ABSTRACT
Background/Aims@#The aim of this study is to compare Friedewald-estimated and directly measured low density lipoprotein cholesterol (LDL-C) values and assess the concordance in guideline risk classification between the two methods. @*Methods@#The data were derived from the 2009 to 2011 Korea National Health and Nutrition Examination Survey. We included subjects with triglyceride (TG) levels < 400 mg/dL. Analysis was done for 6,454 subjects who had all lipid panels— total cholesterol, directly measured LDL-C, high density lipoprotein cholesterol (HDL-C), and TG. @*Results@#The subjects ranged in age from 10 to 87 years old. The mean age was 41.5 ± 17.3 years. For subjects with TG < 400 mg/dL, overall concordance in guideline risk classification was 79.1%. The Friedewald formula tended to underestimate LDL-C more at higher TG or lower HDL-C levels. Especially, the percent of subjects who were misclassified into a lower risk category was 31% when TG were 200 to 299 mg/dL; and 45.6% when TG were 300 to 399 mg/dL. A greater underestimation of LDL-C occurred at higher TG and lower Friedewald-estimated LDL-C levels. Of subjects with a Friedewald-estimated LDL-C < 70 mg/dL, 55.4% had a directly measured LDL-C ≥ 70 mg/dL when TG were 200 to 399 mg/dL. @*Conclusions@#The Friedewald equation tends to underestimate LDL-C in highrisk subjects such as hypertriglyceridemia and hypo-HDL-cholesterolemia. For these individuals accurate assessment of LDL-C is crucial, and therefore additional evaluation is warranted.
ABSTRACT
BACKGROUND: The incidence of osteoporosis and its related fractures are expected to increase significantly in the rapidly aging Korean population. Reliable data on the prevalence of this disease is essential for treatment planning. However, sparse data on Korean patients is available. METHODS: We analyzed data from the Korea National Health and Nutrition Examination Survey (KNHANES) 2008 to 2010. Bone mineral density (BMD) was measured at the femoral neck and lumbar spine using dual-energy X-ray absorptiometry. Osteopenia and osteoporosis were diagnosed according to the World Health Organization T-score criteria. We analyzed the BMD data of 17,208 people (men, 7,837; women, 9,368). RESULTS: The adjusted prevalence of osteoporosis was 7.8% in men versus 37.0% in women. No significant difference was observed in the prevalence of osteopenia between genders (men, 47.0%; women, 48.7%). The prevalence of osteoporosis in men in their 50s was 4.0%, in their 60s was 7.2%, in their 70s was 15.1%, and in their 80s was 26.7%. The figures in women were 15.2%, 36.5%, 62.7%, and 85.8%, respectively. The age group with the maximal BMD differed between genders. In the men, 20s had the highest value in all the skeletal sites. However, in the women, the maximal BMD in the femoral neck, lumbar spine, and the total hip was observed in their 20s, 30s, and 40s, respectively. The onset age of osteoporosis differed between genders. Osteoporosis in the femoral neck began at 55 years in the women and at 60 years in the men. CONCLUSION: The prevalence of osteoporosis in Korea was significantly high. In addition, the age-related changes in the prevalence of osteoporosis differed according to gender and skeletal site.