Tag: HDL cholesterol

Categories : Metabolic Disorders Neurodegenerative DiseasesTags :

Abnormally High Levels of HDL-C Linked to Dementia in Older Adults

On By ModernMedia
Photo by Matteo Vistocco on Unsplash

Abnormally high levels of high density lipoprotein cholesterol (HDL-C), are associated with an increased risk of dementia in older adults, according to study led by Monash University. Researchers said very high levels of the ‘good cholesterol’ HDL-C linked to dementia risk in this study were uncommon and not diet related, but more likely to reflect a metabolic disorder. The findings may help doctors to recognise a group of older patients potentially at risk of dementia, particularly in those aged 75 and older.

Published in The Lancet Regional Health – Western Pacific, this is one of the largest studies of elevated HDL-C levels and dementia in initially healthy older people aged mostly over 70, enrolled in the ASPREE* study.

Over an average 6.3 years, participants with very high HDL-C (> 80mg/dL or > 2.07mmol/L) at study entry were observed to have a 27% higher risk of dementia compared to participants with optimal HDL-C levels, while those aged 75 years and older also showed a 42% increased risk compared to those with optimal levels.

Very high HDL-C levels were categorised as 80mg/dL (> 2.07mmol/L) or above.

The optimal level of HDL-C of 40 to 60mg/dL (1.03–1.55mmol/L) for men and 50 to 60mg/dL (1.55–2.07mmol/L) for women was generally beneficial for heart health.

Among 18 668 participants included in this analysis, 2709 had very high HDL-C at study entry, with 38 incidents of dementia in those aged less than 75 years with very high levels, and 101 in those aged 75 and more with very high levels.

First author and Monash University School of Public Health and Preventive Medicine senior research fellow Dr Monira Hussain said that further research was needed to explain why a very high HDL cholesterol level appeared to affect the risk of dementia.

Dr Hussain said these study findings could help improve our understanding of the mechanisms behind dementia, but more research was required.

“While we know HDL cholesterol is important for cardiovascular health, this study suggests that we need further research to understand the role of very high HDL cholesterol in the context of brain health,” she said.

“It may be beneficial to consider very high HDL cholesterol levels in prediction algorithms for dementia risk.”

*The Aspirin in Reducing Events in the Elderly (ASPREE) trial is a double-blind, randomised, placebo-controlled trial of daily aspirin in healthy older people. 

Source: Monash University

Categories : Cardiovascular DiseaseTags :

‘Good Cholesterol’ may not be Such a Good Cardiovascular Risk Indicator

On By ModernMedia
Source: Wikimedia CC0

A study published in the Journal of the American College of Cardiology found that high-density lipoprotein (HDL) cholesterol, often called ‘good cholesterol’, may not be as effective as scientists once believed in uniformly predicting cardiovascular disease risk among adults of different racial and ethnic backgrounds.

The research found that while low levels of HDL cholesterol predicted an increased risk of heart attacks or related deaths for White adults – a long-accepted association – the same was not true for Black adults. Additionally, higher HDL cholesterol levels were not associated with reduced cardiovascular disease risk for either group.

“The goal was to understand this long-established link that labels HDL as the beneficial cholesterol, and if that’s true for all ethnicities,” said senior author Nathalie Pamir, PhD, an associate professor at Oregon Health & Science University, Portland. “It’s been well accepted that low HDL cholesterol levels are detrimental, regardless of race. Our research tested those assumptions.”

Pamir and colleagues reviewed data from 23 901 participants from the Reasons for Geographic and Racial Differences in Stroke Study (REGARDS). Previous studies that shaped perceptions about ‘good’ cholesterol levels and heart health were conducted in the 1970s through research with a majority of white adult study participants. For the current study, researchers were able to look at how cholesterol levels from Black and White middle-aged adults without heart disease who lived throughout the country overlapped with future cardiovascular events.

Study participants enrolled in REGARDS between 2003–2007 and researchers analysed information collected throughout a 10- to 11-year period. Black and white study participants shared similar characteristics, such as age, cholesterol levels, and underlying risk factors for heart disease, including having diabetes, high blood pressure, or smoking. During this time, 664 Black adults and 951 White adults experienced a heart attack or heart attack-related death. Adults with increased levels of LDL cholesterol and triglycerides had modestly increased risks for cardiovascular disease, which aligned with findings from previous research.

However, the study was the first to find that lower HDL cholesterol levels only predicted increased cardiovascular disease risk for white adults. It also expands on findings from other studies showing that high HDL cholesterol levels are not always associated with reduced cardiovascular events. The REGARDS analysis was the largest US study to show that this was true for both Black and White adults, suggesting that higher than optimal amounts of ‘good’ cholesterol may not provide cardiovascular benefits for either group.

“What I hope this type of research establishes is the need to revisit the risk-predicting algorithm for cardiovascular disease,” Pamir said. “It could mean that in the future we don’t get a pat on the back by our doctors for having higher HDL cholesterol levels.”

Pamir explained that as researchers study HDL cholesterol’s role in supporting heart health, they are exploring different theories. One is quality over quantity. That is, instead of having more HDL, the quality of HDL’s function – in picking up and transporting excess cholesterol from the body – may be more important for supporting cardiovascular health.

The authors conclude that in addition to supporting ongoing and future research with diverse populations to explore these connections, the findings suggest that cardiovascular disease risk calculators using HDL cholesterol could lead to inaccurate predictions for Black adults.

“When it comes to risk factors for heart disease, they cannot be limited to one race or ethnicity,” said Pamir. “They need to apply to everyone.”

Source: NIH/National Heart, Lung and Blood Institute