Metabolic syndrome is a clustering of interrelated cardiometabolic abnormalities that occur together more often than would be expected by chance: abdominal obesity, atherogenic dyslipidemia (raised triglycerides and reduced high-density lipoprotein cholesterol), raised blood pressure, and raised fasting glucose. Under the harmonized definition endorsed jointly by the International Diabetes Federation, the National Heart, Lung, and Blood Institute, the American Heart Association, the World Heart Federation, the International Atherosclerosis Society, and the International Association for the Study of Obesity, the presence of any three of these five components establishes the diagnosis, and no single component is obligatory.

The dominant pathophysiologic drivers are excess and dysfunctional adipose tissue, ectopic lipid deposition in liver and skeletal muscle, insulin resistance with compensatory hyperinsulinemia, and chronic low-grade inflammation. The syndrome is common, affects a large minority of adults in most surveyed populations, and is increasing in prevalence, with the sharpest rises in younger adults and in groups facing adverse social determinants of health.

Clinically, metabolic syndrome approximately doubles the risk of incident cardiovascular disease and cardiovascular death, increases all-cause mortality by roughly half, and confers a several-fold increase in the risk of incident type 2 diabetes mellitus. It is also associated with metabolic dysfunction-associated steatotic liver disease, chronic kidney disease, obstructive sleep apnea, polycystic ovary syndrome, and several common cancers.

The construct has been repositioned in contemporary practice. The American Heart Association now situates metabolic syndrome within a broader, staged cardiovascular-kidney-metabolic framework that runs from preserved health through excess adiposity, established metabolic risk factors or kidney disease, subclinical atherosclerosis, and finally clinical cardiovascular disease. This reframing matters because it aligns diagnosis with a life-course prevention strategy and with contemporary risk-prediction equations that incorporate kidney function.

No therapy has been shown to treat metabolic syndrome as a unitary entity. Management is therefore built on two pillars: intensive lifestyle intervention aimed at sustained weight reduction and increased physical activity, and guideline-directed treatment of each individual component to its own target. Incretin-based pharmacotherapy and metabolic surgery have altered this picture substantially, because they improve several components simultaneously and, in the case of semaglutide in patients with obesity and established cardiovascular disease, reduce hard cardiovascular outcomes.

• The clustering of hypertension, hyperglycemia and gout was described by Kylin in 1923, and Vague drew attention in 1947 to the distinction between android (upper body) and gynoid (lower body) fat distribution and its differing metabolic consequences. Both observations are recounted in modern reviews of the syndrome.^[1]
• In his 1988 Banting Lecture, Reaven proposed that resistance to insulin-mediated glucose uptake was the common thread linking glucose intolerance, hyperinsulinemia, raised very low density lipoprotein triglyceride, reduced high-density lipoprotein cholesterol and hypertension, and named the cluster Syndrome X. Notably, obesity was not part of his original formulation.^[2]
• The World Health Organization produced the first formal diagnostic definition in 1998, making documented insulin resistance or a disorder of glucose regulation an obligatory requirement and including microalbuminuria as a component.^[3]
• The European Group for the Study of Insulin Resistance modified this definition in 1999, substituting fasting insulin in the upper quartile for clamp-derived insulin resistance, excluding patients with diabetes mellitus, and replacing body mass index and waist-to-hip ratio with waist circumference.^[4]
• The National Cholesterol Education Program Adult Treatment Panel III definition of 2001 dispensed with any obligatory component and with any requirement to measure insulin, which made the diagnosis feasible in routine practice and drove its widespread adoption.^[5]
• The American Heart Association and National Heart, Lung, and Blood Institute updated the Adult Treatment Panel III criteria in 2005, lowering the fasting glucose threshold to 100 mg/dL in line with the revised definition of impaired fasting glucose and clarifying that treated risk factors count toward the diagnosis.^[6]
• The International Diabetes Federation definition of 2005 and 2006 took the opposite position, making ethnicity-specific central obesity an obligatory component on the grounds that abdominal adiposity is the principal upstream driver.^[7]
• The competing definitions were reconciled in 2009 by a joint interim statement. Waist circumference was retained as a useful screening measurement but not made obligatory, three of five abnormal findings were agreed as sufficient, and a single set of cut points was adopted for every component except waist circumference, for which national or regional values continue to be used.^[8]
• The CardioMetabolic Health Alliance proposed in 2015 that the syndrome be treated as a chronic condition requiring a coordinated, staged, team-based care model rather than an isolated diagnostic label.^[9]
• In 2023 the American Heart Association issued a presidential advisory defining cardiovascular-kidney-metabolic syndrome and a five-stage staging system, positioning metabolic syndrome as one stage within a continuum that also encompasses chronic kidney disease and clinical cardiovascular disease.^[10]
• Two further nomenclature changes have direct bearing on this page. Nonalcoholic fatty liver disease and nonalcoholic steatohepatitis were renamed metabolic dysfunction-associated steatotic liver disease and metabolic dysfunction-associated steatohepatitis by multisociety Delphi consensus in 2023,^[11] and a 2025 Lancet Commission redefined obesity itself, distinguishing preclinical obesity from clinical obesity and recommending that body mass index no longer be used alone as a measure of individual health.^[12]

