Insulin resistance in the adipose tissue predicts future vascular resistance: The Hiroshima Study on Glucose Metabolism and Cardiovascular Diseases.

BACKGROUND AND AIMS: Diameter, plaque score, and resistance index (RI) in the common carotid artery (CCA) are indicators of arterial remodeling, atherosclerosis, and vascular resistance, respectively. This study investigated the longitudinal association between adipose tissue insulin resistance or serum free fatty acid (FFA) levels and the CCA parameters. METHODS: This retrospective cohort analysis included 1089 participants (mean age 57.6 years; 40.0 % women) with data on health checkups from January 1982 to March 2003 and carotid artery ultrasonography from January 2015 to June 2019. Baseline serum FFA and immunoreactive insulin levels were assessed before and 30, 60, and 120 min after glucose ingestion. Adipose insulin resistance index (Adipo-IR) was calculated as the product of fasting serum insulin and FFA levels. An RI value >0.75 was defined as high RI. RESULTS: A significant association was found between Adipo-IR and RI; however, Adipo-IR showed no association with CCA diameter or plaque score. The incidence of high RI increased with Adipo-IR quartile (Q) groups (47.3 % in Q1, 52.8 % in Q2, 53.3 % in Q3, 62.4 % in Q4; Cochrane-Armitage test for trend, p < 0.001). In multivariate analysis, Adipo-IR levels (Q4 vs. Q1 odds ratio: 1.67, 95 % confidence interval: 1.12-2.51) were positively associated with high RI incidence. Moreover, a significant association was found between RI and serum FFA levels after glucose intake, but not fasting FFA levels. CONCLUSIONS: Future vascular resistance was predicted by insulin resistance in the adipose tissue. After glucose intake, serum FFA levels may significantly impact vascular resistance development.

Upstroke time is a more useful marker of atherosclerosis than percentage of mean arterial pressure for detecting coronary artery disease in subjects with a normal ankle-brachial index.

Upstroke time (UT) and percentage of mean arterial pressure (%MAP) at the ankle have been shown to serve as atherosclerotic markers. The purpose of this study was to directly compare the diagnostic accuracy of UT with that of %MAP for clinical coronary artery disease (CAD) in subjects with a normal ankle-brachial index (ABI) in both legs. We measured UT and %MAP in 1953 subjects with a normal ABI. The optimal cutoff values of UT and %MAP derived from a receiver operating characteristic (ROC) curve to diagnose CAD were 148 ms and 40.4%, respectively. Multivariable analyses revealed that both UT ≥ 148 ms (odds ratio [OR], 2.72; p < 0.001) and %MAP ≥ 40.4% (OR, 1.28; p = 0.003) were significantly associated with CAD. When the subjects were divided into four groups according to the cutoff values of UT and %MAP, there was no significant difference in the risk of CAD between subjects with UT ≥ 148 ms and %MAP < 40.4% and those with UT ≥ 148 ms and %MAP ≥ 40.4% (OR, 1.45; p = 0.09). ROC curve analyses revealed that the area under the curve value of UT was significantly higher than that of %MAP (0.69 vs. 0.53, p < 0.001). The addition of UT to traditional risk factors significantly improved the diagnostic accuracy for CAD (0.82 to 0.84, p = 0.004), whereas the addition of %MAP to traditional risk factors did not improve the diagnostic accuracy for CAD (0.82 to 0.82, p = 0.84). UT is more useful than %MAP for identifying individuals with CAD among those with a normal ABI.

Effects of BNT162b2 mRNA Covid-19 vaccine on vascular function.

The effects of Covid-19 vaccines on vascular function are still controversial. We evaluated the effects of BNT162b2 vaccine (BioNTech and Pfizer) on endothelial function assessed by flow-mediated vasodilation (FMD) and vascular smooth muscle function assessed by nitroglycerine-induced vasodilation (NID). This study was a prospective observational study. A total of 23 medical staff at Hiroshima University Hospital were enrolled in this study. FMD and NID were measured before vaccination and two weeks and six months after the 2nd dose of vaccination. FMD was significantly smaller two weeks after the 2nd dose of vaccination than before vaccination (6.5±2.4% and 8.2±2.6%, p = 0.03). FMD was significantly larger at six months than at two weeks after the 2nd dose of vaccination (8.2±3.0% and 6.5±2.4%, p = 0.03). There was no significant difference between FMD before vaccination and that at six months after the 2nd dose of vaccination (8.2±2.6% to 8.2±3.0%, p = 0.96). NID values were similar before vaccination and at two weeks, and six months after vaccination (p = 0.89). The BNT162b2 Covid-19 vaccine temporally impaired endothelial function but not vascular smooth muscle function, and the impaired endothelial function returned to the baseline level within six months after vaccination.

