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Metabolic interactions in ischemic heart disease. The Que´bec Cardiovascular Study
Monaity 10 October 1994: Poster Abstracts Epidemiology
14
This survey clearly demonstrates that fasting insulin is associated in the elderly with the same clinical conditions as previously observed in younger subjects, but even more strongly. Trans fatty acids in plasma phospholipids and coro@I nary heart disease .. liver LpL, Poppel G van, Houwelingen ACv, Horn&a G, Kmyssen HACM, Dept. of Epidemiology, TN0 Nutrition and Food Research, P Box 360, 3700 AJ Zeist, The Netherlands
A high intake of trans fatty acids increases semm cholesterol levels and may increase risk of CHD. We measured the trans fatty acid concentration of plasma phospholipids in CHD patients, comparing a group (n = 83) with angiographically documented severe CHD (>80% stenosis in one coronary vessel) and a control group (n = 78) with only minor stenosis on coronary angiography (~50% stenosis in all three major vessels). All subjects were under 68. The two groups were similar as to body mass index, blood pressure, number of cigarettes smoked and total fatty acid intake. Controls had significantly higher HDL levels (P
A high intake of /?-carotene has been associated with a decreased risk for cardiovascular disease. To evaluate whether B-carotene may exert a protective effect through an impact on lipoprotein metabolism we conducted a randomized, double-blind trial in healthy male cigarette smokers. Total cholesterol. HDL. aoo A-I. aoo B-100 and liooorotein(a) were measured before and after 14 weeks of treat&&t with Fcarotene (20 mg/day; n = 25) or placebo (n = 25). The /J-carotene group and placebo groups were similar with respect to all initial characteristics, but initial apo B-100 was somewhat higher in the /?-carotene group (1.23 vs 1.44 g/l). During the intervention plasma concentrations of fi-carotene increased 15fold in the treatment group. Mean levels of total and HDL-cholesterol, lipoprotein(a), apo A-I and apo B-100 did not show significant changes in either group after the trial, and the changes during the trial were similar in both groups We conclude that a 20 mg/day /I-carotene supplement does not influence plasma lipoprotein levels in healthy male smokers. 1 vMW,
Influence of Apo E phenotype on concentration of apo B-containing particles: the LDL increase associated with e4 is confined to dense LDL Plan K, St?Ulle S, Keul J, Berg A, Center of
It is known that the e4 allele is associated with higher levels of LDL, while for the e2 allele the opposite is true. As there is strong evidence that individual LDL subspecies are metabolized differently, this study addressed the question whether the concentration of apo B-containing particles of different density is affected specifically by the apo E phenotype. VLDL, IDL and subfractions of LDL from 600 persons were prepared by standard preparative ultracentrifugation. Apo E phenotype was determined by means of isoelectric focusing in immobilized polyacrylamide gels either from VLDL or from semm with subsequent immunoblotting. The results confiimed that the presence of the e2 allele results in higher concentrations of VLDL and lower concentrations of LDL. IDL concentrations were unchanged. The concentration of all six LDL subfractions was significantly lower if the e2 allele was present, although the effect was most pronounced for LDL-2 to LDLJ (d = 1.0311.044 g/ml). The e4 allele increased only the concentration of dense LDL particles LDL4 to LDL-6 (d > 1.037 g/ml). VLDL, IDL, and large LDL (d < 1.037 g/ml) concentrations were unchanged. These findings might be explained by observations showing that dense LDL have a reduced affinity to cellular LDL receptors. As dense LDL contain only traces of apo E, which binds with high affinity to the LDL receptor, it might specifically be influenced by a down-regulation of LDL receptors occurring if the e4 allele is present. Regardless of the exact mechanism, these data further support the concept of metabolically distinct LDL subfractions. Metabolic interactions in ischemic heart disease. The 1441 Quebec Cardiovascular Study m, Despms JP, Moorjani S, Cantin B, Dagenais G, Lupien PJ, Lipid Res. Ctr.. CHUL Res. Ctr. and Dept. of Med., Univ. of Montreal, 2705 Laurier Blvd, Ste-Foy, Canada, GlV 4G2