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Priyamvada Singh, M.B.B.S. [2] ; Aditya Ganti M.B.B.S. [3]

Metabolic syndrome has no single agreed classification, and the literature contains several parallel schemes that answer different questions. Historically the schemes differed on one central issue: whether a single abnormality should be treated as the obligatory upstream driver of the cluster. The World Health Organization and the European Group for the Study of Insulin Resistance placed insulin resistance in that position, the International Diabetes Federation placed central obesity there, and the National Cholesterol Education Program declined to privilege any component. These are not merely academic differences, because they change which patients receive the label and therefore which patients are captured by prevalence estimates and by risk-factor screening programmes.^[1][13]

For contemporary practice, four classification axes are relevant:

• By diagnostic definition. The 2009 harmonized joint interim statement is the current standard for adults and should be used in preference to the earlier schemes, which are retained below for historical and comparative purposes.^[8]
• By population-specific anthropometry. Waist circumference thresholds vary by ethnicity and country, so the same measurement can be diagnostic in one population and normal in another.^[8]
• By disease stage. The American Heart Association cardiovascular-kidney-metabolic staging system places metabolic syndrome within a five-stage continuum that runs from preserved cardiometabolic health to clinical cardiovascular disease, and is the framework best suited to guiding treatment intensity.^[10]
• By age group. Separate pediatric criteria apply below the age of 16 years, and the diagnosis is not made at all below the age of 10 years.^[14]

A practical consequence follows from the first two axes. Because prevalence figures, risk estimates and trial eligibility criteria published before 2009 mostly used the Adult Treatment Panel III or International Diabetes Federation definitions, older numbers are not directly interchangeable with those generated under the harmonized criteria, and the definition used should always be stated when a figure is quoted.^[15]

The harmonized statement retained population-specific waist circumference cut points because a single value could not be justified across ethnic groups.^[8]

The American Heart Association staging system places metabolic syndrome within a broader continuum and is intended to guide prevention across the life course.^[10][16]

The International Diabetes Federation recommends that the diagnosis not be made below the age of 10 years, that in children aged 10 to less than 16 years central obesity defined by a waist circumference at or above the 90th percentile be obligatory together with adult-type thresholds for the remaining components, and that adult criteria be applied from age 16 years onward.^[14]

• A joint statement of the American Diabetes Association and the European Association for the Study of Diabetes argued that the criteria were ambiguous and incomplete, that the rationale for the thresholds was ill defined, that the inclusion of patients with established diabetes mellitus was illogical, and that the cardiovascular risk conveyed by the syndrome appeared to be no greater than the sum of its parts. The authors concluded that clinicians should evaluate and treat each risk factor individually.^[13]
• Reaven himself questioned whether the diagnosis was necessary, noting that dichotomizing continuous variables discards information and that a positive label adds little to individualized risk assessment.^[17]
• The counterargument, reflected in the harmonized statement and in the cardiovascular-kidney-metabolic advisory, is that the label has value as a simple, inexpensive prompt to comprehensive risk assessment and early lifestyle intervention, particularly in primary care.^[8][10]

• The unifying abnormality is resistance to insulin-mediated glucose disposal with compensatory hyperinsulinemia. When beta cell compensation eventually fails, glucose intolerance and then type 2 diabetes mellitus supervene.^[2][1]
• Mechanistically, insulin resistance in skeletal muscle and liver is driven principally by ectopic accumulation of lipid intermediates. Diacylglycerol-mediated activation of protein kinase C isoforms impairs insulin receptor substrate signaling in muscle and hepatic insulin receptor kinase activity in liver, while increased hepatic acetyl-coenzyme A promotes gluconeogenesis.^[18]
• Expansion and dysfunction of visceral and ectopic adipose depots increases the flux of free fatty acids to the liver, promotes secretion of pro-inflammatory adipokines and reduces adiponectin. The result is a chronic low-grade inflammatory state with recruitment of macrophages to adipose tissue.^[19]
• Hepatic overproduction of very low density lipoprotein generates the characteristic atherogenic lipid triad of raised triglycerides, reduced high-density lipoprotein cholesterol and a preponderance of small dense low-density lipoprotein particles.^[6][1]
• Blood pressure rises through several converging mechanisms: sympathetic nervous system activation, activation of the renin-angiotensin-aldosterone system by adipose-derived mediators, renal sodium retention promoted by hyperinsulinemia, and endothelial dysfunction with reduced nitric oxide bioavailability.^[6][19]
• The same processes underlie the strong associations with metabolic dysfunction-associated steatotic liver disease, chronic kidney disease and subclinical atherosclerosis, which is the rationale for the integrated cardiovascular-kidney-metabolic construct.^[10][16]