A Body Shape Index as a Simple Anthropometric Marker of Abdominal Obesity and Risk of Cardiovascular Events.

BACKGROUND: A Body Shape Index (ABSI) has been reported to have associations with cardiovascular risk factors. However, there is no information on the association between ABSI and incidence of cardiovascular events. METHODS: We investigated the associations between ABSI and first major cardiovascular events (death from cardiovascular disease, nonfatal acute coronary syndrome, and nonfatal stroke) in 1857 subjects from the database of Flow-Mediated Dilation Japan registry and from Hiroshima University Vascular Function registry. RESULTS: The areas under the curves of ABSI to predict the first major cardiovascular events were superior to BMI (men: P=0.032, women: P=0.015) and waist circumference in women (men: P=0.078, women: P=0.002). The subjects were divided into two groups based on the cutoff value of ABSI for predicting first major cardiovascular events: a low ABSI group (<0.0822 in men and <0.0814 in women) and a high ABSI group (≥0.0822 in men and ≥0.0814 in women). During a median follow-up period of 41.6 months, 56 subjects died (23 from cardiovascular causes), 16 had nonfatal acute coronary syndrome, and 14 had nonfatal stroke. The Kaplan-Meier curves for first major cardiovascular events were significantly different between the two groups (men, P<0.001; women, P<0.001). Multivariate analysis revealed that high ABSI remained an independent predictor of first major cardiovascular events (men: hazard ratio, 2.33; 95% CI, 1.07 to 5.06; P=0.033; women: hazard ratio, 8.33; 95% CI, 1.06 to 65.49; P=0.044). CONCLUSIONS: High ABSI is independently associated with incidence of cardiovascular events. ABSI calculation should be performed for evaluation of risk of cardiovascular events.

Differences in the impact of newly diagnosed type 2 diabetes on cardiovascular mortality between normotensive and hypertensive individuals.

OBJECTIVE: We investigated the interrelationship between hyperglycemia and hypertension on cardiovascular mortality in the middle-aged and elderly people. METHODS: In this retrospective cohort study that used data from the Hiroshima Study on Glucose Metabolism and Cardiovascular Diseases, we included 16,564 participants without cardiovascular disease (mean age: 65.8 years; 6179 normoglycemic people, 3017 people with newly diagnosed type 2 diabetes, and 7368 people with prediabetes per the 75-g oral glucose tolerance test). Hypertension was defined as the use of antihypertensive medications and/or having a systolic/diastolic blood pressure of at least 140/90 mm Hg. RESULTS: During a median follow-up period of 12.4 years, a total of 1513 cardiovascular death occurred. Cardiovascular death rates per 1000 participant-years were 4.01, 4.98, 8.33, 8.22, 8.81, and 11.1 among normotensive participants with normal glycemia, prediabetes, and diabetes and hypertensive participants with normal glycemia, prediabetes, and diabetes, respectively. Prediabetes was significantly associated with a high risk of cardiovascular mortality in normotensive individuals [hazard ratio: 1.24, 95% confidence interval (95% CI): 1.02-1.50] but not in hypertensive individuals. Type 2 diabetes was associated with a high risk of cardiovascular mortality in both normotensive (hazard ratio: 1.94, 95% CI: 1.55-2.43) and hypertensive individuals (hazard ratio: 1.35, 95% CI: 1.13-1.62). Stratified analyses revealed no significant impact of type 2 diabetes on cardiovascular mortality in hypertensive individuals aged at least 65 years. CONCLUSION: The effect of hyperglycemia on cardiovascular death differed with age and the presence or absence of hypertension, demonstrating the clinical importance of case-specific risk assessments.

