Relationship between peripheral neuropathy, diastolic function and adverse cardiovascular outcome in individuals with type 1 diabetes mellitus without known cardiovascular disease: Results from the Thousand & 1 Study

Variability in benefit from intensive insulin therapy on cardiovascular events in individuals with type 1 diabetes: A post hoc analysis of the DCCT/EDIC study

AIM

To evaluate presence of treatment effect heterogeneity of intensive insulin therapy (INT) on occurrence of major adverse cardiovascular events (MACE) in individuals with type 1 diabetes.

METHODS

In participants from the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study, individual treatment effect of INT (≥3 daily insulin injections/insulin pump therapy) versus conventional therapy (once/twice daily insulin) on the risk of MACE was estimated using a penalized Cox regression model including treatment-by-covariate interaction terms.

RESULTS

In 1441 participants, 120 first MACE events were observed and 1279 individuals (89%) were predicted to benefit from INT with regard to MACE risk reduction. The study population was divided into four groups based on predicted treatment effect: one group with no predicted benefit and three tertiles with predicted treatment benefit. The median absolute reduction in 30-year risk of MACE across groups of predicted treatment effect ranged from -0.2% (i.e. risk increase; interquartile range [IQR] -0.1% to -0.3%) in the group with no predicted benefit to 6.6% (i.e. risk reduction; IQR 3.8%-10.9%; number needed to treat 15) in the highest tertile of predicted benefit. The observed benefit of preventing microvascular complications was stable across all subgroups of predicted MACE benefit.

CONCLUSIONS

Although INT reduces the risk of MACE in the majority of individuals with type 1 diabetes, benefit varies substantially. These individual differences in the effect of INT underline the necessity for a better understanding of the individual response to intensive treatment.

Subclinical left ventricular deformation and microvascular dysfunction in T2DM patients with and without peripheral neuropathy: assessed by 3.0 T cardiac magnetic resonance imaging

BACKGROUND

Diabetic peripheral neuropathy (DPN) has been shown to be independently associated with cardiovascular events and mortality. This study aimed to evaluate changes in left ventricular (LV) microvascular perfusion and myocardial deformation in type 2 diabetes mellitus (T2DM) patients with and without DPN, as well as to investigate the association between myocardial perfusion and LV deformation.

METHODS

Between October 2015 and July 2022, one hundred and twenty-three T2DM patients without DPN, fifty-four patients with DPN and sixty age‑ and sex‑matched controls who underwent cardiovascular magnetic resonance imaging were retrospectively analyzed. LV myocardial perfusion parameters at rest, including upslope, time to maximum signal intensity (TTM), max signal intensity (max SI), and myocardial strains, including global radial, circumferential and longitudinal strain (GRS, GCS and GLS, respectively), were calculated and compared among the groups with One‑way analysis of variance. Univariable and multivariable linear regression analyses were performed to explore the independent factors influencing LV myocardial perfusion indices and LV strains in diabetes.

RESULTS

The LV GLS, upslope and max SI were significantly deteriorated from controls, through patients without DPN, to patients with DPN (all P < 0.001). Compared with controls, TTM was increased and LV GRS and GCS were decreased in both patient groups (all P < 0.05). Multivariable regression analyses considering covariates showed that DPN was independently associated with reduced upslope, max SI and LV GLS (β = - 0.360, - 2.503 and 1.113, p = 0.021, 0.031 and 0.010, respectively). When the perfusion indices upslope and max SI were included in the multivariable analysis for LV deformation, DPN and upslope (β = 1.057 and - 0.870, p = 0.020 and 0.018, respectively) were significantly associated with LV GLS.

CONCLUSION

In patients with T2DM, there was more severe LV microvascular and myocardial dysfunction in patients with complicated DPN, and deteriorated subclinical LV systolic dysfunction was associated with impaired myocardial circulation.