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Priyamvada Singh, M.B.B.S. [2]; Raviteja Guddeti, M.B.B.S. [3]; Aarti Narayan, M.B.B.S [4]

• Sustained positive energy balance with excess or dysfunctional adiposity, particularly visceral and ectopic fat^[19][12]
• Physical inactivity and sedentary behavior^[6]
• Genetic and epigenetic susceptibility, including ethnic differences in the visceral adiposity accompanying any given body mass index^[8]
• Aging, with progressive loss of lean mass and redistribution of fat^[6]

• Cushing’s syndrome and exogenous glucocorticoid exposure^[20]
• Polycystic ovary syndrome^[21]
• Congenital and acquired lipodystrophy syndromes, including antiretroviral-associated lipodystrophy^[22]
• Obstructive sleep apnea and short or disrupted sleep^[16]
• Drug-induced metabolic disturbance, most prominently with second-generation antipsychotics, where clozapine and olanzapine carry the greatest burden of weight gain and lipid and glucose derangement^[23]
• Adverse social determinants of health, including food insecurity, unemployment and low household income, which are independently associated with more advanced cardiovascular-kidney-metabolic disease^[24]

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Metabolic syndrome is a diagnosis of clustering, not of exclusion, but several conditions reproduce the same phenotype and carry different management implications. The table below summarizes the principal alternatives.

• In the United States National Health and Nutrition Examination Survey, the prevalence of metabolic syndrome among adults aged 20 years and older increased from 37.6% (95% CI 34.0%-41.4%) in 2011-12 to 41.8% (95% CI 38.1%-45.7%) in 2017-18. The prevalence of the elevated glucose component rose over the same interval from 48.9% (95% CI 45.7%-52.5%) to 64.7% (95% CI 61.4%-67.9%), and prevalence among participants with low educational attainment rose from 44.4% (95% CI 38.8%-50.1%) to 55.0% (95% CI 50.8%-59.1%).^[25]
• An earlier analysis of the same survey covering 2011 to 2016 also documented rising prevalence, with the steepest relative increases among younger adults, which is of particular concern given the long exposure time to risk.^[26]
• Applying the cardiovascular-kidney-metabolic staging system to United States adults aged 30 to 79 years, the age-standardized prevalence of stages 0 through 4 was 13.6% (95% CI 13.0%-14.3%), 29.9% (95% CI 29.1%-30.7%), 43.7% (95% CI 42.9%-44.5%), 4.7% (95% CI 4.4%-5.0%) and 8.1% (95% CI 7.6%-8.5%) respectively. Advanced disease (stage 3 or 4) was more prevalent among those who were unemployed (18.8%, 95% CI 17.7%-20.1%, versus 11.4%, 95% CI 11.0%-11.9%), had low family income (16.1%, 95% CI 15.4%-16.8%, versus 10.1%, 95% CI 9.5%-10.7%) or experienced food insecurity (18.3%, 95% CI 17.1%-19.6%, versus 11.7%, 95% CI 11.2%-12.2%).^[24]
• An independent analysis of the 2011 to 2020 survey cycles similarly found that the large majority of United States adults meet criteria for at least stage 1 disease, with meaningful differences by race and ethnicity.^[27]
• In children and adolescents, modelled global prevalence in 2020 was 2.8% (95% uncertainty interval 1.4-6.7) among children aged 6 to 12 years and 4.8% (95% uncertainty interval 2.9-8.5) among adolescents aged 13 to 18 years, corresponding to approximately 25.8 million (12.6-61.0) children and 35.5 million (21.3-63.0) adolescents. Regional prevalence in children ranged from 1.4% (0.6-3.1) in northwestern Europe to 8.2% (6.9-10.1) in Central Latin America, and in adolescents from 2.9% (2.6-3.3) in east Asia to 6.7% (5.9-8.3) in high-income English-speaking countries. Prevalence did not rise consistently with national income, indicating that country wealth is not the principal driver.^[28]
• Population-level burden of the constituent risk factors and their trends are tracked annually in the American Heart Association statistical update.^[29]

