Impaired glucose tolerance, but not impaired fasting glucose, is a risk factor for early-stage atherosclerosis

Effect of fasting glucose levels on carotid intima-media thickness in premenopausal versus postmenopausal women

Objective

To investigate the relationship between fasting blood glucose (FBG) and carotid intimamedia thickness (IMT) in premenopausal and postmenopausal women.

Subjects and methods

The study enrolled 2,959 women seen at the Maanshan People's Hospital of Anhui Province from December 2013 to December 2018. Carotid IMT was measured using Doppler ultrasound. Linear regression and R smoothing curves were used to analyze the relationship between blood glucose level and carotid IMT in the premenopausal and postmenopausal groups.

Results

Postmenopausal compared with premenopausal women had higher mean IMT (mIMT; 0.81 ± 0.23 mm versus 0.70 ± 0.14 mm, respectively, p < 0.001) and maximum IMT (maxIMT; 0.86 ± 0.35 mm versus 0.74 ± 0.16 mm, respectively, p < 0.001) values. On linear regression analysis, mIMT values increased with increasing FBG values when FBG level was ≤ 7 mmol/L, but no significance was found between FBG and maxIMT. After stratification by menopausal status, mIMT and maxIMT increased with increasing FBG when FBG was ≤ 7 mmol/L in the premenopausal group. In the postmenopausal group, mIMT and maxIMT increased with increasing FBG. After adjustment for covariate factors, the relationship between FBG and mIMT remained the same as before the adjustment, but when FBG was ≤ 11 mmol/L, the maxIMT increased with increasing FBG. In the stratification analysis, maxIMT increased with increasing FBG when FBG was ≤ 7 mmol/L in the premenopausal group, while both mIMT and maxIMT increased with increasing FBG when FBG was > 10 mmol/L in the postmenopausal group.

Conclusion

Levels of FBG contributed more to increased IMT in postmenopausal than premenopausal women. The influence of FBG was greater on maxIMT than mIMT. Additionally, FBG was helpful in assessing focal thickening of the carotid intima.

The effects of acarbose treatment on cardiovascular risk factors in impaired glucose tolerance and diabetic patients: a systematic review and dose-response meta-analysis of randomized clinical trials

Acarbose (ACB) seems to be an effective drug in the management of cardiovascular risk factors. However, no previous meta-analysis of randomized controlled trials (RCTs) has been done to evaluate the effects of ACB on cardiovascular risk factors on impaired glucose tolerance (IGT), type 2 diabetes mellitus (T2D), and type 1 diabetes mellitus (T1D). We comprehensively searched electronic databases including Scopus, Web of Science, and PubMed for RCTs for related keywords up to September 2022. A random-effects model was used to estimate the weighted mean difference (WMD) and 95% confidence interval (CI). The pooled analysis demonstrated that ACB treatment had a significant effect on fasting blood glucose (FBG) (WMD = -3.55 mg/dL; 95%CI: -6.29, -0.81; p = 0.011), fasting insulin (WMD = -6.73 pmoL/L; 95%CI: -10.37, -3.10; p < 0.001), HbA1c [WMD = -0.32%; 95%CI: -0.45, -0.20; p < 0.001], body weight (WMD = -1.25 kg; 95%CI: -1.79, -0.75; p < 0.001), body mass index (BMI) (WMD = -0.64 kg/m2; 95%CI: -0.92, -0.37; p < 0.001), tumor necrosis factor-alpha (TNF-α) (WMD = -2.70 pg/mL, 95%CI: -5.25, -0.16; p = 0.037), leptin (WMD = -1.58 ng/mL; 95%CI: -2.82, -0.35; p = 0.012), alanine transaminase (ALT) (WMD = 0.71 U/L; 95%CI: -0.31, 1.85; p = 0.164), triglyceride (TG) (WMD = -13.89 mg/dL; 95%CI: -20.69, -7.09; p < 0.001), total cholesterol (TC) (WMD = -2.26 mg/dL; 95%CI: -4.18, -0.34; p = 0.021), systolic blood pressure (SBP) (WMD = -1.29 mmHg; 95%CI: -2.44, -0.15; p = 0.027), and diastolic blood pressure (DBP) (WMD = 0.02 mmHg; 95%CI: -0.41, 0.45; p = 0.925) in an intervention group, compared with a placebo group. The non-linear dose-response analysis showed that ACB reduces the TC in trial duration by >50 weeks, and 180 mg/day is more effective for the decrement of CRP. ACB can improve lipid profiles, glycemic indices, anthropometric indices, and inflammatory markers in T2D, T1D, and IGT patients.

Effect of Amlodipine/Nebivolol combination therapy on central BP and PWV compared to Amlodipine/Valsartan combination therapy

Background

Pulse wave velocity (PWV) and central blood pressure (CBP) have been intoduced into managment of hypertensive patients. PWV is positively correlated with arterial wall stiffness while central aortic pressure becomes better predictor of cardiovascular outcome than peripheral pressure. Reduction in CBP provides protective properties against subclinical organ damage. This work aims to investigate the effect of a new combination therapy of Amlodipine/Nebivolol (A/N) on central BP, peripheral BP and PWV. The results of using this combination will be compared to the well-established fixed-dose combination of Amlodipine/Valsartan (A/V). The study conducted between October 2018 and August 2020. One hundred and two hypertensive patients were assigned for Amlodipine 10 mg/Valsartan 160 mg combination therapy (A/V, n = 52) or Amlodipine 10 mg/Nebivolol 5 mg combination therapy (A/N, n = 50) by simple 1:1 randomization. Office, central blood pressure and PWV were measured on first (0 week), second (4–8 weeks) and third visit (10–12). Difference in BP (in each arm and between arms) was calculated along all visits.

