Associations between Serum Levels of Cholesterol and Survival to Age 90 in Postmenopausal Women

Cholesterol Metabolism in Aging and Age-Related Disorders

All mammalian cell membranes contain cholesterol to maintain membrane integrity. The transport of this hydrophobic lipid is mediated by lipoproteins. Cholesterol is especially enriched in the brain, particularly in synaptic and myelin membranes. Aging involves changes in sterol metabolism in peripheral organs and also in the brain. Some of those alterations have the potential to promote or to counteract the development of neurodegenerative diseases during aging. Here, we summarize the current knowledge of general principles of sterol metabolism in humans and mice, the most widely used model organism in biomedical research. We discuss changes in sterol metabolism that occur in the aged brain and highlight recent developments in cell type-specific cholesterol metabolism in the fast-growing research field of aging and age-related diseases, focusing on Alzheimer's disease. We propose that cell type-specific cholesterol handling and the interplay between cell types critically influence age-related disease processes.

Altered cardiovascular risk pattern of LDL cholesterol in older adults

PURPOSE OF REVIEW

Elevated serum low-density lipoprotein cholesterol (LDL-C) levels at middle-age constitute a strong risk factor for later cardiovascular events. In older populations, however, LDL-C levels are no longer predictive of cardiovascular mortality or may even seem protective. Whether the altered risk pattern of LDL-C in old age reflects a causal mechanism or is due to confounding and bias is subject to debate. In this review, we briefly discuss the possible explanations for the altered risk pattern of LDL-C observed in old age.

RECENT FINDINGS

Using examples from the recent literature we illustrate how LDL-C levels 'lose' their predictive value as a cardiovascular risk factor in old age. We review three potential explanations for the changed cardiovascular risk pattern of LDL-C in older populations: survivorship bias, reverse causation, and effect modification.

SUMMARY

The absent or protective effect of LDL-C on cardiovascular mortality in older populations found in observational studies might be explained by survivorship bias, reverse causation, and effect modification. However, this does not necessarily preclude the possibility that (specific) cholesterol-lowering treatment could decrease the risk of morbidity and mortality. Placebo-controlled trials may importantly add to our understanding of who may benefit from lipid-lowering therapy or statins at an older age.

Evaluation and Management of Blood Lipids Through a Woman's Life Cycle

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There are currently no sex-specific guidelines for evaluation and management of lipids.

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Lipids are impacted by normal hormonal changes in women throughout their life cycle.

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Management of lipids should incorporate sex-specific cardiovascular risk factors at each stage.

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Future objectives should focus on increasing women's presence in trials of lipid-lowering therapies.

There are currently no sex-specific guidelines for evaluation and management of blood lipids. While previous guidelines acknowledge sex-specific risk enhancing factors for lipid management in women for CVD prevention, this review focuses on how lipids are impacted during normal hormonal changes throughout a woman's life cycle- during adolescence, pre-pregnancy, pregnancy, pre- and perimenopause, menopause, and at older ages. In this review, the authors focus on management of primary prevention of CVD by examining sex-specific cardiovascular risk factors at each stage and pay special attention to statin use, statin side effects and non-statin therapies. Women need to understand their personalized cholesterol goals and ally with their clinicians to ensure successful management. Additionally, we highlight the biases that exist when treating dyslipidemia in women and the special care clinicians should take to ensure appropriate and aggressive therapies are made available to female patients. Finally, the authors recommend future research should focus on increasing enrollment of women in lipid trials. This is of paramount importance in discovering sex-specific difference in lipid management.

