Diabetes increases large artery diseases, but not small artery diseases in the brain

Association between haemoglobin A1c and cerebral microbleeds in community-based stroke-free individuals: A cross-sectional study

AIMS

The association between haemoglobin A1c (HbA1c) and cerebral microbleeds (CMBs) remains unclear. We aimed to investigate the association between HbA1c and CMBs in community-based individuals without stroke or transient ischaemic attack (TIA) and whether the association differs between individuals with and without diabetes mellitus (DM).

MATERIALS AND METHODS

All individuals were recruited from a community in Beijing, China, from January 2015 to September 2019. All individuals completed a questionnaire and underwent blood tests and brain magnetic resonance imaging. A susceptibility-weighted imaging sequence was acquired to detect CMBs, which were defined as small, round and low-signal lesions with <10 mm diameter. The association between HbA1c and CMBs was analysed using multivariable logistic regression adjusted for demographics, medical history and blood sample test results. Subgroup analyses stratified by history of DM were performed.

RESULTS

Of 544 recruited individuals, 119 (21.88%) had CMBs. HbA1c was independently associated with CMBs (odds ratio [OR], 1.51; 95% confidence interval [CI], 1.03-2.22). In 87 individuals with DM, multivariable logistic analysis showed that HbA1c was significantly associated with CMBs (OR, 1.67; 95% CI, 1.04-2.69), whereas in individuals without DM, no significant association was observed between HbA1c and CMBs (OR, 1.07; 95% CI, 0.50-2.30).

CONCLUSIONS

HbA1c was associated with CMBs in individuals without stroke or TIA, particularly in individuals with DM, suggesting that the status of glycaemic control warrants attention for the prevention of CMBs. It would be beneficial to manage HbA1c specifically to control the risk of CMBs, especially in individuals with DM.

Prognosis and antiplatelet therapy of small single subcortical infarcts in penetrating artery territory: a post hoc analysis of the Third China National Stroke Registry

Background

Small single subcortical infarction (SSSI) may be classified as parent artery disease-related or only branch involved according to the stenosis of parent artery. The study aimed to evaluate short-term and long-term prognoses and the effectiveness of antiplatelet therapy in SSSI.

Methods

We prospectively enrolled 2890 patients with SSSI from the Third China National Stroke Registry (CNSR-III) database from August 2015 to March 2018. We assessed clinical outcomes and antiplatelet treatment effects in patients with SSSI with and without parent artery stenosis (PAS) identified by magnetic resonance angiography.

Results

Among 2890 patients with SSSI in the perforator territory of the middle cerebral artery and the basilar artery, there were 680 (23.53%) patients with PAS and 2210 (76.47%) patients without PAS, respectively. After adjusting for potential confounders, the PAS group had a greater initial stroke severity (OR 1.262, 95% CI 1.058 to 1.505; p=0.0097) and a higher risk of ischaemic stroke recurrence at 3 months (OR 2.266, 95% CI 1.631 to 3.149; p<0.0001) and 1 year (OR 2.054, 95% CI 1.561 to 2.702; p<0.0001), as well as composite vascular events at 3 months (OR 2.306, 95% CI 1.674 to 3.178; p<0.0001) and 1 year (OR 1.983, 95% CI 1.530 to 2.570; p<0.0001), compared with the non-PAS group. In both groups, dual antiplatelet therapy was not superior to single antiplatelet therapy in preventing stroke recurrence, composite vascular events and disability.

Conclusion

PAS related to significantly higher rates of short-term and long-term stroke recurrence and composite vascular events, suggesting heterogeneous mechanisms in SSSI subgroups. The effectiveness of antiplatelet therapy for SSSI needs further investigation.

Acute Anterior Choroidal Artery Territory Infarction: A Retrospective Study

OBJECTIVES

To explore the clinical features, risk factors, etiopathogenesis, mechanism of progression, effect of intravenous thrombolysis therapy (IVT) and prognosis of acute ischemic stroke (AIS) in the anterior choroidal artery (AChA) territory.