Results

No statistical significant difference was found between A/V and A/N regarding age, gender, BMI and CV history. OBP, CBP and PWV were significantly reduced in each arm, but no differences were found when comparing both arm results to each other. Recorded side effects were insignificant.

Conclusions

The new combination therapy Amlodipine/Nebivolol (A/N) affords a significant reduction in CBP, PBP and PWV with minor and tolerable side effects. It has provided comparable results to Amlodipine/Valsartan (A/V) combination therapy.

Carotid Arterial Stiffness and Cardiometabolic Profiles in Women with Fibromyalgia

Background: The present study aimed to evaluate the association between FM and cardiometabolic risk factors and carotid arterial stiffness in FM patients. Methods: The cardiometabolic risk profile was defined based on the Adult Treatment Panel III panel. Carotid intimal media thickness (cIMT) and arterial stiffness were assessed using high-resolution ultrasonography. Multivariate logistic analysis was performed to estimate the association between FM and cardiometabolic risk factors. We used a general linear regression to compare the cIMT and carotid beta-index between the participants with and without FM. Pearson’s coefficient was calculated to evaluate the potential correlation between cardiometabolic risk profiles, cIMT, and arterial stiffening in FM. Results: FM participants showed a higher risk of central obesity (odds ratio [OR] = 3.21, 95% confidence interval [CI] 1.49, 6.91), high triglyceride (OR = 4.73, 95% CI 2.29, 9.79), and impaired fasting glucose (IFG) (OR = 4.27, 95% CI 2.07, 8.81) compared to the control group. The FM group exhibited higher beta-index values than the control group (p = 0.003). Although IFG and triglyceride glucose index showed a tendency to correlate with the beta-index, statistical significance was not observed. Conclusions: FM was associated with an increased risk of central obesity, high triglyceride levels, and IFG. Furthermore, advanced arterial stiffness of the carotid artery was observed in FM, which might be correlated with insulin resistance.

The Epidemiological Boehringer Ingelheim Employee Study (Part 3): Association of Elevated Fasting Insulin Levels but Not HOMA-IR With Increased Intima Media Thickness and Arteriosclerosis in Middle-Aged Persons

Background: Recently published genetic studies have indicated a causal link between elevated insulin levels and cardiovascular disease (CVD) risk. We, therefore, hypothesized that increased fasting insulin levels are also associated with precursors of CVD such as endothelial lesions. Methods: Middle-aged (≥40 years, n = 1,639) employees were followed up for the occurrence of increased intima media thickness (IMT ≥ 1 mm) or plaques in abdominal or cervical arteries (arteriosclerosis). Multivariable logistic regression analyses determined the incidence of increased IMT or arteriosclerosis. Adjusted relative risk (ARR) for increased IMT and arteriosclerosis was calculated by using Mantel-Haenszel analysis. Results: Increased IMT was diagnosed in 238 participants (15 %) and 328 (20 %) developed arteriosclerosis after 5 years of follow-up. Logistic regression analysis identified fasting insulin, BMI and smoking as risk factors for both cardiovascular endpoints (all p < 0.05), whereas age and diastolic blood pressure were risk factors for increased IMT only, and male sex was associated with incident arteriosclerosis only (all p < 0.01). Additional adjustment for BMI change during follow-up did not modify these associations (including fasting insulin), but adjustment for fasting insulin change during follow-up removed BMI as risk factor for both cardiovascular endpoints. Fasting insulin change during follow-up but not BMI change associated with increased IMT and arteriosclerosis (both p < 0.001). ARR analysis indicated that high fasting insulin and BMI added to age and sex as risk factors. Homeostatic model assessment of insulin resistance (HOMA-IR) did not associate with either cardiovascular endpoint in any model and smoking did not increase the risk conferred by high fasting insulin levels. Conclusions: Higher fasting insulin levels and increases in fasting insulin over time are associated with atherogenic progression and supersede BMI as well as HOMA-IR as risk factors.

Postloading insulinemia is independently associated with arterial stiffness in young Japanese persons

Associations of arterial stiffness with glucose, insulin, and proinsulin dynamics during the oral glucose tolerance test (OGTT) remain under debate. The aim of this study was to investigate whether plasma glucose (PG), insulin, and proinsulin (Pro) contribute to arterial stiffness, measured by pulse wave velocity (PWV), in young Japanese persons. PG, immunoreactive insulin (IRI), and Pro levels were determined in 1193 young Japanese subjects (<40 years of age) with normal glucose tolerance or nondiabetic hyperglycemia before and at 30, 60, and 120 min during a 75-g OGTT. Participants were divided into two groups according to the median PWV. Background factors, PG, IRI, and Pro levels during the OGTT, and insulin sensitivity (SI) indices in each group were compared. Several multiple regression analysis models were used to evaluate factors contributing to PWV. All IRI and Pro levels before and after glucose loading and the area under the curve (AUC) values for IRI and Pro increased with higher PWV. 1/HOMA-IR and ISI-Matsuda as measures of SI decreased with higher PWV. The IRI AUC and Pro level before glucose loading (Pro0) were independently associated with PWV, in addition to male sex, heart rate, and mean blood pressure. The IRI AUC had a stronger relationship with PWV than Pro0. The IRI AUC had an independent relationship with PWV, whereas both SI indices did not. Postloading insulinemia, but not reduced SI, was independently associated with arterial stiffness in young Japanese persons.

