The Heart–Kidney–Metabolic Connection: A More Complete Approach to Preventive Medicine

Why the Heart, Kidneys, and Metabolism Belong in the Same Conversation

A patient may see one clinician for cholesterol, another for blood pressure, and a third for abnormal blood glucose. Kidney function may receive attention only when a laboratory value falls outside the reference range. Weight is often discussed separately, with little consideration of the tissue distribution or metabolic activity underlying it.

These clinical concerns are frequently related. Insulin resistance, abnormal lipoprotein metabolism, hypertension, excess visceral adiposity, kidney dysfunction, and atherosclerosis interact through overlapping biological pathways. Their combined effect on cardiovascular risk may be considerably greater than any one measurement suggests.

The 2026 AHA/ACC/ADA/ASN guideline for cardiovascular-kidney-metabolic syndrome formally integrates these relationships into a staged framework for screening, prevention, treatment, and follow-up.

The guideline does not introduce a new biological discovery. It organizes a substantial body of clinical evidence around an increasingly important reality: chronic disease prevention is less effective when interconnected risks are evaluated independently.

HormoneSynergy® discussed the guideline when it was released in June 2026. The original editorial, CKM Syndrome: Why Heart, Kidney, and Metabolic Health Cannot Be Separated, explains the broader clinical framework. This companion article examines the individual measurements and how they can be interpreted together.

Understanding Cardiovascular-Kidney-Metabolic Syndrome

Cardiovascular-kidney-metabolic syndrome, commonly abbreviated CKM, describes a continuum of risk associated with dysfunctional adipose tissue, metabolic abnormalities, chronic kidney disease, and cardiovascular disease.

The framework identifies five stages, numbered from zero through four.

Stage 0 describes the absence of CKM risk factors. Stage 1 includes excess or dysfunctional adiposity without additional established metabolic risk factors or kidney disease. Stage 2 incorporates metabolic risk factors such as diabetes, hypertension, or hypertriglyceridemia, and/or chronic kidney disease. Stage 3 recognizes subclinical cardiovascular disease or particularly high predicted cardiovascular risk in the presence of CKM risk factors. Stage 4 includes established clinical cardiovascular disease in the setting of CKM syndrome.

These stages allow clinicians to identify when preventive intervention may be appropriate before a heart attack, stroke, heart failure, or advanced kidney disease occurs.

A person with hypertension, insulin resistance, and increased visceral fat may have meaningful risk even when they feel well and have not received a diagnosis of cardiovascular disease. Another person with established coronary plaque may need a different degree of intervention even when current glucose and cholesterol measurements appear relatively favorable.

The staging framework helps organize these differences. It is not intended to replace clinical judgment, established risk equations, or disease-specific treatment guidelines.

ApoB: Measuring the Particles That Contribute to Atherosclerosis

Low-density lipoprotein cholesterol, or LDL-C, remains an important component of cardiovascular risk assessment. It measures the concentration of cholesterol carried within LDL particles, but it does not directly measure the number of particles circulating through the bloodstream.

Apolipoprotein B, or ApoB, provides a complementary measurement. Each major atherogenic lipoprotein particle carries one ApoB molecule. These particles include LDL, intermediate-density lipoproteins, very-low-density lipoproteins, cholesterol-rich remnants, and lipoprotein(a).

Because ApoB concentration reflects the number of these particles, it can help characterize atherogenic particle burden when cholesterol content per particle varies.

This becomes particularly useful in insulin resistance and hypertriglyceridemia. Individuals may carry an increased number of cholesterol-depleted LDL particles while maintaining an LDL cholesterol concentration that does not appear especially elevated.

Atherosclerosis develops when ApoB-containing particles enter and become retained within arterial walls, initiating biological processes that contribute to plaque formation. The cumulative exposure to these particles is central to cardiovascular disease development.

ApoB is therefore particularly valuable when LDL cholesterol, triglycerides, and metabolic status suggest that conventional lipid measurements may underestimate particle-related risk.