PATIENTS AND METHODS

A total of 113 AChA infarction patients were enrolled in the current study retrospectively. The demographic and clinical characteristics were collected and analyzed in all patients. The clinical characteristics were compared between clinical progression and no clinical progression groups, good and poor outcome groups, as well as with and without intravenous rt-PA groups.

RESULTS

Hemiparesis was the most common clinical manifestation (92.9%), followed by dyslexia (54.9%), hemianesthesia (43.4%) and other syndromes. Forty-nine patients (43.4%) suffered from clinical progression and showed a higher rate with multiple risk factors together than patients without clinical progression (30.6% vs.14.1%, P = 0.039). Moreover, more patients with progression were found with carotid plaques (73.5% vs. 51.6%, P = 0.018) or carotid artery stenosis (18.4% vs. 6.3%, P = 0.045) than patients without progression. 69.9% of patients got good prognosis at 6-months. In good prognosis group, the proportion of patients with atrial fibrillation, clinical progression and large infarct size were significantly lower than in poor prognosis group (1.3% vs. 11.8%, P = 0.047; 23.9% vs. 67.6%, P = 0.001; 15.2% vs. 38.2%, P = 0.007). No significant difference was found on rate of clinical progression and good prognosis between patients with and without IVT.

CONCLUSION

Motor deficits are the most frequent and typical symptoms in AChA infarcts. Although small artery disease was considered to be the important etiopathogenesis of the AChA infarcts, large vascular disease may be associated with clinical progression in AChA infarcts. Additionally, prognosis of AChA infarcts is correlated with clinical progression, infarct size and atrial fibrillation. IVT does not seem to prevent the clinical progression and improve prognosis of AChA infarcts.

Atherosclerosis in intracranial or extracranial vessels in diabetic patients and the association with stroke subtype

Background

Diabetes mellitus (DM) is associated with increased prevalence and severity of atherosclerosis. This study aimed to assess the prevalence and location of atherosclerosis in intracranial and extracranial vessels in diabetic patients and to investigate their association with ischemic stroke subtype.

Methods

Diabetes patients (n=128) and nondiabetic patients (n=195) were enrolled. Brain MRI, MR angiography, and digital subtraction angiography (DSA) imaging findings in the two groups were retrospectively compared. The characteristics of atherosclerosis (prevalence, location, severity) and collateral flow in diabetic and nondiabetic patients and their association with stroke subtype were analyzed.

Results

Atherosclerosis in extracranial vessels was more common in diabetes patients than in nondiabetic patients (43.8% vs. 23.1%; P<0.001). Symptomatic stenoses were commonly in the proximal internal carotid artery (ICA) and proximal vertebral artery (pVA). Diabetes patients were more likely to have lacunar infarction (49.2% vs. 32.3%; P=0.002) and less likely to have large artery infarct (36.7% vs. 48.2%; P=0.042). DM (OR, 2.03; 95% CI, 1.96-4.30; P=0.006) and age >65 years (OR, 2.55; 95% CI, 1.24-5.22; P=0.011) were independent risk factors for lacunar infarct. Diabetes patients with symptomatic extracranial stenosis or occlusion, combined with good collateral circulation, had significantly higher risk of lacunar infarction than nondiabetic patients (47.8% vs. 30.5%; P=0.045).

Conclusions

DM aggravates the severity of extracranial atherosclerosis. Lacunar stroke is relatively common in diabetic patients and could even be due to large artery disease (LAD).

Deep Cerebral Microbleeds and Renal Dysfunction in Patients with Acute Lacunar Infarcts

BACKGROUND

Cerebral small-vessel disease (SVD) is associated with renal dysfunction such as chronic kidney disease. Although cerebral microbleeds (CMBs) are common in patients with acute lacunar infarcts (ALI), the association between renal dysfunction and CMBs in such patients remains unclear.