Assessment of Microcirculation in the Type 2 Diabetic and Impaired Glucose Tolerance Feet of Elderly Men by CEUS

OBJECTIVE

To evaluate the foot microcirculation in type 2 diabetes mellitus (T2DM) and impaired glucose tolerance patients (IGT) with contrast-enhanced ultrasound (CEUS).

METHODS

The study included 37 patients with T2DM but without diabetic foot (DM group), 15 patients with impaired glucose tolerance (IGT group) and 10 elderly males with normal fasting blood glucose (FBS) and negative glucose tolerance tests (control group). Color Doppler flow imaging (CDFI) and CEUS were performed on the right foot great toes for detecting the blood perfusion performance. CEUS images were recorded and parameters of CDFI and flow time-intensity curves (TICs) were analyzed by the Student's t-test.

RESULTS

There was no significant difference in CDFI parameters pulse index and peak systolic blood flow velocity (PSV) among the three groups (P >0.05). Compared with control group, CEUS images of IGT and DM groups showed lower microvascular density and were pale. Peak intensity (PI) and area under time-intensity curve (AUC) in control, IGT and DM groups were decreased gradually (PI 46.36±10.96 vs 35.26±11.65 vs 28.15±7.94, P = 0.001, AUC 5.12±1.02 vs 3.25±1.60 vs 2.81±1.20, P = 0.001). The arrival times (AT) and time to peak (TTP) tended to be increased with the extension of DM course, but the difference was not statistically significant (AT, P = 0.260, TTP, P = 0.481).

CONCLUSION

CEUS, as a noninvasive and valuable technique, could detect the alterations in foot microcirculation of DM and IGT patients.

Newly diagnosed abnormal glucose tolerance determines post-MI prognosis in patients with hospital related hyperglycaemia but without known diabetes

AIMS

Investigate if abnormal glucose tolerance (AGT) affects post-myocardial infarction (MI) prognosis in patients with hospital-related hyperglycaemia (HRH) but without known diabetes mellitus (KDM).

METHODS

Post-MI survivors without KDM underwent pre-discharge oral glucose tolerance test. Cardiovascular death and non-fatal re-infarction (MACE) were recorded. We compare the ability of admission (APG), fasting (FPG) and 2 h post-load (2 h-PG) plasma glucose to predict MACE in patients with (HRH) and without HRH (NoHRH).

RESULTS

50.2% and 73% of NoHRH and HRH had AGT respectively. MACE occurred in 19.5% and 18.1% in HRH and NoHRH groups. MACE-free survival was lower in patient with AGT in both groups (NoHRH: HR 1.82, 95% CI 1.19-2.78, p = 0.005; HRH: HR 2.48, 95% CI 1.24-4.96, p = 0.010). AGT predicted MACE-free survival (NoHRH: HR 1.60, 95% CI 1.02-2.51, p = 0.042; HRH: HR 3.09, 95% CI 1.07-8.94, p = 0.037). 2 h-PG, but not FPG or APG, independently predicted MACE free survival (NoHRH: HR 1.17, 95% CI 1.07-1.27, p ≤0.001 and HRH: HR 1.18, 95% CI 1.03-1.37, p = 0.020). Addition of AGT and 2 h-PG, not FPG or APG, improved net reclassification of events in both groups.

CONCLUSION

Post-MI prognosis is worse with AGT irrespective of presence of HRH. 2 h-PG, predicts prognosis in HRH and NoHRH groups.

Adjustment of the GRACE score by 2-hour post-load glucose improves prediction of long-term major adverse cardiac events in acute coronary syndrome in patients without known diabetes

Aims

Global Registry of Acute Coronary Events (GRACE) risk score (GRS), a powerful predictor of prognosis after acute coronary event (ACE), does not include a glucometabolic measure. We investigate whether 2 h post-load plasma glucose (2h-PG) could improve GRS based prognostic models in ACE patients without known diabetes mellitus (DM).

Methods and results

A retrospective cohort study of 1056 ACE survivors without known DM who had fasting plasma glucose (FPG) and 2h-PG measured pre-discharge. Death and non-fatal myocardial infarction were recorded as major adverse cardiac events (MACE) during follow-up. GRS for discharge to 6 months was calculated. Cox proportional-hazards regression was used to identify predictors of event free survival. The predictive value of 2h-PG alone and combined with GRS was estimated using likelihood ratio test, Akaike's information criteria, continuous net reclassification improvement (NRI>0), and integrated discrimination improvement (IDI). During 40.8 months follow-up 235 MACEs (22.3%) occurred, more frequently in the upper 2h-PG quartiles. Two-hour PG, but not FPG, adjusted for GRS independently predicted MACE (hazard ratio 1.091, 95% confidence interval 1.043-1.142; P = 0.0002). likelihood ratio test showed that 2h-PG significantly improved the prognostic models including GRS (χ2 = 20.56, 1 df; P = 0.000). Models containing GRS and 2h-PG yielded lowest corrected Akaike's information criteria, compared to that with only GRS. 2h-PG, when added to GRS, improved net reclassification significantly (NRIe>0 6.4%, NRIne>0 24%, NRI>0 0.176; P = 0.017 at final follow-up). Two-hour PG, improved integrated discrimination of models containing GRS (IDI of 0.87%, P = 0.008 at final follow-up).

