Leukocyte Telomere Length, DNA Oxidation, and Risk of Lower-Extremity Amputation in Patients With Long-standing Type 1 Diabetes

Lower-limb peripheral arterial disease and amputations in people with diabetes: Risk factors, prognostic value and management

Lower-limb peripheral arterial disease (PAD), is a common manifestation of systemic atherosclerosis, resulting from a partial or complete obstruction of at least one lower-limb arteries. PAD is a major endemic disease with an excess risk of major cardiovascular events and death. It also leads to disability, high rates of lower-limb adverse events and non-traumatic amputation. In patients with diabetes, PAD is particularly frequent and has a worse prognosis than in patients without diabetes. The risk factors of PAD are comparable to those for cardiovascular disease. The ankle-brachial index is usually recommended to screen PAD despite its limited performance in patients with diabetes, affected by the presence of peripheral neuropathy, medial arterial calcification, incompressible arteries and infection. Toe brachial index and toe pressure emerge as alternative screening tools. The management of PAD requires strict control of cardiovascular risk factors including diabetes, hypertension and dyslipidaemia, the use of antiplatelet agents and lifestyle management, to reduce cardiovascular adverse events, but few randomized controlled trials have evaluated the benefits of these treatments in PAD. Several advances have been achieved in endovascular and surgical revascularization procedures, with obvious improvement in PAD prognosis. Further studies are required to increase our understanding of the pathophysiology of PAD and to evaluate the interest of different therapeutic strategies in the occurrence and progression of PAD in patients with diabetes. Here, we present a narrative and contemporary review to synthesize the key epidemiology findings, screening and diagnosis methods, and major therapeutic advances regarding PAD in patients with diabetes.

Immune-mediated inflammatory diseases and leukocyte telomere length: A Mendelian randomization study

Objective: To elucidate the potential causality of leukocyte telomere length (LTL) with immune-mediated inflammatory diseases (IMIDs), we conducted a Mendelian randomization (MR) study. Methods: The genetically predicted causation between LTL and IMIDs was evaluated using a two-sample MR method. We analyzed 16 major IMIDs, which included systemic lupus erythematosus (SLE), inflammatory bowel disease (IBD), ulcerative colitis (UC), Crohn's disease (CD), ankylosing spondylitis (AS), sicca syndrome (SS), rheumatoid arthritis (RA), type 1 diabetes (T1D), primary sclerosing cholangitis (PSC), idiopathic pulmonary fibrosis (IPF), atopic dermatitis (AD), sarcoidosis, hypothyroidism, hyperthyroidism, psoriasis, and childhood asthma. The random-effects inverse-variance weighted (IVW) method was performed as the main analytical approach in MR. Various sensitivity analyses, including MR-Egger, MR robust adjusted profile score (MR-RAPS), weighted median, MR pleiotropy residual sum and outlier (MR-PRESSO) methods, weighted mode, radial plot, and radial regression, were used to guarantee the robustness of the results and detect horizontal pleiotropy. Cochran's Q value was calculated to check for heterogeneity, and the MR Steiger approach was used to test the causal direction. Results: The MR results indicated significant inverse associations of LTL with risks of psoriasis (OR: 0.77, 95% CI: 0.66-0.89, and p = 3.66 × 10^-4), SS (OR: 0.75, CI: 0.58-0.98, and p = 0.03), RA (OR: 0.77, 95% CI: 0.68-0.88, and p = 9.85 × 10^-5), hypothyroidism (OR: 0.84, 95% CI: 0.78-0.91, and p = 7,08 × 10^-6), hyperthyroidism (OR: 0.60, 95% CI: 0.44-0.83, and p = 1.90 × 10^-3), sarcoidosis (OR: 0.67, 95% CI: 0.54-0.83, and p = 2.60 × 10^-4), and IPF (OR: 0.41, 95% CI: 0.29-0.58, and p = 4.11 × 10^-7) in the FinnGen study. We observed that longer LTL was associated with an increased risk of AS susceptibility (OR: 1.51, 95% CI: 1.18-1.94, and p = 9.66 × 10^-4). The results of the IVW method showed no causal relationship between TL and SLE (OR: 0.92, 95% CI: 0.62-1.38, and p = 0.69) in the FinnGen study; however, a significantly positive correlation was shown between LTL and SLE in another larger GWAS (OR: 1.87, 95% CI: 1.37-2.54, and p = 8.01 × 10^-5). Conclusion: Our findings reveal that abnormal LTL has the potential to increase the risk of IMIDs. Therefore, it could be treated as a predictor and may provide new potential treatment targets for IMIDs. However, the change of LTL may not be the direct cause of IMIDs. Further studies should aim at the pathogenic mechanism or potential protective effects of LTL in IMIDs.

