Blood tests provide powerful insights into the biological processes that influence cardiovascular and metabolic health. Yet many people receive their lab results without fully understanding what the numbers mean or how they relate to disease risk.
Many of the tests discussed in this article are used to estimate the risk of atherosclerotic cardiovascular disease (ASCVD), the process in which cholesterol-containing particles, inflammation, and metabolic dysfunction gradually damage the arteries over time.
If you’ve ever looked at your lab report and wondered what your cholesterol numbers actually mean, understanding a few key markers can provide important clues about your long-term heart health.
This guide explains common markers found on standard lipid panels and blood tests, what abnormal values may indicate, and how clinicians interpret these markers when evaluating cardiometabolic risk.
How These Tests Inform Nutrition Recommendations
In cardiometabolic nutrition, blood tests help identify the biological processes that contribute to chronic disease risk.
These markers provide insight into several key drivers of cardiovascular disease, including:
- Cholesterol-carrying lipoprotein particles
- Metabolic health and insulin resistance
- Inflammation within blood vessels
- Genetic risk factors
- Kidney function and vascular health
Physicians often use these tests to guide medication decisions, while clinicians working in preventive nutrition use the same information to guide targeted lifestyle and dietary interventions aimed at reducing long-term risk.
How Atherosclerosis Develops
Cardiovascular disease develops gradually over many years through a process called atherosclerosis.
This process begins when cholesterol-carrying lipoproteins enter the wall of an artery. Over time:
- Lipoprotein particles become trapped in the arterial wall
- The immune system responds with inflammation
- Plaque gradually forms and thickens
- Plaques may eventually rupture, causing a heart attack or stroke
From a biological perspective, atherosclerosis is fundamentally a disease of ApoB-containing lipoproteins entering and becoming trapped in the arterial wall.
Many of the blood markers discussed below reflect different steps in this process.
Lipid Panel
LDL Cholesterol (LDL-C)
LDL cholesterol has historically been referred to as “bad cholesterol.” While this term is still widely used, it is somewhat simplified.
Cholesterol itself is an essential molecule used by the body to build hormones, vitamin D, and cell membranes. What matters is how cholesterol travels through the bloodstream and how many particles are circulating.
LDL cholesterol remains the primary treatment target for cardiovascular disease prevention because higher LDL levels are strongly associated with plaque buildup in the arteries.
Current guidelines generally recommend LDL-C levels:
- Below 100 mg/dL for most individuals
- Below 70 mg/dL for people at high cardiovascular risk
- Below 55 mg/dL for those at very high risk
Large clinical studies consistently show that lower LDL cholesterol is associated with lower cardiovascular risk (Durrington et al., 2022; Grundy et al., 2019).
However, LDL-C measures the amount of cholesterol inside LDL particles, not the number of particles themselves. Because each particle has the potential to enter the artery wall, particle number may be a more direct measure of risk.
This is one reason additional markers such as Apolipoprotein B (ApoB) are increasingly used to refine cardiovascular risk assessment.
Recent ACC/AHA dyslipidemia guidelines also emphasize reducing lifetime exposure to LDL cholesterol and support earlier treatment and lower LDL targets in individuals at elevated cardiovascular risk (ACC/AHA, 2026).
HDL Cholesterol (HDL-C)
HDL cholesterol is commonly referred to as “good cholesterol.” HDL particles help transport cholesterol away from tissues and back to the liver, a process known as reverse cholesterol transport.
Higher HDL levels have historically been associated with lower cardiovascular risk in population studies.
However, modern research suggests the relationship is more complex. Clinical trials have not consistently shown that raising HDL cholesterol with medications reduces cardiovascular events (Michos et al., 2019).
This suggests HDL cholesterol may function more as a marker of overall metabolic health rather than a direct protective factor.
Low HDL levels are often seen in individuals with:
- Insulin resistance
- Metabolic syndrome
- Obesity
- Elevated triglycerides
Typical thresholds include:
- Below 40 mg/dL in men
- Below 50 mg/dL in women
Total Cholesterol
Total cholesterol represents the combined amount of cholesterol carried within all lipoproteins in the bloodstream, including LDL, HDL, and other particles.
