RESUMO
Lipoprotein [a] [Lp[a]] is a cholesterol-rich particle with atherothrombogenic properties. Plasma level of Lp[a] is mainly determined genetically, but other factors may also affect it. There is little available data on normal range and biological variations of Lp[a] among Iranian population. To evaluate the biological variations of Lp[a] and other serum lipids in 30 college students during a six-month period. This was a descriptive analytical study in which the fasting serum levels of Lp[a], lipids, and lipoproteins of 30 college students [20 females, 10 males, age ranged between 22 to 26 years, who were clinically health, and coming from various regions of Iran] were measured once a month over a 6-month period. Intra-individual standard deviations, variances and coefficients of variations [CV] were determined for Lp[a], total cholesterol [TC], triglycerides [TG], high-density lipoprotein-cholesterol [HDL-C], and low-density lipoprotein-cholesterol [LDL-C]. Plasma Lp[a] with a mean of 14.7 +/- 12.7 mg/dl showed an intra-individual CV ranged from 5.4 to 53.4% with a mean of 11%. The Lp[a] variations were negatively correlated with Lp[a] concentration and changes in TC, and LDL-C levels. Total intra-individual CV for other lipids ranged from 11% for TC to 24.5% for TG. Plasma Lp[a] showed intermediate mean concentration and relatively high intra-individual variations in our study population. This variation was similar to that of total cholesterol, but hardly lower than triglycerides. Plasma Lp[a] variations was negatively related to cholesterol variations and Lp[a] concentration