Conclusion

Two-hour PG, but not FPG, is an independent predictor of adverse outcome after ACE even after adjusting for the GRS. Two-hour PG, but not FPG, improves the predictability of prognostic models containing GRS.

Effect of acarbose on cardiovascular events and new-onset diabetes in patients with coronary heart disease and impaired glucose tolerance

Many studies indicated postprandial hyperglycemia was closely related to the development of diabetes and the risk of cardiovascular disease. Acarbose was shown to delay the onset of diabetes in people with impaired glucose tolerance that was at low cardiovascular risk. The Acarbose Cardiovascular Evaluation (ACE) trial formally evaluated whether acarbose could reduce the frequency of cardiovascular events in patients with established coronary heart disease and impaired glucose tolerance, and whether the incidence of Type 2 diabetes could be reduced. The Acarbose Cardiovascular Evaluation trial represented that acarbose did not reduce the risk of Major Adverse Cardiovascular Events (MACE), but the risk of new-onset diabetes by 18% for a median of 5.0 years follow-up.

The Relationship between Carotid Intima-Media Thickness and Ocular Circulation in Type-2 Diabetes

Purpose

To compare clinical findings, including ocular blood flow and intima-media thickness (IMT) of the carotid artery, in mild nonproliferative diabetic retinopathy (NPDR) and no diabetic retinopathy (NDR) patients, and to determine risk factors contributing to mild NPDR.

Methods

In 129 subjects (129 eyes) with type-2 diabetes patients and mild NPDR or NDR, standard statistical techniques were used to determine associations between clinical findings, including diabetes duration, blood levels of creatinine and hemoglobin A1c (HbA1c), central macular thickness (CMT; measured with optical coherence tomography), mean blur rate (MBR; measured with laser speckle flowgraphy), and ultrasound-measured carotid IMT.

Results

Diabetes duration, IMT, and CMT were significantly higher in the mild NPDR patients than the NDR patients (P=0.004, P=0.004, and P=0.003, respectively), while conversely, MBR in the overall optic nerve head (MBR-A) was lower in the mild NPDR patients. Furthermore, a logistic regression analysis showed that diabetes duration (OR, 1.11; P=0.006), diastolic blood pressure (OR, 0.93; P=0.025), heart rate (OR, 1.07; P=0.004), IMT (OR, 8.65; P=0.005), and CMT (OR, 1.03; P=0.007) were independent contributing factors to mild NPDR. Spearman's rank correlation test also showed that IMT was negatively correlated with MBR-A (P=0.011).

Conclusions

Increased IMT showed a close association with ocular ischemia in patients with type-2 diabetes and contributed to the presence of mild NPDR. These findings suggest that IMT may be an early biomarker of mild NPDR.

Two-hour post-challenge glucose is a better predictor of adverse outcome after myocardial infarction than fasting or admission glucose in patients without diabetes

AIMS

We evaluate prevalence of new abnormal glucose tolerance (AGT) in post-MI survivors without known diabetes (DM) if guidelines are followed and compare the ability of admission (APG), fasting (FPG) and 2-h post-load plasma glucose (2h-PG) to predict prognosis.

METHODS

A total of 674 patients were followed up for 4 years for incidence of major adverse cardiovascular events (MACE) of cardiovascular death, non-fatal re-infarction or non-haemorrhagic stroke. Ability of models including APG, FPG and 2h-PG to predict MACE was compared.

RESULTS

Of the total, 93-96% of impaired glucose tolerance and 64-75% of DM would be missed with current guidelines. MACE was higher in the upper quartiles of 2h-PG. When 2h-PG and FPG were included simultaneously in models, only 2h-PG predicted MACE (HR 1.12, CI 1.04-1.20, p = 0.0012), all cause mortality (HR 1.17, CI 1.05-1.30, p = 0.0039), cardiovascular mortality (HR 1.17, CI 1.02-1.33, p = 0.0205) and non-fatal MI (HR 1.10, CI 1.01-1.20, p = 0.0291). Adding 2h-PG significantly improved ability of models including FPG (χ² = 16.01, df = 1, p = 0.0001) or FPG and APG (χ² = 17.36, df = 1, p = 0.000) to predict MACE. Model including 2h-PG only had the lowest Akaike's information criteria and highest Akaike weights suggesting that this was the best in predicting events. Adding 2h-PG to models including FPG or APG with other co-variates yielded continuous net reclassification improvement (NRI) of 0.22 (p = 0.026) and 0.27 (p = 0.005) and categorical NRI of 0.09 (p = 0.032) and 0.12 (p = 0.014), respectively. Adding 2 h-PG to models including only FPG, only APG and both yielded integrated discrimination improvement of 0.012 (p = 0.015), 0.022 (p = 0.001) and 0.013 (p = 0.014), respectively.

CONCLUSIONS

AGT is under-diagnosed on current guidelines. 2h-PG is a better predictor of prognosis compared to APG and FPG.