General interpretation includes:
- Below 200 mg/dL: desirable
- 200–239 mg/dL: borderline high
- 240 mg/dL or higher: high
Because total cholesterol does not distinguish between different lipoprotein particles or particle numbers, it provides less precise information about cardiovascular risk than more specific lipid markers.
Non-HDL Cholesterol
Non-HDL cholesterol is calculated by subtracting HDL cholesterol from total cholesterol.
This measurement captures all cholesterol contained in atherogenic lipoproteins, including LDL and VLDL particles. These particles all contain ApoB and can contribute to plaque formation.
Research suggests non-HDL cholesterol may be a better predictor of cardiovascular risk than LDL-C alone (Brunner et al., 2019).
Target levels are typically about 30 mg/dL higher than LDL-C targets.
Triglycerides
Triglycerides are a type of fat circulating in the bloodstream that reflects how the body processes and stores energy.
Elevated triglycerides often indicate underlying metabolic disturbances such as insulin resistance, excess calorie intake, or impaired lipid metabolism.
Typical ranges include:
- Below 150 mg/dL: normal
- 150–199 mg/dL: borderline high
- 200–499 mg/dL: high
- 500 mg/dL or higher: very high
Very high triglyceride levels (above 500 mg/dL) increase the risk of pancreatitis.
Because triglycerides are highly responsive to diet and lifestyle, they are often one of the most modifiable lipid markers.
Total Cholesterol / HDL Ratio (TC/HDL)
The total cholesterol to HDL ratio compares the amount of cholesterol carried in lipoproteins with the amount associated with HDL.
This ratio provides a rough estimate of the balance between cholesterol carried in potentially harmful particles and cholesterol associated with HDL particles.
Typical interpretation includes:
- Below 3.5: optimal
- Above 5: increased cardiovascular risk
Research suggests this ratio may provide additional cardiovascular risk information beyond individual lipid measurements (Arsenault et al., 2009).
Triglyceride / HDL Ratio (TG/HDL)
The triglyceride to HDL ratio is increasingly used as a marker of metabolic health.
Higher ratios often reflect insulin resistance and impaired lipid metabolism, which can accelerate the development of cardiovascular disease.
A higher TG/HDL ratio often reflects:
- Increased production of triglyceride-rich lipoproteins
- Reduced HDL levels
- Metabolic environments that promote atherosclerosis
Many clinicians consider ratios below 2 to be favorable.
Advanced Lipid Markers
Apolipoprotein B (ApoB)
Apolipoprotein B measures the number of atherogenic lipoprotein particles circulating in the bloodstream. Each LDL and VLDL particle contains exactly one ApoB molecule, making ApoB a direct count of particles capable of contributing to plaque buildup.
This distinction is important because two individuals may have the same LDL cholesterol level but very different numbers of LDL particles, which can translate into different cardiovascular risk.
Because atherosclerosis is driven by the accumulation of these particles in the artery wall, particle number may better reflect the biological drivers of disease than cholesterol concentration alone. For this reason, ApoB is increasingly recognized as an important marker for cardiovascular risk assessment, particularly in individuals with elevated triglycerides or metabolic syndrome (Newman et al., 2020).
Levels above 130 mg/dL are generally considered elevated.
Lipoprotein(a) — Lp(a)
Lipoprotein(a), or Lp(a), is a specialized cholesterol particle that is largely determined by genetics.
Elevated Lp(a) levels increase cardiovascular risk because the particle has properties that promote both cholesterol deposition and blood clot formation.
Lp(a) contributes to plaque formation and may increase the likelihood that plaques become unstable or rupture.
Levels considered elevated are:
- <50 mg/dL
- <125 nmol/L
Because Lp(a) levels are largely genetic and not strongly influenced by lifestyle changes, experts recommend measuring Lp(a) at least once in adulthood, particularly in individuals with a family history of early cardiovascular disease (Reyes-Soffer et al., 2021).
Inflammatory and Metabolic Markers
Hemoglobin A1c (HbA1c)
Hemoglobin A1c reflects average blood sugar levels over the previous 2–3 months.
Chronically elevated blood glucose contributes to cardiovascular disease by promoting oxidative stress, inflammation, and damage to blood vessel walls.
