Do Turkish adults really have lower serum levels of high-density lipoprotein cholesterol?

Background - Coronary heart disease is the leading cause of death in Turkey.The Turkish Heart Study and TEKHARF study have been carried out at various times and in different parts of Turkey and have suggested that the Turkish population has a low high-density lipoprotein-cholesterol (HDLC) level. However, in our daily practice, mean HDL-C levels were not as low as previously reported. Here, we investigated the lipid profile, especially the HDL-C level, in the population of the Duzce region of northwest Turkey. Methods - Serum triglyceride, total cholesterol, and HDL-C levels were measured in 674 healthy volunteers (398 women and 276 men); low-density lipoprotein cholesterol (LDL-C) levels were calculated using the Frieclewald equation. Results - The mean serum HDL-C level was 46.1 +/- 9.8 mg/dl in men and 53.2 +/- 10.7 mg/dl in women; these values are higher than expected based on the Turkish Heart Study. The mean serum total cholesterol level was 196.7 +/- 43.2 mg/dL in men and 198.4 +/- 43.9 mg/dL in women; the mean LDL-C level was 119.6 +/- 34.9 mg/dL in men and 118.7 +/- 34.1 mg/dL in women; and the mean serum triglycericle level was 151.4 +/- 80.9 mg/dL in men and 132.1 +/- 68.9 mg/dL in women. Conclusions - Our finding that the HDL-C level in this population was higher than the previously reported levels in Turkey indicates that HDL-C levels may not be as low as previously thought.We believe that lower HDL-C levels that were previously reported might be due to the difference between techniques of analysis, nutritional status, and percent of subjects who were fasting in the day of analysis or improper subject inclusion which did not reflect the Turkish population causing selection bias.