Erythropoiesis and estimated fluid volume regulation following initiation of ipragliflozin treatment in patients with type 2 diabetes mellitus and chronic kidney disease: A post-hoc analysis of the PROCEED trial.

AIMS: To analyse the changes in erythropoietic and estimated fluid volume parameters after the initiation of ipragliflozin, a sodium-glucose co-transporter 2 inhibitor, in patients with type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD). METHODS: This was a post-hoc analysis of the PROCEED trial, which evaluated the effect of 24-week ipragliflozin treatment on endothelial dysfunction in patients with T2DM and CKD. We evaluated the changes in erythropoietic and estimated fluid volume parameters from baseline to 24 weeks post-treatment in 53 patients who received ipragliflozin (ipragliflozin group) and 55 patients with T2DM and CKD without sodium-glucose co-transporter 2 inhibitors (control group), a full analysis set of the PROCEED trial. RESULTS: The increases in haemoglobin [estimated group difference, 0.5 g/dl; 95% confidence interval (CI), 0.3-0.8; p < .001], haematocrit (estimated group difference, 2.2%; 95% CI, 1.3-3.1; p < .001) and erythropoietin (estimated log-transformed group difference, 0.1; 95% CI, 0.01-0.3; p = .036) were significantly greater in the ipragliflozin group than those in the control group. Ipragliflozin treatment was significantly associated with an increase in erythropoietin, independent of the corresponding change in haemoglobin (ß = 0.253, p < .001) or haematocrit (ß = 0.278, p < .001). Reductions in estimated plasma volume (estimated group difference, -7.94%; 95% CI, -11.6 to -4.26%; p < .001) and estimated extracellular volume (estimated group difference, -181.6 ml; 95% CI, -275.7 to -87.48 ml; p < .001) were significantly greater in the ipragliflozin group than those in the control group. CONCLUSIONS: Erythropoiesis was enhanced and estimated fluid volumes were reduced by ipragliflozin in patients with T2DM and CKD. CLINICAL TRIAL: PROCEED trial (registration number: jRCTs071190054).

An Extended Follow-Up on Blood Pressure in a Patient With New-Onset Essential Hypertension: Early-Morning Home, Morning Home, and Office Readings.

The patient was a 63-year-old man with a 24-year history of hypertension. During long-term follow-up, when outpatient clinic blood pressure and morning blood pressure are well-regulated, exceptionally elevated early-morning blood pressure does not play a significant role in the development of hypertensive target organ disease or cardiovascular disease.

Association of cumulative low-density lipoprotein cholesterol exposure with vascular function.

BACKGROUND: The relationship between cumulative low-density lipoprotein cholesterol (LDL-C) exposure and progression of atherosclerosis remains uncertain. OBJECTIVE: The aim of this study was to determine the relationship between cumulative LDL-C level and flow-mediated vasodilation (FMD), nitroglycerine-induced vasodilation (NID) and the presence of plaque in the common carotid artery (CCA). METHODS: This was a cross-sectional study. We measured FMD in 8208 subjects, NID in 1822 subjects, and CCA plaque in 591 subjects who were not taking lipid-lowering drugs. The subjects were divided into four groups based on cumulative LDL-C exposure: <4000 mg·year/dL, 4000-4999 mg·year/dL, 5000-5999 mg·year/dL, and ≥6000 mg·year/dL. RESULTS: The odds ratio of the lower quartile of FMD in the cholesterol-year-score <4000 mg·year/dL group was significantly higher than the odds ratios in the other groups. The odds ratio of the lower quartile of NID in the <4000 mg·year/dL group was significantly higher than the odds ratios in the 5000-5999 mg·year/dL and ≥6000 mg·year/dL groups. The odds ratio of the prevalence of CCA plaque in the <4000 mg·year/dL group was significantly higher than that in the ≥6000 mg·year/dL group. CONCLUSIONS: Endothelial dysfunction occurred from cumulative LDL-C exposure of 4000 mg·year/dL, vascular smooth muscle dysfunction occurred from cumulative LDL-C exposure of 5000 mg·year/dL, and prevalence of CCA plaque occurred from cumulative LDL-C exposure of 6000 mg·year/dL. CLINICAL TRIAL REGISTRY INFORMATION: http://www.umin.ac.jp (UMIN000012950, UMIN000012951, and UMIN000012952, UMIN000003409).