It does not replace LDL-C, non-HDL cholesterol, blood pressure assessment, or family history. Lipoprotein(a), a largely genetically determined contributor to cardiovascular risk, also deserves consideration because it may add risk not adequately captured by conventional lipid measurements alone.

The 2026 CKM guideline continues to emphasize evidence-based LDL cholesterol reduction and recognizes ApoB or non-HDL cholesterol as useful additional measurements, particularly in patients with hypertriglyceridemia.

For a fuller explanation, see ApoB Explained: The Particle Count Standard Cholesterol Testing Can Miss.

Insulin Resistance: Metabolic Changes Before Diabetes

Insulin resistance develops when tissues become less responsive to insulin signaling. The pancreas may compensate by producing additional insulin, allowing blood glucose concentrations to remain within the normal range for a considerable period.

Consequently, normal fasting glucose does not always establish normal insulin sensitivity.

Insulin resistance is associated with changes in hepatic lipid metabolism, elevated triglycerides, lower HDL cholesterol, increased visceral fat, altered blood pressure regulation, and fatty liver disease. These abnormalities frequently occur together and can contribute to CKM risk long before diabetes is diagnosed.

Fasting glucose and hemoglobin A1c remain central clinical measurements because they identify established abnormalities in glycemic regulation and help diagnose prediabetes and diabetes.

Fasting insulin and the homeostatic model assessment of insulin resistance, or HOMA-IR, may provide additional physiological context in selected patients. HOMA-IR uses fasting glucose and insulin to estimate insulin resistance, although results are influenced by assay methods and individual physiology. There is no universally accepted cutoff that reliably diagnoses insulin resistance across all populations.

These additional measures should not be confused with mandatory components of guideline-based CKM assessment. Their usefulness depends on the clinical question and whether the result changes interpretation or management.

Triglycerides, HDL cholesterol, waist circumference, blood pressure, liver enzymes, and body composition often contribute valuable context. A person with normal glucose but elevated triglycerides, increased visceral adiposity, and hypertension warrants a broader metabolic assessment.

See HOMA-IR and Insulin Resistance: How to Interpret the Number and Metabolic Health and Insulin Resistance: A Longevity Medicine Guide.

Kidney Function: Why Creatinine Alone Is Not Enough

The kidneys regulate fluid balance, electrolytes, acid-base physiology, and the elimination of metabolic waste. They also participate in blood pressure regulation and the hormonal systems that influence red blood cell production, bone metabolism, and vascular health.

Kidney disease and cardiovascular disease share several major risk factors, including hypertension, diabetes, aging, and vascular dysfunction. Their relationship is also bidirectional. Impaired kidney function increases cardiovascular risk, while cardiovascular disease and poorly controlled blood pressure can accelerate kidney damage.

A serum creatinine result provides useful information, but it is generally more informative when used to calculate estimated glomerular filtration rate, or eGFR.

eGFR estimates kidney filtration function. Because serum creatinine depends partly on muscle mass, nutritional status, and other factors, interpretation can become more complicated in people with unusually high or low muscle mass.

Cystatin C can be useful when a creatinine-based estimate may be misleading. Combining creatinine and cystatin C often improves the accuracy of estimated kidney function, although the choice to order it should be individualized.

Urine albumin-to-creatinine ratio, or UACR, provides different information. It evaluates whether an abnormal amount of albumin is passing into the urine, which can reflect damage affecting the kidney's filtration barrier.

A person may have preserved eGFR while already demonstrating albuminuria. Conversely, filtration may decline without significant albuminuria. Either pattern can be clinically relevant.

For this reason, kidney assessment should consider both filtration and albumin excretion.

Persistently elevated UACR of at least 30 mg/g is a marker of kidney damage, although transient elevations can occur with exercise, infection, fever, and other conditions. Chronic kidney disease generally requires abnormalities that persist for at least three months.

The 2026 CKM guideline recommends at least annual assessment of both eGFR and UACR for adults with stage 2 or higher CKM syndrome. Testing intervals differ for people at lower risk.