Leukocyte telomere length, allelic variations in related genes and risk of coronary heart disease in people with long-standing type 1 diabetes

Background

Type 1 diabetes is associated with accelerated vascular aging and advanced atherosclerosis resulting in increased rates of cardiovascular disease and premature death. We evaluated associations between Leukocyte telomere length (LTL), allelic variations (SNPs) in LTL-related genes and the incidence of coronary heart disease (CHD) in adults with long-standing type 1 diabetes.

Methods

We assessed associations of LTL, measured at baseline by RT–PCR, and of SNPs in 11 LTL-related genes with the risk of coronary heart disease (CHD: myocardial infarction or coronary revascularization) and all-cause death during follow-up in two multicenter French-Belgian prospective cohorts of people with long-standing type 1 diabetes.

Results

In logistic and Cox analyses, the lowest tertile of LTL distribution (short telomeres) at baseline was associated with the prevalence of myocardial infarction at baseline and with increased risk of CHD (Hazard ratio 3.14 (1.39–7.70), p = 0.005, for shorter vs longer tertile of LTL) and all-cause death (Hazard ratio 1.63 (95% CI 1.04–2.55), p = 0.03, for shorter vs combined intermediate and longer tertiles of LTL) during follow-up. Allelic variations in six genes related to telomere biology (TERC, NAF1, TERT, TNKS, MEN1 and BICD1) were also associated with the incidence of CHD during follow-up. The associations were independent of sex, age, duration of diabetes, and a range of relevant confounding factors at baseline.

Conclusions

Our results suggest that short LTL is an independent risk factor for CHD in people with type 1 diabetes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01635-0.

Telomere Lengths and Serum Proteasome Concentrations in Patients with Type 1 Diabetes and Different Severities of Diabetic Retinopathy in Latvia and Lithuania

The aim of the study was to compare telomere lengths and circulating proteasome concentrations in patients with different stages of diabetic retinopathy and type 1 diabetes in Latvia and Lithuania. Methods. Patients with no diabetic retinopathy and with non-proliferative diabetic retinopathy were included in the NDR/NPDR group (n = 187). Patients with proliferative diabetic retinopathy and status post laser-photocoagulation were included int the PDR/LPC group (n = 119). Telomeres were evaluated by real-time quantitative polymerase chain reaction. Proteasome concentration was measured by ELISA. Results. Telomeres were longer in PDR/LPC (ΔCT 0.21 (0.12−0.28)) vs. NDR/NPDR (ΔCT 0.18 (0.1−0.28)), p = 0.036. In NDR/NPDR, telomeres were correlated negatively with age (R = −0.17, p = 0.019), BMI (R = −0.21, p = 0.004), waist/hip ratio (R = −0.21, p = 0.005), total cholesterol (R = −0.18, p = 0.021), and low-density cholesterol (R = −0.20, p = 0.010), and positively with estimated glomerular filtration rate (eGFR) (R = 0.28, p < 0.001). None of the above correlations were observed in PRD/LPC. Proteasome concentrations were lower in PDR/LPC (130 (90−210) ng/mL) vs. NDR/NPDR (150 (100−240) ng/mL), p = 0.024. This correlated negatively with eGFR (R = −0.17, p = 0.025) in the NDR/NPDR group and positively with age (R = 0.23, p = 0.014) and systolic blood pressure (R = 0.20, p = 0.032) in the PRD/LPC group. Telomere lengths did not correlate with proteasome concentrations. Conclusion. Longer telomeres and lower circulating proteasome concentrations are observed in patients with type 1 diabetes and advanced diabetic retinopathy.