Seasonal variations in endothelium-dependent flow-mediated vasodilation and endothelium-independent nitroglycerine-induced vasodilation.

Cardiovascular mortality has been shown to vary seasonally. However, it has not been determined whether vascular function is affected by the season. The purpose of this study was to investigate the associations of vascular function with season and outdoor temperature. Between April 2007 and March 2022, measurements of flow-mediated vasodilation (FMD) of the brachial artery as an index of endothelial function and nitroglycerine-induced vasodilation (NID) as an index of endothelium-independent vasodilation were performed in 2190 subjects. There was no significant seasonal difference in FMD (spring, 3.9 ± 3.1%; summer, 3.5 ± 3.0%; fall, 3.7 ± 3.0%; winter, 3.6 ± 3.2%; P = 0.14). There was no significant correlation between FMD and daily mean outdoor temperature (r = -0.02, P = 0.25). Multivariate analyses revealed that neither season (ß = -0.020, P = 0.31) nor outdoor temperature (ß = 0.005, P = 0.81) was significantly associated with FMD after adjustment for other confounding factors. There were significant seasonal differences in NID (spring, 12.8 ± 6.3%; summer, 12.0 ± 6.1%; fall, 11.7 ± 6.1%; winter, 12.3 ± 5.9%; P = 0.02). However, multivariate analysis revealed that there was no significant association between season and NID after adjustment for other confounding factors (ß = -0.012, P = 0.56). There was no significant correlation between NID and daily outdoor mean temperature (r = -0.03, P = 0.17). Multivariate analysis revealed that outdoor temperature was not significantly associated with NID (ß = -0.006, P = 0.78). There was no significant association of FMD or NID with season or outdoor temperature, suggesting that it is not necessary to take into account the effects of season and outdoor temperature on vascular function when interpreting the results of FMD and NID measurements. Public trials registry number: UMIN000039512.

Association of serum uric acid levels with blood pressure and the incidence of hypertension in the middle-aged and elderly populations.

OBJECTIVE: This study aimed to investigate the relationship between serum uric acid (SUA) levels and hypertension in the middle-aged and elderly populations. METHODS: The cross-sectional analysis included 13 349 middle-aged and elderly general health checkup examinees without cardiovascular disease. The retrospective cohort analysis included 6659 normotensive participants (mean age: 64.6 years). Participants were divided into three groups based on their SBP/DBP levels: normal (<120/<80 mmHg), high normal (120-129/<80 mmHg), and elevated (130-139/80-89 mmHg), and were classified into three groups based on the results of 75 g oral glucose tolerance test: normoglycemia, prediabetes, and diabetes. RESULTS: SUA levels were significantly associated with SBP and DBP in this cross-sectional study. Over a mean 6.5-year follow-up period, 2038 participants developed hypertension. According to the SUA quartiles, the incidence of hypertension increased [26.1% in quartile (Q1) (≤4.1 mg/dl), 28.6% in Q2 (4.2-4.9 mg/dl), 32.6% in Q3 (5.0-5.8 mg/dl), 34.9% in Q4 (≥5.9 mg/dl); P for trend <0.001]. In multivariable analyses, SUA levels were positively associated with hypertension incidence only in the normal BP group [Q4 vs. Q1 odds ratio (OR): 1.64, 95% confidence intervals (CIs): 1.11-2.44; Q3 vs. Q1 OR: 1.69, 95% CI: 1.19-2.42] and in the normoglycemic group (Q4 vs. Q1 OR: 1.34, 95% CI: 1.02-1.76; Q3 vs. Q1 OR: 1.36, 95% CI: 1.07-1.74). CONCLUSION: In the middle-aged and elderly populations, normotensive or normoglycemic individuals with SUA levels at least 5 mg/dl may be potential targets for SUA management to prevent hypertension.

Sparing and enhancing dose protraction effects for radiation damage to the aorta of wild-type mice.

