HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Clearfield, M. Articles by McConathy, W. Search for Related Content PubMed PubMed Citation Articles by Clearfield, M. Articles by McConathy, W.

In the enrollment phase of the Air Force/Texas Coronary Atherosclerosis Prevention Study (AFCAPS/TexCAPS), a number of heart disease-free potential subjects did not qualify to participate in the study because their low-density lipoprotein cholesterol (LDL-C) levels fluctuated. This report looks at the incidence of lability of LDL-C levels and premature coronary heart disease (CHD) in the nuclear family based on data collected on a group excluded primarily based on lipid levels during the enrollment phase at the TexCAPS site. Lipid inclusion criteria were total cholesterol (TC), 180 mg/dL to 264 mg/dL; low-density lipoprotein cholesterol (LDL-C), 130 mg/dL to 190 mg/dL; high-density lipoprotein cholesterol (HDL-C), less than or equal to 45 mg/dL for men and less than or equal to 47 mg/dL for women; and triglyceride (TG) concentrations, less than or equal to 400 mg/dL. After participants had been on the American Heart Association (AHA) step 1 diet for 8 to 10 weeks, lipid parameters were again tested in a total of 4257 individuals. Both lipid screening measurements at 8 and 10 weeks were required to be within 15% of each other for inclusion in subsequent study. A total of 2868 individuals met the study criteria and were randomly assigned to groups; 1389 failed to qualify for a variety of reasons. Of these, 1070 (25.1% of those who initially qualified based on lipid levels) were excluded because of unacceptable lipid levels on the evaluations repeated at 8 and 10 weeks. This excluded subpopulation (n = 1070) was stratified into three groups based on changes of LDL-C between 8 and 10 weeks on the AHA step 1 diet. One group had a less than 15% fluctuation in LDL-C (LN group, n = 637, 15.0% of cohort, n = 4257). Of those with LDL-C variability, 177 had a greater than 15% increase in LDL-C (LI group, n = 177, 4.2% of cohort); and 256 had a greater than 15% decrease in LDL-C (LD, n = 256, 6.0% of cohort). At week 8, TC and LDL-C levels were lower and the HDL-C level was higher in the LN group compared with both groups having labile lipid levels (LI and LD groups). Changes by gender showed similar trends; however, HDL-C was 5 mg/dL lower at 8 weeks in both groups of women with labile LDL-C levels (groups LI and LD) when compared with the women in the LN group (P < .01). The frequency of TG concentrations greater than 150 mg/dL was greater in men having labile LDL-C level when compared with the control group. The trend was similar for women. In assessing the incidence of CHD in the nuclear family, parents of probands with labile LDL-C levels (LI and LD groups) had a higher frequency (P = .0044) of premature CHD than parents of probands with stable LDL-C (LN). The following conclusions can be drawn: (1) within the general population, there is a substantial number (10%, 433 of 4257) of individuals with labile LDL-C levels; (2) labile LDL-C levels in the probands were found to be associated with an increased familial frequency of premature CHD in their parents. Definition of the molecular basis for this lability of LDL-C could reveal new opportunities to regulate plasma cholesterol levels and thus have an impact on CHD-associated morbidity and mortality in a substantial portion of the general population.