The impact of diabetic nephropathy and severe diabetic retinopathy on chronic limb threatening ischemia risk in individuals with type 1 diabetes: a nationwide, population study.

Background: The prevalence, incidence and risk factors and especially the effect of diabetic nephropathy (DN) and diabetic retinopathy on the risk of chronic limb threatening ischemia (CLTI) have been sparsely studied in individuals with type 1 diabetes (T1D). Methods: The prospective cohort study consisted of 4697 individuals with T1D from the nationwide Finnish Diabetic Nephropathy (FinnDiane) Study. Medical records were thoroughly reviewed in order to ascertain all CLTI events. The key risk factors were DN and severe diabetic retinopathy (SDR). Findings: There were 319 events of confirmed CLTI, 102 prevalent events at baseline and 217 incident events during the follow-up of 11.9 (IQR 9.3-13.8) years. The 12-year cumulative incidence of CLTI was 4.6% (95% CI 4.0-5.3). Risk factors included presence of DN, SDR, age, duration of diabetes, HbA1c, systolic blood pressure, triglycerides and current smoking. Sub-hazard ratios (SHRs) according to combinations of DN status and presence (+) or absence (-) of SDR were 4.8 (2.0-11.7) for normoalbuminuria/SDR+, 3.2 (1.1-9.4) for microalbuminuria/SDR-, 11.9 (5.4-26.5) for microalbuminuria/SDR+, 8.7 (3.2-23.2) for macroalbuminuria/SDR-, 15.6 (7.4-33.0) for macroalbuminuria/SDR+ and 37.9 (17.2-78.9) for kidney failure compared with individuals with normal albumin excretion rate and without SDR. Interpretation: Diabetic nephropathy, especially kidney failure, is associated with high risk of limb threatening ischemia in individuals with T1D. The risk of CLTI increases gradually according to the severity of diabetic nephropathy. Also, diabetic retinopathy is independently and additively associated with high risk of CLTI. Funding: This research was funded by grants from Folkhälsan Research Foundation, Academy of Finland (316664), Wilhelm and Else Stockmann Foundation, Liv och Hälsa Society, Novo Nordisk Foundation (NNF OC0013659), Finnish Foundation for Cardiovascular Research, Finnish Diabetes Research Foundation, Medical Society of Finland, Sigrid Jusélius Foundation and Helsinki University Hospital Research Funds.

Genome-Wide Association Study of Peripheral Artery Disease.

BACKGROUND: Peripheral artery disease (PAD) affects >200 million people worldwide and is associated with high mortality and morbidity. We sought to identify genomic variants associated with PAD overall and in the contexts of diabetes and smoking status. METHODS: We identified genetic variants associated with PAD and then meta-analyzed with published summary statistics from the Million Veterans Program and UK Biobank to replicate their findings. Next, we ran stratified genome-wide association analysis in ever smokers, never smokers, individuals with diabetes, and individuals with no history of diabetes and corresponding interaction analyses, to identify variants that modify the risk of PAD by diabetic or smoking status. RESULTS: We identified 5 genome-wide significant (Passociation ≤5×10-8) associations with PAD in 449 548 (Ncases=12 086) individuals of European ancestry near LPA (lipoprotein [a]), CDKN2BAS1 (CDKN2B antisense RNA 1), SH2B3 (SH2B adaptor protein 3) - PTPN11 (protein tyrosine phosphatase non-receptor type 11), HDAC9 (histone deacetylase 9), and CHRNA3 (cholinergic receptor nicotinic alpha 3 subunit) loci (which overlapped previously reported associations). Meta-analysis with variants previously associated with PAD showed that 18 of 19 published variants remained genome-wide significant. In individuals with diabetes, rs116405693 at the CCSER1 (coiled-coil serine rich protein 1) locus was associated with PAD (odds ratio [95% CI], 1.51 [1.32-1.74], Pdiabetes=2.5×10-9, Pinteractionwithdiabetes=5.3×10-7). Furthermore, in smokers, rs12910984 at the CHRNA3 locus was associated with PAD (odds ratio [95% CI], 1.15 [1.11-1.19], Psmokers=9.3×10-10, Pinteractionwithsmoking=3.9×10-5). CONCLUSIONS: Our analyses confirm the published genetic associations with PAD and identify novel variants that may influence susceptibility to PAD in the context of diabetes or smoking status.