Circulating PCSK9 levels and 2-hPG are positively correlated in metabolic diseases in a Chinese Han population

Background

Proprotein convertase subtilisin/kexin type 9 (PCSK9), which plays a crucial role in lipoprotein metabolism, has been also regarded as an important marker for atherosclerosis. Available evidence indicated that 2-h postchallenge plasma glucose (2-hPG) could be another biomarker for atherosclerosis. However, currently the association between circulating PCSK9 and 2-hPG remains unclear. Here, we explored this potential link in a Chinese Han population.

Methods

Totally, 600 Chinese Han subjects from Nanjing district, China, were enrolled for the 75-g oral glucose tolerance test (OGTT), and they included normal glucose tolerance (NGT, n = 200), impaired glucose regulation (IGR, n = 200), and type 2 diabetes (T2DM, n = 200). Anthropometric and biochemical determinations such as serum lipid measurements were made. A sandwich ELISA assay was performed to measure serum PCSK9 levels in all subjects.

Results

Serum PCSK9 concentrations were higher in IGR group (77.63 ± 28.14 ng/ml) and T2DM group (90.62 ± 39.96 ng/ml) than in NGT group (65.33 ± 32.68 ng/ml), and it was significantly higher in T2DM group than in IGR group (p < 0.01). Serum PCSK9 levels positively correlated with 2-hPG and LDL-C in all subgroups, but presented a positive correlation with fasting blood glucose (FBG) only in T2DM group. Using multiple regression model analysis, we also found that PCSK9 levels closely correlated with 2-hPG in all tested groups. According to multinomial logistic regression analysis, PCSK9 levels positively correlated with T2DM (OR = 1.017[1.010–1.025], p < 0.001) even after adjustment for lipid levels. Moreover, in subjects with normal FBG level, 2-hPG gradually and significantly increased across PCSK9 tertiles (6.68 ± 2.01, 7.48 ± 2.10 and 8.27 ± 2.41 mmol/L, respectively, p < 0.01); however, in subjects with normal 2-hPG levels, no such difference was observed.

Conclusions

PCSK9 levels increase as glucose metabolism deteriorated. Serum PCSK9 levels positively correlated with 2-hPG in patients with metabolic diseases.

Association between 1-h post-load plasma glucose levels and arterial stiffness in normotensive subjects with normal glucose tolerance

OBJECTIVE

To investigate the relationship between 1-h post-load plasma glucose, measured during an oral glucose tolerance test, and arterial stiffness, determined by brachial-ankle pulse-wave velocity, in normotensive subjects with normal glucose tolerance.

METHODS

Study subjects were non-industrial workers aged 25-55 years ( n = 8381) who underwent a regular health check-up every 5 years. We included only normotensive subjects with normal glucose tolerance based on the American Diabetes Association criteria. Subjects taking medication and having an abnormal ankle-brachial index (⩽1.0 or ⩾1.3) were excluded. The final sample comprised 4970 participants (mean age: 38.8 ± 9.4 years; women: n = 2048).

RESULTS

1-h post-load plasma glucose correlated with brachial-ankle pulse-wave velocity in men ( β = 0.04, p = 0.01), but not women ( β = -0.03, p = 0.13) in multivariate linear regression analysis. We found a significant interaction between 1-h post-load plasma glucose and age in men ( p = 0.04); therefore, a subgroup analysis was performed in each 5-year age group. The correlation between 1-h post-load plasma glucose and brachial-ankle pulse-wave velocity was significant in the 55-year-old age group ( β = 0.12, p = 0.01) and neared significant in 45-year-old ( β = 0.08, p = 0.07) and 50-year-old ( β = 0.09, p = 0.07) age groups.

CONCLUSION

Elevated 1-h post-load plasma glucose levels were associated with arterial stiffness in normotensive, middle-aged men with normal glucose tolerance.

Grading effect of abnormal glucose status on arterial stiffness and a new threshold of 2-h post-load glucose based on a Chinese community study

AIMS/INTRODUCTION

To investigate the relationship between various glucose metabolic status and arterial stiffness, and further explore the threshold of blood glucose indices for the risk of arterial stiffness.

MATERIALS AND METHODS

The present cross-sectional study included 4,851 individuals from a Chinese community. Overnight fasting blood glucose and 2-h post-load glucose were sampled. Arterial stiffness was measured as brachial-ankle pulse wave velocity. The association was examined using generalized linear regression models. The threshold effect was explored using two piecewise linear regression models by the smoothing plot.

RESULTS

After adjustment for covariates, isolated impaired fasting glucose, isolated impaired glucose tolerance, combined glucose intolerance and newly diagnosed diabetes mellitus were associated with a greater risk of arterial stiffness compared with normal glucose tolerance (B = 18.09, 95% confidence interval [CI] 0.42-35.76, P = 0.045; B = 28.51, 95% CI: 3.40-53.62, P = 0.026; B = 60.70, 95% CI: 38.37-83.04, P < 0.001; B = 95.06, 95% CI: 71.88-118.25, P < 0.001, respectively). Furthermore, there was a non-linear relationship between 2-h post-load glucose and arterial stiffness. A threshold for 2-h post-load glucose of 6.14 mmol/L was observed for the risk of arterial stiffness.

CONCLUSIONS

Impaired fasting glucose, impaired glucose tolerance, combined glucose intolerance and newly diagnosed diabetes mellitus were related to a greater risk of arterial stiffness compared with normal glucose levels. A threshold for 2-h post-load glucose of 6.14 mmol/L probably exists for the risk of arterial stiffness.