Differential prognostic burden of cardiovascular disease and lower-limb amputation on the risk of all-cause death in people with long-standing type 1 diabetes

Background

Cardiovascular disease (CVD) and nontraumatic lower-limb amputation (LLA) each results in reduced life expectancy in patients with type 1 diabetes, but the differential burden between these conditions is unknown. We compared the effects of CVD and LLA on the risk of mortality in people with type 1 diabetes.

Methods

We used pooled data from the SURGENE, GENEDIAB, and GENESIS prospective cohorts. Data were divided into: 1/absence of CVD (myocardial infarction and/or stroke) nor LLA, 2/history of CVD alone without LLA, 3/LLA alone without CVD or 4/both conditions at baseline. Participants with baseline history of peripheral artery disease were excluded from groups 1 and 2. The study endpoint was any death occurring during follow-up, regardless of the causes.

Results

Among 1169 participants (male 55%, age 40 ± 13 years, diabetes duration 23 ± 11 years), CVD, LLA or both were present at baseline in 49 (4.2%), 62 (5.3%) and 20 (1.7%) subjects, respectively. All-cause death occurred in 304 (26%) participants during 17-year follow-up, corresponding to 18,426 person-years and an incidence rate of 16 (95%CI, 15–18) per 1000 person-years. The risk of death increased in individuals with baseline history of CVD (adjusted HR 2.00 [95% CI 1.34–3.01], p = 0.0008) or LLA (2.26 [1.56–3.28], p < 0.0001), versus no condition, with an additive effect in people with both conditions (5.32 [3.14–9.00], p < 0.0001). No incremental risk of death was observed in people with CVD versus LLA (0.87 [0.54–1.41]). Compared with no condition, CVD and LLA were similarly associated with reduced life expectancy during follow-up: 2.79 (95% CI 1.26–4.32) and 3.38 (1.87–4.88) years, respectively. Combined conditions expose to 7.04 (4.76–9.31) less years of life expectancy (all p < 0.0001).

Conclusions

CVD and LLA conferred a similar burden regarding mortality in type 1 diabetes population. Our findings encourage a careful consideration of people with type 1 diabetes and LLA as usually recommended for those with CVD, in terms of management of risk factors, treatments and prevention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01487-8.

Association Between the ACE Insertion/Deletion Polymorphism and Risk of Lower-Limb Amputation in Patients With Long-Standing Type 1 Diabetes

OBJECTIVE

The ACE insertion/deletion (I/D) polymorphism has been widely studied in people with diabetes, albeit not with regard to lower-limb amputation (LLA). We examined associations among this polymorphism, plasma ACE concentration, and LLA in people with type 1 diabetes.

RESEARCH DESIGN AND METHODS

ACE I/D genotype and plasma ACE were assessed in three prospective cohorts of participants with type 1 diabetes. LLA was defined as minor (below-the-ankle amputation consisting of at least one ray metatarsal resection) or major (transtibial or transfemoral) amputation. Linear, logistic, and Cox regression models were computed to evaluate the likelihood of prevalent and incident LLA by ACE genotype (XD [ID or ID] vs. II) and plasma ACE, after adjusting for confounders.

RESULTS

Among 1,301 participants (male 54%, age 41 ± 13 years), 90 (6.9%) had a baseline history of LLA. Baseline LLA was more prevalent in XD (7.4%) than in II genotype (4.5%, odds ratio [OR] 2.17 [95 %CI 1.03-4.60]). Incident LLA occurred in 53 individuals during the 14-year follow-up and was higher in XD versus II carriers (hazard ratio 3.26 [95% CI 1.16-13.67]). This association was driven by excess risk of minor, but not major, LLA. The D allele was associated with increased prevalent LLA at the end of follow-up (OR 2.48 [1.33-4.65]). LLA was associated with higher mean (95% CI) ACE levels in II (449 [360, 539] vs. 354 [286, 423] ng/mL), but not XD (512 [454, 570] vs. 537 [488, 586]), carriers.