Typical interpretation includes:
- Below 5.7%: normal
- 5.7–6.4%: prediabetes
- 6.5% or higher: diabetes
For most individuals with diabetes, treatment goals aim for HbA1c below 7%, though individualized targets may vary depending on age, health status, and complications (Sacks et al., 2023; Samson et al., 2023).
Nutrition, body composition, physical activity, and sleep all influence blood sugar control, making HbA1c an important marker of metabolic health.
High-Sensitivity C-Reactive Protein (hs-CRP)
High-sensitivity C-reactive protein measures systemic inflammation, which plays an important role in cardiovascular disease. Inflammation contributes to plaque formation and can also destabilize existing plaques, increasing the risk of plaque rupture.
Typical interpretation includes:
- Below 1 mg/L: low cardiovascular risk
- 1–3 mg/L: average risk
- Above 3 mg/L: higher risk
Values above 10 mg/L may indicate acute infection and should be repeated once the illness resolves (Ridker, 2016; Mensah et al., 2025).
Homocysteine
Homocysteine is an amino acid involved in metabolism. Elevated levels have been associated with cardiovascular risk because they may contribute to endothelial dysfunction and oxidative stress, which can damage blood vessel walls.
Typical levels range from 5–15 µmol/L.
Elevated levels may result from deficiencies in vitamin B12, folate, or vitamin B6.
Kidney Function Markers
Estimated Glomerular Filtration Rate (eGFR)
The estimated glomerular filtration rate (eGFR) measures how efficiently the kidneys filter waste products from the blood. Kidney function and cardiovascular health are closely linked. Reduced kidney function is associated with higher rates of cardiovascular disease and mortality.
Interpretation generally includes:
- 90 or higher: normal kidney function
- Below 60: chronic kidney disease if present for three months or longer
These categories align with international kidney disease guidelines (KDIGO, 2024).
Uric Acid
Uric acid is a metabolic waste product normally filtered by the kidneys. Elevated levels can cause gout, but research also suggests higher uric acid levels may contribute to vascular inflammation, endothelial dysfunction, and kidney disease progression.
Hyperuricemia is defined as 6.8 mg/dL or higher.
Even mild elevations within the normal range may be associated with declining kidney function in some populations (Tsai et al., 2017; Kamei et al., 2014; Toyama et al., 2015).
Common Lab Patterns That Increase Cardiometabolic Risk
In clinical practice, cardiovascular risk often appears as patterns rather than a single abnormal number.
Examples include:
• Elevated triglycerides combined with low HDL cholesterol
• High ApoB despite normal LDL cholesterol
• Elevated HbA1c alongside elevated triglycerides
• Elevated Lp(a) combined with other lipid abnormalities
Looking at these patterns together helps identify the biological drivers of cardiometabolic disease and guide prevention strategies.
What These Numbers Mean Together
Your lab values should always be interpreted as part of a broader health picture, not in isolation.
Cardiovascular risk depends on the interaction between multiple biological processes, including:
- Lipoprotein particle burden
- Metabolic health and insulin resistance
- Systemic inflammation
- Kidney function
- Genetic risk factors
In my work with patients across Boston and Massachusetts, these patterns often appear in individuals trying to improve cholesterol levels, metabolic health, or long-term cardiovascular risk. Regular monitoring allows clinicians to track changes over time and evaluate whether lifestyle changes or medical therapies are improving cardiometabolic health.
Bottom Line
Blood tests provide valuable insights into the biological processes that influence cardiovascular disease.
Markers such as LDL cholesterol, ApoB, triglycerides, blood sugar, and inflammatory markers each reflect different aspects of cardiometabolic risk. When interpreted together, they help clinicians understand the underlying drivers of disease and guide personalized prevention strategies.
Because cardiovascular disease develops over decades, identifying these patterns early provides an opportunity to intervene with nutrition, lifestyle changes, and medical care that support long-term heart health.
About the Author
Joseph Lehrberg, MS, RD is a registered dietitian specializing in cardiovascular and metabolic health and founder of CardioFunction Integrative Nutrition Services, a nutrition practice based in Boston. He works with patients with elevated cholesterol, high coronary artery calcium scores, high triglycerides, statin intolerance, and other cardiometabolic risk factors to develop evidence-based nutrition strategies for long-term heart health.
Learn more about working with him here.
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