Associations and interactions between lipid profiles, retinopathy and nephropathy in patients with type 1 diabetes: the FinnDiane Study

Abstract

Objectives: The aim of this study was to investigate the associations between lipid profiles and retinopathy in the large nationwide FinnDiane Study and to examine interactions and correlations between retinopathy, nephropathy and lipid variables.

Design and subjects: A total of 1465 patients with type 1 diabetes, available lipid profiles, ophthalmic records and fundus photographs were included in the study. The Early Treatment of Diabetic Retinopathy Study scale was used to assess the severity of retinopathy. In an independent cohort of 1100 patients, laser treatment was used to define severe diabetic retinopathy.

Results: HDL cholesterol was associated with proliferative retinopathy (PDR), and triglycerides were associated with mild nonproliferative retinopathy (NPDR) independently of nephropathy and other conventional risk factors (P < 0.01). Significant interactions were seen between albumin excretion rate (AER), retinopathy status and lipid parameters (including triglycerides, non-HDL cholesterol and apolipoprotein B; P < 0.001). Highly different correlations between AER and lipid variables were observed in patients without retinopathy or with mild NPDR compared with patients with moderate to severe NPDR or PDR. Similar interactions and correlations were observed in an independent cohort stratified by laser treatment. In patients without retinopathy or with mild NPDR, AER was low despite HDL cholesterol in the lowest or triglycerides, total cholesterol or LDL cholesterol in the highest quartiles.

Conclusions: Nephropathy had a strong effect on the associations between lipid variables and retinopathy, whilst dyslipidaemia was associated with nephropathy only in the presence of retinopathy. This finding suggests the existence of shared pathogenic mechanisms between retinopathy and nephropathy which could be targeted to prevent complications in patients with metabolic risk factors.

Keywords: apolipoproteins; diabetic nephropathy; lipids; lipoproteins; type 1 diabetes.