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Priyamvada Singh, M.B.B.S. [2]

• Increasing age^[6]
• Ethnicity, with South Asian, Chinese, Hispanic and certain other populations developing metabolic abnormalities at lower waist circumference and body mass index thresholds^[8]
• Family history of type 2 diabetes mellitus or premature cardiovascular disease^[6]
• Personal history of gestational diabetes or polycystic ovary syndrome^[21][30]

• Excess and centrally distributed adiposity^[19][12]
• Physical inactivity and prolonged sedentary time^[31]
• Diets high in refined carbohydrate, sugar-sweetened beverages and ultra-processed foods^[32]
• Cigarette smoking and short or poor-quality sleep, both included in the Life’s Essential 8 cardiovascular health construct^[32]
• Second-generation antipsychotic and long-term glucocorticoid therapy^[23]
• Adverse social determinants of health, including food insecurity and low income^[24]

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Priyamvada Singh, M.B.B.S. [2]; Raviteja Guddeti, M.B.B.S. [3]

• There is no recommendation to screen the general population for metabolic syndrome as a discrete entity. Screening is instead directed at its components and at global cardiovascular risk.^[13][33]
• The United States Preventive Services Task Force recommends screening for prediabetes and type 2 diabetes mellitus in adults aged 35 to 70 years who have overweight or obesity, and referral of those with abnormal results to preventive interventions (B recommendation).^[34]
• The Task Force also recommends offering or referring adults with a body mass index of 30 kg/m² or higher to intensive multicomponent behavioral interventions (B recommendation),^[35] and recommends initiating a statin in adults aged 40 to 75 years who have one or more cardiovascular risk factors and an estimated 10-year cardiovascular risk of 10% or greater (B recommendation), with selective offering where estimated risk is 7.5% to less than 10% (C recommendation).^[36]
• The practical screening panel therefore comprises waist circumference, blood pressure measured with correct technique, a fasting lipid profile, and fasting glucose or glycated hemoglobin. Assessment of kidney function with estimated glomerular filtration rate and urinary albumin-to-creatinine ratio is added in the cardiovascular-kidney-metabolic framework, since kidney disease defines stage 2 and modifies risk prediction.^[10]
• Global risk should be quantified with a contemporary equation. The American Heart Association Predicting Risk of Cardiovascular Disease EVENTs (PREVENT) equations estimate 10-year and 30-year risk of total cardiovascular disease, atherosclerotic cardiovascular disease and heart failure in adults aged 30 to 79 years, are sex-specific and race-free, incorporate estimated glomerular filtration rate, and optionally accept urinary albumin-to-creatinine ratio, glycated hemoglobin and a social deprivation index. In external validation the median C-statistic for total cardiovascular disease was 0.794 (interquartile interval 0.763-0.809) in female and 0.757 (interquartile interval 0.727-0.778) in male participants.^[37]

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] ; Associate Editor(s)-in-Chief: Aditya Ganti M.B.B.S. [2]

• Metabolic syndrome typically develops over years, beginning with weight gain and central fat accumulation, progressing through isolated abnormalities of triglycerides or blood pressure, and culminating in the full cluster. Progression to type 2 diabetes mellitus occurs when beta cell compensation for insulin resistance fails.^[1][2]
• In a meta-analysis of 87 studies including 951,083 patients, metabolic syndrome was associated with a relative risk of 2.35 (95% CI 2.02 to 2.73) for cardiovascular disease, 2.40 (95% CI 1.87 to 3.08) for cardiovascular mortality, 1.58 (95% CI 1.39 to 1.78) for all-cause mortality, 1.99 (95% CI 1.61 to 2.46) for myocardial infarction and 2.27 (95% CI 1.80 to 2.85) for stroke. Patients with the syndrome but without diabetes mellitus retained a high cardiovascular risk.^[38]
• An earlier meta-analysis of 37 studies comprising 43 cohorts and 172,573 individuals found a relative risk of cardiovascular events and death of 1.78 (95% CI 1.58 to 2.00), which remained elevated at 1.54 (95% CI 1.32 to 1.79) after adjustment for traditional cardiovascular risk factors. The association was stronger in women and in lower-risk populations.^[39]
• Pooled prospective data using the exact Adult Treatment Panel III definition gave relative risks of 1.27 (95% CI 0.90 to 1.78) for all-cause mortality, 1.65 (95% CI 1.38 to 1.99) for cardiovascular disease and 2.99 (95% CI 1.96 to 4.57) for diabetes mellitus. The corresponding population-attributable fractions were approximately 6% to 7% for all-cause mortality, 12% to 17% for cardiovascular disease and 30% to 52% for diabetes.^[15]
• Cancer risk is also increased. In cohort studies, metabolic syndrome was associated in men with liver (relative risk 1.43), colorectal (1.25) and bladder cancer (1.10), and in women with endometrial (1.61), pancreatic (1.58), postmenopausal breast (1.56), rectal (1.52) and colorectal cancer (1.34).^[40]
• Additional recognized complications include metabolic dysfunction-associated steatotic liver disease with progression to steatohepatitis, fibrosis and cirrhosis,^[11] chronic kidney disease,^[10] obstructive sleep apnea, hyperuricemia and gout, and reproductive dysfunction.^[6][21]
• Prognosis improves substantially with weight reduction and component control, and the syndrome is frequently reversible in its earlier stages.^[41]

