The association of diabetes mellitus with carotid atherosclerosis and arterial stiffness in the Corinthia study

BACKGROUND AND AIMS

Evaluation of arterial stiffness and carotid atherosclerotic burden can provide important prognostic information regarding the risk of future cardiovascular events. The aim of this study was to assess these vascular properties in patients with diabetes mellitus (DM).

METHODS AND RESULTS

In the context of the observational "Corinthia" study, we analyzed 1757 participants with determined DM status. Carotid ultrasonography was performed to evaluate intima-media thickness (cIMT) and carotid plaque burden. Arterial stiffness was estimated via assessment of carotid-to-femoral pulse wave velocity (cfPWV). Individuals with DM had increased mean cIMT, maximum cIMT, carotid plaque burden, and cfPWV compared to those without DM. After multivariable regression analysis, the presence of DM was still associated with significantly increased mean cIMT (by 0.074 mm, p = .004), maximum cIMT (by 0.134 mm, p = .007), cfPWV (by 0.929 m/s, p < .001), and a higher prevalence of carotid plaques (odds ratio 1.52, 95% confidence intervals 1.11, 2.10, p = .01). In a propensity score-matched cohort, mean cIMT, maximum cIMT, and carotid plaque burden were significantly higher in individuals with DM. Analysis according to territory of cIMT measurement displayed substantial differences in left (DM: 1.32 ± 0.78 mm vs. no DM: 1.20 ± 0.66 mm, p = .04) and right carotid bulbs (DM: 1.33 ± 0.82 mm vs. no DM: 1.18 ± 0.69 mm, p = .02) with respect to DM status while non-significant variations were observed in left (DM: 0.98 ± 0.49 mm vs. no DM: 0.91 ± 0.35 mm, p = .06) and right common carotid artery (DM: 0.95 ± 0.50 mm vs. no DM: 0.92 ± 0.40 mm, p = .36).

CONCLUSIONS

Diabetes mellitus is associated with increased cfPWV and cIMT, with more pronounced lesions in the carotid bulb.

Breakfast association with arterial stiffness and carotid atherosclerotic burden. Insights from the 'Corinthia' study

BACKGROUND AND AIMS

The role of dietary patterns, in cardiovascular diseases has been challenged. The role of breakfast as an element of balance energy intake has gained research interest. However, the effects of dietary patterns related to breakfast consumption on vascular function are unknown. We explored the association of breakfast consumption habits with arterial wall elastic properties and carotid atherosclerosis.

METHODS AND RESULTS

In this cross-sectional study we enrolled 2043 inhabitants of the Corinthia region in Greece. Carotid-femoral pulse wave velocity (cf-PWV) was used to assess arterial stiffness. Carotid intima-media thickness (cIMT) was measured and the mean and the maximum cIMT were calculated. According to food frequency questionnaires, breakfast contribution in total daily energy intake (>20%; 5-20% and <5%) was estimated. Subjects were categorized as high-energy breakfast consumers (HeBC), low-energy breakfast consumers (LeBC) and those skipping breakfast (SBf) respectively. From the study population 240 subjects were categorized as HeBC, 897 as LeBC, and 681 as SBf. The mean cf-PWV was significantly higher in subjects SBf compared to LeBC and HeBC (9.35 ± 2.82 m/s vs. 9.09 ± 2.77 m/s vs. 8.76 ± 2.69 m/s, p = 0.02). The mean cIMT was significantly higher in subjects SBf compared to LeBC and HeBC (1.04 ± 0.46 mm vs. 0.99 ± 0.43 mm vs. 0.92 ± 0.39 mm, p = 0.01). Even after adjustment for potential confounders and cardiovascular risk factors SBf subjects have significantly increased mean cIMT and cf-PWV.

CONCLUSION

Skipping breakfast has an adverse effect on arterial stiffness and carotid atheromatic burden. Increased breakfast total energy intake may act protectively against atherosclerosis, a finding worth of further pathophysiologic exploration with potential clinical implications.

Theobromine consumption does not improve fasting and postprandial vascular function in overweight and obese subjects

Backgound

Theobromine, a component of cocoa, may favorably affect conventional lipid-related cardiovascular risk markers, but effects on flow-mediated dilation (FMD) and other vascular function markers are not known.

Objective

To evaluate the effects of 4-week theobromine consumption (500 mg/day) on fasting and postprandial vascular function markers.

