Arterial stiffness and carotid intima-media thickness in diabetic peripheral neuropathy

The Association between the Severity of Distal Sensorimotor Polyneuropathy and Increased Carotid Atherosclerosis in Individuals with Type 2 Diabetes

BACKGROUND

Diabetes contributes to a spectrum of complications encompassing microvascular and macrovascular disorders. This study aimed to explore the correlation between distal sensorimotor polyneuropathy (DSPN) severity and heightened carotid atherosclerosis among individuals with type 2 diabetes mellitus (T2DM). Method: Participants underwent comprehensive assessments including nerve conduction studies (NCS), Toronto Clinical Neuropathy Score (TCNS) evaluations, assessment of cardiometabolic risk factors, and carotid sonography studies covering dynamic and morphological parameters. The resistance index (RI), pulsatility index (PI), peak systolic velocity (PSV), and end-diastolic velocity (EDV) in both the common carotid artery (CCA) and internal carotid artery (ICA), carotid intima-media thickness (IMT), and carotid plaque score (CPS) were also measured. Peripheral nerve function severity was assessed using composite amplitude scores (CAS) derived from NCS.

RESULTS

Individuals with DSPN exhibited lower EDV in the CCA and ICA (p < 0.0001 and p = 0.002), higher PI and RI in both CCA and ICA (all p < 0.0001), and higher CPS (p = 0.002). They also demonstrated a higher prevalence of retinopathy as an underlying condition, higher index HbA1c, and reduced estimated glomerular filtration rate (eGFR) (all p < 0.0001). Multiple linear regression analysis revealed significant associations where eGFR, ICA-PI, index HbA1c, waist circumference, and age were correlated with CAS. Meanwhile, diabetes duration, waist circumference, age, and index HbA1c showed significant associations with TCNS.

CONCLUSIONS

Our study suggests that individuals with T2DM who exhibit more severe carotid atherosclerosis may not only be at increased risk of developing DSPN but also may experience greater severity of DSPN. PI in both the CCA and ICA, along with the CPS, serve as surrogate biomarkers for DSPN severity.

Association of arterial stiffness and neuropathy in diabetes: a systematic review and meta-analysis

Evidence is still emerging on the relationships of arterial stiffness with cardiac autonomic neuropathy (CAN) and peripheral neuropathy (PN). To our knowledge no systematic reviews or meta-analyses of these associations have been published. The purpose of our review was to assess the association of arterial stiffness with each type of neuropathy. Medline and Embase were systematically searched for observational studies of arterial stiffness and neuropathy.The systematic review of 60 studies (25 for CAN and 37 for PN), 59 including people with diabetes, showed arterial stiffness overall was higher in people with neuropathy than people without neuropathy. Forty-three studies were included in the meta-analysis. For CAN (19 studies), arterial stiffness was increased in people with neuropathy compared with without, as measured by pulse wave velocity (PWV) (mean difference: 1.32 m/s, 95% CI 0.82 to 1.81, p<0.00001), pulse pressure (PP) (mean difference: 6.25 mmHg, 95% CI 4.51 to 7.99, p<0.00001) or augmentation index (mean difference: 5.52%, 95% CI 3.46 to 7.58, p<0.0001). For PN (26 studies), arterial stiffness was increased in people with neuropathy compared with those without, as measured by PWV (mean difference: 1.22 m/s, 95% CI 0.87 to 1.58, p<0.00001) or PP (mean difference: 4.59 mmHg, 95% CI 2.96 to 6.22, p<0.00001). Only two cohort studies were located so the temporality of the association between arterial stiffness and neuropathy remains unclear. Increased arterial stiffness is associated with CAN and PN.PROSPERO registration number: CRD42019129563.

Plasma levels of Asymmetric Di Methyl Arginine and endothelial dysfunction in diabetic subjects with neuropathic foot ulcer

OBJECTIVE

Asymmetric dimethyl arginine (ADMA) is an amino acid that acts as an endogenous competitive inhibitor of Nitric oxide synthase, leading to endothelial dysfunction (ED). The aim of this study was to evaluate the relationship between plasma ADMA (p-ADMA) level and ED in diabetic subjects with neuropathic foot ulcer (NFU), and the possible predictors of p-ADMA level.