Fasting glucose levels, incident diabetes, subclinical atherosclerosis and cardiovascular events in apparently healthy adults: A 12-year longitudinal study

We aimed to study the association between fasting plasma glucose, diabetes incidence and cardiovascular burden after 10-12 years. We evaluated diabetes and cardiovascular events incidences, carotid intima-media thickness and coronary artery calcium scores in ELSA-Brasil (the Brazilian Longitudinal Study of Adult Health) baseline (2008-2010) of 1536 adults without diabetes in 1998. We used regression models to estimate association with carotid intima-media thickness (in mm), coronary artery calcium scores (in Agatston points) and cardiovascular events according to fasting plasma glucose in 1998. Adjusted diabetes incidence rate was 9.8/1000 person-years (95% confidence interval: 7.7-13.6/1000 person-years). Incident diabetes was positively associated with higher fasting plasma glucose. Fasting plasma glucose levels 110-125 mg/dL were associated with higher carotid intima-media thickness (β = 0.028; 95% confidence interval: 0.003-0.053). Excluding those with incident diabetes, there was a borderline association between higher carotid intima-media thickness and fasting plasma glucose 110-125 mg/dL (β = 0.030; 95% confidence interval: -0.005 to 0.065). Incident diabetes was associated with higher carotid intima-media thickness (β = 0.034; 95% confidence interval: 0.015-0.053), coronary artery calcium scores ⩾400 (odds ratio = 2.84; 95% confidence interval: 1.17-6.91) and the combined outcome of a coronary artery calcium scores ⩾400 or incident cardiovascular event (odds ratio = 3.50; 95% confidence interval: 1.60-7.65). In conclusion, fasting plasma glucose in 1998 and incident diabetes were associated with higher cardiovascular burden.

Subcutaneous abdominal adipose tissue is associated with an index of insulin sensitivity/resistance

To assess whether there is any clinical significance for determining the normal range of subcutaneous abdominal fat area, we compared fat area with insulin sensitivity. Visceral and subcutaneous abdominal fat area the L4-L5 thoracic level was determined by computed tomography (CT). Plasma glucose and insulin levels were determined after an overnight fast and calculated by the homeostatic model assessment of insulin resistance (HOMA-IR). We analyzed 350 (180 male and 170 female) subjects whose BMI was 18.5≤BMI<25. The subcutaneous abdominal fat area of the female subjects was 124.7 ± 46.13 cm² and that of male subjects was 77.53 ± 37.53 cm² (mean ± SD). We compared HOMA-IR between subjects whose visceral abdominal fat area was above 100 cm² and subcutaneous abdominal fat area below the mean + 2SD (15 subjects, 6 male and 9 female) with subjects whose visceral abdominal fat area was also above 100 cm² but whose subcutaneous abdominal fat area was above the mean + 2SD (20 subjects, 7 male and 13 female). The HOMA-IR of the former subjects group was 8.17+/-6.22 and that of the latter subjects group was 3.37+/-2.07 (p = 0.0486). Subjects with increased subcutaneous abdominal fat area displayed lower HOMA-IR values, demonstrating a protective effect of subcutaneous fat for individuals with visceral fat area above 100² cm.

The Independent and Joint Association of Blood Pressure, Serum Total Homocysteine, and Fasting Serum Glucose Levels With Brachial-Ankle Pulse Wave Velocity in Chinese Hypertensive Adults

This study aimed to investigate the independent and joint association of blood pressure (BP), homocysteine (Hcy), and fasting blood glucose (FBG) levels with brachial-ankle pulse wave velocity (baPWV, a measure of arterial stiffness) in Chinese hypertensive adults.The analyses included 3967 participants whose BP, Hcy, FBG, and baPWV were measured along with other covariates. Systolic BP (SBP) was analyzed as 3 categories (SBP < 160 mmHg; 160 to 179 mmHg; ≥ 180 mmHg); Hcy as 3 categories (< 10 μmol/L; 10 to 14.9 μmol/L; ≥ 15.0 μmol/L) and FBG: normal (FBG < 5.6 mmol/L), impaired (5.6 mmol/L ≤ FBG < 7.0 mmol/L), and diabetes mellitus (FBG ≥ 7.0 mmol/L). We performed linear regression analyses to evaluate their associations with baPWV with adjustment for covariables.When analyzed individually, BP, Hcy, and FBG were each associated with baPWV. When BP and FBG were analyzed jointly, the highest baPWV value (mean ± SD: 2227 ± 466 cm/s) was observed in participants with FBG ≥ 7.0 mmol/L and SBP ≥ 180 mmHg (β = 432.5, P < 0.001), and the lowest baPWV value (mean ± SD: 1692 ± 289 cm/s) was seen in participants with NFG and SBP < 160 mmHg. When Hcy and FBG were analyzed jointly, the highest baPWV value (2072 ± 480 cm/s) was observed in participants with FBG ≥ 7.0 mmol/L and Hcy ≥ 15.0 μmol/L (β = 167.6, P < 0.001), while the lowest baPWV value (mean ± SD: 1773 ± 334 cm/s) was observed in participants with NFG and Hcy < 10 μmol/L.In Chinese hypertensive adults, SBP, Hcy, and FBG are individually and jointly associated with baPWV.Our findings underscore the importance of identifying individuals with multiple risk factors of baPWV including high SBP, FBG, and Hcy.

