Association of Aortic Compliance and Brachial Endothelial Function with Cerebral Small Vessel Disease in Type 2 Diabetes Mellitus Patients: Assessment with High-Resolution MRI

Retinal vascular density as a potential biomarker of diabetic cerebral small vessel disease

AIM

The retina and brain share similar anatomical and physiological features. Thus, retinal imaging by optical coherence tomography angiography (OCTA) might be a potential tool for the early diagnosis of diabetic cerebral small vessel disease (CSVD). In this study, we aimed to evaluate retinal vascular density (VD) in diabetic CSVD by OCTA imaging and explore the associations between retinal VD and cerebral magnetic resonance imaging (MRI) markers and cognitive function.

METHODS

In total, 131 patients were enrolled, including CSVD (n = 43) and non-CSVD groups (n = 88). The VD and foveal avascular zone of the retinal capillary plexus were measured with OCTA. A brain MRI was performed.

RESULTS

MRI imaging showed that in the diabetic CSVD group, white matter hyperintensities (WMHs), particularly deep WMHs (58.82%), are the most common MRI marker, followed by cerebral microbleeds in the subtentorial and cortical areas (34.78%). The CSVD group showed increases in the prevalence of cognitive dysfunction (p = .034) and depression (p = .033) and decreases in visuospatial/executive ability and delayed recall ability. In the CSVD group, VDs of the macular superficial vascular plexus (32.93 ± 7.15% vs. 36.97 ± 6.59%, p = .002), intermediate capillary plexus (20.87 ± 4.30% vs. 23.08 ± 4.30%, p = .005) and deep capillary plexus (23.54 ± 5.00% vs. 26.05 ± 4.20%, p = .003) were lower than those of the non-CSVD group. Multiple linear regression analysis showed that VD of the macular superficial vascular plexus was independently associated with cerebral microbleeds. Meanwhile, VD of the macular intermediate capillary plexus was associated with white matter lacunar infarcts after adjustment.

CONCLUSIONS

Diabetic CSVDs are characterized by MRI markers, including deep WMHs and cerebral microbleeds, and showed impaired cognition with decreased visuospatial/executive ability and delayed recall ability. OCTA imaging revealed a significant decrease in retinal microvascular perfusion in diabetic CSVD, which was related to MRI markers and cognitive function. OCTA might be a valuable potential measurement for the early diagnosis of CSVD.

Associations of Cerebrovascular Regulation and Arterial Stiffness With Cerebral Small Vessel Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Cerebral small vessel disease (cSVD) is a major contributing factor to ischemic stroke and dementia. However, the vascular pathologies of cSVD remain inconclusive. The aim of this systematic review and meta-analysis was to characterize the associations between cSVD and cerebrovascular reactivity (CVR), cerebral autoregulation, and arterial stiffness (AS).

METHODS AND RESULTS

MEDLINE, Web of Science, and Embase were searched from inception to September 2023 for studies reporting CVR, cerebral autoregulation, or AS in relation to radiological markers of cSVD. Data were extracted in predefined tables, reviewed, and meta-analyses performed using inverse-variance random effects models to determine pooled odds ratios (ORs). A total of 1611 studies were identified; 142 were included in the systematic review, of which 60 had data available for meta-analyses. Systematic review revealed that CVR, cerebral autoregulation, and AS were consistently associated with cSVD (80.4%, 78.6%, and 85.4% of studies, respectively). Meta-analysis in 7 studies (536 participants, 32.9% women) revealed a borderline association between impaired CVR and cSVD (OR, 2.26 [95% CI, 0.99-5.14]; P=0.05). In 37 studies (27 952 participants, 53.0% women) increased AS, per SD, was associated with cSVD (OR, 1.24 [95% CI, 1.15-1.33]; P<0.01). Meta-regression adjusted for comorbidities accounted for one-third of the AS model variance (R2=29.4%, Pmoderators=0.02). Subgroup analysis of AS studies demonstrated an association with white matter hyperintensities (OR, 1.42 [95% CI, 1.18-1.70]; P<0.01).

CONCLUSIONS

The collective findings of the present systematic review and meta-analyses suggest an association between cSVD and impaired CVR and elevated AS. However, longitudinal investigations into vascular stiffness and regulatory function as possible risk factors for cSVD remain warranted.