CONCLUSIONS

This report is the first of an independent association between ACE D allele and excess LLA risk, mainly minor amputations, in patients with type 1 diabetes.

Reduced leukocyte telomere lengths and sirtuin 1 gene expression in long-term survivors of type 1 diabetes: A Dialong substudy

AIMS/INTRODUCTION

The shortening of leukocyte telomere length with age has been associated with coronary disease, whereas the association with type 1 diabetes is unclear. We aimed to explore telomere lengths in diabetes patients with regard to coronary artery disease, compared with healthy controls. The longevity factors sirtuin 1 and growth-differentiating factor 11 were investigated accordingly.

MATERIALS AND METHODS

We carried out a cross-sectional study of 102 participants with long-term type 1 diabetes and 75 controls (mean age 62 and 63 years, respectively), where 88 cases and 60 controls without diagnosed coronary artery disease completed computed tomography coronary angiography. Telomere lengths and gene expression of sirtuin 1 and growth-differentiating factor 11 were quantified in leukocytes.

RESULTS

Telomere lengths and sirtuin 1 were reduced in diabetes patients versus controls, medians (25th to 75th percentiles): 0.97 (0.82-1.15) versus 1.08 (0.85-1.29) and 0.88 (0.65-1.14) vs 1.01 (0.78-1.36), respectively, adjusted P < 0.05, both. Previous coronary artery disease in diabetes patients (n = 15) was associated with lower sirtuin 1 and growth-differentiating factor 11 messenger ribonucleic acid expression (adjusted P < 0.03, both). In the combined diabetes and control group, previous artery coronary disease (n = 18) presented with significantly shorter telomeres (adjusted P = 0.038). Newly diagnosed obstructive coronary artery disease, defined as >50% stenosis, was not associated with the investigated variables.

CONCLUSIONS

Long-term type 1 diabetes presented with reduced telomeres and sirtuin 1 expression, with additional reduction in diabetes patients with previous coronary artery disease, showing their importance for cardiovascular disease development with potential as novel biomarkers in diabetes and coronary artery disease.

ACE I/D Polymorphism, Plasma ACE Levels, and Long-term Kidney Outcomes or All-Cause Death in Patients With Type 1 Diabetes

OBJECTIVE

The deletion (D) allele of the ACE insertion/deletion (I/D) polymorphism is a risk factor for diabetic kidney disease. We assessed its contribution to long-term kidney outcomes and all-cause death in patients with long-standing type 1 diabetes.

RESEARCH DESIGN AND METHODS

A total of 1,155 participants from three French and Belgian cohorts were monitored for a median duration of 14 (interquartile range 13) years. The primary outcome was the occurrence of end-stage kidney disease (ESKD) or a 40% drop in the estimated glomerular filtration rate (eGFR). Secondary outcomes were the individual components of the primary outcome, rapid decline in eGFR (steeper than -3 mL/min/1.73 m² per year), incident albuminuria, all-cause death, and a composite ESKD or all-cause death. Hazard ratios (HRs) for XD versus II genotype and for baseline plasma ACE levels were computed by Cox analysis. Genotype performance in stratifying the primary outcome was tested.

RESULTS

Genotype distribution was 954 XD and 201 II. The primary outcome occurred in 20% of XD and 13% of II carriers: adjusted HR 2.07 (95% CI 1.32-3.40; P = 0.001). Significant associations were also observed for rapid decline in eGFR, incident albuminuria, ESKD, all-cause death, and ESKD or all-cause death. Baseline plasma ACE levels were higher in XD carriers and significantly associated with an increased risk of the primary outcome. The ACE genotype enhanced net reclassification improvement (0.154, 95% CI 0.007-0.279; P = 0.04) and integrated discrimination improvement (0.012, 95%CI 0.001-0.021; P = 0.02) for primary outcome stratification.