Machine learning to predict rapid progression of carotid atherosclerosis in patients with impaired glucose tolerance

Objectives

Prediabetes is a major epidemic and is associated with adverse cardio-cerebrovascular outcomes. Early identification of patients who will develop rapid progression of atherosclerosis could be beneficial for improved risk stratification. In this paper, we investigate important factors impacting the prediction, using several machine learning methods, of rapid progression of carotid intima-media thickness in impaired glucose tolerance (IGT) participants.

Methods

In the Actos Now for Prevention of Diabetes (ACT NOW) study, 382 participants with IGT underwent carotid intima-media thickness (CIMT) ultrasound evaluation at baseline and at 15–18 months, and were divided into rapid progressors (RP, n = 39, 58 ± 17.5 μM change) and non-rapid progressors (NRP, n = 343, 5.8 ± 20 μM change, p < 0.001 versus RP). To deal with complex multi-modal data consisting of demographic, clinical, and laboratory variables, we propose a general data-driven framework to investigate the ACT NOW dataset. In particular, we first employed a Fisher Score-based feature selection method to identify the most effective variables and then proposed a probabilistic Bayes-based learning method for the prediction. Comparison of the methods and factors was conducted using area under the receiver operating characteristic curve (AUC) analyses and Brier score.

Results

The experimental results show that the proposed learning methods performed well in identifying or predicting RP. Among the methods, the performance of Naïve Bayes was the best (AUC 0.797, Brier score 0.085) compared to multilayer perceptron (0.729, 0.086) and random forest (0.642, 0.10). The results also show that feature selection has a significant positive impact on the data prediction performance.

Conclusions

By dealing with multi-modal data, the proposed learning methods show effectiveness in predicting prediabetics at risk for rapid atherosclerosis progression. The proposed framework demonstrated utility in outcome prediction in a typical multidimensional clinical dataset with a relatively small number of subjects, extending the potential utility of machine learning approaches beyond extremely large-scale datasets.

Prediabetes and Diabetes Are Associated With Arterial Stiffness in Older Adults: The ARIC Study

BACKGROUND

To determine whether prediabetes and diabetes in older adults are associated with arterial stiffness measured in central and peripheral arteries and to examine characteristics that modify these associations.

METHODS

Cohort members attending the 5th exam (2011-2013) of the Atherosclerosis Risk in Communities (ARIC) study had pulse wave velocity (PWV) measures performed at the carotid-femoral (cfPWV), brachial-ankle (baPWV), and femoral-ankle (faPWV) segments. Fasting glucose ≥126mg/dl, glycated hemoglobin (HbA1c) ≥6.5%, or currently taking diabetes medication defined diabetes. Fasting glucose 100-125mg/dl or HbA1c 5.7%-6.4% among those without diabetes defined prediabetes. Cross-sectional associations were modeled using multivariable linear regression.

RESULTS

Among 4,279 eligible participants with cfPWV measures (mean age 75 years), 22% were African-American, 25.5% had diabetes, and 54.7% had prediabetes. Compared to those with normal glucose, cfPWV was 95.8cm/s higher (stiffer) on average for those with diabetes (for reference: being 1 year older was associated with 14.4cm/s higher cfPWV). Similar findings were seen for diabetes and baPWV, although attenuated. Interestingly, faPWV was 17.6cm/s lower for those with diabetes compared to normal glucose. There was a significant positive association between baPWV and prediabetes. Among those with diabetes, cfPWV was higher for those with albuminuria, reduced kidney function, duration of diabetes ≥10 years, and elevated HbA1c (HbA1c ≥7).

CONCLUSION

Among older adults, diabetes is associated with higher central arterial stiffness and lower peripheral arterial stiffness, and prediabetes is associated with higher baPWV. Cross-sectionally, the magnitude of the effect of diabetes on central stiffness is equivalent to 6 years of arterial aging.

Increased arterial stiffness in subjects with impaired fasting glucose

AIMS

The present study investigated the association between fasting glucose and arterial stiffness in subjects with normal fasting glucose (NFG) and impaired fasting glucose (IFG).

METHODS

The study group consisted of 1043 subjects, including 683 subjects with NFG and 360 subjects with IFG (100≤fasting glucose <126 mg/dL). All subjects were evaluated for glucose, insulin, lipid profiles, high sensitivity C-reactive protein (hs-CRP), malondialdehyde (MDA), 8-epi-prostaglandin F2α (8-epi-PGF2α) and brachial-ankle pulse wave velocity (ba-PWV).

RESULTS

MDA (P<0.001) and ba-PWV (P<0.001) in the IFG group were higher than those in the NFG group after adjustment for sex, age, BMI, smoking and drinking, waist, blood pressure, serum lipid profiles. Ba-PWV in the IFG group was still higher than that in the NFG group after further adjustment for hs-CRP, MDA, 8-epi-PGF2α (P=0.031). Through multiple linear regression analysis, ba-PWV was found to be independently and positively associated with fasting glucose, age, systolic blood pressure, triglyceride, hs-CRP and insulin and negatively associated with male:female ratio, BMI.

CONCLUSION

Arterial stiffness was higher in the IFG group than in subjects with NFG even after adjustment for all confounding variables including hs-CRP and oxidative stress markers. In addition, fasting glucose and insulin were positively and independently associated with the ba-PWV in non-diabetic healthy adults.