PURPOSE: Our previous work indicated the greater magnitude of damage to the thoracic aorta at 6 months after starting 5 Gy irradiation in descending order of exposure to X-rays in 25 fractions > acute X-rays > acute γ-rays > X-rays in 100 fractions ≫ chronic γ-rays, in which the limitations of the study included a lack of data for fractionated γ-ray exposure. To better understand effects of dose protraction and radiation quality, the present study examined changes after exposure to γ-rays in 25 fractions, and compared its biological effectiveness with five other irradiation regimens. MATERIALS AND METHODS: Male C57BL/6J mice received 5 Gy of 137Cs γ-rays delivered in 25 fractions spread over six weeks. At 6 months after starting irradiation, mice were subjected to echocardiography, followed by tissue sampling. The descending thoracic aorta underwent scanning electron microscopy, immunofluorescence staining and histochemical staining. The integrative analysis of multiple aortic endpoints was conducted for inter-regimen comparisons. RESULTS: Exposure to γ-rays in 25 fractions induced vascular damage (evidenced by increases in endothelial detachment and vascular endothelial cell death, decreases in endothelial waviness, CD31, endothelial nitric oxide synthase and vascular endothelial cadherin), inflammation (evidenced by increases in tumor necrosis factor α, CD68 and F4/80) and fibrosis (evidenced by increases in transforming growth factor ß1, alanine blue stain and intima-media thickness). The integrative analysis revealed biological effectiveness in descending order of exposure to X-rays in 25 fractions > acute X-rays > γ-rays in 25 fractions > acute γ-rays > X-rays in 100 fractions ≫ chronic γ-rays. CONCLUSIONS: The results suggest that dose protraction effects on aortic damage depend on radiation quality, and are not a simple function of dose rate and the number of fractions.

2023 update and perspectives.

Total 276 manuscripts were published in Hypertension Research in 2022. Here our editorial members picked up the excellent papers, summarized the current topics from the published papers and discussed future perspectives in the sixteen fields. We hope you enjoy our special feature, 2023 update and perspectives in Hypertension Research.

Percentage of mean arterial pressure as a marker of atherosclerosis for detecting patients with coronary artery disease.

The percentage of mean arterial pressure (%MAP) is the height of the mean arterial waveform divided by the peak amplitude of the waveform of pulse volume recording. The purpose of this study was to determine whether the cutoff value of 45% for %MAP at the ankle, which is recommended for the diagnosis of lower extremity artery disease, in combination with ankle-brachial index (ABI) is useful for detecting patients with clinical coronary artery disease (CAD) and investigate the optimal cutoff value of %MAP to diagnose patients with CAD.　We measured ABI and %MAP in 2213 subjects　(mean age: 61.2 ± 15.5 years). Multivariate analysis revealed that %MAP ≥ 45% was significantly associated with a higher risk of CAD after adjusting for traditional cardiovascular risk factors (odds ratio [OR], 2.14; 95% confidence interval [CI], 1.43-3.21; p < 0.001). However, the association was no longer significant after adjusting for ABI (OR, 1.39; 95% CI, 0.83-2.33; p = 0.21), whereas ABI was significantly associated with CAD (OR, 0.98; 95% CI, 0.97-0.99; p = 0.005). The optimal cutoff value of %MAP derived from a receiver operating characteristic curve to diagnose CAD was 40.3%. Multivariate analysis revealed that %MAP ≥ 40.3% was significantly associated with a higher risk of CAD (OR, 1.63; 95% CI, 1.19-2.24; p = 0.002) independent of ABI (OR, 0.98; 95% CI, 0.97-0.99; p = 0.002). The cutoff value of 40.3%, but not 45%, for %MAP may be useful for detecting patients with advanced atherosclerosis and for cardiovascular risk assessment independent of ABI. REGISTRATION INFORMATION: http://www.umin.ac.jp (University Hospital Medical Information Network Clinical Trials Registry) (UMIN000039512).

Role of Small Dense Low-density Lipoprotein Cholesterol in Cardiovascular Events in Patients with Coronary Artery Disease and Type 2 Diabetes Mellitus Receiving Statin Treatment.