METHODS

Between April 2007 and March 2013, we evaluated consecutive first-ever ALI patients, who were admitted to our hospital within 24 hours of stroke onset. CMBs were defined as focal areas of signal loss in brain parenchyma less than 5 mm on T2(∗)-weighted gradient-echo imaging. Renal dysfunction was defined as an estimated glomerular filtration rate less than 60 mL/minute/1.73 m(2) on admission. Correlations between renal dysfunction and the presence (model 1) and location of CMBs (model 2; any deep or infratentorial CMBs) were determined by multivariable logistic regression analyses.

RESULTS

Among 152 patients (33.6% men; mean age, 67.6 years), 53 had CMBs. Patients with CMBs were older (69.9 versus 66.3 years, P = .03) and had a higher frequency of white matter hyperintensity (WMH; 62.3% versus 25.3%, P < .001), silent lacunar infarcts (SLI; 75.5% versus 43.3%, P < .001), and renal dysfunction (41.5% versus 22.2%, P = .015) than those without CMBs. On multivariable analyses, renal dysfunction (odds ratio, 95% confidence interval; model 1: 2.38, 1.02-5.66; model 2: 2.78, 1.16-6.81), WMH (3.87, 1.76-8.80; 3.72, 1.64-8.71), SLI (3.85, 1.71-9.14; 4.20, 1.77-10.8), and diabetes mellitus (.26, .09-.63; .24, .08-.63) were independently associated with CMBs.

CONCLUSIONS

In patients with ALI, renal dysfunction was positively associated with CMBs independent of cerebral SVD.

Is type 2 diabetes related to leukoaraiosis? an updated review

A significantly increased interest has been dedicated to the study of the effects of diabetes mellitus (DM) on the brain. DM is associated with an increased risk of stroke and cognitive decline. In patients with DM, neuroimaging discloses with high-frequency structural changes, such as cerebral atrophy, infarcts and white matter lesions, also called leukoaraiosis (LA), an expression of small vessel disease. A previous review showed a relation between DM and both cerebral atrophy and lacunar infarcts, while the question about the relation between DM and LA remained unanswered. In this review, we provide an update on data on this last association. In the reviewed studies, we examined the presence of DM, other disease characteristics, such as duration and complications, and laboratory markers of the disease such as blood glycated hemoglobin (HbA1c), insulin resistance, insulin concentrations and their association with LA. About 40% of the reviewed studies reported a statistically significant association between DM and LA. Long-standing DM and a poor glycemic control were associated with severe LA. Studies using innovative MRI techniques, such as diffusion tensor imaging (DTI), reported a significant association between microstructural white matter alterations and DM. This review highlights more firmly than previously reported the existence of a relation between DM and both presence and severity of LA. These results are possibly due to more sensitive and advanced imaging techniques recently used to study the extent of LA. However, because of the heterogeneous methodology used in the reviewed studies, a definitive conclusion cannot be drawn.

HCV, but not HIV, is a risk factor for cerebral small vessel disease

OBJECTIVES

With the aging of HIV populations, vascular contributions to neuropathogenesis are increasingly important. Indirect analyses of cerebral small vessel disease have been performed, but there have been no direct studies of human brain to elucidate risk factors for arteriolar sclerosis.

METHODS

Mean arteriolar wall thickness (sclerotic index, SI) was measured in the deep cerebral white matter of 126 brains (96 HIV+, 30 HIV-). Correlations with SI were performed for age, sex, race, hypertension, hyperlipidemia, diabetes, obesity, cirrhosis, hepatitis C virus (HCV) infection, herpes infection, HIV infection, HIV risk, cocaine use, CD4 count, plasma HIV load, and combination antiretroviral therapy (cART) at the time of death.

RESULTS

Age, hypertension, race, HCV, and cirrhosis were associated with SI; of the HIV variables, only cART at death was associated with SI. To address colinearity, partial correlations were run with HCV and cirrhosis, hypertension and race, and hypertension and age. With HCV controlled, cirrhosis lost significance; with hypertension controlled, age lost significance. For the entire sample, HCV, African American race, and hypertension accounted for 15% of SI variance in multivariate analysis. Each was independently associated with SI, and HCV had the largest effect. For the HIV sample, inclusion of cART in the model increased R (2) to 0.205, with only HCV, hypertension, and cART remaining significant or trend level.

