Reference Values for Serum Lipid Profiles in Iranian Adults: Tehran Lipid and Glucose Study

Lipid abnormalities are major risk factors for cardiovascular diseases. In addition to age and sex, other variables can affect serum lipid levels, warranting the determination of population-specific reference values. This study aimed to determine age- and sex-specific reference values for serum total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), and triglycerides (TG) in healthy Tehranian adults.

TC, TG, and HDL-C were measured using the enzymatic colorimetric method and the Friedewald equation (LDL-C = TC - HDL-C - TG/5) was used to calculate LDL-C concentrations in individuals with TG <400 mg/dL. After applying the exclusion criteria, 1147 participants (548 men and 599 women) aged ≥20 years were included. For determining reference values, the International Federation of Clinical Chemistry guidelines (non-parametric method) and the robust method were used for sample sizes ≥120 and <120, respectively.

Reference values for serum TC, LDL-C, HDL-C, and TG were 121.0-261.0, 54.1-175.2, 30.9-71.9, and 46.9-301.2 mg/ dL in men and 117.8-235.9, 49.9-160.9, 36.0-83.9, and 38.1-184.2 mg/dL in women, respectively. All parameters except HDL-C were higher in men than women and showed an increasing trend with age.

Reference values for serum TC, LDL-C, HDL-C, and TG in healthy Tehranian adults were determined, and these values could provide the basis for better decision making in both prevention and clinical settings.