Blood Pressure Is the Determinant for the Increased Risk for Intracranial Arterial Stenosis in Subjects with Elevated Glycated Hemoglobin Levels: The Kangbuk Samsung Health Study

Associations of hematological and biochemical markers with intracranial atherosclerotic stenosis in stroke-free populations: A systematic review and meta-analysis of observational studies

BACKGROUND AND AIMS

Intracranial atherosclerotic stenosis (ICAS) is an important cause of ischemic stroke and transient ischemic attack. We aimed to synthesize relevant evidence on the associations of hematological and biochemical markers with ICAS in stroke-free populations.

METHODS AND RESULTS

We searched MEDLINE and EMBASE for articles reporting associations of hematological and biochemical markers with ICAS presence in stroke-free populations. Weighted mean difference (WMD) and 95% confidence interval (CI) for each biomarker were pooled using fixed- or random-effects models. Among 32 studies included in the systematic review, 23 studies (48,326 subjects) with 22 biomarkers were meta-analyzed. Compared with subjects without ICAS, those with ICAS had significantly higher white blood cell (4118 subjects, WMD 0.28 per 10⁹/L, 95% CI 0.01-0.56), neutrophil (4326 subjects, WMD 0.24 per 10⁹/L, 0.10-0.38), neutrophil/lymphocyte ratio (4326 subjects, WMD 0.16, 0.07-0.26), low-density lipoprotein (28,606 subjects, WMD 0.12 mmol/L, 0.05-0.19), non-high-density lipoprotein (3671 subjects, WMD 0.17 mmol/L, 0.08-0.25), C-reactive protein (CRP; 5355 subjects, WMD 0.06 mg/dL, 0.04-0.07), high-sensitivity CRP (9383 subjects, WMD 0.07 mg/dL, 0.01-0.13), uric acid (5966 subjects, WMD 17.91 μmol/L, 11.16-24.66), creatinine (5731 subjects, WMD 4.03 μmol/L, 0.77-7.29), and homocysteine (7053 subjects, WMD 2.25 μmol/L, 1.02-3.48), but lower lymphocyte (4326 subjects, WMD -0.12 per 10⁹/L, -0.19--0.04). Sensitivity analyses showed similar results.

CONCLUSIONS

Several hematological and biochemical markers easily accessible were associated with ICAS presence in stroke-free populations. This can facilitate early identification of subjects at a high risk of ICAS, who may benefit from ICAS screening and prevention.

PROSPERO REGISTRATION NUMBER

CRD42021247990.

Association of self-measured home, ambulatory, and strictly measured office blood pressure and their variability with intracranial arterial stenosis

OBJECTIVE

Hypertension and intracranial artery stenosis (ICAS) are closely related; however, few studies have compared the strength of the relationship between strictly measured office and out-of-office blood pressure (BP) measurements. The relationship of day-by-day or short-term variability in BP to asymptomatic ICAS also remains unclear.

METHODS

In apparently healthy 677 men (mean age, 70 years) from a population-based cohort, we examined the association of strictly measured office BP and 7-day home BP with ICAS on magnetic resonance angiography. We conducted 24-h ambulatory BP monitoring in 468 of the men. Variability indices included day-by-day, daytime, and night-time variability, nocturnal decline, and morning pressor surge. Any ICAS was defined as either mild (1-49%) or severe (≥50%) stenosis.

RESULTS

We observed mild and severe ICAS in 153 (22.6%) and 36 (5.3%) participants, respectively. In multivariable-adjusted Poisson regression with robust error variance, higher SBP in office, home, or ambulatory BP monitoring was associated with the presence of any or severe ICAS. The associations with ICAS were comparable between office, home, and ambulatory SBP (all heterogeneity P values >0.1). Independent of mean SBP, greater nocturnal decline or morning pressor surge, but not day-by-day, daytime, or night-time variability, in SBP was associated with higher burden of any or severe ICAS.

CONCLUSION

The magnitude of association of strictly measured office BP for asymptomatic ICAS was comparable with that of BP measured at home or in ambulatory BP monitoring. Circadian BP variation based on ambulatory BP monitoring was positively associated with asymptomatic ICAS burden.

Fasting glucose and HbA1c levels as risk factors for the presence of intracranial atherosclerotic stenosis

Background

Intracranial atherosclerotic stenosis (ICAS) is the most common cause of stroke, but the relationship of ICAS with fasting blood glucose (FBG) and glycated hemoglobin A1c (HbA_1c) is unclear. This study aimed to investigate the effects of increased FBG and HbA_1c concentration on ICAS.

Methods

A total of 4,012 patients aged over 40 years who underwent cerebral magnetic resonance angiography (MRA) were enrolled in this study, including 1,434 non-stroke controls and 2,578 patients with ischemic stroke. Participants were classified into four groups according to stroke and ICAS status. ICAS was defined as the presence of ≥50% stenosis in any intracranial artery. Multivariate regression analysis was used to evaluate the associations of FBG and HbA_1c with ICAS.