The interactions among plasma cholesterol (C), triglyceride (TG), LDL-C, HDL-C and apoprotein (apo) B and A-I concentrations were examined in a cohort of 2290 men (mean age 57 years) from the Qu&ec City suburban area. The correlation between plasma HDL-C and apo A-I levels was highly significant (r = 0.64, P < 0.0001) but of lower magnitude than the correlation between plasma LDL-C and apo B levels (r = 0.76, P < 0.0001). The relationship of plasma TG with apo A-I levels (r = -0.10, P < 0.0001) was much weaker than with HDL-C (r=-O.49, P< O.OOOl), suggesting that apo A-I measurements may not always provide adequate information on HDL composition in subjects with elevated TG levels. The relationship between plasma TG and HDL-C levels was not linear since most of the decrease in plasma HDL-C levels occurred with TG concentrations below 2.2 mmol/I. As ischemic heart disease (IHD) patients represented 10% of the cohort studied, we have investigated the joint contribution of plasma TG and HDL-C levels as correlates of II-ID. 31% of men without IHD had hypoalphalipoproteinemia (HDL-C < 0.9 mmol/ 1) compared to 50% in the IHD group. Whereas the prevalence of isolated hypertriglyceridemia (TG > 2.3 mmolA) was similar in IHD patients (7%) vs controls (9%), the prevalence of the low HDL-C:high TG phenotype was greater in IHD patients (19%) than in healthier subjects (13%). Prevalence of diabetes (8%), hypertension (20%) and obesity (60%) were also higher in subjects with the low HDL-C:high TG phenotype than in men with normal HDL-C and TG levels (5%, 155, 30% respectively, P < 0.05). These results suggest that the low HDL-C:high TG condition is a prevalent dyslipidemic state in IHD which is frequently associated with additional risk factors.
Internal Medicine, D-79106 Freiburg, Germany Atherosclerosis X, Montreal, October 1994
14
This survey clearly demonstrates that fasting insulin is associated in the elderly with the same clinical conditions as previously observed in younger subjects, but even more strongly. Trans fatty acids in plasma phospholipids and coro@I nary heart disease .. liver LpL, Poppel G van, Houwelingen ACv, Horn&a G, Kmyssen HACM, Dept. of Epidemiology, TN0 Nutrition and Food Research, P Box 360, 3700 AJ Zeist, The Netherlands
A high intake of trans fatty acids increases semm cholesterol levels and may increase risk of CHD. We measured the trans fatty acid concentration of plasma phospholipids in CHD patients, comparing a group (n = 83) with angiographically documented severe CHD (>80% stenosis in one coronary vessel) and a control group (n = 78) with only minor stenosis on coronary angiography (~50% stenosis in all three major vessels). All subjects were under 68. The two groups were similar as to body mass index, blood pressure, number of cigarettes smoked and total fatty acid intake. Controls had significantly higher HDL levels (P
A high intake of /?-carotene has been associated with a decreased risk for cardiovascular disease. To evaluate whether B-carotene may exert a protective effect through an impact on lipoprotein metabolism we conducted a randomized, double-blind trial in healthy male cigarette smokers. Total cholesterol. HDL. aoo A-I. aoo B-100 and liooorotein(a) were measured before and after 14 weeks of treat&&t with Fcarotene (20 mg/day; n = 25) or placebo (n = 25). The /J-carotene group and placebo groups were similar with respect to all initial characteristics, but initial apo B-100 was somewhat higher in the /?-carotene group (1.23 vs 1.44 g/l). During the intervention plasma concentrations of fi-carotene increased 15fold in the treatment group. Mean levels of total and HDL-cholesterol, lipoprotein(a), apo A-I and apo B-100 did not show significant changes in either group after the trial, and the changes during the trial were similar in both groups We conclude that a 20 mg/day /I-carotene supplement does not influence plasma lipoprotein levels in healthy male smokers. 1 vMW,