The association of apolipoproteins with later-life all-cause and cardiovascular mortality: a population-based study stratified by age

Midlife lipid levels are important predictors of cardiovascular diseases, yet their association with mortality in older adults is less clear. We aimed to (1) identify lipid profiles based on cholesterol, triglycerides, and apolipoproteins using cluster analysis, and (2) investigate how lipid profiles and lipid levels at different ages are associated with later-life all-cause and cardiovascular mortality. We used data from 98,270 individuals in the Swedish AMORIS cohort who had blood measurements between 1985-1996 and were followed until 2012. Over the follow-up (mean 18.0 years), 30,730 (31.3%) individuals died. Three lipid profiles were identified. Compared with reference profile, a high lipid profile (low ApoA-I and high total cholesterol (TC), triglycerides, ApoB, and ApoB/ApoA-I ratio) at ages 39-59 or 60-79 was associated with higher all-cause mortality. A high lipid profile at ≥ 80 years, however, did not confer higher mortality. For the specific markers, high TC (≥ 7.25 mmol/L) was associated with higher all-cause mortality in ages 39-59 but lower mortality in ages 60-79 and ≥ 80. Low ApoA-I (< 1.28 g/L) and high ApoB/ApoA-I ratio (≥ 1.18), on the other hand, were associated with higher cardiovascular mortality regardless of age at lipid measurement, highlighting their potential relevance for survival in both young and older individuals.

Cardiovascular health is associated with the epigenetic clock in the Berlin Aging Study II (BASE-II)

The epigenetic clock parameter DNAm age acceleration is a promising biomarker of aging. We have recently described an epigenetic clock based on only seven cytosine-phosphate-guanine sites, which is highly associated with chronological age. The aim of this study was to examine this epigenetic clock with respect to its relationship with cardiovascular health (CVH) in older adults. We used data from the Berlin Aging Study II (BASE-II; 1,671 participants; 68.8 ± 3.7 years old). CVH was operationalized using two different CVH scores, the Framingham Risk Score (FRS), and the Life's simple 7 (LS7). To adjust for potential confounding, e.g. by sex, we performed regression analyses. The LS7 score was higher, i.e. more favorable, in woman than in men (8.8 ± 2 vs. 8.2 ± 2, p < 0.001). DNAm age acceleration was associated with the FRS (β = 0.122, p = 0.028) and with the LS7 (β = -0.804, p = 0.032). In more detail, physical activity (β = -0.461, p = 0.05), HDL-cholesterol (β = 0.343, p = 0.03) and total cholesterol (β = -0.364, p = 0.002) were associated with epigenetic age acceleration. We present evidence suggesting that better CVH is associated with decelerated biological aging measured by the epigenetic clock.

An impact of lipid profile and lipid lowering drugs on ≥70 year olds of an upper socioeconomic class: a retrospective cohort study

BACKGROUND

Life expectancy has greatly increased, generating an improvement in screening programs for disease prevention, lifesaving drugs and medical devices. The impact of lowering low-density lipoprotein cholesterol (LDL-C) in the very elderly is not well-established. Our aim was to explore the association of LDL-C, high density lipoprotein cholesterol (HDL-C) and lipid lowering drugs (LLDs) on cognitive decline, malignancies and overall survival.

METHODS

This was a retrospective cohort study. Our study comprised 1498 (72.7%) males and 561 (27.3%) females, aged ≥70 who had attended the Institute for Medical Screening (IMS), Sheba Medical Center, Israel at least twice during 2013-2019. Data were obtained from the computerized database of the IMS. A manual quality control to identify potential discrepancies was performed.

RESULTS

Overall, 6.3% of the subjects treated with LLDs (95/1421) versus 4.2% not treated (28/638), cognitively declined during the study years. No statistically significant effects of LDL-C, HDL-C and LLDs on cognitive decline were observed after correcting for age, prior stroke and other vascular risk factors. With regard to cancer, after adjusting for confounders and multiple inferences, no definite relationships were found.

CONCLUSIONS

This analysis of an elderly, high socioeconomic status cohort suggests several relationships between the use of LLDs and health outcomes, some beneficial, especially, with regard to certain types of cancer, but with a higher risk of cognitive decline. Further studies are warranted to clarify the health effects of these medications in the elderly.

