Treating Arterial Ageing in Patients with Diabetes: From Mechanisms to Effective Drugs

Effects of metformin on arterial elasticity and pro-inflammatory markers in black diabetes patients

Background

Pro-inflammatory markers are linked with the development and progression of type 2 diabetes mellitus and arterial stiffening. Pulse Wave Velocity (PWV) and Augmentation Index (Aix) are non-invasive standard markers of arterial elasticity and predictors of cardiovascular mortality and morbidity.

Aim

To investigate the effects of metformin alone and in combination with glimepiride on arterial elasticity, pro-inflammatory cytokines in black type 2 diabetes mellitus patients.

Settings

Participants were enrolled from Sefako Makgatho Health Sciences University community, Gauteng, South Africa.

Methods

PWV and Aix were measured using the AtCor SphygmoCor® system (AtCor Medical, Inc., Sydney, Australia). Cytokines levels were measured using Multiplexing with Bio-Plex Pro™ human inflammation panel I assay. Treatment naïve type 2 diabetes participants were divided into two groups: metformin (M) (n = 10) and metformin glimepiride (MS) (n = 14). The study participants were followed up at 4 and 8 months after treatment initiation.

Results

In the M and MS, IL-1β increased significantly at four months (58.19 ± 0.03 pg/ml, 58.35 ± 0.30 pg/ml) when compared to baseline (33.05 ± 18.56 pg/ml, 34.79 ± 18.77 pg/ml) then decreased significantly at eight months (29.25 ± 11.64 pg/ml, 32.54 ± 14.26 pg/ml) when compared to four months (58.19 ± 0.03 pg/ml, 58.35 ± 0.3 pg/ml) (p < 0.05). There were no significant changes in PWV, Aix, IL-1ra, IL-2, IL-6, IL-8, TNF-α and hs-CRP levels at both treatment intervals.

Conclusion

Metformin alone or in combination with glimepiride did not improve arterial elasticity and did not reduce pro-inflammatory cytokines levels in T2DM black South African patients.

Contribution

The context-based knowledge generated by the current study is expected to enhance the continuum of care for T2DM patients.

MAFLD and glomerular hyperfiltration in subjects with normoglycemia, prediabetes and type 2 diabetes: A cross-sectional population study

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD, 2020 diagnostic criteria) and glomerular hyperfiltration share common risk factors, including obesity, insulin resistance, impaired glucose tolerance, diabetes, dyslipidemia, and hypertension.

AIMS

To assess the prevalence of MAFLD and its association with glomerular hyperfiltration and age-related worsening of kidney function in subjects with normoglycemia, prediabetes and type 2 diabetes mellitus (T2DM).

METHODS

We analysed data recorded during occupational health visits of 125,070 Spanish civil servants aged 18-65 years with a de-indexed glomerular filtration rate (GFR) estimated with the chronic-kidney-disease-epidemiological (CKD-EPI) equation (estimated glomerular filtration rate [eGFR]) ≥60 mL/min. Subjects were categorised according to fasting plasma glucose levels <100 mg/dL (normoglycemia), ≥100 and ≤ 125 mg/dL (prediabetes), or ≥126 mg/dL and/or antidiabetic treatment (T2DM). The association between MAFLD and glomerular hyperfiltration, defined as a de-indexed eGFR above the age- and gender-specific 95th percentile, was assessed by multivariable logistic regression.

RESULTS

In the whole study group, MAFLD prevalence averaged 19.3%. The prevalence progressively increased from 14.7% to 33.2% and to 48.9% in subjects with normoglycemia, prediabetes and T2DM, respectively (p < 0.001 for trend). Adjusted odds ratio (95% CI) for the association between MAFLD and hyperfiltration was 9.06 (8.53-9.62) in the study group considered as a whole, and 8.60 (8.03-9.21), 9.52 (8.11-11.18) and 8.31 (6.70-10.30) in subjects with normoglycemia, prediabetes and T2DM considered separately. In stratified analyses, MAFLD amplified age-dependent eGFR decline in all groups (p < 0.001).

CONCLUSIONS

MAFLD prevalence increases across the glycaemic spectrum. MAFLD is significantly associated with hyperfiltration and amplifies the age-related eGFR decline.

