Brachial-Ankle Pulse Wave Velocity as a Novel Modality for Detecting Early Diabetic Nephropathy in Type 2 Diabetes Patients

Retinal neurovascular alteration in type 2 diabetes with renal impairment in association with systemic arterial stiffness

BACKGROUND

Diabetic retinopathy (DR) patients should be alert for subclinical macroangiopathy. We aimed to investigate the association between retinal neurovascular alteration and systemic arterial stiffness in type 2 diabetes mellitus (type 2 DM) patients with varying degrees of renal impairment.

METHODS

The study included 170 patients with confirmed diagnosis of type 2 DM aged ≥18 years old. Renal function was assessed by estimated glomerular filtration rate (eGFR). Arterial stiffness was measured by brachial-ankle pulse wave velocity (baPWV) and ankle brachial index (ABI). Retinal neurovascular parameters were derived from Optical Coherence Tomography (OCT)/OCT-Angiography, represented by vessel density (VD Central, Inner, Outer, Full), foveal avascular zone (FAZ area and FAZ perimeter) of the superficial capillary plexus, the average of macular ganglion cell-inner plexiform layer thickness (ave mGC-IPLt) and the average of retinal nerve fiber layer thickness (aveRNFLt). The association between variables among the groups (according to renal function, diabetic retinopathy (DR) severity, and arterial stiffness categories) were analyzed by regression analysis with multiple hypothesis testing commands.

RESULTS

Out of the 265 eyes, the mean DM duration and HbA1c were 6.21 ± 6.37 years and 8.44 ± 2.06% respectively. While the mean of eGFR, baPWV and ABI were 66.78 ± 32.80 ml/min/1.73m2, 15.49 ± 3.07 m/s, and 1.05 ± 0.12, respectively. Patients with more severe renal impairment demonstrated longer DM duration (p < 0.001), higher baPWV (p < 0.0001), and retinal vascular alteration. Proliverative DR group showed the lowest eGFR (p < 0.0001), highest baPWV (p < 0.0001), and retinal neurovascular changes. Significantly lower eGFR and retinal vascular alteration were found in the baPWV > 14 group. Some neurovascular parameters were significantly negatively correlated with baPWV; moreover, retinal neurovascular changes were also noted in the abnormal ABI group.

CONCLUSIONS

The strong association between changes in the retinal neurovascular system, DR severity, renal impairment, and arterial stiffness in type 2 DM was confirmed. Patients with more severe renal impairment had higher levels of arterial stiffness, more severe DR and retinal neurovascular alteration. Retinal neurovascular changes seen in OCT/OCTA might mimic renal microvascular alteration and systemic arterial stiffness. Therefore, assessment of baPWV and OCT/OCTA should be integrated in DR screening to enhance cardiovascular risk stratification and prognosis as well as to provide clinically useful early identification of subclinical micro- and macrovascular alterations.

Characterization of peripheral blood inflammatory indicators and OCT imaging biological markers in diabetic retinopathy with or without nephropathy

Objective

To observe the distribution characteristics of peripheral blood inflammatory indexes and retinal macular area optical coherence tomography (OCT) imaging biomarkers in patients with diabetic retinopathy (DR) with or without diabetic nephropathy (DN), in order to seek clinical biomarkers that can predict the development of DR and DN.

Methods

A total of 169 inpatients with DR who visited the ophthalmology department of the Affiliated Hospital of Chengdu University of Traditional Chinese Medicine from October 2020 to June 2022 and had complete clinical data were collected, and the patients with DR were divided into two major groups, DR and DR/DN, according to whether they had DN, and then further divided into four subgroups, Non-proliferative DR(NPDR), proliferative DR(PDR), NPDR/DN and PDR/DN, according to the stage of DR. The distribution characteristics of peripheral blood inflammatory indexes [Neutrophil to lymphocyte ratio(NLR) and Platelet to neutrophil ratio(PLR)], renal function indexes [Cystatin-C(CYS-C), Creatinine(Crea), Uric acid(UA)and Urinary albumin to creatinine ratio(UACR)] and OCT imaging indexes [Hyperreflective foci(HRF), Disorgnization of retinal inner layers(DRIL), Outer retinal tubulations(ORTs), Central retinal thickness(CRT), Retinal nerve fiber layer(RNFL) and Ganglion cell layer(GCL)] were analyzed between the above subgroups.

Results

There was no difference between DR and DR/DN groups in terms of gender, family history of diabetes, duration of diabetes and Body mass index(BMI) (P>0.05), the mean age of the DR/DN group was significantly lower than that of the DR group (P<0.05), and the proportion of the DR/DN group with a history of hypertension was significantly higher than that of the DR group (P<0.05); there was no significant difference in hemoglobin A1C(HbA1c) between DR and DR/DN groups (P>0.05). (P>0.05), Hemoglobin(HGB) was significantly higher in the DR group than in the DR/DN group (P <0.05), NLR, PLR, Crea, UA and CYS-C were significantly higher in the DR/DN group than in the DR group (P<0.05); there was no significant difference in the comparison of HRF, DRIL, ORTs positive rate and CRT between the DR and DR/DN groups (P>0.05). RNFL and GCL thickness were significantly lower in the DR/DN group than in the DR group (P<0.05); history of hypertension (OR=2.759), NLR (OR=1.316), PLR (OR=1.009), Crea (OR=1.018), UA (OR=1.004), CYS-C (OR=3.742) were the independent (OR=0.951), age (OR=0.951), HGB (OR=0.976), RNFL (OR=0.909) and GCL (OR=0.945) were independent protective factors for DR/DN; RNFL (OR=0.899) and GCL (OR=0.935) were independent protective factors for NPDR/DN, RNFL (OR=0.852) and GCL (OR=0.928) were independent protective factors for PDR/DN. ROC curve analysis showed that the area under the curve (AUC) for CYS-C, PLR, Crea, UA and the combination of the four indicators to predict DR/DN were 0.717, 0.625, 0.647, 0.616 and 0.717, respectively.