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Priyamvada Singh, M.B.B.S. [2]; Raviteja Guddeti, M.B.B.S. [3]; Aarti Narayan, M.B.B.S [4]

Diagnostic Criteria | History and Symptoms | Physical Examination | Laboratory Findings | Electrocardiogram | Chest X Ray | CT | MRI | Echocardiography or Ultrasound | Other Imaging Findings |Other Diagnostic Studies

The harmonized criteria are the current standard. Any three of the five components below establish the diagnosis, and drug treatment of a component counts as a positive finding.^[8]

• Metabolic syndrome is usually asymptomatic and is detected through measurement rather than symptoms.^[6]
• The history should cover weight trajectory and previous weight-loss attempts, dietary pattern, physical activity and sedentary time, sleep duration and symptoms of obstructive sleep apnea, alcohol and tobacco use, menstrual and reproductive history, family history of premature cardiovascular disease and diabetes mellitus, and a full medication review including antipsychotics, glucocorticoids and antiretroviral agents.^[6][23]
• Symptoms suggesting an alternative or superimposed diagnosis should be sought explicitly, including proximal weakness and easy bruising, cold intolerance, acral enlargement, and oligomenorrhea with hirsutism.^[20][21]

• Waist circumference measured at the top of the iliac crest at the end of a normal expiration, with a non-stretch tape held horizontally and snug without compressing the skin.^[8]
• Height, weight and body mass index, recognizing that body mass index alone is an inadequate individual measure of adiposity and should be paired with an anthropometric measure of fat distribution.^[12]
• Blood pressure using validated equipment and correct technique, with out-of-office confirmation before a diagnosis of hypertension is made.^[42]
• Skin examination for acanthosis nigricans, skin tags, eruptive xanthomas and xanthelasma, and for the violaceous striae and centripetal fat redistribution of Cushing’s syndrome.^[20]
• Assessment of fat distribution for the selective subcutaneous fat loss of lipodystrophy, and examination for hepatomegaly.^[22]

• Core panel: fasting lipid profile (total cholesterol, triglycerides, high-density lipoprotein cholesterol and calculated or measured low-density lipoprotein cholesterol), fasting plasma glucose, and glycated hemoglobin.^[8][30]
• Kidney assessment: serum creatinine with estimated glomerular filtration rate and urinary albumin-to-creatinine ratio, which are required for cardiovascular-kidney-metabolic staging and improve risk prediction, particularly where albuminuria exceeds 300 mg/g.^[10][37]
• Liver assessment: alanine aminotransferase and aspartate aminotransferase, with non-invasive fibrosis scoring where steatosis is present.^[11]
• Selective testing directed by clinical suspicion: thyroid stimulating hormone, overnight dexamethasone suppression or late-night salivary cortisol, androgen profile, insulin-like growth factor 1, and serum uric acid.^[20][21]
• Measurement of fasting insulin or formal quantification of insulin resistance is not required for the harmonized diagnosis and is generally reserved for research.^[8]

• A resting 12-lead electrocardiogram is not diagnostic of metabolic syndrome but is used to detect left ventricular hypertrophy, prior silent myocardial infarction, conduction disease and atrial fibrillation, all of which are more frequent in this population and which influence staging and treatment intensity.^[10][42]

• A chest x ray has no role in establishing the diagnosis. It is obtained where symptoms suggest heart failure or other cardiopulmonary disease.^[6]