Diabetic Neuropathy Is Independently Associated With Worse Graft Outcomes and Incident Cardiovascular Disease After Pancreas Transplantation: A Retrospective Cohort Study in Type 1 Diabetes

BACKGROUND

Information about the impact of diabetic neuropathy (DN) on outcomes after pancreas transplantation (PT) is scarce. We assessed the independent relationship between DN markers with both graft survival and incident cardiovascular disease (CVD) after transplantation.

METHODS

A cohort study in individuals with type 1 diabetes and end-stage kidney disease who underwent PT between 1999 and 2015 was conducted. DN was assessed with vibration perception thresholds (VPTs) and orthostatic hypotension (pre-PT and 6 mo, 2-3, 5-6, and 8-10 y after transplantation). Pretransplantation and posttransplantation DN markers were related with graft failure/dysfunction and incident CVD during follow-up.

RESULTS

We included 187 participants (70% men, age 39.9 ± 7.1 y, diabetes duration 27.1 y), with a median follow-up of 11.3 y. Abnormal VPTs (≥25 V) were observed in 53%. After transplantation, VPTs improved (22.4 ± 8.4 pretransplant versus 16.1 ± 6.1 V at 8-10 y post-PT; P < 0.001); additionally, the prevalence of abnormal VPTs decreased (53% pretransplant versus 24.4% at 8-10 y; P < 0.001). After adjusting for age, sex, diabetes duration, blood pressure, body mass index, and previous CVD, pretransplant VPTs ≥25 V were independently associated with pancreas graft failure/dysfunction (hazard ratio [HR], 2.01 [1.01-4.00]) and incident CVD (HR, 2.57 [1.17-5.64]). Furthermore, persistent abnormal VPTs after 6 mo posttransplantation were associated with the worst outcomes (HR, 2.80 [1.25-6.23] and HR, 3.19 [1.14-8.96], for graft failure/dysfunction and incident CVD, respectively).

CONCLUSIONS

In individuals with type 1 diabetes and end-stage kidney disease, PT was associated with an improvement of VPTs. This simple and widely available DN study was independently associated with pancreas graft function and CVD posttransplantation.

The association between distal symmetric polyneuropathy in diabetes with all-cause mortality - a meta-analysis

BACKGROUND

Distal symmetric polyneuropathy (DSPN) is a common microvascular complication of both type 1 and 2 diabetes with substantial morbidity burden and reduced quality of life. Its association with mortality is equivocal.

PURPOSE

To describe the association between DSPN and all-cause mortality in people with diabetes and further stratify by the type of diabetes based on a meta-analysis of published observational studies.

DATA SOURCES

We searched Medline from inception to May 2021.

STUDY SELECTION

Original data were collected from case-control and cohort studies that reported on diabetes and DSPN status at baseline and all-cause mortality during follow-up.

DATA EXTRACTION

was completed by diabetes specialists with clinical experience in neuropathy assessment.

DATA SYNTHESIS

Data was synthesized using random-effects meta-analysis. The difference between type 1 and 2 diabetes was investigated using meta-regression.

RESULTS

A total of 31 cohorts (n=155,934 participants, median 27.4% with DSPN at baseline, all-cause mortality 12.3%) were included. Diabetes patients with DSPN had an almost twofold mortality (HR: 1.96, 95%CI: 1.68-2.27, I2 = 91.7%), I^{2 =} 91.7%) compared to those without DSPN that was partly explained by baseline risk factors (adjusted HR: 1.60, 95%CI: 1.37-1.87, I^{2 =} 78.86%). The association was stronger in type 1 compared to type 2 diabetes (HR: 2.22, 95%CI: 1.43-3.45). Findings were robust in sensitivity analyses without significant publication bias.

LIMITATIONS

Not all papers reported multiple adjusted estimates. The definition of DSPN was heterogeneous.

CONCLUSIONS

DSPN is associated with an almost twofold risk of death. If this association is causal, targeted therapy for DSPN could improve life expectancy of diabetic patients.