Albuminuria as a Cardiovascular Warning Sign

Albuminuria is commonly associated with diabetic kidney disease, but it has broader clinical implications.

Urinary albumin excretion can reflect abnormalities in renal microvascular function and is independently associated with cardiovascular events, heart failure, and mortality. These associations can be present even when eGFR remains relatively preserved.

The kidney's small blood vessels share physiological vulnerabilities with vascular networks throughout the body. Hypertension, metabolic dysfunction, endothelial injury, and systemic inflammation can influence both renal and cardiovascular health.

Albuminuria is not simply a measurement of how well the kidneys remove waste. It can contribute to a more complete understanding of vascular and metabolic risk.

Persistent albuminuria also has treatment implications. Depending on the clinical circumstances, renin-angiotensin system inhibitors, SGLT2 inhibitors, and other kidney-protective therapies may reduce progression of kidney disease and cardiovascular events.

The significance of albuminuria depends on its degree, persistence, associated kidney function, and the patient's broader medical history. It should be interpreted within the clinical context rather than treated as an isolated laboratory finding.

Visceral Fat: A More Useful Question Than Weight Alone

Body mass index provides a practical population-level indicator of body size, but it does not distinguish fat mass from muscle or describe where adipose tissue is stored.

Visceral adipose tissue is located within the abdominal cavity surrounding internal organs. It differs from subcutaneous fat in its anatomical location and metabolic activity.

Excess visceral adiposity is associated with insulin resistance, altered inflammatory signaling, dyslipidemia, metabolic dysfunction-associated steatotic liver disease, hypertension, and cardiovascular disease.

These relationships help explain why two individuals with similar body weights may have substantially different metabolic risk profiles.

Waist circumference offers an inexpensive and useful approximation of central adiposity and is incorporated into the CKM assessment framework. When more detailed evaluation is appropriate, DEXA body composition analysis can estimate visceral adipose tissue along with total fat mass, lean mass, and regional tissue distribution.

At HormoneSynergy®, DEXA and SECA bioelectrical impedance assessments can help evaluate body composition in the context of metabolic health and physical function.

DEXA-derived visceral fat estimates are not direct measures of inflammatory activity and do not independently diagnose insulin resistance. Their greatest value comes from integration with metabolic laboratory findings, blood pressure, family history, physical activity, and other clinical information.

Maintaining adequate muscle mass remains important during efforts to reduce excess adiposity. Nutritional interventions, resistance training, aerobic exercise, and appropriate medical treatment can improve metabolic health, while body composition monitoring may help identify unintended losses in lean tissue.

See Visceral Fat and DEXA: What VAT Measurements Mean for Metabolic Risk.

Vascular Imaging: Has Atherosclerosis Already Developed?

Blood testing provides information about current physiological risk factors. Imaging addresses a different question: whether structural vascular disease is already present.

ApoB may indicate ongoing exposure to atherogenic particles, but it does not reveal how much plaque has accumulated over previous decades. A patient may have favorable lipid results after treatment while still carrying substantial established atherosclerosis.

Similarly, insulin resistance and visceral fat may increase the likelihood of cardiovascular disease without establishing that plaque is present in any particular individual.

When clinical risk remains uncertain, selected imaging studies can provide additional information.

Coronary Artery Calcium Scoring

Coronary artery calcium scoring uses noncontrast CT to quantify calcified plaque within the coronary arteries.

A calcium score of zero is generally associated with relatively low near-term coronary event risk in appropriately selected asymptomatic patients. It does not establish the complete absence of atherosclerosis, since noncalcified plaque may be present without detectable calcium.

Calcium scoring can help refine preventive treatment decisions when estimated risk and other clinical factors leave uncertainty, particularly regarding the initiation or intensity of lipid-lowering therapy.

The test has limitations in younger patients, individuals with symptoms, and certain high-risk populations. A calcium score should not be used to dismiss substantial clinical risk or replace appropriate evaluation of possible coronary symptoms.