Association of pulse pressure and aortic root diameter in elderly Chinese patients with chronic heart failure

Background

High pulse pressure (PP) and aortic root diameter (AoD) are hallmarks of arterial stiffness or vascular aging and they are considered as risk factors for age-related cardiovascular disease, including heart failure (HF). However, the relationship between PP and AoD in patients with heart failure (HF) is uncertain. This study aimed to evaluate the relationship between PP and AoD in the middle-aged and the elderly with HF.

Methods

A total of 1,027 Chinese middle-aged and elderly patients with HF, including HF with reduced ejection fraction (HFrEF), HF with mid-range EF (HFmrEF), and HF with preserved EF (HFpEF) were included in this study. Pearson correlation analysis was used to evaluate the relationship between PP and AoD in the three types of HF. Multiple linear regression analysis was performed to assess the factors that affected AoD. Multivariate logistic regression was performed to determine the association between the PP level quartiles and AoD. The results were validated in an independent dataset included a total of 378 consecutive patients with HFrEF hospitalized at the Pingtan Branch of Fujian Medical University Union Hospital (Fujian, China).

Results

There was a positive correlation between PP and AoD in the middle-aged and the elderly with HFrEF. Multiple linear regression analysis revealed that PP, age, and body mass index (BMI) were independently correlated with AoD in HFrEF patients. In multivariate logistic regression analysis, an increased risk of aortic root dilation was observed in the highest quartile of the PP level compared with the lowest quartile. Age significantly interacted with PP (p = 0.047). A significant association between PP levels and AoD was only observed in patients ≥ 65 years old, but not in patients < 65 years old. In the validation dataset, PP was independently related to AoD in patients with HFrEF (β = 0.205, p = 0.001).

Conclusions

PP level was independently and positively associated with AoD, especially in the elderly with HFrEF, but not in patients with HFmrEF and HFpEF. Arterial stiffening or vascular aging may play a certain role in the elderly HFrEF patients.

Physical activity has a stronger correlation with arterial stiffness than strength, balance, or BMI in an older population

Background: Arterial stiffness is associated with an array of debilitating health conditions. While exercise typically has beneficial effects on both arterial stiffness and overall health, more research is needed to understand the associations of different types of fitness indices with arterial stiffness. Aim: To investigate the relationship between balance, strength, cardiovascular fitness and physical activity with arterial stiffness (as measured by pulse wave velocity (PWV)) in older adults. Method: Eighty retirement-village residents (24 males, 56 females, age: 78.2 ± 6.4 years, weight: 69.4 ± 12.5 kg, height: 162.9 ± 8.5 cm) completed the Yale Physical Activity Survey, PWV measurement, 30-s sit-to-stand leg strength test, hand grip strength assessment, 4-stage balance test, and a 6-min walk fitness test. The number of exiting risk factors (smoking, previous heart incidents, previous stroke(s), having hypertension, or taking anti-hypertension medication) were tallied. Pearson's correlations were used to assess the relationship between PWV and health and fitness parameters. Results were interpreted using qualitative inference. Results: The number of risk factors (r = 0.57, p < 0.001), age (r = 0.51, p < 0.001) and systolic blood pressure (r = 0.50, p = 0.001) had strong, harmful associations with PWV. Total physical activity minutes/week (r = -0.31 p = 0.01), total energy expenditure Kcal/week (r = -0.30, p = 0.01), and the 6-min walk test (r = -0.29, p = 0.01) had a moderate, beneficial association with PWV, while sit-to-stand (r = -0.27, p = 0.02) and balance (r = -0.27, p = 0.01) had a weak, beneficial association with PWV. Hand grip strength (r = 0.02, p = 0.94) and body mass index (r = -0.04, p = 0.75) had no significant associations with PWV. Discussion: All measured fitness indices had beneficial associations with PWV. However, having more risk factors, increased age, and higher systolic blood pressure had significant (harmful) associations with PWV in our older population. Conclusion: Controlling cardiovascular risk factors, especially high systolic blood pressure, is likely to have the largest beneficial effect on PWV. Improving general physical activity, including walking capacity, may prove beneficial in improving PWV in an older population.

