, arterial stiffness and standard cardiovascular risk factors. Arterial stiffness was associated with incidence of aortic calcification over the follow-up period among participants without aortic calcification (n=297) and with an increase in aortic calcification among participants with prevalent aortic calcification at baseline (n=388). Our findings suggest aortic calcification may be causally linked to arterial stiffness.

Aims/hypothesis At the same level of BMI, white people have less visceral adipose tissue (VAT) and are less susceptible to developing type 2 diabetes than Japanese people. No previous population-based studies have compared insulin resistance and insulin secretion between these two races in a standardised manner that accounts for VAT. We compared HOMA-IR, HOMA of beta cell function (HOMA-β%) and disposition index (DI) in US white men and Japanese men in Japan. Methods We conducted a population-based, cross-sectional study, comprising 298 white men and 294 Japanese men aged 40–49 years without diabetes. Insulin, glucose, VAT and other measurements were performed at the University of Pittsburgh. We used ANCOVA to compare geometric means of HOMA-IR, HOMA-β% and DI, adjusting for VAT and other covariates. Results White men had higher HOMA-IR, HOMA-β% and DI than Japanese men, and the difference remained significant (p<0.01) after adjusting for VAT (geometric mean [95% CI]): 3.1 (2.9, 3.2) vs 2.5 (2.4, 2.6), 130.8 (124.6, 137.3) vs 86.7 (82.5, 91.0), and 42.4 (41.0, 44.0) vs 34.8 (33.6, 36.0), respectively. Moreover, HOMA-IR, HOMA-β% and DI were significantly higher in white men even after further adjustment for BMI, impaired fasting glucose and other risk factors. Conclusions/interpretation The higher VAT-adjusted DI in white men than Japanese men may partly explain lower susceptibility of white people than Japanese people to developing type 2 diabetes. The results, however, should be interpreted with caution because the assessment of insulin indices was made using fasting samples and adjustment was not made for baseline glucose tolerance. Further studies using formal methods to evaluate insulin indices are warranted.

Background Brachial-ankle pulse wave velocity (baPWV) is a simple and reproducible measure of arterial stiffness and is extensively used to assess cardiovascular disease (CVD) risk in eastern Asia. We examined whether baPWV is associated with coronary atherosclerosis in an international study of healthy middle-aged men. Methods A population-based sample of 1,131 men aged 40–49 years was recruited– 257 Whites and 75 Blacks in Pittsburgh, US, 228 Japanese-Americans in Honolulu, US, 292 Japanese in Otsu, Japan, and 279 Koreans in Ansan, Korea. baPWV was measured with an automated waveform analyzer (VP2000, Omron) and atherosclerosis was examined as coronary artery calcification (CAC) by computed-tomography (GE-Imatron EBT scanner). Association of the presence of CAC (defined as ≥10 Agatston unit) was examined with continuous measure as well as with increasing quartiles of baPWV. Results As compared to the lowest quartile of baPWV, the multivariable-adjusted odds ratio (95% confidence-interval [CI]) for presence of CAC in the combined sample was 1.70 (0.98, 2.94) for 2nd quartile, 1.88 (1.08, 3.28) for 3rd quartile, and 2.16 (1.19, 3.94) for 4th quartile (p-trend = 0.01). The odds for CAC increased by 19% per 100 cm/s increase (p<0.01), or by 36% per standard-deviation increase (p<0.01) in baPWV. Similar effect-sizes were observed in individual races, and were significant among Whites, Blacks and Koreans. Conclusion baPWV is cross-sectionally associated with CAC among healthy middle-aged men. The association was significant in Whites and Blacks in the US, and among Koreans. Longitudinal studies are needed to determine its CVD predictive ability.

Equol, a metabolite of the dietary isoflavone daidzein, is produced by the action of gut bacteria in some individuals who are termed as equol-producers. It is proposed to have stronger atheroprotective properties than dietary isoflavones. We examined a cross-sectional association of dietary isoflavones and equol-producer status with coronary artery calcification (CAC), a biomarker of coronary atherosclerosis, among men in Japan. A population-based sample of 272 Japanese men aged 40-49 years recruited from 2004 to 2007 was examined for serum isoflavones, serum equol, CAC and other factors. Equol-producers were classified as individuals having a serum level of equol >83 nm. The presence of CAC was defined as a coronary Ca score ≥10 Agatston units. The associations of dietary isoflavones and equol-producers with CAC were analysed using multiple logistic regression. The median of dietary isoflavones, equol and CAC were 512·7 (interquartile range (IQR) 194·1, 1170·0), 9·1 (IQR 0·10, 33·1) and 0·0 (IQR 0·0, 1·0) nm, respectively. Prevalence of CAC and equol-producers was 9·6 and 16·0 %, respectively. Dietary isoflavones were not significantly associated with CAC. After multivariable adjustment, the OR for the presence of CAC in equol-producers compared with equol non-producers was 0·10 (95 % CI 0·01, 0·90, P<0·04). Equol-producers had significantly lower CAC than equol non-producers, but there was no significant association between dietary isoflavones and CAC, suggesting that equol may be a key factor for atheroprotective properties of isoflavones in Japanese men. This finding must be confirmed in larger studies or clinical trials of equol that is now available as a dietary supplement.

Objective One-hour plasma glucose (1-h PG) during the oral glucose tolerance test (OGTT) is an accurate predictor of type 2 diabetes. We performed a meta-analysis to determine the optimum cutoff of 1-h PG to detect type 2 diabetes using 2-h PG as the gold standard. Research Design and MethodsWe included 15 studies with 35,551 participants from multiple ethnic groups (53.8% Caucasian) and 2705 newly detected cases of diabetes based on 2-h PG during OGTT. We excluded cases identified only by elevated fasting plasma glucose and/or HbA1c. We determined the optimal 1-h PG threshold and its accuracy at this cut-off to detect diabetes (2-h PG ≥ 11.1 mmol/L) using a mixed linear effects regression model with different weights to sensitivity/specificity (2/3, 1/2, and 1/3).