Influence of Apo E phenotype on concentration of apo B-containing particles: the LDL increase associated with e4 is confined to dense LDL Plan K, St?Ulle S, Keul J, Berg A, Center of
It is known that the e4 allele is associated with higher levels of LDL, while for the e2 allele the opposite is true. As there is strong evidence that individual LDL subspecies are metabolized differently, this study addressed the question whether the concentration of apo B-containing particles of different density is affected specifically by the apo E phenotype. VLDL, IDL and subfractions of LDL from 600 persons were prepared by standard preparative ultracentrifugation. Apo E phenotype was determined by means of isoelectric focusing in immobilized polyacrylamide gels either from VLDL or from semm with subsequent immunoblotting. The results confiimed that the presence of the e2 allele results in higher concentrations of VLDL and lower concentrations of LDL. IDL concentrations were unchanged. The concentration of all six LDL subfractions was significantly lower if the e2 allele was present, although the effect was most pronounced for LDL-2 to LDLJ (d = 1.0311.044 g/ml). The e4 allele increased only the concentration of dense LDL particles LDL4 to LDL-6 (d > 1.037 g/ml). VLDL, IDL, and large LDL (d < 1.037 g/ml) concentrations were unchanged. These findings might be explained by observations showing that dense LDL have a reduced affinity to cellular LDL receptors. As dense LDL contain only traces of apo E, which binds with high affinity to the LDL receptor, it might specifically be influenced by a down-regulation of LDL receptors occurring if the e4 allele is present. Regardless of the exact mechanism, these data further support the concept of metabolically distinct LDL subfractions. Metabolic interactions in ischemic heart disease. The 1441 Quebec Cardiovascular Study m, Despms JP, Moorjani S, Cantin B, Dagenais G, Lupien PJ, Lipid Res. Ctr.. CHUL Res. Ctr. and Dept. of Med., Univ. of Montreal, 2705 Laurier Blvd, Ste-Foy, Canada, GlV 4G2
The interactions among plasma cholesterol (C), triglyceride (TG), LDL-C, HDL-C and apoprotein (apo) B and A-I concentrations were examined in a cohort of 2290 men (mean age 57 years) from the Qu&ec City suburban area. The correlation between plasma HDL-C and apo A-I levels was highly significant (r = 0.64, P < 0.0001) but of lower magnitude than the correlation between plasma LDL-C and apo B levels (r = 0.76, P < 0.0001). The relationship of plasma TG with apo A-I levels (r = -0.10, P < 0.0001) was much weaker than with HDL-C (r=-O.49, P< O.OOOl), suggesting that apo A-I measurements may not always provide adequate information on HDL composition in subjects with elevated TG levels. The relationship between plasma TG and HDL-C levels was not linear since most of the decrease in plasma HDL-C levels occurred with TG concentrations below 2.2 mmol/I. As ischemic heart disease (IHD) patients represented 10% of the cohort studied, we have investigated the joint contribution of plasma TG and HDL-C levels as correlates of II-ID. 31% of men without IHD had hypoalphalipoproteinemia (HDL-C < 0.9 mmol/ 1) compared to 50% in the IHD group. Whereas the prevalence of isolated hypertriglyceridemia (TG > 2.3 mmolA) was similar in IHD patients (7%) vs controls (9%), the prevalence of the low HDL-C:high TG phenotype was greater in IHD patients (19%) than in healthier subjects (13%). Prevalence of diabetes (8%), hypertension (20%) and obesity (60%) were also higher in subjects with the low HDL-C:high TG phenotype than in men with normal HDL-C and TG levels (5%, 155, 30% respectively, P < 0.05). These results suggest that the low HDL-C:high TG condition is a prevalent dyslipidemic state in IHD which is frequently associated with additional risk factors.
Internal Medicine, D-79106 Freiburg, Germany Atherosclerosis X, Montreal, October 1994