CONCLUSIONS

The D-allele of the ACE I/D polymorphism was associated with an increased risk of major kidney events and all-cause death in patients with long-standing type 1 diabetes.

The Association between Antidiabetic Agents and Leukocyte Telomere Length in the Novel Classification of Type 2 Diabetes Mellitus

AIMS

This study aimed to explore the new role of telomere length (TL) in the novel classification of type 2 diabetes mellitus (T2DM) patients driven by cluster analysis.

MATERIALS AND METHODS

A total of 541 T2DM patients were divided into 4 subgroups by k-means analysis: mild obesity-related diabetes (MOD), severe insulin-deficient diabetes (SIDD), severe insulin-resistant diabetes (SIRD), and mild age-related diabetes (MARD). After patients with insufficient data were excluded, further analysis was conducted on 246 T2DM patients. The TL was detected using telomere restriction fragment, and the related diabetic indexes were also measured by clinical standard procedures.

RESULTS

The MARD group had significantly shorter TLs than the MOD and SIDD groups. Then, we subdivided all T2DM patients into the MARD and NONMARD groups, which included the MOD, SIDD, and SIRD groups. The TLs of the MARD group, associated with age, were discovered to be significantly shorter than those of the NONMARD group (p = 0.0012), and this difference in TL disappeared after metformin (p = 0.880) and acarbose treatment (p = 0.058). The linear analysis showed that metformin can more obviously reduce telomere shortening in the MARD group (r = 0.030, 95% CI 0.010-0.051, p = 0.004), and acarbose can more apparently promote telomere attrition in the SIRD group (r = -0.069, 95% CI -0.100 to -0.039, p< 0.001) compared with other T2DM patients after adjusting for age and gender.

CONCLUSIONS

The MARD group was found to have shorter TLs and benefit more from the antiaging effect of metformin than other T2DM. Shorter TLs were observed in the SIRD group after acarbose use.

Telomere-Related Disorders in Fetal Membranes Associated With Birth and Adverse Pregnancy Outcomes

Telomere disorders have been associated with aging-related diseases, including diabetes, vascular, and neurodegenerative diseases. The main consequence of altered telomere is the induction of the state of irreversible cell cycle arrest. Though several mechanisms responsible for the activation of senescence have been identified, it is still unclear how a cell is indeed induced to become irreversibly arrested. Most tissues in the body will experience senescence throughout its lifespan, but intrinsic and extrinsic stressors, such as chemicals, pollution, oxidative stress (OS), and inflammation accelerate the process. Pregnancy is a state of OS, as the higher metabolic demand of the growing fetus results in increased reactive oxygen species production. As a temporary organ in the mother, senescence in fetal membranes and placenta is expected and linked to term parturition (>37 weeks of gestation). However, a persistent, overwhelming, or premature OS affects placental antioxidant capacity, with consequent accumulation of OS causing damage to lipids, proteins, and DNA in the placental tissues. Therefore, senescence and its main inducer, telomere length (TL) reduction, have been associated with pregnancy complications, including stillbirth, preeclampsia, intrauterine growth restriction, and prematurity. Fetal membranes have a notable role in preterm births, which continue to be a major health issue associated with increased risk of neo and perinatal adverse outcomes and/or predisposition to disease in later life; however, the ability to mediate a delay in parturition during such cases is limited, because the pathophysiology of preterm births and physiological mechanisms of term births are not yet fully elucidated. Here, we review the current knowledge regarding the regulation of telomere-related senescence mechanisms in fetal membranes, highlighting the role of inflammation, methylation, and telomerase activity. Moreover, we present the evidences of TL reduction and senescence in gestational tissues by the time of term parturition. In conclusion, we verified that telomere regulation in fetal membranes requires a more complete understanding, in order to support the development of successful effective interventions of the molecular mechanisms that triggers parturition, including telomere signals, which may vary throughout placental tissues.