Design

In a randomized, double-blind crossover study, 44 apparently healthy overweight (N = 30) and obese (N = 14) men and women with low HDL-C concentrations, consumed daily 500 mg theobromine or placebo for 4 weeks. After 4 weeks, FMD, peripheral arterial tonometry (PAT), augmentation index (AIx), pulse wave velocity (PWV), blood pressure (BP) and retinal microvasculature measurements were performed. These measurements were carried out under fasting conditions and 2.5 h after a high-fat mixed meal challenge.

Results

4-week theobromine consumption did not change fasting vascular function markers, except for a decrease in central AIx (cAIx, − 1.7 pp, P = 0.037) and a trend towards smaller venular calibers (− 2 µm, P = 0.074). Consuming a high-fat mixed meal decreased FMD (0.89 pp, P = 0.002), reactive hyperemia index (RHI, − 0.30, P < 0.001), peripheral systolic BP (SBP, − 3 mmHg, P ≤ 0.001), peripheral diastolic BP (DBP, − 2 mmHg, P ≤ 0.001), central SBP (− 6 mmHg, P ≤ 0.001) and central DBP (− 2 mmHg, P ≤ 0.001), but increased heart rate (HR, 2 bpm, P < 0.001). Theobromine did not modify these postprandial effects, but increased postprandially the brachial artery diameter (0.03 cm, P = 0.015), and decreased the cAIx corrected for a HR of 75 (cAIx75, − 5.0 pp, P = 0.004) and peripheral AIx (pAIx, − 6.3 pp, P = 0.017).

Conclusion

Theobromine consumption did not improve fasting and postprandial endothelial function, but increased postprandial peripheral arterial diameters and decreased the AIx. These findings do not suggest that theobromine alone contributes to the proposed cardioprotective effects of cocoa.

This trial was registered on clinicaltrials.gov under study number NCT02209025.

Electronic supplementary material

The online version of this article (10.1007/s00394-018-1612-6) contains supplementary material, which is available to authorized users.

Postprandial Effects of Breakfast Glycemic Index on Vascular Function among Young Healthy Adults: A Crossover Clinical Trial

This study aimed to evaluate the postprandial effects of high and low glycemic index (GI) breakfasts on vascular function. It was a crossover trial that included 40 young healthy adults (50% women), aged 20-40 years, who were recruited at primary care settings. They consumed three experimental breakfasts in randomized order, each one separated by a 1-week washout period: (1) control conditions (only water); (2) low GI (LGI) breakfast (29.4 GI and 1489 KJ energy); and (3) high GI (HGI) breakfast (64.0 GI and 1318 KJ energy). Blood samples were collected at 60 and 120 min after each breakfast to determine glucose and insulin levels. Vascular parameters were measured at 15 min intervals. Augmentation index (AIx) was studied as a primary outcome. Secondary outcomes comprised glucose, insulin, heart rate (HR) and pulse pressures (PPs). We found a trend toward increased AIx, HR and PPs for the HGI versus the LGI breakfast. A significant interaction between the type of breakfast consumed and all measured parameters was identified (p < 0.05) except for central PP. Stratifying data by sex, this interaction remained significant for AIx and augmentation pressure only in males (p < 0.05). In conclusion, breakfast GI could affect postprandial vascular responses in young healthy adults.

High trans but not saturated fat beverage causes an acute reduction in postprandial vascular endothelial function but not arterial stiffness in humans

A diet high in trans-fatty acids (TFAs) is associated with a higher risk of cardiovascular disease (CVD) than a diet high in saturated fatty acids (SFAs), but the mechanisms remain unclear. We hypothesized that a beverage high in TFAs would cause a larger reduction in postprandial endothelial function and an increase in arterial stiffness, in part from greater reductions in insulin sensitivity, compared with a beverage high in SFAs. Eleven healthy adults (aged 47±5 years) ingested a warm test beverage (520 kcal, 56 g total fat, 5 g carbohydrate, 1 g protein) high in either TFAs or SFAs in a randomized cross-over study. Ingestion of the beverage high in TFAs (p<0.01) but not high in SFAs (p=0.49) decreased endothelial function (brachial artery flow-mediated dilation, mmΔ) at 3-4 hours (p<0.01 for time; p=0.034 for interaction), but did not alter aortic stiffness or carotid β-stiffness. The homeostasis model of insulin resistance (interaction p=0.062) tended to decrease after SFAs but not TFAs. A beverage high in TFAs but not SFAs results in a postprandial reduction in endothelial function and a trend for decreased insulin sensitivity, potentially explaining the higher risk of CVD with a diet high in TFAs.