scholarly journals PENETUAN FORMULA UNTUK MENETAPKAN ESTIMASI KOLESTEROL-LDL

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Gilang Nugraha ◽  
Soebagijoh Poegoeh Edijanto
Keyword(s):  
Correlation Coefficient ◽  
Ldl Cholesterol ◽  
Clinical Pathology ◽  
Statistical Test ◽  
Validation Methods ◽  
Clinical Laboratories ◽  
Friedewald Formula

Abstract: Measurement LDL-Cholesterol (LDL-C) can be performed by estimating LDL-C (cLDL-C) inthe blood. In addition to the first proposed Friedewald formula, several new formulas that promise betterexamination in determining LDL-C levels, proposed by Anandaraja, Puavilai, Chen, Vujovic, deCordova and Dansethakul. The subjects of the study were patients who performed routine lipid profileexamination in Institution of Clinical Pathology of Gedung Pusat Diagnostik Terpadu RSUD Dr.Soetomo Surabaya who performs 10 to 12 hours of fasting with TG less than 400 mg / dL. The sampleconsisted of 41 men and 48 women with an average age of 52 years. The statistical test on each cLDLC gave the Friedewald -1.32% bias value; Anandaraja -3,92%; Puavilai 4.26%, Chen -2.19%; Vujovic-23.65%; de Cordova -0.91% and Dansethakul 4.45%. The correlation coefficient on Friedewald0.9509; Anandaraja 0.9013; Puavilai 0.9576, Chen 0.9585; Vujovic 0.8745; de Cordova 0.9300 andDansethakul 0.9505. The proposed cLDL-C formula Chen et al promises in determining the LDL-Cestimate and the Vujovic formula gives a poor result in this study. Validation methods should be appliedto each of the cLDL formulas if they are to be applied to clinical laboratories.

Does the weather affect the Chinese stock markets? Evidence from the analysis of DCCA cross-correlation coefficient

2014 ◽  
Vol 29 (01) ◽  
pp. 1450236 ◽  
Author(s):  
Guangxi Cao ◽  
Yan Han
Keyword(s):  
Correlation Coefficient ◽  
Stock Markets ◽  
Cross Correlation ◽  
Sunshine Duration ◽  
Statistical Test ◽  
Nonlinear Method ◽  
Weather Variables ◽  
Chinese Stock Markets ◽  
The Cross ◽  
The Relationship

Recent studies confirm that weather affects the Chinese stock markets, based on a linear model. This paper revisits this topic using DCCA cross-correlation coefficient (ρ DCCA (n)), which is a nonlinear method, to determine if weather variables (i.e., temperature, humidity, wind and sunshine duration) affect the returns/volatilities of the Shanghai and Shenzhen stock markets. We propose an asymmetric ρ DCCA (n) by improving the traditional ρ DCCA (n) to determine if different cross-correlated properties exist when one time series trending is either positive or negative. Further, we improve a statistical test for the asymmetric ρ DCCA (n). We find that cross-correlation exists between weather variables and the stock markets on certain time scales and that the cross-correlation is asymmetric. We also analyze the cross-correlation at different intervals; that is, the relationship between weather variables and the stock markets at different intervals is not always the same as the relationship on the whole.

scholarly journals Reagent-free, Simultaneous Determination of Serum Cholesterol in HDL and LDL by Infrared Spectroscopy

2002 ◽  
Vol 48 (3) ◽  
pp. 499-506 ◽  
Author(s):  
Kan-Zhi Liu ◽  
R Anthony Shaw ◽  
Angela Man ◽  
Thomas C Dembinski ◽  
Henry H Mantsch
Keyword(s):  
Ir Spectroscopy ◽  
Ldl Cholesterol ◽  
Clinical Laboratory ◽  
Hdl Cholesterol ◽  
Serum Samples ◽  
Clinical Method ◽  
Predicted Values ◽  
Friedewald Formula ◽  
Spectral Ranges