MATERIALS AND METHODS

80 diabetic subjects of matched age, sex and BMI were included; 40 with NFU (G1), 20 with peripheral nerve dysfunction (PND) (G2) and 20 without PND (G3), plus 20 matched healthy subjects (G4). Flow-mediated-dilatation (FMD) of brachial artery and Carotid-intima-media-thickness (CIMT) were measured to evaluate ED and subclinical atherosclerosis, respectively.

RESULTS

G1&2 had a significantly lower FMD than G3&4 [-5.09 (-22.5 to 22.92), 4.67 (-15 to 23.91) vs. 15.74 (8.33-36.59) and 20.1 (10.0-46.15)%, respectively] (p < 0.001), and higher CIMT [0.9 (0.6-1.5), 0.9 (0.6-1.3) vs. 0.6 (0.5-0.8) and 0.7 (0.5-0.9) cm, respectively] (p < 0.001, r = 0.237, p = 0.034, r = 0.330, p = 0.003, respectively), with no significant correlation with FMD (r = -0.176, p = 0.118). FMD was inversely and strongly related to CIMT (r = -0.520, p < 0.001). p-ADMA levels were significantly higher in uncontrolled hypertensive patients in comparison to controlled and normotensive subjects [717 (286-3611) vs. 648 (335-874) and 686 (526-857) ng/L, respectively] (p = 0.026). Metformin users and hypertensive subjects on ACEIs or ARBs had the lowest p-ADMA levels than the non-users (p < 0.001, p = 0.007, respectively).

CONCLUSION

The remarkable ED in diabetic subjects with NFU is unlikely to be due to alteration in p-ADMA. Further studies are needed in order to conclude a causal association between p-ADMA and ED in this group of patients.

Diabetic Peripheral Neuropathy Is Associated With Higher Systolic Blood Pressure in Adults With Type 2 Diabetes With and Without Hypertension in the Chinese Han Population

OBJECTIVES

Our aim in this study was to investigate the association between diabetic peripheral neuropathy (DPN) and above-normal blood pressure in nonhypertensive adult patients with type 2 diabetes mellitus (T2DM). We also compared achievement of clinical targets for DPN and non-DPN with T2DM.

METHODS

A retrospective survey was administered to 3,810 patients with T2DM. Cases were grouped according to the Toronto Clinical Scoring System as follows: non-DPN, mild DPN, moderate DPN and severe DPN. A total of 1,835 patients (hypertensive, 1,247; nonhypertensive, 588) also underwent nerve conduction velocity testing, and then was divided into quartile groups.

RESULTS

Irrespective of hypertension, systolic blood pressure (SBP) and glycated hemoglobin levels in the DPN group were higher than those in the non-DPN group (p<0.001). In hypertensive patients, blood pressure goal achievement was lower in the DPN group compared with the non-DPN group (31.1% vs 40.5%, p<0.05). Compared with the nerve conduction velocity Q1 (<P25%) group, optimal SBP of the Q2 (P25% to P50%), Q3 (P50% to P75%) and Q4 (>P75%) groups decreased by 62.2%, 68.2% and 78.0%, respectively. In the nonhypertensive patients, detection of optimal SBP was lower in the DPN group than in the non-DPN group (p<0.05). After adjusting for age, sex and diabetes duration (model 2), a 3-point higher DPN score on the Toronto Clinical Scoring System was associated with an SBP level of 4.2 mmHg higher (95% confidence interval, 0.01 to 0.17; p<0.01) in nonhypertensive patients with diabetes.

CONCLUSIONS

DPN is associated with difficulty in hypertension management in T2DM. It is also associated with elevated systolic blood hypertension, even in nonhypertensive patients with diabetes. Elevated SBP in nonhypertensive T2DM may be also worthy of further attention.

Nerve conduction velocity is negatively associated with intima-media thickness and brachial-ankle pulse wave velocity in men with type 2 diabetes mellitus

Objective

Previous studies suggest that the presence of diabetic peripheral polyneuropathy (DPN) is associated with atherosclerotic diseases; however, little is known about the relationship between diabetic nerve conduction velocity (NCV) versus arterial stiffness and atherosclerosis parameters.