• Computed tomography quantifies visceral and subcutaneous adipose tissue accurately and has been central to research defining the metabolic consequences of fat distribution, but it is not recommended for routine diagnosis because of cost and radiation exposure.^[19]
• Coronary artery calcium scoring by non-contrast computed tomography may be used as a risk-refining test in selected adults at intermediate estimated risk, and a positive result places the patient in the subclinical cardiovascular disease stage of the cardiovascular-kidney-metabolic framework.^[33][10]

• Magnetic resonance imaging and magnetic resonance spectroscopy quantify visceral, hepatic and intramyocellular lipid and remain the reference standards for ectopic fat measurement in research settings.^[18][19]
• Magnetic resonance imaging proton density fat fraction and magnetic resonance elastography are used in specialist hepatology practice and in clinical trials of steatohepatitis.^[11]

• Abdominal ultrasound is the usual first-line test for hepatic steatosis, and transient elastography with controlled attenuation parameter provides simultaneous assessment of steatosis and stiffness.^[11]
• Echocardiography is used to evaluate left ventricular hypertrophy and diastolic dysfunction where clinically indicated.^[42]
• Carotid ultrasound may demonstrate subclinical atherosclerosis in selected patients.^[10]

• Dual-energy x-ray absorptiometry can quantify total and regional body fat and is one of the direct measures of adiposity endorsed for confirming excess adiposity when available.^[12]

• Ambulatory or home blood pressure monitoring is recommended to confirm hypertension and to identify white-coat and masked patterns.^[42]
• Polysomnography or home sleep apnea testing where obstructive sleep apnea is suspected.^[16]
• Oral glucose tolerance testing where fasting glucose and glycated hemoglobin are discordant or where polycystic ovary syndrome or prior gestational diabetes raises the pre-test probability of dysglycemia.^[30][21]

Dietary Therapy | Physical Activity | Medical Therapy | Surgery | Primary Prevention | Secondary Prevention | Tertiary Prevention | Cost-Effectiveness of Therapy | Future or Investigational Therapies

No agent has been licensed to treat metabolic syndrome as a single entity, and the evidence base is component-directed. The two therapeutic pillars are sustained lifestyle change with weight reduction, and guideline-directed treatment of each abnormal component.^[6][13]

• Intensive lifestyle intervention is first-line for every patient. In the Diabetes Prevention Program, 3,234 participants with impaired glucose tolerance were randomized to placebo, metformin 850 mg twice daily, or a lifestyle programme targeting at least 7% weight loss and at least 150 minutes of physical activity per week. Over an average of 2.8 years the incidence of diabetes mellitus was 11.0, 7.8 and 4.8 cases per 100 person-years respectively; lifestyle reduced incidence by 58% (95% CI 48 to 66) and metformin by 31% (95% CI 17 to 43) compared with placebo.^[43]
• The same trial provides the most direct randomized evidence for treating metabolic syndrome itself. Fifty-three percent of participants (n = 1,711) met Adult Treatment Panel III criteria at baseline. Among the remainder, the incidence of the syndrome was reduced by 41% in the lifestyle group (P < 0.001) and by 17% in the metformin group (P = 0.03) compared with placebo, with three-year cumulative incidences of 51%, 45% and 34% in the placebo, metformin and lifestyle groups respectively.^[41]
• Benefit is durable. Long-term follow-up of the Diabetes Prevention Program Outcomes Study showed persistent reductions in diabetes incidence in both the lifestyle and metformin groups over 15 years.^[44]
• The Finnish Diabetes Prevention Study independently demonstrated that individualized counselling on weight reduction, dietary fat and fibre, and physical activity substantially reduced progression from impaired glucose tolerance to diabetes mellitus.^[45]
• Dietary pattern matters more than any single macronutrient target. A Mediterranean-style diet reduced the prevalence of metabolic syndrome and improved endothelial function in a randomized trial of patients meeting Adult Treatment Panel III criteria,^[46] and in the PREDIMED trial a Mediterranean diet supplemented with extra-virgin olive oil or mixed nuts reduced major cardiovascular events compared with a reduced-fat control diet (hazard ratio 0.69, 95% CI 0.53 to 0.91 and 0.72, 95% CI 0.54 to 0.95 respectively).^[47]
• The DASH dietary pattern, rich in fruit, vegetables and low-fat dairy products and reduced in saturated and total fat, lowers blood pressure substantially and is an appropriate alternative or complement.^[48]
• Physical activity should target at least 150 to 300 minutes of moderate-intensity or 75 to 150 minutes of vigorous-intensity aerobic activity per week, with muscle-strengthening activity on two or more days per week and reduction of sedentary time.^[31]
• An important caveat should be stated plainly. In the Look AHEAD trial, 5,145 overweight or obese adults with type 2 diabetes mellitus were randomized to intensive lifestyle intervention or diabetes support and education. Despite greater weight loss (8.6% versus 0.7% at 1 year and 6.0% versus 3.5% at study end) and better risk-factor control, the primary cardiovascular composite occurred at 1.83 versus 1.92 events per 100 person-years (hazard ratio 0.95, 95% CI 0.83 to 1.09, P = 0.51) and the trial was stopped for futility at a median follow-up of 9.6 years.^[49]

