Apolipoprotein(B) identifies dyslipidemic phenotypes associated with cardiovascular risk in normocholesterolemic type 2 diabetic patients

OBJECTIVE - Apolipoprotein(B) (apo(B)] reflects the total mass of atherogen ic particles (VLDL, IDL, and LDL), and its increase is associated with card iovascular disease independently of LDL cholesterol (LDLc) levels. Apo(B) d etermination has been recently standardized, but attention to regional refe rence limits is advisable. Our aim was to analyze the frequency of dyslipid emic phenotypes, including those dependent on increased apo(B) in normochol esterolemic type-2 diabetic patients. RESEARCH DESIGN AND METHODS - A total of 100 consecutively seen type 2 diab etic patients (63 men, 37 women; aged 59 +/- 11 years) were included, after excluding those on lipid-lowering therapy. Apo(B) cutoff(1.1 g/l) was obta ined from a group of normolipidemic (47 men, 21 women) control subjects, an d LDLc, triglycerides, and HDL cholesterol (HDLc) cutoff points were those from the National Cholesterol Education Program guidelines. LDLc levels wer e obtained by ultracentrifugation if triglyceride levels were >3.45 mmol/l; otherwise, they were calculated (Friedewald). Apo(B) levels were measured by immunoturbidimetry. RESULTS - Normocholesterolemia (LDLc <4.13 mmol/l) appeared in 75 of the 10 0 patients, of whom 55 were normo- and 20 hypertriglyceridemic. Hyperapolip oprotein(B) [hyperapo(B)] was the most frequent lipid disorder, present in 34 (45%) of the normocholesterolemic patients (22 normo- and 12 hypertrigly ceridemic). Low HDLc levels were more prevalent (53%) in patients with hype rapo(B) than in the rest (24%). CONCLUSIONS - Hyperapo(B) was found in almost half of the normocholesterole mic type 2 diabetic patients and was frequently associated with low HDLc le vels and hypertriglyceridemia. Thus, given its independent association with cardiovascular disease and that it identifies high-risk phenotypes in norm ocholesterolemic diabetic patients, apo(B) should be used to evaluate the l ipidic pattern of these patients.