Results

Levels of fasting glucose and HbA_1c in patients with ICAS were significantly higher than those in patients without ICAS among both stroke and non-stroke groups. Multivariate regression analysis showed that elevated levels of fasting glucose (OR 1.14, 95% CI, 1.11-1.18, P<0.001) and HbA_1c (OR 1.22, 95% CI, 1.16-1.28, P<0.001) were independent risk factors for ICAS. In addition, patients with the DM (FBG ≥7.0 mmol/L) were at the high risk of ICAS in both non-stroke (OR 2.90, 95% CI, 2.11-3.99, P<0.001) and stroke (OR 1.99, 95% CI, 1.67-2.39, P<0.001) groups. Besides, subjects with the high risk of ICAS were found in the fourth HbA_1c quartile in both non-stroke (OR 3.50, 95% CI, 2.23-5.61, P<0.001) and stroke (OR 1.98, 95% CI, 1.50-2.63, P<0.001) groups.

Conclusions

The results suggest that elevated fasting glucose and HbA_1c levels are associated with high risk for ICAS.

Burden of high blood pressure as a contributing factor to stroke in the Japanese community-based diabetic population

Diabetes mellitus is characterized by alterations in blood glucose (BG) metabolism, and glycated hemoglobin (HbA₁c) has been widely used as a marker of the BG concentration. Diabetes often coexists with high blood pressure (BP). High BP and hyperglycemia are well-known risk factors of stroke. We examined the extent to which the increased risk of stroke in diabetic individuals is attributable to BP and BG using prospectively collected data from the Japanese general population. During an average 8.3 ± 2.2 years of follow-up, out 1606 diabetic individuals aged ≥40 years who were free of cardiovascular disease, 119 participants (7.4%) developed stroke. In multivariable analysis, a significant difference in the risk of incident stroke was noted among the BP categories, including normotension (BP1), prehypertension (BP2), and hypertension (BP3; P for trend = 0.001). By contrast, no difference was noted among the BG categories, including HbA₁c levels <7.0% (HB1), 7.0–7.9% (HB2), and ≥8.0% (HB3; P for trend = 0.430). Compared with the category that included both BP1 and HB1, the population-attributable fraction (PAF) for stroke incidence was 52.0% from the BP2 and BP3 categories and 24.1% from the HB2 and HB3 categories, and the increased incidence from the HB2 and HB3 categories was mostly caused from coexistent BP2 and BP3 categories. In conclusion, in the Japanese community-based diabetic population, concomitant BP elevation largely contributes to the increased incidence of stroke and links BG elevation, as indicated by HbA₁c, to the increased risk of stroke.

Short-term poor glycemic control and retinal microvascular changes in pediatric Type 1 Diabetes patients in Singapore: a pilot study

Background

Poor glycemic control in Type 1 Diabetes (T1D) patients is strongly associated with an increased risk of diabetes-related microvascular complications later in life, but it is unclear whether short period of poor glycemic control in children with T1D can cause evident microvascular morphological changes long before any pathological manifestation. Our study aimed to investigate the longitudinal association between poor glycemic control and subsequent changes in retinal microvasculature, in a pilot study of 55 pediatric T1D patients from Singapore after a one-year follow-up.

Methods

This is a hospital-based, exposure-matched and retrospective longitudinal study. A total of 55 T1D patients were included from Singapore KK Women’s and Children Hospital, 28 of whom had poor glycemic control (average glycated hemoglobin [HbA1c] ≥8% during the year) while the other 27 age- and gender-matched subjects had good glycemic control (HbA1c <8%). Retinal photography was taken at diabetes annual screening and images were graded by trained graders using a semi-automated computer-based program (Singapore I Vessel Assessment [SIVA], version 4.0, Singapore Eye Research Institute, Singapore) and a spectrum of retinal vascular parameters (e.g. caliber, tortuosity, branching angle and fractal dimension) were measured quantitatively from 0.5 to 2.0 disc diameters.

Results

There was no significant difference in ethnicity, duration of T1D, blood pressure, body mass index (BMI) and low-density cholesterol lipoprotein (LDL) between the two groups. Retinal imaging was obtained at the end of 1 year of glycemic control assessment. In multiple linear regression adjusting for ethnicity, BMI, LDL and duration of T1D, patients with poor glycemic control tended to have marginally wider retinal arteriolar caliber (6.0 μm, 95% CI: −0.9, 12.8) and had significantly larger retinal arteriolar branching angle (10.1 degrees, 95% CI: 1.4, 18.9) compared with their age- and gender- matched counterparts with good glycemic control.

Conclusions

Our findings showed that abnormal retinal microvascular morphology was evident in pediatric patients with T1D after one-year’s poor glycemic control. Such morphological abnormalities may lead to future development of microvascular complications among T1D pediatric patients with poor glycemic control.