Contribution of remnant cholesterol to cardiovascular risk.

BACKGROUND: Remnant cholesterol in triglyceride-rich lipoproteins is associated observationally and genetic, causally with increased risk of atherosclerotic cardiovascular disease in healthy individuals. OBJECTIVES: We tested the hypothesis that an unmet medical need exists in individuals with high nonfasting remnant cholesterol and prior atherosclerotic cardiovascular disease. METHODS: From amongst 109 574 individuals in a prospective cohort study of the Danish general population, we included 2973 individuals aged 20-80 with baseline diagnoses of myocardial infarction/ischaemic stroke ascertained from national Danish health registries. RESULTS: The recurrent major cardiovascular event (MACE) incidence rates per 1000 person-years were 39 (95% confidence interval: 30-50) for individuals with remnant cholesterol levels ≥ 1.5 mmol L-1 (≥58 mg dL-1 ), 31 (26-37) for 1-1.49 mmol L-1 (39-57 mg dL-1 ), 27 (24-31) for 0.5-0.99 mmol L-1 (19-38 mg dL-1 ) and 23 (19-27) for individuals with remnant cholesterol < 0.5 mmol L-1 (<19 mg dL-1 ). Compared to individuals with remnant cholesterol < 0.5 mmol L-1 (<19 mg dL-1 ), the subhazard ratio for recurrent MACE was 1.23 (95% CI: 0.98-1.55) for individuals with remnant cholesterol levels of 0.5-0.99 mmol L-1 (19-38 mg dL-1 ), 1.48 (1.14-1.92) for 1-1.49 mmol L-1 (39-57 mg dL-1 ) and 1.79 (1.28-2.49) for ≥ 1.5 mmol L-1 (≥58 mg dL-1 ). The recurrent MACE incidence rates per 1000 person-years for individuals with remnant cholesterol levels < 0.5 mmol L-1 (<19 mg dL-1 ) and ≥ 1.5 mmol L-1 (≥58 mg dL-1 ) were 10 (6.6-15) and 31 (21-47) for those below age 65 and correspondingly 25 (21-30) and 43 (32-59) for those with LDL cholesterol levels < 3 mmol L-1 (<116 mg dL-1 ), respectively. For a 20% recurrent MACE risk reduction in secondary prevention, an estimated remnant cholesterol lowering of 0.83 mmol L-1 (32 mg dL-1 ) would be needed. CONCLUSIONS: In individuals with a diagnosis of myocardial infarction/ischaemic stroke, a lower remnant cholesterol of 0.8 mmol L-1 (32 mg dL-1 ) was estimated to reduce recurrent MACE by 20% in secondary prevention. Our data indicate an unmet medical need for secondary prevention in individuals with high nonfasting remnant cholesterol levels.

Chylomicronemia risk factors ranked by importance for the individual and community in 108 711 women and men.

BACKGROUND: Hypertriglyceridemia prevalence is increasing as more individuals become obese, and chylomicronemia risk factors for the individual and community have not been described previously. OBJECTIVE: To describe chylomicronemia risk factors in the general population for individuals and community. METHODS: A total of 108 711 individuals from the Copenhagen General Population Study were grouped as unlikely chylomicronemia (nonfasting triglycerides <2 mmol L-1 (177 mg dL-1 )), possible chylomicronemia (2-4.99 mmol L-1 (177-442 mg dL-1 )), probable chylomicronemia (5-9.99 mmol L-1 (443-885 mg dL-1 )) and definite chylomicronemia (≥10 mmol L-1 (≥ 886 mg dL-1 )). Relative risk (RR) from Poisson regression ranked dichotomized chylomicronemia risk factors for individuals, and population attributable fractions (PAF) for the community: type 2 diabetes, alcohol intake, obesity, fat intake, hypothyroidism, kidney function, education, sedentary lifestyle, menopause and hormone replacement (women). RESULTS: For women and men, chylomicronemia was unlikely in 81% and 64%, possible in 18% and 33%, probable in 1% and 3% and definite in 0.03% and 0.14%, respectively. For the individual, the three top-ranked risk factors for probable/definite versus unlikely chylomicronemia in women were type 2 diabetes (RR: 4.21; 95% confidence interval: 3.30-5.36), menopause (RR: 3.74; 2.62-5.36) and obesity (RR: 3.44; 2.81-4.21). Corresponding top-ranked risk factors in men were obesity (RR: 3.86; 3.46-4.30), type 2 diabetes (RR: 1.88; 1.61-2.19) and reduced kidney function (RR: 1.86; 1.48-2.34). For the community, top-ranked risk factors in women were menopause (PAF: 63%), obesity (PAF: 29%) and type 2 diabetes (PAF: 15%). Corresponding top-ranked risk factors in men were obesity (PAF: 29%), type 2 diabetes (PAF: 6.4%) and sedentary lifestyle (PAF: 6.0%). CONCLUSIONS: Obesity and type 2 diabetes were the most important modifiable chylomicronemia risk factors in women and men, both for the individual and community. This could influence chylomicronemia prevention and help design randomized trials aimed at reducing triglycerides.