Coronary CT Angiography and Cleerly® Plaque Analysis

Coronary CT angiography, or CCTA, uses contrast-enhanced CT to examine the coronary arteries. Unlike calcium scoring alone, it can visualize both calcified and noncalcified plaque and assess the degree of coronary narrowing.

When appropriate, Cleerly® analysis can provide structured quantitative measurements of coronary plaque burden and composition from CCTA images.

This information may help clinicians characterize existing atherosclerosis more fully, particularly when the type, extent, or distribution of plaque is relevant to management.

CCTA requires consideration of radiation exposure, iodinated contrast, kidney function, image quality, and clinical indication. It is not a routine screening test for every asymptomatic adult and should not be ordered simply because more detailed imaging is available.

Cleerly is an image-analysis platform rather than a substitute for coronary CT angiography or medical interpretation. More detailed plaque measurements do not independently prove that routine use of the technology improves cardiovascular outcomes in all patient populations.

For a detailed comparison, see Coronary Calcium Score vs. CCTA vs. Cleerly® Plaque Analysis.

Carotid Ultrasound and CIMT

Carotid ultrasound evaluates the arteries supplying blood to the brain. Depending on the examination, it may identify plaque, characterize plaque burden, and measure carotid intima-media thickness, or CIMT.

The presence of carotid plaque can provide evidence of systemic atherosclerosis and may contribute useful information in selected clinical situations.

Routine CIMT measurement alone is not universally recommended for cardiovascular risk prediction in asymptomatic adults. Plaque detection and detailed CIMT measurements should not be treated as interchangeable findings, and their clinical usefulness depends on the question being investigated.

HormoneSynergy® offers VasoLabs® carotid ultrasound assessment, including measurements of intima-media thickness and evaluation of plaque presence and burden.

Learn more in the Carotid Ultrasound and CIMT Guide.

Putting the Findings Together

The value of integrated assessment becomes clearer when considering patients whose laboratory results do not fit a simple pattern.

Consider an individual with normal fasting glucose but increased visceral fat, elevated triglycerides, and higher ApoB. The combination suggests a metabolic and lipoprotein pattern that may deserve attention before diabetes develops. Blood pressure, family history, kidney function, and overall cardiovascular risk would help determine the appropriate next steps.

Another individual may have reasonably controlled blood glucose and blood pressure but persistent albuminuria. Kidney protection and cardiovascular risk reduction remain important even when those familiar measurements appear acceptable.

A third patient may have improved cholesterol levels through treatment yet already have measurable coronary plaque. The presence and extent of established disease may influence treatment intensity and follow-up independently of the current lipid result.

These examples illustrate why the interpretation of risk depends on the relationships among findings. They do not mean that every patient needs every test. A carefully chosen assessment should answer a question that has practical implications for prevention or treatment.

Risk Prediction and the PREVENT Equations

The 2026 CKM guideline incorporates the American Heart Association's PREVENT risk equations to estimate cardiovascular risk and support treatment decisions.

PREVENT can estimate 10-year and, in eligible age groups, 30-year risk of cardiovascular outcomes using established clinical variables. The equations incorporate kidney function and may use additional available measurements to refine estimation.

Risk prediction offers a useful starting point, particularly for people without known cardiovascular disease. It does not provide a precise forecast of an individual's future health and cannot fully represent every genetic, metabolic, or imaging-related contributor to risk.

ApoB, lipoprotein(a), family history, and selected imaging findings may add useful context when the initial assessment leaves uncertainty.

The guideline uses predicted risk to help inform CKM staging, decisions about detecting subclinical cardiovascular disease, and selection of preventive treatments.

Clinical judgment remains necessary because the consequences of treatment, patient preferences, comorbidities, and expected absolute benefits vary substantially.

Treatment Must Address the Connected Risks

Integrated assessment becomes meaningful when it leads to appropriate intervention.

Nutrition, regular physical activity, resistance training, sleep, smoking cessation, weight management where indicated, and blood pressure control influence multiple CKM pathways. They remain foundational even when medication is necessary.

