Decreased stroke volume−brachial pulse pressure ratio in patients with type 2 diabetes over 50 years: the role of peripheral neuropathy

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.

Diabetic polyneuropathy, deep white matter lesions, and carotid atherosclerosis: is there any association?

The morphologic and functional damages of diabetes mellitus (DM) on microcirculation can play a role in the pathogenesis of both polyneuropathy and cerebral white matter lesions. The aim of this study is to investigate the relation between polyneuropathy and cerebral deep white matter lesions (DWMLs) and carotid atherosclerosis in patients with type 2 DM. Sixty-six patients with type 2 DM without any disorder that may cause polyneuropathy, and vascular risk factors except for DM and hyperlipidemia were included in the study. DWMLs and carotid atherosclerosis were investigated in patients with and without polyneuropathy. Forty patients (60.6%) had diabetic sensorimotor polyneuropathy. DWMLs were more frequent in patients with polyneuropathy compared to patients without polyneuropathy (p = 0.003). Logistic regression analysis confirmed association between polyneuropathy and DWMLs after adjusted for age (p = 0.013), duration of DM (p = 0.007), and both age and duration of DM (p = 0.016). No statistically significant difference was found between patients with and without polyneuropathy for carotid atherosclerosis. Among patients with polyneuropathy, those having DWMLs had higher mean age (p = 0.003) and longer symptom duration (p = 0.020) compared to patients without DWMLs. No association was found between DWMLs and carotid atherosclerosis. Polyneuropathy and cerebral DWMLs in type 2 DM patients may share common pathogenesis; presence and duration of polyneuropathy symptoms may predict ischemic white matter damage independent of carotid atherosclerosis.

Arterial stiffness is elevated in normotensive type 2 diabetic patients with peripheral neuropathy

BACKGROUND AND AIMS

Arterial stiffness, a measure of macrovascular damage predictive of poor cardio-vascular outcomes, is strongly related to age and hypertension (HT). In diabetic patients peripheral neuropathy (PN) has been found to be associated with increased arterial stiffness, which might be due to the concomitant presence of HT. The aim of this study was to examine in type-2 diabetic patients, the relationship between arterial stiffness and presence or absence of PN and HT separately.

METHODS AND RESULTS

Arterial stiffness was measured with the gold standard carotid-femoral pulse wave velocity (PWV) in 447 type-2 diabetic subjects of whom 66% were hypertensive, 53% had PN, and 40% had both. Patients with PN were older, more often hypertensive and had higher PWV than those free of PN. Patients were separated according to the presence or absence of PN and HT. PWV values above the 90th percentile age- and blood pressure-adjusted reference range (PWV+) were different across these groups (p < 0.005) with the following respective prevalences: 27.2%, 53.4%, 33.3% and 30.6%. Only PWV+ was significantly associated with PN and hypertension in the interaction analysis.

CONCLUSION

Well controlled hypertensive patients did not have elevated arterial stiffness compared to normotensive patients. This might be due to anti-hypertensive treatment although our study design does not allow us to confirm it. A strong association between PN and arterial stiffness was only present in normotensive patients, suggesting that normotensive type 2 diabetic patients with PN and elevated arterial stiffness should be carefully managed to prevent future macrovascular complications.

Aging, the metabolic syndrome, and ischemic stroke: redefining the approach for studying the blood-brain barrier in a complex neurological disease

The blood-brain barrier (BBB) has many important functions in maintaining the brain's immune-privileged status. Endothelial cells, astrocytes, and pericytes have important roles in preserving vasculature integrity. As we age, cell senescence can contribute to BBB compromise. The compromised BBB allows an influx of inflammatory cytokines to enter the brain. These cytokines lead to neuronal and glial damage. Ultimately, the functional changes within the brain can cause age-related disease. One of the most prominent age-related diseases is ischemic stroke. Stroke is the largest cause of disability and is third largest cause of mortality in the United States. The biggest risk factors for stroke, besides age, are results of the metabolic syndrome. The metabolic syndrome, if unchecked, quickly advances to outcomes that include diabetes, hypertension, cardiovascular disease, and obesity. The contribution from these comorbidities to BBB compromise is great. Some of the common molecular pathways activated include: endoplasmic reticulum stress, reactive oxygen species formation, and glutamate excitotoxicity. In this chapter, we examine how age-related changes to cells within the central nervous system interact with comorbidities. We then look at how comorbidities lead to increased risk for stroke through BBB disruption. Finally, we discuss key molecular pathways of interest with a focus on therapeutic targets that warrant further investigation.