Nonfasting cholesterol and triglycerides and association with risk of myocardial infarction and total mortality: the Copenhagen City Heart Study with 31 years of follow-up.

OBJECTIVES: We compared the ability of very high levels of nonfasting cholesterol and triglycerides to predict risk of myocardial infarction and total mortality. DESIGN: Prospective study from 1976 to 1978 until 2007. SETTING: Danish general population. PARTICIPANTS: Randomly selected population of 7581 women and 6391 men, of whom 768 and 1151 developed myocardial infarction and 4398 and 4416 died, respectively. Participation rate was 72%, and follow-up was 100% complete. Less than 2% of participants were taking lipid-lowering therapy. RESULTS: Compared to women with cholesterol <5 mmol L(-1) , multivariate-adjusted hazard ratios for myocardial infarction ranged from 1.3 [95% confidence interval (CI): 0.9-1.8] for a cholesterol level of 5.0-5.99 mmol L(-1) to 2.5 (95%CI: 1.6-4.0) for cholesterol ≥ 9 mmol L(-1) (trend: P < 0.0001). Compared with women with nonfasting triglycerides <1 mmol L(-1) , hazard ratios for myocardial infarction ranged from 1.5 (95%CI: 1.2-1.8) for triglycerides of 1.0-1.99 mmol L(-1) to 4.2 (95%CI: 2.5-7.2) for triglycerides ≥ 5 mmol L(-1) (p<0.0001). In men, corresponding hazard ratios ranged from 1.2 (95%CI: 1.0-1.5) to 5.3 (95%CI: 3.6-8.0) for cholesterol (P < 0.0001) and from 1.3 (95%CI: 1.0-1.6) to 2.1 (95%CI: 1.5-2.8) for triglycerides (P < 0.0001). Increasing cholesterol levels were not consistently associated with total mortality in women (trend: P = 0.39) or men (P = 0.02). By contrast, compared with women with triglycerides <1 mmol L(-1) , multivariate-adjusted hazard ratios for total mortality ranged from 1.1 (95%CI: 1.0-1.2) for triglycerides of 1.0-1.99 mmol L(-1) to 2.0 (95%CI: 1.5-2.9) for triglycerides ≥5 mmol L(-1) (trend: P < 0.0001); corresponding hazard ratios in men ranged from 1.1 (95%CI: 1.0-1.2) to 1.5 (95%CI: 1.2-1.7) (P < 0.0001). CONCLUSIONS: Stepwise increasing levels of nonfasting cholesterol and nonfasting triglycerides were similarly associated with stepwise increasing risk of myocardial infarction, with nonfasting triglycerides being the best predictor in women and nonfasting cholesterol the best predictor in men. Even more surprisingly, only increasing levels of nonfasting triglycerides were associated with total mortality, whereas increasing cholesterol levels were not.

Nonfasting hyperlipidemia and cardiovascular disease.

Most humans are in the nonfasting or postprandial state in the majority of a 24 hour cycle; however, lipids, lipoproteins, and apolipoproteins are usually measured in the fasting state. Recent studies demonstrate that these values at most change minimally in response to normal food intake, changes that are clinically unimportant. Also, elevated levels of nonfasting triglycerides as a marker of elevated remnant lipoprotein cholesterol associate strongly with increased risk of myocardial infarction, ischemic stroke, and early death. The mechanism behind these findings likely involves entrance of remnant lipoproteins into the arterial intima with subsequent retention leading to atherogenesis, while low HDL cholesterol levels may be an innocent bystander. Finally, nonfasting levels of total cholesterol, non-HDL cholesterol, LDL cholesterol, apolipoprotein B, triglycerides, HDL cholesterol, apolipoprotein A1, total cholesterol/HDL cholesterol, and apolipoprotein B/apolipoprotein A1 all associate with increased risk of cardiovascular disease. These new data open the possibility that nonfasting rather than fasting lipid profiles can be used for cardiovascular risk prediction. If implemented, this would simplify blood sampling for lipid measurements for millions of patients worldwide. Furthermore, the results also highlight the need for randomized double-blind trials of new and established drugs to reduce nonfasting triglycerides and remnant lipoprotein cholesterol, with the ultimate aim of reducing risk of cardiovascular disease and early death.