For atherosclerotic cardiovascular risk, statins and other evidence-based lipid-lowering therapies may reduce exposure to ApoB-containing particles and lower the risk of cardiovascular events. Treatment selection depends on the patient's clinical risk, established disease, response to therapy, and medication tolerance.

In chronic kidney disease, renin-angiotensin system inhibitors and SGLT2 inhibitors have important roles in appropriately selected patients. Their benefits can extend beyond glucose reduction and include protection against kidney deterioration and cardiovascular complications.

GLP-1-based therapies have demonstrated important weight-related, metabolic, and cardiovascular benefits in selected populations, while specific therapies also have evidence supporting kidney protection.

These treatments are not interchangeable. Their use depends on the underlying diagnoses, kidney function, cardiovascular history, individual risk, contraindications, and the evidence supporting each indication.

For patients receiving weight-loss therapy, protecting skeletal muscle and maintaining adequate nutrition are particularly important. Improvements in body weight should be interpreted alongside changes in metabolic health, body composition, and physical function.

The HormoneSynergy® Approach

HormoneSynergy® has long approached preventive medicine through the relationships among cardiovascular, metabolic, hormonal, and functional health. Under the clinical leadership of Dr. Kathryn Retzler, the emphasis is on identifying clinically meaningful risk before preventable disease progresses.

The CKM framework closely aligns with this approach. ApoB and related lipid measurements help characterize atherogenic exposure, while glucose and insulin-related assessments provide information about metabolic regulation. Kidney filtration and urine albumin measurements reveal additional aspects of cardiovascular and renal risk. Body composition assessment can identify excess visceral fat and changes in lean tissue, and selected vascular imaging may establish whether atherosclerosis has already developed.

The Optimal Aging Assessment brings these findings into the context of an individual's medical history, family history, blood pressure, lifestyle, physical function, and long-term health goals. Advanced laboratory testing, DEXA body composition assessment, SECA measurements, carotid ultrasound, and other appropriate evaluations contribute different information to that process.

Coronary CT angiography with Cleerly® plaque analysis may be considered when clinically indicated. No single test determines the entire prevention strategy, and more intensive evaluation is not automatically better care.

The goal is to understand which findings are actionable, which require monitoring, and which may be less clinically significant than they initially appear.

HormoneSynergy® provides comprehensive care without billing insurance, allowing additional time for individualized assessment and follow-up. Patients maintain their relationship with a primary care physician, and preventive recommendations should remain coordinated with existing medical care and specialty treatment when appropriate.

Improving healthspan involves protecting organs and preserving function over time. Cardiovascular prevention, kidney protection, metabolic regulation, muscle maintenance, and cognitive health are related clinical objectives, even when they require different interventions.

What a More Complete Approach Can Accomplish

The CKM framework encourages earlier recognition of interacting risks, but its effectiveness depends on what clinicians and patients do with that information.

An elevated ApoB result may support more intensive lipid management. Persistent albuminuria may identify a need for kidney-protective treatment. Increasing visceral adiposity may justify greater attention to nutrition, resistance training, and metabolic health. Imaging evidence of plaque may influence the urgency or intensity of cardiovascular prevention.

Each finding becomes useful when interpreted within the patient's overall clinical condition and translated into an appropriate plan.

Additional laboratory testing and advanced imaging cannot independently prevent a heart attack, preserve kidney function, or improve metabolic health. Their value lies in informing decisions about interventions capable of changing clinically meaningful outcomes.

The growing integration of cardiovascular, kidney, and metabolic medicine reflects a broader change in how preventive care is understood. Rather than waiting for chronic diseases to become established and treating each separately, clinicians have an opportunity to recognize shared risk earlier and intervene more thoughtfully.