CONCLUSIONS

This tissue-based analysis of cerebral arteriolar disease demonstrates that HCV constitutes an independent risk, in addition to African American race, hypertension, and cART. Further study is needed to understand what aspects of HCV and cART contribute to cerebrovascular neuropathogenesis.

Combined effects of type 2 diabetes and hypertension associated with cortical thinning and impaired cerebrovascular reactivity relative to hypertension alone in older adults

OBJECTIVE

Type 2 diabetes mellitus is characterized by metabolic dysregulation in the form of hyperglycemia and insulin resistance and can have a profound impact on brain structure and vasculature. The primary aim of this study was to identify brain regions where the combined effects of type 2 diabetes and hypertension on brain health exceed those of hypertension alone. A secondary objective was to test whether vascular impairment and structural brain measures in this population are associated with cognitive function.

RESEARCH DESIGN AND METHODS

We enrolled 18 diabetic participants with hypertension (HTN + T2DM, 7 women, 71.8 ± 5.6 years) and 22 participants with hypertension only (HTN, 12 women, 73.4 ± 6.2 years). Cerebrovascular reactivity (CVR) was assessed using blood oxygenation level dependent (BOLD) MRI during successive breath holds. Gray matter structure was evaluated using cortical thickness (CThk) measures estimated from T1-weighted images. Analyses of cognitive and blood data were also performed.

RESULTS

Compared to HTN, HTN + T2DM had decreased CVR and CThk in a spatially overlapping region of the right occipital lobe (P < 0.025); CVR group differences were more expansive and included bilateral occipito-parietal areas (P < 0.025). Whereas CVR showed no significant associations with measures of cognitive function (P > 0.05), CThk in the right lingual gyrus ROI and regions resulting from a vertex-wise analysis (including posterior cingulate, precuneus, superior and middle frontal, and middle and inferior temporal regions (P < 0.025) were associated with executive function.

CONCLUSIONS

Individuals with T2DM and HTN showed decreased CVR and CThk compared to age-matched HTN controls. This study identifies brain regions that are impacted by the combined effects of comorbid T2DM and HTN conditions, with new evidence that the corresponding cortical thinning may contribute to cognitive decline.

Intracranial atherosclerosis

Atherosclerotic disease often involves the intracranial arteries including those encased by cranial bones and dura, and those located in the subarachnoid space. Age, hypertension, and diabetes mellitus are independent risk factors for intracranial atherosclerosis. Intracranial atherosclerosis can result in thromboembolism with or without hypoperfusion leading to transient or permanent cerebral ischaemic events. High rates of recurrent ischaemic stroke and other cardiovascular events mandate early diagnosis and treatment. Present treatment is based on a combination of antiplatelet drugs, optimisation of blood pressure and LDL cholesterol values, and intracranial angioplasty or stent placement, or both, in selected patients.

Cerebral microbleeds: their associated factors, radiologic findings, and clinical implications

Cerebral microbleeds (CMBs) are tiny, round dark-signal lesions that are most often detected on gradient-echo MR images. CMBs consist of extravasations of blood components through fragile microvascular walls characterized by lipohyalinosis and surrounding macrophages. The prevalence of CMBs in elderly subjects with no history of cerebrovascular disease is around 5%, but is much higher in patients with ischemic or hemorrhagic stroke. Development of CMBs is closely related to various vascular risk factors; in particular, lobar CMBs are thought to be associated with cerebral amyloid angiopathy. The presence of CMBs has been hypothesized to reflect cerebral-hemorrhage-prone status in patients with hypertension or amyloid microangiopathy. Stroke survivors with CMBs have been consistently found to have an elevated risk of subsequent hemorrhagic stroke or an antithrombotic-related hemorrhagic complication, although studies have failed to establish a link between CMBs and hemorrhagic transformation after thrombolytic treatment. A large prospective study is required to clarify the clinical significance of CMBs and their utility in a decision-making index.

