Lipid, lipoprotein, apolipoprotein and lipoprotein(a) levels: reference intervals in a healthy Indian population.

The role of lipids, lipoproteins and lipoprotein(a) [Lp(a)] in coronary artery disease (CAD) is known but the role of major apolipoproteins (apos) other than apo A-I and apo B remains unclear. In this study, using immunoturbidimetry we have estimated serum levels of total cholesterol, HDL-C, LDL-C, triglyceride, LDL-apoB and all major apos; A-I, A-II, B, C-II, C-III and E, in 751 healthy Indian subjects (470 men and 281 women, age 25-65 years), determined their percentiles, and established reference intervals. The effects of age, smoking and alcohol on all these analytes were also evaluated. This is the first study to provide reference intervals for all apos, in both sexes from a general population. The percentiles and the reference intervals have clinical relevance and will be useful in assessing the risk of CAD in patients with hyperlipidemia and other diseases.