Statistical analysis showed that when triglyceride is <100 mg/dL, calculated low- density lipoprotein cholesterol is significantly overestimated (average :12.17 mg/dL or 0.31 mmol/L), where as when triglyceride is between 150 and 300 mg/dL no significant difference between calculated and measured low-density lipoprotein cholesterol is observed.
In patients with low serum triglyceride and undesirably high total cholesterol levels, Friedewald equation may overestimate low-density lipoprotein cholesterol concentration and it should be either directly assayed or be calculated by a modified Friedewald equation.