Diabetes, intracranial stenosis and microemboli in asymptomatic carotid stenosis

BACKGROUND

The risk of stroke in patients with asymptomatic carotid stenosis (ACS) is now so low that it is important to have methods to identify those patients most likely to benefit from intervention, or who may require special consideration in choice of medical therapy. We studied the prediction of stroke, death or transient ischemic attacks (stroke/death/TIA) in patients with ACS by intracranial arterial stenosis, and microemboli on transcranial Doppler (TCD), and the effect of diabetes mellitus on microemboli, intracranial stenosis and risk of events.

METHODS

Patients with ACS > 60% by Doppler ultrasound were recruited from the Stroke Prevention Clinic of University Hospital, London, Canada. All 339 participants underwent TCD for detection of intracranial stenosis and detection of microemboli, and carotid ultrasound to measure extracranial stenosis and total carotid plaque area. Participants were followed for three years, to determine the risk of stroke/death/TIA.

RESULTS

Stroke/death/TIA occurred in 38% of patients with microemboli versus 10% without (p=0.0001), and in 18% of patients with intracranial stenosis, versus 10% without (p=0.042). Diabetics were significantly more likely to have intracranial stenosis (45% vs. 29%, p =0.014), microemboli (38% vs. 10%, p <0.0001), and had significantly higher risk of stroke/death/TIA over three years (21% vs. 11% without; p=0.024). Survival free of stroke, TIA or death was significantly better without microemboli or intracranial stenosis (p<0.0001).

CONCLUSIONS

Diabetes, microemboli and intracranial stenosis predicted higher risk of stroke, death or TIA than did extracranial stenosis or total plaque area; diabetics may need more intensive therapy.

The Relation between Chronic Kidney Disease and Cerebral Microbleeds: Difference between Patients with and without Diabetes

Background

Cerebral microbleeds are an important radiologic marker of bleeding-prone brain and have been reported to be associated with the increased risk of intracerebral haemorrhage.

Aims

We sought to examine the association of chronic kidney disease with cerebral microbleeds, and determine whether the association differs between patients with and without diabetes.

Methods

A total of 909 patients with ischemic stroke who were consecutively admitted to our hospital were included in this study. We collected demographic, clinical, and laboratory data (including serum creatinine levels) and documented the presence and numbers of microbleeds. Kidney function was estimated by using the Modification of Diet in Renal Disease formula. We categorized estimated glomerular filtration rates into moderate to severe, mild, and normal (<60, 60–90, and >90 ml/min/1.73 m2, respectively).

Results

Cerebral microbleeds is most frequent in the moderate-to-severe chronic kidney disease group (45.6%). In patients without diabetes, mild and moderate-to-severe chronic kidney disease was found to be independently associated with the presence of cerebral microbleeds (adjusted odds ratio, 1.68; 95% confidence interval, 1.04–2.71 and adjusted odds ratio, 3.74; 95% confidence interval, 1.87–7.47) compared with normal kidney function. In patients with diabetes, however, this relationship was not found. Furthermore, ordinal logistic regression analysis revealed that an increased serum creatinine level and a reduced kidney function were associated with the number of cerebral microbleeds.

Conclusion

We found that chronic kidney disease is independently associated with cerebral microbleeds in patients without diabetes but not in patients with diabetes.

Dynamic temporal change of cerebral microbleeds: long-term follow-up MRI study

Background

Cerebral microbleeds (MBs) are understood as an important radiologic marker of intracerebral hemorrhage. We sought to investigate the temporal changes of MBs and clinical factors associated with the changes using long-term follow-up MRI.

Methods/Principal Findings

From October 2002 to July 2006, we prospectively enrolled patients with stroke or transient ischemic attack, and followed-up their brain MRIs with an interval >12 mo. We compared demographic factors, vascular risk factors, laboratory findings, and radiologic factors according to the presence or changes of MBs. A total of 224 patients successfully completed the follow-up examinations (mean, 27 months). Newly developed MBs were noted in 10 patients (6.8%) among those without MBs at baseline (n = 148), and in those with MBs at baseline (n = 76), the MB count had decreased in 11 patients (14.5%), and increased in 41 patients (53.9%). The estimated annual rate of change of MB numbers was 0.80 lesions per year in all patients, a value which became greater in those patients who exhibited MBs at baseline (MBs≥5, 5.43 lesions per year). Strokes due to small vessel occlusion and intracerebral hemorrhage, as well as white matter lesions were independently associated with an increased MB count, whereas the highest quartile of low-density lipoprotein (LDL) cholesterol was associated with a decreased MB count.

