[The validity of the separate determination of total cholesterol in the primary prevention of coronary risk].
BACKGROUND
The aim of this study was to validate total cholesterol (TC) determination in the primary prevention of coronary risk and evaluate the prevalence of low HDL cholesterol (HDL-C) levels at the different TC cut-off points to thereby determine the TC level at which HDL-C determination is of interest.


METHODS
The atherogenic index was used as the reference method in TC evaluation with the values of low HDL-C levels being evaluated at the following TC cut-off points: 160, 180, 200, 220, 240, 250, and 300 mg/dl (4.44; 4.66; 5.18; 5.70; 6.22; 6.48; 7.77 mmol/l). According to the results of the Framingham study the atherogenic index or the existence of low HDL-C levels were considered as abnormal. The sample included 4,162 workers from the province of Alicante (Spain) selected by consecutive sampling and opportunistic search in January and February, 1993. Validity was calculated with confidence interval of 95%.


RESULTS
The atherogenic index was high in 43.7% of the sample, ranging from 6% in the population with TC lower than 160 mg/dl (4.14 mmol/l) to 76.4% in those oscillating between 250-299 mg/dl (6.48-7.76 mmol/l). Low HDL-C levels were detected in 20.1% with a prevalence ranging from 38.8% in those with a TC of less than 160 mg/dl (4.14 mmol/l) to 11.9% in those with TC > or = 250 mg/dl (> or = 6.48 mmol/l). The cut-off points for low TC had high sensitivity (S) and low specificity (SP) (160 mg/dl [4.14 mmol/l]: S = 91.1%, SP = 11.5%; 180 mg/dl [4.66 mmol/l]: S = 95.2%, SP = 30.2%). The highest TC points presented very low S and very high SP (250 mg/dl [6.48 mmol/l]: S = 46.3%, SP = 87.7%; 300 mg/dl [6.48 mmol/l]: S = 7.4%, SP = 97%).


CONCLUSIONS
The HDL-cholesterol should be determined in people with a total cholesterol of less than 200 mg/dl (5.18 mmol/l) since, in this group there is an important percentage of individuals with an altered atherogenic index and low HDL-C levels.
Gil
V F
VF
Departamento de Medicina, Universidad de Alicante e Ibermutua.
Rubio
C
C
Belda
J
J
Pascual
R
R
Pérez Barba
C
C
Merino
J
J
D000328:Adult; D002784:Cholesterol / Q000097:blood*; D016001:Confidence Intervals; D003327:Coronary Disease / Q000097:blood / Q000453:epidemiology / Q000517:prevention & control*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011322:Primary Prevention; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013030:Spain / Q000453:epidemiology
D002784:Cholesterol
Validez de la determinación aislada del colesterol total en la prevención primaria del riesgo coronario.