Abstract Background: The purpose of this study was to assess the feasibility of infrared (IR) spectroscopy for the simultaneous quantification of serum LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C) concentrations. Methods: Serum samples (n = 90) were obtained. Duplicate aliquots (5 μL) of the serum specimens were dried onto IR-transparent barium fluoride substrates, and transmission IR spectra were measured for the dry films. In parallel, the HDL-C and LDL-C concentrations were determined separately for each specimen by standard methods (the Friedewald formula for LDL-C and an automated homogeneous HDL-C assay). The proposed IR method was then developed with a partial least-squares (PLS) regression analysis to quantitatively correlate IR spectral features with the clinical analytical results for 60 randomly chosen specimens. The resulting quantification methods were then validated with the remaining 30 specimens. The PLS model for LDL-C used two spectral ranges (1700–1800 and 2800–3000 cm−1) and eight PLS factors, whereas the PLS model for HDL-C used three spectral ranges (800–1500, 1700–1800, and 2800–3500 cm−1) with six factors. Results: For the 60 specimens used to train the IR-based method, the SE between IR-predicted values and the clinical laboratory assays was 0.22 mmol/L for LDL-C and 0.15 mmol/L for HDL-C (r = 0.98 for LDL-C; r = 0.91 for HDL-C). The corresponding SEs for the test spectra were 0.34 mmol/L (r = 0.96) and 0.26 mmol/L (r = 0.82) for LDL-C and HDL-C, respectively. The precision for the IR-based assays was estimated by the SD of duplicate measurements to be 0.11 mmol/L (LDL-C) and 0.09 mmol/L (HDL-C). Conclusions: IR spectroscopy has the potential to become the clinical method of choice for quick and simultaneous determinations of LDL-C and HDL-C.

scholarly journals Analytical and clinical performance of a homogeneous enzymatic LDL-cholesterol assay compared with the ultracentrifugation-dextran sulfate-Mg2+ method

1998 ◽  
Vol 44 (6) ◽  
pp. 1242-1250 ◽  
Author(s):  
Nader Rifai ◽  
Elizabeth Iannotti ◽  
Kristen DeAngelis ◽  
Terence Law
Keyword(s):  
Dextran Sulfate ◽  
Ldl Cholesterol ◽  
Clinical Performance ◽  
Total Error ◽  
Analytical Performance ◽  
Medical Decision ◽  
Serum Samples ◽  
Predictive Values ◽  
Clinical Laboratories ◽  
Wide Range

Abstract LDL-cholesterol (LDL-C) concentration is currently determined in most clinical laboratories by the Friedewald calculation. This approach has several limitations and may not meet the current total error requirement in LDL-C measurement of ≤ 12%. We evaluated the analytical and clinical performance of the direct N-geneous LDL-C assay (Equal Diagnostics). The N-geneous method correlated highly with the modified beta-quantification assay (r = 0.95; y = 0.91x + 70.6 mg/L; n = 199), showed no significant effect of increased triglyceride or other common interferants, and performed adequately in serum samples from nonfasting individuals. This assay demonstrated a mean total error of 6.75% over a wide range of LDL-C concentrations. In addition, at the medical decision cutoff points, this LDL-C assay showed positive predictive values of 78–95% and negative predictive values of 84–99%. We conclude that the N-geneous LDL-C meets the currently established analytical performance goals and appears to have a role in the diagnosis and management of hypercholesterolemic patients.

scholarly journals Analytical and Clinical Evaluation of Two Homogeneous Assays for LDL-Cholesterol in Hyperlipidemic Patients

2000 ◽  
Vol 46 (8) ◽  
pp. 1121-1131 ◽  
Author(s):  
Margarita Esteban-Salán ◽  
Amada Guimón-Bardesi ◽  
Jesús María de la Viuda-Unzueta ◽  
María Nerea Azcarate-Ania ◽  
Pilar Pascual-Usandizaga ◽  
...  
Keyword(s):  
Ldl Cholesterol ◽  
Treatment Guidelines ◽  
Clinical Performance ◽  
Total Error ◽  
Direct Methods ◽  
Lipid Lowering ◽  
Serum Samples ◽  
Wide Range ◽  
Friedewald Formula ◽  
Homogeneous Assays