Conclusion

During the follow-up period, most of MBs showed dynamic temporal change. Symptomatic or asymptomatic small vessel diseases appear to act as risk factors while in contrast, a high level of LDL cholesterol may act as a protective factor against MB increase.

Correlations between left ventricular mass index and cerebrovascular lesion

Left ventricular (LV) mass and LV geometry are well-established measures of hypertension chronicity and severity, have a prognostic value on cardiovascular morbidity and mortality, and are related to asymptomatic cerebral small-artery disease (SAD) and largeartery disease (LAD). The aim of the present study was to clarify the different effects of LV mass and LV geometry on underlying SAD compared with its effects on underlying LAD in ischemic stroke patients. Four hundred three ischemic stroke patients underwent echocardiography to determine LV mass index and relative wall thickness. Brain magnetic resonance imaging, angiography, and carotid magnetic resonance angiography were preformed to detect LAD (≥50% stenosis) and SAD (leukoaraiosis, microbleeds, and old lacunar infarction) in the brain. Multivariate analyses showed that the LV mass index was highly associated with underlying SAD but not with underlying LAD. Among the various subtypes of SAD, only cerebral microbleeds were closely related to the LV mass index. Concentric LV hypertrophy was not related to the presence of either SAD or LAD. Subgroup analyses revealed that, among the various subtypes of SAD, only cerebral microbleeds were associated with concentric LV hypertrophy. In conclusion, cerebral microbleeds may imply more advanced target organ damage than underlying LAD and ischemic subtypes of SAD.

Vascular Retinal, Neuroimaging and Ultrasonographic Markers of Lacunar Infarcts

Background

Lacunar infarcts may be caused by macro-or microvascular disease due to several mechanisms.

Aim

This study aims to demonstrate that retinal vascular disturbances in patients with lacunar infarcts associated with neuroimaging and ultrasound markers can help to identify small-vessel disease.

Methods

Prospective ambulatory study of patients with ischaemic stroke and a control group. A retinographic study was performed by 20° bilateral optic disc stereophotography and 50° bilateral optic fundus retinography. Microangiopathy was evaluated as the presence of nonparenchymal vascular affectation and retinopathy as at least one retinal disturbance. Ultrasonographic study evaluated carotid disorder parameters and the mean pulsatility index. The MRI protocol included T1-weighted, T2-weighted, DP-weighted and FLAIR.

Results

We included 156 nonlacunar infarcts, 39 lacunar infarcts and 50 controls. Microangiopathy was more frequent in hypertensive (62.6% vs. 35.7%, P<0.0001) and vascular retinopathy in diabetic patients (11.7% vs. 3.8%, P=0.039). Microangiopathy (97.4% vs. 41.1%, P<0.0001) and leukoaraiosis (94.4% vs. 50.3%, P<0.0001) were more frequent and the mean pulsatility index was higher (1.9±0.2 vs. 1.4±0.5, P<0.0001) in patients with lacunar infarcts. Lacunar infarcts were independently associated with microangiopathy (odds ratio 12.81, 95% CI 1.52–107.86), the mean pulsatility index (odds ratio 8.13, 95% CI 1.17–56.20) and leukoaraiosis (odds ratio 3.45, 95% CI 1.09–10.93). The presence of leukoaraiosis plus microangiopathy was associated with lacunar infarcts with odds ratio 21.31 (95% CI 8.74–51.93).

Conclusions

The association of retinal microangiopathy (but not vascular retinopathy) and leukoaraiosis is linked to small-vessel disease and may be a useful marker of lacunar infarcts not secondary to a macrovascular lesion.