The Association of Severe Diabetic Retinopathy With Cardiovascular Outcomes in Long-standing Type 1 Diabetes: A Longitudinal Follow-up.

OBJECTIVE: It is well established that diabetic nephropathy increases the risk of cardiovascular disease (CVD), but how severe diabetic retinopathy (SDR) impacts this risk has yet to be determined. RESEARCH DESIGN AND METHODS: The cumulative incidence of various CVD events, including coronary heart disease (CHD), peripheral artery disease (PAD), and stroke, retrieved from registries, was evaluated in 1,683 individuals with at least a 30-year duration of type 1 diabetes drawn from the Finnish Diabetic Nephropathy Study (FinnDiane). The individuals were divided into four groups according to the presence of diabetic kidney disease (DKD) and/or SDR (+DKD/+SDR, +DKD/-SDR, -DKD/+SDR, and -DKD/-SDR) at baseline visit. Furthermore, age-specific incidences were compared with 4,016 control subjects without diabetes. SDR was defined as laser photocoagulation and DKD as estimated glomerular filtration rate <60 mL/min/1.73 m2. RESULTS: During 12,872 person-years of follow-up, 416 incident CVD events occurred. Even in the absence of DKD, SDR increased the risk of any CVD (hazard ratio 1.46 [95% CI 1.11-1.92]; P < 0.01), after adjustment for diabetes duration, age at diabetes onset, sex, smoking, blood pressure, waist-to-hip ratio, history of hypoglycemia, and serum lipids. In particular, SDR alone was associated with the risk of PAD (1.90 [1.13-3.17]; P < 0.05) and CHD (1.50 [1.09-2.07; P < 0.05) but not with any stroke. Moreover, DKD increased the CVD risk further (2.85 [2.13-3.81]; P < 0.001). However, the risk was above that of the control subjects without diabetes also in patients without microvascular complications, until the patients reached their seventies. CONCLUSIONS: SDR alone, even without DKD, increases cardiovascular risk, particularly for PAD, independently of common cardiovascular risk factors in long-standing type 1 diabetes. More remains to be done to fully understand the link between SDR and CVD. This knowledge could help combat the enhanced cardiovascular risk beyond currently available regimens.

Development of new peripheral arterial occlusive disease in patients with type 2 diabetes during a mean follow-up of 11 years.

OBJECTIVE: To assess the occurrence and development of new peripheral arterial occlusive disease (PAOD), its risk factors, and the outcome in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: A total of 130 type 2 diabetic patients (mean age 58 years) were examined at baseline and after a mean follow-up of 11 years (range 7-14). The ankle-brachial index (ABI) and toe-brachial index were used to detect PAOD. Blood and urine samples were taken at baseline, and a history of cardiovascular events was recorded during follow-up. RESULTS: PAOD was diagnosed in 21 (16%) patients at baseline. During follow-up, 21 of 89 (24%) patients developed new PAOD. There were 29 patients who died, 21 (72%) of them from cardiovascular disease. Patients with PAOD suffered an excess mortality compared with patients without PAOD (58 vs. 16%; P < 0.001). Logistic regression analysis showed that PAOD at baseline was associated with age, duration of diabetes, smoking, and urinary albumin excretion rate. Patients who developed new PAOD during follow-up had higher serum LDL cholesterol concentrations and lower HDL cholesterol concentrations and were older than the patients who remained free of PAOD. CONCLUSIONS: Objectively measured PAOD is frequent in type 2 diabetic patients. It presents the early clinical signs of atherosclerosis and is strongly associated with cardiovascular death. The risk factor pattern for PAOD was different at baseline and after a mean follow-up of 11 years. We consider routine ABI measurements and modification of risk factors necessary also in patients with asymptomatic PAOD.