Ischemic Stroke and Cerebral Microbleeds: A Two-Sample Bidirectional Mendelian Randomization Study

INTRODUCTION

Recent observational studies have reported the association between ischemic stroke (IS) and cerebral microbleeds (CMBs). Whether this reflects a causal association remains to be established. Herein, we adopted a two-sample bidirectional Mendelian randomization (MR) analysis to comprehensively evaluate the causal association of IS and CMBs.

METHODS

The summary-level genome-wide association studies (GWASs) data of IS were obtained from the GIGASTROKE consortium (62,100 European ancestry cases and 1,234,808 European ancestry controls). All IS cases could be further divided into large-vessel atherosclerosis stroke (LVS, n = 6399), cardio-embolic stroke (CES, n = 10,804) and small-vessel occlusion stroke (SVS, n = 6811). Meanwhile, we used publicly available summary statistics from published GWASs of CMBs (3556 of the 25,862 European participants across 2 large initiatives). A bidirectional MR analysis was conducted using inverse-variance weighting (IVW) as the major outcome, whereas MR-Egger and weighted median (WM) were used to complement the IVW estimates as they can provide more robust estimates in a broader set of scenarios but are less efficient (wider CIs). A Bonferroni-corrected threshold of p < 0.0125 was considered significant, and p values between 0.0125 and 0.05 were considered suggestive of evidence for a potential association.

RESULTS

We detected that higher risk of IS [IVW odds ratio (OR) 1.47, 95% confidence interval (CI) 1.04-2.07, p = 0.03] and SVS (IVW OR 1.62, 95% CI 1.07-2.47, p = 0.02) were significantly associated with CMBs. Reverse MR analyses found no significant evidence for a causal effect of CMBs on IS and its subtypes.

CONCLUSIONS

Our study provides potential evidence that IS and SVS are causally linked to increased risk of CMBs. Further research is needed to determine the mechanisms of association between IS and CMBs.

Association between brachial-ankle pulse wave velocity and microvascular complications in type 2 diabetes mellitus

PURPOSE/AIM

To investigate the relationship between brachial-ankle pulse wave velocity (baPWV) and microvascular complications in type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

From 2019 to 2021, our hospital enrolled 322 patients with T2DM. Clinical information and biochemical indicators of patients were collected from the inpatient electronic medical record system and analyzed retrospectively. Fundus photography, nerve conduction testing, and sensory threshold measurement were all conducted on the subjects. We measured the pulse wave velocity on both sides of the arm and ankle, then averaged the results. The enrolled cases were divided into two groups based on the baPWV: Group 1 (<the reference cutoff value, n = 160) and Group 2 (≥ the reference cutoff value, n = 162). The association between associated factors and baPWV abnormalities was investigated using a logistic regression model.

RESULTS

Group 2 had higher Systolic Blood Pressure(SBP), Diastolic Blood Pressure (DBP), duration of diabetes, Fasting Plasma Glucose (FPG), Blood Urea Nitrogen (BUN) and Serum Uric Acid (SUA) than group 1 (all p < 0.05). The prevalence of diabetic retinopathy, peripheral neuropathy and nephropathy in group 2 was higher compared to group 1 (p < 0.05). After classifying subjects according to the presence or absence of diabetic complications, we found that the baPWV of the Diabetic Peripheral Neuropathy (DPN) group and Diabetic Nephropathy (DN) group was noticeably higher than that of non-DPN group and non-DN group, respectively (both p < 0.05). The baPWV increased with the aggravation of Diabetic Retinopathy (DR) (p < 0.05). Multivariate logistic regression analysis showed that DBP (OR 1.039, 95%CI 1.010-1.068 p = 0.008), duration of diabetes (OR 1.059, 95%CI 1.017-1.103 p = 0.006), FPG (OR 1.104, 95%CI 1.025-1.188 p = 0.009) and BUN (OR 1.128, 95%CI 1.001-1.270 p = 0.048) were all independently and positively associated with baPWV.

CONCLUSIONS

The baPWV is strongly associated with microvascular complications of T2DM. The DBP, duration of diabetes, FPG, and BUN were all independent associated factors of baPWV.