Abstract Background: LDL-cholesterol (LDL-C) concentrations are the primary basis for treatment guidelines established for hyperlipidemic patients. LDL-C concentrations are commonly monitored by means of the Friedewald formula, which provides a relative estimation of LDL-C concentration when the triglyceride concentration is <2000 mg/L and there are no abnormal lipids. The Friedewald formula has several limitations and may not meet the current total error requirement of <12% in LDL-C measurements. Methods: We evaluated the analytical and clinical performance of two direct methods (Roche and Wako) by analyzing 313 fresh serum samples obtained from dyslipidemic patients in a lipid clinic and comparing them with modified β-quantification. Results: Both homogeneous assays displayed excellent precision (CV <2%). The Roche method showed a mean total error of 7.72%, and the Wako method showed a mean total error of 4.46% over a wide range of LDL-C concentrations. The Roche method correlated highly with the modified β-quantification assay (r = 0.929; y = 1.052x − 168 mg/L; n = 166) and showed a bias of −4.5% as a result of the assigned standard value. The Wako method also correlated highly with β-quantification (r = 0.966; y = 0.9125x + 104.8 mg/L; n = 145) without significant bias. The Roche method correctly classified 97% of patients with triglycerides <2000 mg/L, 75% of patients with type IIb hyperlipemia (HPL), and 84% of patients with type IV HPL based on the cutpoints of 1300 and 1600 mg/L, compared with 98%, 78.4%, and 89%, respectively, for the Wako method. In dysbetalipoproteinemic patients, both methods have a 30% mean positive bias compared with β-quantification. Conclusions: Both direct methods can be a useful alternative when ultracentrifugation is not available for the diagnosis and control of lipid-lowering medication for patients with mixed HPL, but not for patients with type III hyperlipidemia.

Statistical test for Multiple Detrended Cross-Correlation Coefficient

2021 ◽  
Vol 562 ◽  
pp. 125285 ◽  
Author(s):  
A.M. da Silva Filho ◽  
G.F. Zebende ◽  
A.P.N. de Castro ◽  
E.F. Guedes
Keyword(s):  
Correlation Coefficient ◽  
Cross Correlation ◽  
Statistical Test

scholarly journals Validation of the Modified Friedewald’s Formula to Calculate Low-density Lipoprotein Cholesterol in Bangladeshi Population

2012 ◽  
Vol 30 (3) ◽  
pp. 141-144
Author(s):  
Mimi Parvin ◽  
Muhammad Saiedullah ◽  
Aminul Haque Khan ◽  
Muhammad Rezwanur Rahman ◽  
Md Saiful Islam
Keyword(s):  
Correlation Coefficient ◽  
Ldl Cholesterol ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Serum Triglyceride ◽  
Lipoprotein Cholesterol ◽  
Low Density ◽  
Low Density Lipoprotein Cholesterol ◽  
Bangladeshi Population ◽  
Modified Formula

Objective: A modification of Friedewald’s formula was proposed to calculate LDL cholesterol in Bangladeshi population up to serum triglyceride concentration of 1000 mg/dL. The aim of this study was to validate the modification of Friedewald’s formula in Bangladeshi population.Methods: Serum total cholesterol, triglyceride, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol concentrations were measured in specimens obtained form 314 adult Bangladeshi subjects selected conveniently. LDL cholesterol concentrations were also calculated by modified Friedewald’s formula and original Friedewald’s formula. Results were expressed as mean ± SD and calculated LDL cholesterol was compared with measured LDL cholesterol by two-tailed paired t test and Pearson’s correlation coefficient (r).Results: The mean ± SD of measured LDL cholesterol was 138.3 ± 54.58 mg/dL. LDL cholesterol calculated by modified Friedewald’s formula and original Friedewald’s formula were 135.9 ± 59.26 mg/dL (P>0.05) and 123.5 ± 65.75 mg/dL (P<0.001) respectively. Compared to measured LDL cholesterol, calculated LDL cholesterol were 2.47 mg/ dL and 17.20 mg/dL lower for modified formula and original formula respectively. The correlation coefficient (r) with measured LDL cholesterol was 0.8601 (P<0.0001) for LDL cholesterol calculated by the modified Friedewald’s formula and 0.8565 (P<0.0001) for the LDL cholesterol calculated by the original Friedewald’s formula.Conclusion: The study validates the modified Friedewald’s formula to calculate LDL cholesterol in Bangladeshi    population. DOI: http://dx.doi.org/10.3329/jbcps.v30i3.12463 J Bangladesh Coll Phys Surg 2012; 30: 141-144

scholarly journals RELATIONSHIP BETWEEN SCREEN TIME AMONG CHILDREN WITH NUTRITIONAL STATUS AND THEIR DEVELOPMENT

2021 ◽  
Vol 3 (2) ◽  
pp. 69-75
Author(s):  
Siska Nawang Ayunda Maqfiro ◽  
Irmasanti Fajrin ◽  
Nurkila Suaib
Keyword(s):  
Nutritional Status ◽  
Digital Media ◽  
Correlation Coefficient ◽  
Screen Time ◽  
Positive Relationship ◽  
Statistical Test ◽  
P Value ◽  
Cross Sectional ◽  
Spearman Rank ◽  
The Relationship

