Diabetic nephropathy (DN) is a polygenic disorder with few risk variants showing robust replication in large-scale genome-wide association studies. To understand the role of DNA methylation, it is important to have the prevailing genomic view to distinguish key sequence elements that influence gene expression. This is particularly challenging for DN because genome wide methylation patterns are poorly defined. While methylation is known to alter gene expression the importance of this causal relationship is obscured by array-based technologies since coverage outside promoter regions is low.To overcome these challenges, we performed methylation sequencing using leukocytes derived from participants of the Finnish Diabetic Nephropathy (FinnDiane) type 1 diabetes (T1D) study (n=39) that was subsequently replicated in a larger validation cohort (n=296). Gene body related regions made up >60% of the methylation differences and emphasised the importance of methylation sequencing. We observe differentially methylated genes associated with DN (DDN) in three independent T1D registries originating from Denmark (n=445), Hong Kong (n=107) and Thailand (n=130). Reduced DNA methylation at CTCF and Pol2B sites were tightly connected with DN pathways that include insulin signalling, lipid metabolism and fibrosis. To define the pathophysiological significance of these population findings, methylation indices were assessed in human renal cells such as podocytes and proximal convoluted tubules. The expression of core genes was associated with reduced methylation, elevated CTCF and Pol2B binding and the activation of insulin signalling phosphoproteins in hyperglycaemic cells. These experimental observations also closely parallel methylation-mediated regulation in human macrophage and vascular endothelial cells.

OBJECTIVE Few studies have compared midregional proatrial natriuretic peptide (MR-proANP) and N-terminal probrain natriuretic peptide (NT-proBNP). We compared their value as risk markers for all-cause mortality and cardiovascular (CV) and renal complications in individuals with type 1 diabetes. RESEARCH DESIGN AND METHODS MR-proANP and NT-proBNP were measured in 664 individuals. Hazard ratios (HRs) were assessed per doubling of NT-proBNP or MR-proANP for risk of a composite of ischemic events, heart failure (HF), a combined renal end point of end-stage kidney disease (ESKD), decline in estimated glomerular filtration rate (eGFR) ≥30%, and all-cause mortality or individual end points. Adjustments included CV risk factors and addition of MR-proANP or NT-proBNP. RESULTS Median follow-up was 5.1–6.2 years. MR-proANP was associated with higher risk of all-cause mortality (n = 57; HR 1.7, 95% CI 1.1–2.7), combined CV end point (n = 94; 1.6, 1.1–2.2), HF (n = 27; 2.8, 1.5–5.2), combined renal end point (n = 123; 1.6, 1.2–2.1), and ESKD (n = 21; 3.1, 1.2–7.8) independent of CV risk factors (P ≤ 0.02). After addition of NT-proBNP, significance for all end points was lost. A doubling of NT-proBNP was associated with higher risk of all-cause mortality (HR 1.5, 95% CI 1.2–1.8), the combined CV end point (1.3, 1.1–1.5), HF (1.7, 1.3–2.1), and the combined renal end point (1.3, 1.1–1.4) independent of CV risk factors (model 2 [P < 0.001]) and MR-proANP (model 3 [P ≤ 0.03]). There was no association with decline in eGFR ≥30% (n = 93). CONCLUSIONS Higher NT-proBNP was independently associated with all-cause mortality, CV disease, HF, and the combined renal end point. MR-proANP was associated with all end points but decline in eGFR, although not independent of NT-proBNP. MR-proANP may contribute to the predictive value of NT-proBNP for risk stratification in type 1 diabetes.

Objective <p>Few studies have compared Midregional Proatrial Natriuretic Peptide (MR-proANP) and N-terminal pro-brain natriuretic peptide (NT-proBNP). We compared their value as risk markers for all-cause mortality, cardiovascular (CV) and renal complications in persons with type 1 diabetes.</p>Research design and methods <p>MR-proANP and NT-proBNP were measured in 664 individuals. Hazard ratios (HR) were assessed per doubling of NT-proBNP or MR-proANP for risk of a composite of ischemic events, heart failure (HF), a combined renal endpoint of end-stage kidney disease (ESKD), decline in estimated glomerular filtration rate (eGFR) ≥30% and all-cause mortality or individual endpoints. Adjustments included CV risk factors and addition of MR-proANP or NT-proBNP.</p>Results <p>Median follow-up was 5.1-6.2 years. MR-proANP was associated with higher risk of all-cause mortality n=57; HR 1.7, 95% CI 1.1-2.7, combined CV endpoint (n=94; 1.6(1.1-2.2)), HF (n=27; 2.8(1.5-5.2)), combined renal endpoint (n=123; 1.6(1.2-2.1)) and ESKD (n=21; 3.1(1.2-7.8)) independent of CV risk factors (p≤0.02). After addition of NT-proBNP significance for all endpoints was lost. A doubling of NT-proBNP was associated with higher risk of all-cause mortality (1.5(1.2-1.8)), the combined CV endpoint (1.3(1.1-1.5)), HF (1.7(1.3-2.1)) and the combined renal endpoint (1.3(1.1-1.4)) independent of CV risk factors (model 2;p<0.001) and MR-proANP (model 3;p≤0.03). There was no association with decline in eGFR ≥30% (n=93).</p>Conclusions <p><a>Higher NT-proBNP was independently associated with all-cause mortality, CV disease, HF and the combined renal endpoint. </a>MR-proANP was associated with all endpoints but decline in eGFR, although not independent of NT-proBNP. MR-proANP may contribute to the predictive value of NT-proBNP for risk-stratification in type 1 diabetes.</p>

Objective <p>Few studies have compared Midregional Proatrial Natriuretic Peptide (MR-proANP) and N-terminal pro-brain natriuretic peptide (NT-proBNP). We compared their value as risk markers for all-cause mortality, cardiovascular (CV) and renal complications in persons with type 1 diabetes.</p>Research design and methods <p>MR-proANP and NT-proBNP were measured in 664 individuals. Hazard ratios (HR) were assessed per doubling of NT-proBNP or MR-proANP for risk of a composite of ischemic events, heart failure (HF), a combined renal endpoint of end-stage kidney disease (ESKD), decline in estimated glomerular filtration rate (eGFR) ≥30% and all-cause mortality or individual endpoints. Adjustments included CV risk factors and addition of MR-proANP or NT-proBNP.</p>Results <p>Median follow-up was 5.1-6.2 years. MR-proANP was associated with higher risk of all-cause mortality n=57; HR 1.7, 95% CI 1.1-2.7, combined CV endpoint (n=94; 1.6(1.1-2.2)), HF (n=27; 2.8(1.5-5.2)), combined renal endpoint (n=123; 1.6(1.2-2.1)) and ESKD (n=21; 3.1(1.2-7.8)) independent of CV risk factors (p≤0.02). After addition of NT-proBNP significance for all endpoints was lost. A doubling of NT-proBNP was associated with higher risk of all-cause mortality (1.5(1.2-1.8)), the combined CV endpoint (1.3(1.1-1.5)), HF (1.7(1.3-2.1)) and the combined renal endpoint (1.3(1.1-1.4)) independent of CV risk factors (model 2;p<0.001) and MR-proANP (model 3;p≤0.03). There was no association with decline in eGFR ≥30% (n=93).</p>Conclusions <p><a>Higher NT-proBNP was independently associated with all-cause mortality, CV disease, HF and the combined renal endpoint. </a>MR-proANP was associated with all endpoints but decline in eGFR, although not independent of NT-proBNP. MR-proANP may contribute to the predictive value of NT-proBNP for risk-stratification in type 1 diabetes.</p>