Background: The purpose of this study was to examine the lipid abnormalities associated with urinary albumin excretion rate (UAER) in type 2 diabetic patients.
Methods: A total of 275 (122 men and 153 women; aged 60.6 +/- 11.1 years) patients were selected with stringent criteria to prevent confounders. Normoalbuminuria (N= 152) and albuminuria (N= 123) were defined as urinary albumin-to-creatinine ratio (ACR) of <30 and > or =30 microg/mg, respectively. Total cholesterol, triglycerides, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, and apolipoproteins A1 (ApoA1) and B (ApoB) were measured and non-HDL cholesterol calculated. The subjects were divided into four phenotypes based on triglycerides (<1.5 or > or =1.5 mmol/L) and ApoB (<1.2 or > or =1.2 g/L).
Results: Total cholesterol, ApoB, and non-HDL cholesterol were significantly (P < 0.05) higher in patients with albuminuria. For quartiles of the lipid parameters, prevalences of albuminuria showed significant association with ApoB and non-HDL cholesterol (P trend <0.05). After adjusting for age, systolic blood pressure and hemoglobin A(1c) (HbA(1c)) correlation coefficients between the natural logarithm (ln) ACR and lipid parameters, odds ratios for albuminuria, and standardized regression coefficients for ln ACR, were significant for total cholesterol, ApoB and non-HDL cholesterol in all subjects and in men, but only ApoB was significant in women. For patients with normoalbuminuria, frequencies of normotriglycerides/normo-ApoB, hypertriglycerides/normo-ApoB, normotriglycerides/hyper-ApoB, and hypertriglycerides/hyper-ApoB were 44.7%, 28.9%, 10.5%, and 15.8%, respectively; and were 30.1%, 19.5%, 15.4%, and 35.0% for patients with albuminuria (P < 0.001). The respective adjusted odds ratio for albuminuria for the four phenotypes was 1.00, 1.04 (0.54 to 2.00), 2.25 (1.02 to 5.00), and 3.38 (1.75 to 6.53).
Conclusion: Increased UAER is associated with ApoB-containing lipoproteins and the phenotype of hypertriglycerides/hyper-ApoB is associated with the highest risk of albuminuria. The surrogate marker of non-HDL cholesterol for ApoB is more applicable to the diabetic men.