Background: The growth and development of children are two events that are different in nature but are related to one another. It is possible for people in downtown areas to experience easy internet access, so that everything cannot be separated from digital media. Especially during the COVID-19 pandemic like today, where children have to stay at home more, besides that learning is also done from home, so the screen time has increased. The goals of the research is to analyze the relationship between screen time among children with nutritional status and their development.Methods: The research design used cross sectional analysis. The population is all children aged 3-5 years in Kalumpang Village in November 2020 as many as 497 children, the number of samples is 84 children using purposive sampling technique.Results: Based on the spearman-rank statistical test, it is known that p-value = 0.002 (p-value α), which with the correlation coefficient (r) = 0.330 that the relationship between Screen time with nutritional status is in the low category and has a positive relationship direction, namely the higher the screen time, the higher the nutritional status. Meanwhile, based on the spearman-rank statistical test, it is known that p-value = 0.001 (p-value α), with the correlation coefficient (r) = 0.371 that the relationship between Screen time with development is in the low category and has a positive relationship direction, namely the higher the screen time, the development will deviate from age.Conclusion: There is a relationship between screen time and nutritional status and  there is a relationship between screen time and children development. So it is very important to improve parental control behavior towards the use of electronic devices in children aged 3-5 years old.

scholarly journals KESESUAIAN KOLESTEROL LDL HASIL PERHITUNGAN SEJUMLAH FORMULA DENGAN KOLESTEROL LDL DIREK METODE ENZIMATIK

2021 ◽  
Vol 5 (2) ◽  
pp. 281
Author(s):  
Dona Liazarti ◽  
May Valzon
Keyword(s):  
Coronary Heart Disease ◽  
Heart Disease ◽  
Ldl Cholesterol ◽  
Clinical Chemistry ◽  
Inclusion Criteria ◽  
Altman Plot ◽  
Cholesterol Levels ◽  
The Mean ◽  
Friedewald Formula ◽  
Enzymatic Methods