Conclusions

(1) Low age combined with hypertension HGB, NLR, PLR, CYS-C, Crea and UA may be serum biological markers for predicting DN in DR; meanwhile, PLR, CYS-C, Crea, UA and the combination of the four indicators can be used for risk assessment and adjunctive diagnosis of DN in DR combined with hypertension. (2) The RNFL and GCL thickness in the temporal aspect of the central macular sulcus may be imaging biological markers for predicting DN in DR; meanwhile, GCL thickness may have important value for risk prediction and diagnosis of DN in combination with DR.

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.

The effect of arteriosclerosis on new-onset renal damage in diabetic patients

The aim of this study was to investigate the effect of arteriosclerosis on new-onset renal damage in a Chinese community population with diabetes. Patients with diabetes who had attended at least one physical examination after the Brachial-ankle pulse wave velocity (BaPWV) test from 2010 to 2018 were selected as subjects. A total of 4,462 patients were included in the study cohort. BaPWV levels <1,400 cm/s, 1,400-1,799 cm/s, and ≥1,800 cm/s were applied to divide the subjects into a normal arterial stiffness group, borderline atherosclerosis group and atherosclerosis group. Renal damage was defined by isolated proteinuria, isolated eGFR <60 mL/min/1.73 m², proteinuria and eGFR <60 mL/min/1.73 m². A Cox proportional risk model was used to analyze the effect of different groups on new-onset renal damage. After a median follow-up of 2.85 (1.88-4.90) years, Cox proportional risk models showed that after adjusting for risk factors, compared with the normal group, the HR and 95% CI of the risk of new-onset renal damage were 1.29 (95% CI: 0.95-1.76) and 1.59 (95% CI: 1.14-2.22) in the borderline atherosclerosis group and the atherosclerosis group, respectively. Atherosclerosis is a risk factor for new-onset renal damage, especially new-onset proteinuria, in diabetic patients.

Association of interleukin 6 and uric acid levels in patients with type 2 diabetes mellitus

Type 2 Diabetes Mellitus (T2DM) patients with coronary artery disease (CAD) coupled with hypertension (HTN) are leading cause of morbidity and mortality. Association of Interleukin 6 and uric acid levels can be used for early detection of CAD in patients with T2DM. This cross sectional study included 120 study participants, were sub grouped into three Group 1: controls (n=30), Group 2: CAD, HTN without T2DM (n=30) and Group 3: CAD, HTN with T2DM (n=30). Basic biochemical, clinical and experimental parameters were analysed and recorded for all the study subjects. The statistical analysis was done by using the SPSS 20.0. Individuals with CAD, HTN with T2DM had higher BMI, weight, SBP, and DBP levels than patients CAD, HTN without diabetes and controls. In CAD, HTN with T2DM study participants has been found to have higher serum levels of inflammatory cytokines like IL-6 and uric acids when compared to CAD, HTN without T2DM and controls. IL6 was significantly positive association with uric acid and negative association with age and HDL. These findings demonstrated a statistically significant positive connection between IL-6, and uric acid concentrations. The identified elevated levels of inflammatory cytokines and uric acids in type 2 diabetic and hypertensive CAD patients may aid in the identification of patients at higher risk.

Association between remnant cholesterol and arterial stiffness: A secondary analysis based on a cross-sectional study

The relationship between conventional lipid parameters and arterial stiffness (AS) has been verified by previous studies. However, it remains unknown whether non‐conventional lipid parameters have certain predictive effect on AS represented by brachial‐ankle pulse wave velocity (baPWV). Therefore, the study was to explore the relationship between remnant cholesterol (RC) and other non‐conventional lipid parameters and AS in the general population free from cardiovascular disease. The study included 912 participants aged 24–84 years from a medical health checkup center of Murakami Memorial Hospital. Logistic regression analysis and receiver operating characteristic (ROC) curves were used to examine the association between non‐conventional lipid parameters and AS. The results showed that compared with non‐AS group, the AS group had higher RC, non‐high‐density lipoprotein cholesterol (Non‐HDL‐C), atherogenic index of plasma (AIP), lipoprotein combine index (LCI), atherosclerosis index (AI), triglycerides/HDL‐C (TG/HDL‐C), Castelli's risk index I (CRI‐I) and Castelli's risk index II (CRI‐II). Then, the authors divided participants into two groups by the optimal cutoff point of 23.6 of RC determined by Youden index. The baPWV was significantly higher in higher RC group compared with lower RC group, and RC was positively correlated with baPWV. Multivariate Logistic regression analysis showed that, regarding lower RC as reference, higher RC was independently associated with higher risk of AS, independent of other risk factors (OR = 1.794, 95% CI: 1.267‐2.539, p = .001). The area under the curve of AS predicted by RC was higher than that of other non‐conventional lipid parameters (almost all p < .05). The findings indicated that increased RC was a significant predictor of AS.