The new European guidelines for prevention of cardiovascular disease are misleading

Introduction: The European Society of Cardiology and European Atherosclerosis Society (ESC/EAS) have recently published three major revisions of their guidelines for the management of chronic heart disease, blood lipids, and diabetes. Areas covered: We have scrutinized these guidelines in detail and found that the authors have ignored many studies that are in conflict with their conclusions and recommendations. Expert commentary: The authors of the guidelines have ignored that LDL-cholesterol (LDL-C) of patients with acute myocardial infarction is lower than normal; that high cholesterol is not a risk factor for diabetics; that the degree of coronary artery calcification is not associated with LDL-C; and that 27 follow-up studies have shown that people with high total cholesterol or LDL-C live just as long or longer than people with low cholesterol. They have also ignored the lack of exposure-response in the statin trials; that several of these trials have been unable to lower CVD or total mortality; that no statin trial has succeeded with lowering mortality in women, elderly people, or diabetics; and that cholesterol-lowering with statins has been associated with many serious side effects.

Association between lipoprotein cholesterol and future cardiovascular disease and mortality in older adults: a Korean nationwide longitudinal study

BACKGROUND

Dyslipidemia is considered an independent health risk factor of cardiovascular disease (CVD), a leading cause of mortality in older adults. Despite its importance, there have been few reports on the association between lipoprotein cholesterol and future CVD and cardiovascular (CV) mortality among elderly Asians aged ≥ 65 years. This study investigated the association between lipoprotein cholesterol and future CVD and CV mortality in an elderly Korean population using a large nationwide sample.

METHODS

From the cohort database of the Korean National Health Insurance Service, 62,604 adults aged ≥ 65 years (32,584 men and 30,020 women) were included. High-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) levels were categorized by quartiles. Cox proportional hazard models and linear regression analyses were used to assess the association between the quartiles of lipoprotein cholesterol and future CV events or mortality.

RESULTS

The mean follow-up period was 3.3 years. The incidence rates of ischemic heart disease and ischemic brain disease were 0.97 and 0.61 per 1,000 person-years, respectively, and the mortality rates from these diseases were 0.22 and 0.34 per 1,000 person-years, respectively. In a completely adjusted model, high HDL-C and LDL-C levels were not associated with total CV events and CVD mortality. However, high LDL-C levels were significantly associated with a lower incidence of ischemic brain disease. Furthermore, diabetic patients with high LDL-C levels were more likely to have higher CV mortality, whereas non-smokers with high LDL-C levels were less likely to be at risk of CV events.

CONCLUSIONS

Neither high LDL-C nor HDL-C levels were significantly associated with future CV mortality in older adults aged ≥ 65 years. High LDL-C levels do not seem to be a risk factor for CVD in elderly individuals, and further studies are required.

Genetics of Hypercholesterolemia: Comparison Between Familial Hypercholesterolemia and Hypercholesterolemia Nonrelated to LDL Receptor

Severe hypercholesterolemia (HC) is defined as an elevation of total cholesterol (TC) due to the increase in LDL cholesterol (LDL-C) >95th percentile or 190 mg/dl. The high values of LDL-C, especially when it is maintained over time, is considered a risk factor for the development of atherosclerotic cardiovascular disease (ASCVD), mostly expressed as ischemic heart disease (IHD). One of the best characterized forms of severe HC, familial hypercholesterolemia (FH), is caused by the presence of a major variant in one gene (LDLR, APOB, PCSK9, or ApoE), with an autosomal codominant pattern of inheritance, causing an extreme elevation of LDL-C and early IHD. Nevertheless, an important proportion of serious HC cases, denominated polygenic hypercholesterolemia (PH), may be attributed to the small additive effect of a number of single nucleotide variants (SNVs), located along the whole genome. The diagnosis, prevalence, and cardiovascular risk associated with PH has not been fully established at the moment. Cascade screening to detect a specific genetic defect is advised in all first- and second-degree relatives of subjects with FH. Conversely, in the rest of cases of HC, it is only advised to screen high values of LDL-C in first-degree relatives since there is not a consensus for the genetic diagnosis of PH. FH is associated with the highest cardiovascular risk, followed by PH and other forms of HC. Early detection and initiation of high-intensity lipid-lowering treatment is proposed in all subjects with severe HC for the primary prevention of ASCVD, with an objective of LDL-C <100 mg/dl or a decrease of at least 50%. A more aggressive reduction in LDL-C is necessary in HC subjects who associate personal history of ASCVD or other cardiovascular risk factors.