Increased cholesterol levels are the main cause of coronary heart disease. The results of examining LDL must be precise and accurate, but direct LDL examination (LDL-Direct) is quite expensive to do in a place with limited facilities so various experiments are carried out to get LDL formula (LDL-Cal) that is appropriate than formula commonly used, Friedewald formula. The aimed of this study was to determine the correlation between LDL cholesterol from calculation a number formulas with direct LDL cholesterol in order to obtain the best formula to be applied in laboratory of Lubuk Sikaping Hospital. This research was conducted on 75 patients who did lipid profile examination in laboratory of Lubuk Sikaping Hospital, who meet the inclusion criteria. Examination of total cholesterol, HDL, LDL and triglycerides were carried out by enzymatic methods on clinical chemistry analyzer. LDL cholesterol also calculated by several formulas namely Friedelwald formula (TC- (TG/5) -HDL), Chen formula (90% nonHDLC-10% TG), Anandaraja formula (0.9 TC- (0.9 TG/5) -28), Puavilai formula (TC-HDLC-TG/6), Vujovic formula (TC-HDLC-TG/3), and Cordova formula (3/4 (TC-HDLC.) Bland & Altman plot was used to compare the calculated LDL cholesterol level of each formula with the direct LDL. The mean LDL levels were 136.41 (35.92); 116.64 (32.72); 117.03 (30.83); 121.95 (32.79); 121.83 (33.23); 96.84 (32.47); 109.97 (28.24) for Direct, Friedelwald, Chen, Anandaraja, Puavilai, Vujovic, and Cordova respectively. Based on the Bland & Altman Plot, the calculation of LDL cholesterol from the Chen formula has the best compatibility with LDL-Direk with the mean difference of 19.3867 ± 19.0489 mg / dl at triglyceride levels <400 mg / dl, so it can be applied at RSUD Lubuk Sikaping with limited facilities. Keywords: LDL Cholesterol; LDL-Direct; LDL-CalAbstrakPeningkatan kadar kolesterol merupakan penyebab utama penyakit jantung koroner. Hasil pemeriksaan kadar LDL serum harus tepat dan akurat, namun pemeriksaan kadar LDL secara langsung (LDL-Direk) cukup mahal untuk dilakukan di tempat dengan fasilitas terbatas sehingga dilakukan berbagai percobaan untuk mendapatkan formula perhitungan LDL (LDL-Cal) yang lebih tepat dibandingkan formula yang telah umum digunakan yaitu formula Friedewald. Penelitian ini bertujuan untuk mengetahui kesesuaian antara kolesterol LDL hasil perhitungan sejumlah formula dengan kolesterol LDL direk sehingga diperoleh formula perhitungan terbaik untuk dapat diterapkan di laboratorium RSUD Lubuk Sikaping. Penelitian ini dilakukan terhadap 75 orang pasien yang melakukan pemeriksaan profil lipid lengkap ke Laboratorium RSUD Lubuk Sikaping. yang memenuhi kriteria inklusi. Pemeriksaan kolesterol total, HDL, LDL dan trigliserida dilakukan dengan metode enzimatik pada alat kimia klinik otomatis. Untuk kolesterol LDL juga dihitung dengan beberapa rumus yaitu formula Friedelwald (TC-(TG/5)-HDL). formula Chen (90%nonHDLC-10%TG), formula Anandaraja (0.9 TC- (0.9 TG/5)-28), formula Puavilai (TC-HDLC-TG/6), formula Vujovic (TC-HDLC-TG/3), dan formula Cordova (3/4 (TC-HDLC). Bland & Altman plot digunakan untuk membandingkan antara kadar kolesterol LDL hasil hitung masing-masing formula dengan LDL direk. Rerata kadar LDL (mg/dl) berturut-turut adalah 136,41 (35,92); 116,64 (32,72); 117,03 (30,83); 121,95 (32,79); 121,83 (33,23); 96,84 (32,47); 109,97 (28,24) untuk LDL-Direk, Friedelwald, Chen, Anandaraja, Puavilai, Vujovic, dan Cordova. Berdasarkan Bland & Altman Plot, perhitungan kolesterol LDL Formula Chen memiliki kesesuaian paling baik dengan LDL-Direk dengan selisih rerata 19,3867 ± 19,0489 mg/dl pada kadar trigliserida < 400 mg/dl, sehingga dapat diterapkan di RSUD Lubuk Sikaping dengan fasilitas yang terbatas.

Limitations of the Friedewald formula for estimating low-density lipoprotein cholesterol in alcoholics with liver disease

1994 ◽  
Vol 40 (3) ◽  
pp. 404-406 ◽  
Author(s):  
C Matas ◽  
M Cabré ◽  
A La Ville ◽  
E Prats ◽  
J Joven ◽  
...  
Keyword(s):  
Liver Disease ◽  
Ldl Cholesterol ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Minimal Change ◽  
Contributory Factor ◽  
Similar Degree ◽  
Low Density ◽  
Friedewald Formula ◽  
Lipoprotein Composition

Abstract The accuracy of the Friedewald formula in estimating low-density lipoprotein (LDL) cholesterol was investigated in 47 alcoholic patients with liver disease (21 minimal-change, 26 cirrhotic) by comparing the results with those obtained by sequential preparative ultracentrifugation. In 14% of subjects with minimal-change disease, the error in the estimated LDL cholesterol was 50% +/- 9% (mean +/- SD; range 40-59%) and was related to the degree of attendant hypertriglyceridemia (r = 0.98; P &lt; 0.001). A similar degree of error was observed in patients with cirrhosis, despite the absence of hypertriglyceridemia; an abnormal VLDL cholesterol: triglyceride ratio was the contributory factor in the discrepancy. We conclude that, as is the case in other clinical pathologies in which abnormalities of lipoprotein composition have been described (e.g., diabetes), the Friedewald formula to estimate LDL cholesterol may be inappropriate in chronic alcoholics, particularly those in whom a degree of hepatic dysfunction may be suspected.

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