Association between Intracranial Arterial Dolichoectasia and Cerebral Small Vessel Disease and Its Underlying Mechanisms

Intracranial arterial dolichoectasia (IADE), also known as dilatative arteriopathy of the brain vessels, refers to an increase in the length and diameter of at least one intracranial artery, and accounts for approximately 12% of all patients with stroke. However, the association of IADE with stroke is usually unclear. Cerebral small vessel disease (CSVD) is characterized by pathological changes in the small vessels. Clinically, patients with CSVD can be asymptomatic or present with stroke or cognitive decline. In the past 20 years, a series of studies have strongly promoted an understanding of the association between IADE and CSVD from clinical and pathological perspectives. It has been proposed that IADE and CSVD may be attributed to abnormal vascular remodeling driven by an abnormal matrix metalloproteinase/tissue inhibitor of metalloproteinase pathway. Also, IAD-Erelated hemodynamic changes may result in initiation or progression of CSVD. Additionally, genetic factors are implicated in the pathogenesis of IADE and CSVD. Patients with Fabry’s disease and late-onset Pompe’s disease are prone to developing concomitant IADE and CSVD, and patients with collagen IV alpha 1 or 2 gene (COL4A1/COL4A2) and forkhead box C1 (FOXC1) variants present with IADE and CSVD. Race, strain, familial status, and vascular risk factors may be involved in the pathogenesis of IADE and CSVD. As well, experiments in mice have pointed to genetic strain as a predisposing factor for IADE and CSVD. However, there have been few direct genetic studies aimed towards determining the association between IADE and CSVD. In the future, more clinical and basic research studies are needed to elucidate the causal relationship between IADE and CSVD and the related molecular and genetic mechanisms.

Correlation of Electrophotonic Imaging Parameters With Fasting Blood Sugar in Normal, Prediabetic, and Diabetic Study Participants

INTRODUCTION

Electrophotonic imaging (EPI), also known as gas discharge visualization, is a technique of capturing images of phenomena not quantifiable by the naked eye. Different sectors at the tip of fingers represent various organs and systems as per the Chinese system of acupuncture. The images from these fingertips can be used to determine the state of health. This is done with the help of a CCD camera fitted in the EPI equipment and the specific software relevant for analysis.

AIM

To observe the correlation between EPI parameters and fasting blood sugar (FBS) levels in normal, prediabetic, and diabetic study participants.

MATERIALS AND METHODS

A total of 102 participants were selected for this study from various yoga camps and Arogyadham at Swami Vivekananda Yoga Anusandhana Samsthana Yoga University, Bengaluru, India. The selected participants belonged to 3groups-normal, prediabetic, and diabetic-depending on the FBS levels. The distribution of participants was 29 normal, 13 prediabetic, and 60 diabetic.

RESULTS

Regression analysis in the case of prediabetics showed a significant relationship of FBS with pancreas and right kidney. In the case of normal participants, a significant relationship of FBS was found with area and form coefficient of the EPI gram. For diabetics, regression analysis showed significant relationship of FBS with immune organs, left kidney, area, intensity, and entropy of EPI grams.

CONCLUSION

FBS correlates differently in the normal, prediabetic, and diabetic groups. In the prediabetic group, correlation of FBS with EPI parameters pancreas and right kidney is noteworthy and in line with latest findings in medical research.

Diabetes Mellitus Type 2 and Yoga: Electro Photonic Imaging Perspective

Background:

Yoga is the most popular form of alternative medicine for the management of diabetes mellitus type 2. The electro-photonic imaging (EPI) is another contribution from alternative medicine in health monitoring.

Aim:

To evaluate diabetes from EPI perspective.

Objectives:

(1) Compare various EPI parameters in normal, prediabetic and diabetic patients. (2) Find difference in controlled and uncontrolled diabetes. (3) Study the effect of 7 days diabetes-specific yoga program.

Materials and Methods:

For the first objective, there were 102 patients (normal 29, prediabetic 13, diabetic 60). In the second study, there were 60 patients (controlled diabetes 27, uncontrolled diabetes 33). The third study comprised 37 patients. EPI parameters were related to general health as well to specific organs.

Results:

In the first study, significant difference was observed between (1) Diabetics and normal: average intensity 5.978, form coefficient 3.590, immune organs 0.281 all P < 0.001; (2) Diabetics and prediabetics: average intensity 6.676, form coefficient 4.158, immune organs 5.890 P < 0.032; (3) Normal and prediabetes: immune organs (−6.171 P = 000). In the second study, remarkable difference was in the immune organs (0.201, P = 0.031). In the pre- and post-study, the mean difference was: area 630.37, form coefficient 1.78, entropy 0.03, liver 0.24, pancreas 0.17, coronary vessels 0.11, and left kidney 29, with all P < 0.02.

Conclusion:

There is a significant difference in EPI parameters between normal, prediabetics and diabetics, the prominent being average intensity, form coefficient, and immune organs. Between controlled and uncontrolled diabetes, immune organs show significant change. Intervention of yoga results in change in most parameters.