• Treat according to the 2025 multisociety high blood pressure guideline, which retires and replaces the 2017 guideline. Lifestyle measures are foundational, and pharmacologic therapy is guided by blood pressure stage and estimated cardiovascular risk, with team-based care and out-of-office monitoring emphasized.^[42]
• Agents with favorable or neutral metabolic profiles are generally preferred as initial therapy in this population.^[6]

• Low-density lipoprotein cholesterol is the primary target, with statin intensity determined by clinical atherosclerotic cardiovascular disease status, LDL-C level, diabetes mellitus and estimated 10-year risk, and with risk-enhancing factors used to guide decisions in the intermediate-risk group.^[50]
• Statin therapy is associated with a small increase in incident diabetes mellitus (odds ratio 1.09, 95% CI 1.02 to 1.17), amounting to one extra case for 255 patients (95% CI 150 to 852) treated for 4 years. This risk is small in absolute terms and is outweighed by the reduction in coronary events, and it should not change practice in patients at moderate or high cardiovascular risk or with established cardiovascular disease.^[51]

• Metformin may be considered for diabetes prevention in selected high-risk individuals, particularly those with body mass index of 35 kg/m² or higher, younger age, or prior gestational diabetes, as set out in the American Diabetes Association Standards of Care.^[30][43]
• In patients who have progressed to type 2 diabetes mellitus, agent selection should be driven by cardiovascular and kidney comorbidity rather than by glucose lowering alone.^[52]
• Glucagon-like peptide-1 receptor agonists reduce major adverse cardiovascular events, cardiovascular death and kidney outcomes in patients with type 2 diabetes mellitus in meta-analysis of cardiovascular outcome trials.^[53]
• Sodium-glucose cotransporter 2 inhibitors slow progression of chronic kidney disease and reduce cardiovascular events across a broad range of patients with and without diabetes.^[54]
• Pioglitazone is the only agent tested against insulin resistance itself as the therapeutic target in a cardiovascular outcome trial. In the Insulin Resistance Intervention after Stroke trial, 3,876 patients without diabetes who had a recent ischemic stroke or transient ischemic attack and a homeostasis model assessment of insulin resistance index above 3.0 were randomized to pioglitazone or placebo. By 4.8 years the primary outcome of fatal or non-fatal stroke or myocardial infarction occurred in 175 of 1,939 patients (9.0%) versus 228 of 1,937 (11.8%) (hazard ratio 0.76, 95% CI 0.62 to 0.93, P = 0.007), and diabetes developed in 73 patients (3.8%) versus 149 (7.7%) (hazard ratio 0.48, 95% CI 0.33 to 0.69, P < 0.001). Pioglitazone caused more weight gain exceeding 4.5 kg (52.2% versus 33.7%, P < 0.001), edema (35.6% versus 24.9%, P < 0.001) and fracture requiring surgery or hospitalization (5.1% versus 3.2%, P = 0.003).^[55]

• Obesity pharmacotherapy is indicated as an adjunct to lifestyle intervention according to body mass index and the presence of weight-related complications, with agent selection individualized to comorbidity.^[56]
• In the STEP 1 trial, once-weekly subcutaneous semaglutide 2.4 mg produced a mean change in body weight of -14.9% versus -2.4% with placebo at week 68 in adults with overweight or obesity without diabetes, with improvement in waist circumference, blood pressure and lipids.^[57]
• In SURMOUNT-1, tirzepatide produced mean weight reductions of -15.0%, -19.5% and -20.9% at the 5 mg, 10 mg and 15 mg doses versus -3.1% with placebo at 72 weeks.^[58] Comparable, somewhat smaller reductions were seen in SURMOUNT-2 in patients with type 2 diabetes mellitus.^[59]
• Most importantly for this population, the SELECT trial showed that once-weekly semaglutide 2.4 mg reduced the composite of cardiovascular death, non-fatal myocardial infarction and non-fatal stroke in patients with overweight or obesity and pre-existing cardiovascular disease but without diabetes (hazard ratio 0.80, 95% CI 0.72 to 0.90). This is the first demonstration that treating the adiposity component improves hard cardiovascular outcomes independently of glucose lowering.^[60]