Elevated 1-h plasma glucose following 75-g oral glucose load is a predictor of arterial stiffness in subjects with normal glucose tolerance

AIMS

The study aimed to investigate arterial stiffness in subjects with normal glucose tolerance.

METHODS

BMI, systolic blood pressure, fasting plasma glucose, lipid variables, ankle-brachial pressure index and brachial-ankle pulse wave velocity were measured in 2059 subjects from Takasaki city, located approximately 100 km north of Tokyo in Japan. Following a 75-g oral glucose tolerance test, only subjects with normal glucose tolerance were selected.

RESULTS

One-hour post-challenge plasma glucose levels were correlated with brachial-ankle pulse wave velocity values (r = 0.340, P < 0.0001). When subjects with normal glucose tolerance were divided into three groups-group 1 (1-h plasma glucose < 8.56 mmol/l, n = 1595), group 2 (1-h plasma glucose ≥ 8.56 and < 10.17 mmol/l, n = 334) and group 3 (1-h plasma glucose ≥ 10.17 mmol/l, n = 130)-the brachial-ankle pulse wave velocity of group 3 (1473 ± 322 cm/s) was significantly higher than that of group 2 (1355 ± 252 cm/s) and brachial-ankle pulse wave velocity of group 2 was also significantly higher than that of group 1 (1275 ± 212 cm/s).

CONCLUSIONS

We have identified that, in normal glucose tolerance, arterial stiffness is advanced in subjects with higher 1-h post-challenge plasma glucose in spite of the normal range for BMI, systolic blood pressure, fasting plasma glucose and lipid variables. Higher 1-h plasma glucose level is a risk factor for arterial stiffness in normal glucose tolerance.

Pioglitazone induces regression and stabilization of coronary atherosclerotic plaques in patients with impaired glucose tolerance

AIMS

To observe the effects of pioglitazone on coronary plaque area, plaque burden, serum high-sensitivity C-reactive protein, adiponectin and plasma endothelin-1 levels in patients with impaired glucose tolerance and coronary borderline lesions.

METHODS

Thirty patients were randomly divided into two groups: a pioglitazone group and a control group. The latter was administered placebo in addition to standard therapy; the former pioglitazone 15 mg/d in addition to standard therapy. Before treatment and 6 months later, left ventricular ejection fraction, serum lipid profile, high-sensitivity C-reactive protein, adiponectin and plasma endothelin-1 levels were detected. Coronary plaque area and plaque burden were examined using intravascular ultrasound.

RESULTS

No significant differences were found in left ventricular ejection fraction and serum lipid levels pre- and post-trial. Compared with the control group, 6 months' treatment with pioglitazone significantly decreased coronary plaque burden (50.7 ± 11.1 vs. 64.1 ± 10.3%, P < 0.05), plaque area (6.22 ± 2.03 vs. 8.31 ± 4.29, P < 0.05), thin-cap fibroatheroma prevalence (11 vs. 22%, P < 0.05) and percentage of necrotic core area (16 ± 8 vs. 31 ± 7%, P < 0.05). Compared with the control group, serum high-sensitivity C-reactive protein and plasma endothelin-1 levels were significantly lower and adiponectin level significantly higher in patients in the pioglitazone group. Serum adiponectin level was negatively correlated with plasma endothelin-1 level and coronary plaque area (r = 0.739 and -0.431, respectively, both P < 0.05).

CONCLUSIONS

Pioglitazone may induce regression and stabilization of coronary atherosclerotic plaques. The mechanisms might involve inhibition of inflammation, increase in adiponectin level and improvement in endothelial function.

Postchallenge hyperglycemia is closely related with early vascular damage in overweight and obese patients

OBJECTIVE

There is ongoing discussion on how best to screen for diabetes mellitus. Previous studies suggest that an abnormal oral glucose tolerance test (OGTT) is better than fasting glucose levels in predicting cardiovascular mortality, which is largely determined by macrovascular complications in type 2 diabetes. We examined the relationship between screening methods for diabetes and indices of vascular damage in young individuals at high risk of type 2 diabetes.

METHODS

Overweight and obese individuals (n = 76, average age 38 ± 6 years) were screened for diabetes by measuring fasting glucose levels, HbA1c and by performing the OGTT. Indices of early vascular damage, including the central augmentation index (cAIx) and pulse pressure amplification (PPA), were assessed by pulse wave analysis (Sphygmocor). Linear regression analyses were performed to identify independent predictors of vascular damage.

RESULTS

Central SBP and DBP (BPs) were best predicted by age and by peripheral BP levels. cAIx was independently predicted by age (r = +0.324, P = 0.008), DBP (r = +0.294, P = 0.011) and 2-h glucose values of the OGTT (r = +0.390, P = 0.001). PPA was independently predicted by age (r = -0.445, P < 0.001) and 2-h glucose value of the OGTT (r = -0.353, P = 0.003).

CONCLUSIONS

The 2-h value of the OGTT was superior to fasting glucose levels and HbA1c in predicting cAIx and PPA in young individuals at high risk of type 2 diabetes. Cardiovascular mortality is largely determined by macrovascular complications in type 2 diabetes, and these data suggest that diabetes screening by OGTT may help to identify those individuals with the greatest risk of future vascular complications.