Methods

The subjects in this study were 292 men with type 2 diabetes mellitus (T2DM). All subjects underwent NCV examination at median and tibial nerves as motor nerve (MCV) as well as median and sural nerves as sensory nerve (SCV). Brachial-ankle pulse wave velocity (baPWV) and carotid intima-media thickness (IMT) were evaluated as arterial stiffness and atherosclerosis parameters.

Results

Pearson’s correlation coefficient showed that NCV at all sites negatively correlated with baPWV, maximal and mean IMT (IMT-Max and IMT-Mean), and plaque score (all p values p<0.01 at least). Multiple regression analyses adjusted for confounding factors such as age, duration of diabetes, body mass index, HbA1c, fasting C-peptide, systolic blood pressure, HDL-cholesterol, LDL-cholesterol and albuminuria showed that the association of NCV with IMT-Max, ITM-Mean, and plaque score remained significant (all p values p<0.05 at least) except that between SCV at median and IMT-Max. Moreover, SCV at median (forearm) and sural were significantly associated with baPWV (p = 0.023 and p = 0.027, respectively).

Conclusion

The present study showed that DPN estimated by quantitative NCV is linearly associated with the deterioration of arterial stiffness and atherosclerosis parameters in T2DM independently of various diabetic and atherosclerotic factors.

Vascular factors and neuropathy in lower limb of diabetic patients

Asymmetric clinical presentation in some patients with diabetic polyneuropathy may result from the different vascular environments in both lower limbs. The aim of the study is to determine the association of neuropathy with vascular factors in each lower limb of diabetic patients. A total of 102 patients (204 lower limbs) given a diagnosis of diabetic polyneuropathy were enrolled. The primary end points are sensory nerve action potential (SNAP) amplitude and conduction velocity (CV) of the sural nerve and independent variables are vascular and nonvascular factors. Vascular factors include mean arterial pressure and pulse pressure at the ankle, ankle-brachial index, and arterial stiffness assessed by pulse wave velocity. Nonvascular factors include age, gender, height, body weight, body mass index, total cholesterol, and hemoglobin A₁C. Age, hemoglobin A₁C, and ankle pulse pressure were inversely correlated with SNAP amplitude of the sural nerve, while no factors were correlated with CV of the sural nerve. Increased arterial stiffness was significant in the limbs group with abnormal SNAP amplitude of the sural nerve, while increased height was significant in the limbs group with abnormal CV of the sural nerve. Vascular factors were more significantly associated with decreased SNAP amplitude rather than decreased CV of the sural nerve in the nerve conduction study of diabetic patients.

Vitamin D Level is Associated with Increased Left Ventricular Mass and Arterial Stiffness in Older Patients with Impaired Renal Function

BACKGROUND Impaired renal function is common among older patients. Deficiency of vitamin D is a frequent phenomenon among patients with impaired renal function, who are likely to develop cardiovascular diseases. This study aimed to explore the association of 25 (OH) D levels with left ventricular mass and arterial stiffness in older patients with impaired renal function. MATERIAL AND METHODS Based on their admission estimate glomerular filtration rate (eGFR), 273 inpatients (≥65 years) were allocated into a normal eGFR group (≥60 ml/min) and an impaired eGFR group (<60 ml/min). The 25 (OH) D levels were measured and the left ventricular mass index (LVMI) was estimated. Pulse wave velocity (PWV) was used to explore arterial stiffness. RESULTS The 25 (OH) D levels of patients in the impaired eGFR group were significantly lower than in the normal eGFR group [(11.92±6.01) μg/L vs. (18.14±8.07) μg/L, p<0.05). LVMI and PWV were both significantly higher in the impaired eGFR group than in the normal eGFR group [(104.89±33.50) g/m2 vs. (92.95±18.95) g/m2, P<0.05; (15.99±3.10) m/s vs. (13.62±2.90) m/s, P<0.05]. After adjusting for age, sex, eGFR, cardiovascular risk factors, serum calcium, and iPTH levels, the inverse association between LVMI and 25 (OH) D, PWV, and 25 (OH) D were statistically significant. CONCLUSIONS Vitamin D level is lower in older patients with impaired renal function. Lower vitamin D levels were correlated with higher left ventricular mass and increased arterial stiffness in older patients.