AIM: There is little information on the relationships of serum small dense low-density lipoprotein cholesterol (sdLDL-C) levels and serum triglyceride (TG) levels with cardiovascular events in patients with coronary artery disease (CAD) and type 2 diabetes mellitus (DM) who are receiving statins. The aim of this study was to evaluate the relationships of serum TG levels and sdLDL-C levels as residual risks for cardiovascular events in patients with CAD and type 2 DM who were being treated with statins. METHODS: The subjects were divided into four groups based on TG levels and sdLDL-C levels: sdLDL-C of ＜40.0 mg/dL and TG of ＜150 mg/dL, sdLDL-C of ≥ 40.0 mg/dL and TG of ＜150 mg/dL, sdLDL-C of ＜40.0 mg/dL and TG of ≥ 150 mg/dL, and sdLDL-C of ≥ 40.0 mg/dL and TG of ≥ 150 mg/dL. During a median follow-up period of 1419 days, cardiovascular events occurred in 34 patients. RESULTS: The incidences of cardiovascular events were significantly higher in patients with sdLDL-C of ≥ 40.0 mg/dL and TG of ＜150 mg/dL and in patients with sdLDL-C of ≥ 40.0 mg/dL and TG of ≥ 150 mg/dL, but not in patients with sdLDL-C of ＜40.0 mg/dL and TG of ≥ 150 mg/dL, than in patients with sdLDL-C of ＜40.0 mg/dL and TG of ＜150 mg/dL. CONCLUSIONS: Under the condition of treatment with statins, patients with CAD and type 2 DM who had sdLDL-C levels of ≥ 40.0 mg/dL had a high risk for cardiovascular events even though serum TG levels were controlled at ＜150 mg/dL.

Impact of overnight 1 mg dexamethasone on vascular function in patients with nonfunctioning adrenal adenomas.

The purpose of this study was to evaluate the effects of administration of overnight 1 mg dexamethasone on vascular function in patients with nonfunctioning adrenal adenomas (NFA). Flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation (NID) were measured to assess vascular function in 22 patients with NFA who had hypertension and/or diabetes mellitus (DM) and 272 patients without adrenal incidentalomas who had hypertension and/or DM (control patients with hypertension and/or DM). FMD and NID were measured in the morning before and after administration of 1 mg of dexamethasone at 2300 h in 18 patients with NFA. There were no significant differences in FMD and NID between control patients with hypertension and/or DM and patients with NFA who had hypertension and/or DM (3.4 ± 2.8% vs. 2.9 ± 1.9% and 11.5 ± 5.7% vs. 11.4 ± 4.3%, P = 0.46, and P = 0.99, respectively). There were no significant differences in vascular function between control patients with hypertension and/or DM and patients with NFA who had hypertension and/or DM even after adjustment for cardiovascular risk factors. Overnight 1 mg dexamethasone increased FMD from 2.4 ± 1.9% to 5.3 ± 3.2% (P < 0.01) and increased NID from 12.1 ± 4.2% to 14.0 ± 2.8% (P < 0.01) in patients with NFA. The overnight 1 mg dexamethasone suppression test does not impair FMD and NID in patients with NFA. Decreases in circulating levels of cortisol may improve vascular function.Clinical Trial Registration: This study was approved by principal authorities and ethical issues in Japan (URL for Clinical Trial: http://www.umin.ac.jp/ctr/index.htm Registration Number for Clinical Trial: UMIN000039512).

Smoking cessation and vascular endothelial function.

Smoking is associated with vascular endothelial dysfunction. It is thought that smoking impairs vascular endothelial function through a decrease in nitric oxide bioavailability induced by activation of oxidative stress and inflammation. Endothelial dysfunction can be improved or augmented by appropriate interventions including pharmacotherapy, administration of supplements and lifestyle modifications. Although there have not been many studies, the effects of smoking cessation on endothelial function have been shown. In those studies, it was shown that smoking cessation does not always have a positive effect on vascular endothelial function. In this review, I will focus on the role of smoking in endothelial function and the effects of smoking cessation on endothelial function. Smoking impairs vascular endothelial function and leads to atherosclerosis. Smoking cessation is expected to improve vascular endothelial function. Effects of smoking cessation on endothelial function are not always consistent. Further studies are needed to determine whether smoking cessation directly improves endothelial function. NO indicates nitric oxide.