Pharmacological modulation of vascular ageing: A review from VascAgeNet

Vascular ageing, characterized by structural and functional changes in blood vessels of which arterial stiffness and endothelial dysfunction are key components, is associated with increased risk of cardiovascular and other age-related diseases. As the global population continues to age, understanding the underlying mechanisms and developing effective therapeutic interventions to mitigate vascular ageing becomes crucial for improving cardiovascular health outcomes. Therefore, this review provides an overview of the current knowledge on pharmacological modulation of vascular ageing, highlighting key strategies and promising therapeutic targets. Several molecular pathways have been identified as central players in vascular ageing, including oxidative stress and inflammation, the renin-angiotensin-aldosterone system, cellular senescence, macroautophagy, extracellular matrix remodelling, calcification, and gasotransmitter-related signalling. Pharmacological and dietary interventions targeting these pathways have shown potential in ameliorating age-related vascular changes. Nevertheless, the development and application of drugs targeting vascular ageing is complicated by various inherent challenges and limitations, such as certain preclinical methodological considerations, interactions with exercise training and sex/gender-related differences, which should be taken into account. Overall, pharmacological modulation of endothelial dysfunction and arterial stiffness as hallmarks of vascular ageing, holds great promise for improving cardiovascular health in the ageing population. Nonetheless, further research is needed to fully elucidate the underlying mechanisms and optimize the efficacy and safety of these interventions for clinical translation.

MAFLD and Glomerular Hyperfiltration in Subjects with Prediabetes, Visceral Obesity and "Preserved" Kidney Function:A Cross-Sectional Study

AIMS

To investigate the prevalence of metabolic dysfunction-associated fatty liver disease (MAFLD) in prediabetes, visceral obesity, and preserved kidney function, and explore whether MAFLD is associated with hyperfiltration.

METHODS

We analyzed data from 6697 Spanish civil servants, aged 18-65 years, with fasting plasma glucose ≥100 and ≤125 mg/dL (prediabetes, ADA), waist circumference ≥94 cm in men and ≥80 cm in women (visceral obesity, IDF) and de-indexed estimated glomerular filtration rate (eGFR) ≥60 mL/min, collected during occupational health visits. The association between MAFLD and hyperfiltration (eGFR >age- and sex-specific 95^th percentile) was tested by multivariable logistic regression analyses.

RESULTS

Overall, 4213 patients (62.9%) had MAFLD, and 330 (4.9%) were hyperfiltering. MAFLD was more frequent in hyperfiltering than in non-hyperfiltering subjects (86.4% vs 61.7%, P<0.001). BMI, waist circumference, systolic, diastolic, mean arterial pressure, and prevalence of hypertension were higher in hyperfiltering than in non-hyperfiltering subjects (P<0.05). MAFLD was independently associated with hyperfiltration, even after adjusting for common confounders [OR (95% CI): 3.36 (2.33-4.84), P<0.001]. In stratified analyses MAFLD potentiated age-related eGFR decline vs. non-MAFLD (P<0.001).

CONCLUSIONS

More than half of subjects with prediabetes, visceral obesity and eGFR ≥60 ml/min presented MAFLD that was associated with hyperfiltration and potentiated the age-related eGFR decline.

A miR-125/Sirtuin-7 pathway drives the pro-calcific potential of myeloid cells in diabetic vascular disease

AIMS/HYPOTHESIS

Ectopic calcification is a typical feature of diabetic vascular disease and resembles an accelerated ageing phenotype. We previously found an excess of myeloid calcifying cells in diabetic individuals. We herein examined molecular and cellular pathways linking atherosclerotic calcification with calcification by myeloid cells in the diabetic milieu.

METHODS

We first examined the associations among coronary calcification, myeloid calcifying cell levels and mononuclear cell gene expression in a cross-sectional study of 87 participants with type 2 diabetes undergoing elective coronary angiography. Then, we undertook in vitro studies on mesenchymal stem cells and the THP-1 myeloid cell line to verify the causal relationships of the observed associations.

RESULTS

Coronary calcification was associated with 2.8-times-higher myeloid calcifying cell levels (p=0.037) and 50% elevated expression of the osteogenic gene RUNX2 in mononuclear cells, whereas expression of Sirtuin-7 (SIRT7) was inversely correlated with calcification. In standard differentiation assays of mesenchymal stem cells, SIRT7 knockdown activated the osteogenic program and worsened calcification, especially in the presence of high (20 mmol/l) glucose. In the myeloid cell line THP-1, SIRT7 downregulation drove a pro-calcific phenotype, whereas SIRT7 overexpression prevented high-glucose-induced calcification. Through the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway, high glucose induced miR-125b-5p, which in turn targeted SIRT7 in myeloid cells and was directly associated with coronary calcification.

