The status of fasting triglycerides as a risk factor for coronary artery disease (CAD) has been considered weak because in multivariate analyses, triglycerides tend to be eliminated by high density lipoprotein (HDL) cholesterol. To further evaluate the role of triglycerides in CAD, we employed postprandial lipemia as a more informative means of characterizing triglyceride metabolism. In 61 male subjects with severe CAD and 40 control subjects without CAD as verified by angiography, we measured cholesterol; triglycerides; HDL cholesterol; HDL 2 cholesterol; and apolipoproteins A-I, A-II, and B in fasting plasma and triglycerides before and 2, 4, 6, and 8 hours after a standardized test meal. Both the maximal triglyceride increase and the magnitude of postprandial lipemia (area under the triglyceride curve over 8 hours after the meal) were higher in cases than in control subjects. Single postprandial triglyceride levels 6 and 8 hours after the meal were highly discriminatory (p<0.001), and by logistic-regression analysis displayed an accuracy of 68% in predicting the presence or absence of CAD. In this respect, accuracy was higher than that of HDL 2 cholesterol (64%) and equal to that of apolipoprotein B (68%), the most discriminatory fasting parameter. Multivariate logistic-regression analysis was performed to reduce the number of risk factors to those that were statistically independent. This statistical procedure selected postprandial but not fasting triglycerides into the most accurate multivariate model, which also contained the accepted risk factors HDL 2 cholesterol, apolipoprotein B, and age. This model classified 82% of subjects correctly. We conclude that triglycerides are independent predictors of CAD in multivariate analyses including HDL cholesterol, provided that a challenge test of triglyceride metabolism such as postprandial lipemia is used. The study suggests that the metabolism of triglycerides is a critical determinant of cholesterol metabolic routing. The findings support the concept that the negative association between HDL cholesterol levels and CAD actually originates in part from a positive relation between CAD and plasma triglycerides, as ascertained in the postprandial state. (

To determine the characteristics of transition zone and peripheral zone prostate cancer, we examined a series of 42 stage A and 54 stage B radical prostatectomy specimens with particular attention to the number of separate foci of cancer, zone of origin, volume and grade of each focus, and presence of severe intraductal dysplasia (high grade prostatic intraepithelial neoplasia), extra-capsular extension and seminal vesicle invasion associated with cancer in each zone. We found that there were fundamental differences between transition zone and peripheral zone cancers, and that the features that characterize these tumors were apparent in stages A and B disease. Although the total tumor burden was similar in stages A (3.98 cc) and B (4.56 cc) disease, stage A cancer tended to be multifocal (3.1 tumors per prostate) and more diffuse. While 81% of stage A prostate specimens contained a tumor of transition zone origin and 93% had cancer of peripheral zone origin, transurethral resection of the prostate sampled a transition zone cancer in 77% and a peripheral zone cancer in 31% (8% had both types). Stage B cancer tended to be more focal (2.3 cancers per prostate). All stage B prostate specimens contained a peripheral zone cancer and 43% had a transition zone cancer as well. In only 1 stage B cancer patient was the transition zone tumor the palpable or index cancer. In stages A and B disease, peripheral zone tumors were less well differentiated (median Gleason sum 6 and 7) than transition zone tumors (5 and 5, respectively) and more likely to extend through the capsule (44% versus 11%). Seminal vesicle invasion arose from 19% of the peripheral zone but none of the transition zone cancers. Peripheral zone tumors were almost always (93%) associated with high grade prostatic intraepithelial neoplasia, while none of the transition zone cancers was so associated. For peripheral zone disease there was a moderate correlation between volume and grade (tau = 0.46, p less than 0.001) so that the larger the tumor the higher the Gleason sum but within transition zone disease this correlation was poor (tau = 0.23) and not statistically significant (p greater than 0.05). Extracapsular extension occurred at a smaller volume with peripheral zone cancer (mean 3.86, minimum 0.06 cc) than transition zone cancer (mean 4.98, minimum 0.39 cc). Cancer that arises in the transition zone appears to have a different histogenesis, is associated with more favorable pathological features and may have less malignant potential than tumors that arise in the peripheral zone.

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