Related HormoneSynergy® Resources

• CKM Syndrome: Why Heart, Kidney, and Metabolic Health Cannot Be Separated — The original HormoneSynergy® review of the 2026 guideline.
• ApoB Explained: Atherogenic Particle Burden
• HOMA-IR and Insulin Resistance
• Metabolic Health and Insulin Resistance Guide
• Visceral Fat and DEXA: What VAT Means
• Calcium Score vs. CCTA vs. Cleerly®
• Carotid Ultrasound and CIMT Guide
• Preventive Cardiology and Longevity Medicine
• Optimal Aging Assessment
• HormoneSynergy® Longevity Medicine Model
• HormoneSynergy® Resource Library

Selected Research and Clinical Guidelines

1. Ndumele CE, Rodriguez F, Dixon DL, et al. 2026 AHA/ACC/ADA/ASN Guideline for the Prevention, Detection, Evaluation, and Management of Cardiovascular-Kidney-Metabolic Syndrome. Journal of the American College of Cardiology. 2026. Full guideline.
2. American Heart Association. 2026 Cardiovascular-Kidney-Metabolic Syndrome Guideline. Guideline summary.
3. American Heart Association and American College of Cardiology. Use of Predicted Risk and Expected Benefit to Guide Decision-Making in Cardiovascular-Kidney-Metabolic Syndrome for the Primary Prevention of Cardiovascular Disease. 2026. Scientific statement.
4. Khan SS, et al. Development and Validation of the American Heart Association's PREVENT Equations. Circulation. 2024. Risk prediction research.
5. KDIGO. Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney International. 2024. CKD guideline.

Frequently Asked Questions

What is cardiovascular-kidney-metabolic syndrome?

CKM syndrome describes the interconnected relationship among metabolic dysfunction, chronic kidney disease, and cardiovascular disease. Its staged framework helps clinicians identify risk earlier and select appropriate prevention and treatment strategies.

Why measure ApoB if LDL cholesterol is already available?

ApoB estimates the number of circulating atherogenic lipoprotein particles, while LDL cholesterol measures cholesterol concentration within LDL particles. ApoB can provide additional information when particle number and cholesterol concentration are discordant, particularly in insulin resistance and hypertriglyceridemia.

Can insulin resistance develop before blood glucose becomes abnormal?

Yes. Increased insulin production can compensate for reduced insulin sensitivity, allowing blood glucose to remain normal during earlier stages of metabolic dysfunction. Fasting insulin and HOMA-IR may provide additional context in selected patients, although they are not universally required diagnostic tests.

Why are both eGFR and urine albumin needed?

eGFR estimates kidney filtration function, while urine albumin-to-creatinine ratio helps identify abnormal urinary albumin excretion. These measurements assess complementary aspects of kidney health and help characterize cardiovascular and kidney disease risk.

Does visceral fat matter more than BMI?

Visceral fat distribution can provide metabolic information not captured by BMI alone. However, BMI, waist circumference, body composition, laboratory findings, and clinical history serve different purposes and are most useful when interpreted together.

Should everyone undergo coronary CT angiography or carotid ultrasound?

No. Imaging should be selected according to cardiovascular risk, symptoms, clinical history, and whether the result is likely to influence management. Routine advanced vascular imaging is not necessary for every asymptomatic adult.

Can someone have cardiovascular disease with normal cholesterol?

Yes. Atherosclerosis reflects cumulative exposure to multiple risk factors over time. Current cholesterol results do not always reveal previous exposure or existing plaque, particularly after lifestyle changes or medication treatment.

Editorial Transparency: This article reviews clinical guidelines and established research on cardiovascular, kidney, and metabolic health. Recommendations for advanced testing are individualized, and the availability of a diagnostic service does not establish that it is necessary or appropriate for every patient.

About HormoneSynergy®: HormoneSynergy® provides evidence-based preventive longevity medicine in Portland and Lake Oswego, Oregon, under the clinical leadership of Dr. Kathryn Retzler. The practice integrates advanced assessment, individualized treatment, and long-term monitoring of cardiovascular, metabolic, hormonal, cognitive, and physical health.

Medical Disclaimer: This article is educational and does not replace individualized medical advice. Testing, treatment, and imaging decisions should be made with an appropriate healthcare professional based on clinical indications, medical history, expected benefits, and potential risks.