CONCLUSIONS/INTERPRETATION

We describe a new pathway elicited by high glucose through the JAK/STAT cascade, involving regulation of SIRT7 by miR-125b-5p and driving calcification by myeloid cells. This pathway is associated with coronary calcification in diabetic individuals and may be a target against diabetic vascular disease.

DATA AVAILABILITY

RNA sequencing data are deposited in GEO (accession number GSE193510; https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE193510 ).

The positive correlation between brachial-ankle pulse wave velocity and aortic diameter in Chinese patients with diabetes

Aortic dilation is associated with an increased risk of cardiovascular diseases. Increased brachial-ankle pulse wave velocity (baPWV) is a hallmark of vascular aging and arterial stiffness, as well as an important risk factor for vascular disease. This study aimed to retrospectively analyze the correlation between baPWV and aortic diameter (AoD) of inpatients with diabetes. A total of 1294 diabetic patients with the detailed medical records were investigated. Arterial stiffness was assessed using baPWV and AoD using echocardiography. The results showed that baPWV and AoD increase with age (p <0.05). Based on multiple linear regression analysis, age, systolic and diastolic blood pressure, left atrial diameter, right ventricle diameter, pulmonary artery diameter, peak velocity of early transmitral blood flow/peak velocity of late transmitral blood flow, and baPWV independently correlated with AoD in patients with diabetes. Additionally, an increased risk of aortic dilation occurred in the highest baPWV quartile compared with the lowest quartile (p <0.001). In conclusion, baPWV is independently and positively associated with AoD. Hence, prospective cohorts or randomized clinical trials will be the next step to further determine whether interventions designed to improve arterial stiffness in patients with diabetes will reduce the risk of aortic dilation.

Glomerular resistances predict long-term GFR decline in type 2 diabetic patients without overt nephropathy: a longitudinal subgroup analysis of the DEMAND trial

AIMS

Investigating whether and to what extent changes in glomerular hemodynamic parameters, beyond glomerular hyperfiltration, could predict glomerular filtration rate (GFR) decline in hypertensive, non-proteinuric type 2 diabetic patients.

MATERIALS AND METHODS

We estimated baseline afferent (Ra) and efferent (Re) arteriolar resistances and glomerular hydrostatic pressure in 60 consecutive patients from DEMAND study, using the Gomez' equations. Baseline renal plasma flow was measured by para-aminohippurate plasma clearance, and GFR was measured by iohexol plasma clearance at baseline and every 6 months for a median of 4.0 years [IQR 3.5-4.0 years]. Patients with a GFR decline > or ≤ 3 mL/min/1.73 m²/year were categorized as "Progressors" and "Non-progressors," respectively. Predictors of GFR decline were studied by univariable and multivariable logistic regression analysis.

RESULTS

•The GFR declined by a median [IQR] of 4.06 [5.46-2.00] mL/min/1.73 m²/year in the study group as a whole and by 5.35 [6.60-4.48] mL/min/1.73 m²/year and 1.71 [2.14-1.33] mL/min/1.73 m²/year in Progressors and Non-progressors, considered separately. Progressors had a higher baseline Ra (3487.3 ± 1349.3 dyne•sec•cm^-5 vs. 2877.0 ± 668.9 dyne•sec•cm^-5, p < 0.05) and higher Ra/Re ratio (1.4 ± 0.5 vs. 1.1 ± 0.3, p < 0.01) than Non-progressors. At multivariable logistic regression analysis, Ra/Re ratio and arterial hypertension duration were independently associated with GFR decline (odds ratio [95% CI] 8.50 [1.56-46.28] and 1.14 [1.01-1.28]), respectively.

CONCLUSIONS

Increased Ra/Re ratio and arterial hypertension duration predict early GFR decline in hypertensive non-proteinuric type 2 diabetic patients. These findings could be explained by glomerular hypoperfusion and chronic ischemic injury related to pre-glomerular arteriolar narrowing.

CLINICAL TRIAL REGISTRATION

DEMAND, NCT00157586, September 12, 2005.