• Metabolic and bariatric surgery should be considered where response to lifestyle and pharmacologic therapy is inadequate. The 2022 American Society for Metabolic and Bariatric Surgery and International Federation for the Surgery of Obesity and Metabolic Disorders statement recommends surgery for individuals with body mass index of 35 kg/m² or greater regardless of comorbidity, and for individuals with body mass index of 30 to 34.9 kg/m² with metabolic disease, and endorses lower thresholds in Asian populations. These criteria supersede the 1991 National Institutes of Health consensus thresholds.^[61]
• In the STAMPEDE trial, Roux-en-Y gastric bypass and sleeve gastrectomy were superior to intensive medical therapy alone for glycemic control, weight loss and medication reduction at 5 years in patients with type 2 diabetes mellitus and obesity.^[62]
• The Swedish Obese Subjects study, a prospective matched intervention trial, demonstrated that bariatric surgery reduced overall mortality^[63] and the incidence of cardiovascular events compared with usual care.^[64]

• Metabolic syndrome should be managed as a chronic condition with structured, team-based follow-up rather than as an incidental finding.^[9][10]
• Annual reassessment should include all five components, weight and waist circumference, estimated glomerular filtration rate and urinary albumin-to-creatinine ratio, hepatic enzymes with non-invasive fibrosis assessment where steatosis is present, and recalculation of global cardiovascular risk.^[10][37][11]
• Weight regain after discontinuation of pharmacotherapy is expected, and treatment should be planned as long-term rather than time-limited.^[56]
• Population-level maintenance of cardiovascular health is usefully framed by the Life’s Essential 8 metrics, which combine diet, physical activity, nicotine exposure, sleep, weight, lipids, glucose and blood pressure.^[32]
• European guidance offers a stepwise risk-based approach to prevention that is broadly concordant with North American recommendations and may be preferred in some settings.^[65]

• Chronic kidney disease defines cardiovascular-kidney-metabolic stage 2 and markedly amplifies risk. Management should follow the KDIGO 2024 guideline, including risk-based use of renin-angiotensin system blockade, sodium-glucose cotransporter 2 inhibition and statin therapy.^[66][67]

• Steatotic liver disease is now defined by hepatic steatosis together with at least one cardiometabolic criterion, so most patients with metabolic syndrome and steatosis meet the definition.^[11]
• In the phase 3 ESSENCE trial, 1,197 patients with biopsy-defined steatohepatitis and stage 2 or 3 fibrosis were randomized 2:1 to once-weekly semaglutide 2.4 mg or placebo. At the week 72 interim analysis of the first 800 patients, resolution of steatohepatitis without worsening of fibrosis occurred in 62.9% versus 34.3% (estimated difference 28.7 percentage points, 95% CI 21.1 to 36.2, P < 0.001), and reduction in fibrosis without worsening of steatohepatitis in 36.8% versus 22.4% (estimated difference 14.4 percentage points, 95% CI 7.5 to 21.3, P < 0.001). Mean body-weight change was -10.5% versus -2.0%.^[68]
• Resmetirom, a liver-directed thyroid hormone receptor beta agonist, improved both steatohepatitis resolution and fibrosis in the MAESTRO-NASH trial and represents the first agent approved specifically for this indication.^[69]

• Cardiometabolic screening should be performed at diagnosis and repeated periodically, since insulin resistance, dyslipidemia and dysglycemia are common irrespective of body mass index.^[21]

• The diagnosis should not be applied below age 10 years. Management is centred on family-based lifestyle intervention, and the high absolute numbers of affected young people worldwide argue for multisectoral prevention rather than individual treatment alone.^[14][28]

• Baseline and serial monitoring of weight, waist circumference, blood pressure, fasting glucose and lipids is required, and agent selection should take account of large differences between drugs in metabolic burden.^[23]

• These patients require disease-specific therapy directed at the underlying disorder, since conventional lifestyle and lipid-lowering approaches alone are usually insufficient.^[22][20]

Case #1

• Chronic Somogyi rebound
• Hyperinsulinemia
• Insulin resistance
• Obesity
• Type 2 diabetes mellitus
• Hypertension
• Dyslipidemia
• Metabolic dysfunction-associated steatotic liver disease
• Polycystic ovary syndrome
• Obstructive sleep apnea
• Chronic kidney disease
• Cardiovascular disease

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