Metabolic Syndrome

Metabolic syndrome is a collective term for a group of conditions that occur simultaneously and increase the risk of cardiovascular disease, stroke, and type 2 diabetes. The syndrome is characterized by elevated blood pressure, high blood sugar, abnormal fat distribution with fat accumulation around the abdomen (so-called apple-shaped body type)¹², as well as unfavorable blood lipids such as low HDL cholesterol and high triglyceride levels.

These factors share one common denominator: they are all linked to increased abdominal fat, particularly fat located around the internal organs (visceral fat), also known as intra-abdominal or ectopic fat³⁴. This fat acts hormonally and pro-inflammatory in the body and plays a central role in the development of insulin resistance, which is a core problem in metabolic syndrome.

Prevalence and Significance

Approximately 25% of adults in the general population have metabolic syndrome, with rising prevalence in older age⁴⁵. After the age of 65, the prevalence increases to between 30–40%, primarily driven by adult weight gain and a congenital or epigenetic tendency to store fat in the abdomen⁶. The presence of even one of the criteria (such as high blood pressure or low HDL) indicates elevated risk of later developing the full syndrome and reflects a high lifelong burden of cardiovascular risk⁶.

The development of metabolic syndrome largely mirrors the global obesity epidemic, where lifestyle and genetic vulnerability act together in an unfavorable synergy⁷. The earlier weight control and lifestyle measures are introduced, the greater the chance of preventing future disease.

Causes and Predisposing Factors

The development of metabolic syndrome is mainly based on two factors: genetic/epigenetic predisposition and lifestyle⁸.

People with a congenital tendency to store fat in the abdomen (in the liver, pancreas, heart, and surrounding tissues) are more prone to developing underlying disorders such as insulin resistance, fatty liver, and hypertension⁹. In addition, individuals with low birth weight, poor intrauterine growth, or exposure to maternal smoking during pregnancy are more likely to develop this fat distribution pattern – a sign of epigenetic programming⁷¹¹.

Nevertheless, lifestyle is the most important triggering factor:

• Weight gain in adulthood

• Energy-dense and nutrient-poor diet

• Physical inactivity

• High intake of saturated fat, sugar, and alcohol

• Smoking

• Psychosocial stress, especially in socioeconomically vulnerable groups¹⁰

These factors contribute to a shift in body composition where fat accumulates viscerally, which in turn increases the risk of metabolic disturbances that define the syndrome. Individual variations in genetic expression and environmental exposure explain why not all develop the full syndrome, though many may have a “latent” metabolic risk.

Pathophysiological Mechanisms

Metabolic syndrome is not a single disease but a combination of multiple metabolic processes. The key components involve:

1. Insulin resistance and glucose intolerance

Insulin resistance means that the body’s cells respond poorly to insulin. To compensate, the pancreas increases insulin production, leading to hyperinsulinemia and eventually impaired glucose tolerance and diabetes²¹³.

2. Hypertension and insulin resistance

Blood pressure is often elevated in metabolic syndrome. Although the link with insulin is not entirely clear, obesity clearly plays a role in the development of both hypertension and insulin resistance, and weight loss improves both.

3. Dyslipidemia

Low HDL cholesterol and high triglycerides are typical findings. This reflects impaired lipid metabolism in the liver and further contributes to atherosclerosis.

4. Abdominal obesity

Measured by waist circumference, this reflects increased visceral fat. This fat acts pro-inflammatory and hormonally disruptive and is considered a direct driver of the syndrome⁷.

Diagnostic Criteria

Several international organizations have formulated criteria for the diagnosis of metabolic syndrome. There are minor differences, but the main principle is that at least three of the following must be present:

• Increased waist circumference (national cut-offs)

• Elevated fasting blood glucose (≥5.6 mmol/L)

• Elevated triglycerides (≥1.7 mmol/L)

• Low HDL cholesterol (<1.0 mmol/L in men, <1.3 mmol/L in women)

• Elevated blood pressure (≥130/85 mmHg) or use of antihypertensive medication

Values and thresholds differ somewhat between WHO, IDF, NCEP ATP III, and other international guidelines, but most emphasize the same five risk factors. Some definitions require insulin resistance as a prerequisite, while others do not.

Clinical Relevance and the Role of Physiotherapy

Metabolic syndrome is not only a biochemical condition – it has major consequences for patient function, quality of life, and disease risk. Physiotherapists have an important role in both prevention and management.

By assessing physical activity, measuring waist circumference, and evaluating physical capacity, physiotherapists can help identify patients at risk. Physical activity has proven effects on all five components of the syndrome, particularly visceral fat, insulin resistance, and blood pressure.

Regular aerobic exercise, strength training, and structured lifestyle interventions should be an integral part of the treatment plan. In addition, patients at high risk should be referred to a physician for medical evaluation and monitoring of lipid profile and blood glucose.

Table: Summary of Risk Factors and Mechanisms

Component	Description
Waist circumference	Indicator of visceral fat. Increased risk at ≥102 cm (men), ≥88 cm (women).
Fasting glucose	Elevated in insulin resistance. ≥5.6 mmol/L = risk.
Triglycerides	>1.7 mmol/L. Reflects lipid metabolism disorder.
HDL cholesterol	Protects against atherosclerosis. Low levels increase risk.
Blood pressure	≥130/85 mmHg. Hypertension contributes to CVD risk.
Underlying cause	Obesity, physical inactivity, genetic predisposition, epigenetics.

Treatment and Prevention of Metabolic Syndrome

The goal of treatment for metabolic syndrome is to reverse modifiable risk factors and prevent serious complications such as cardiovascular disease, fatty liver, and cancer. Lifestyle changes are the cornerstone, and interventions should be tailored to each individual’s risk profile and degree of metabolic burden⁷.

Dietary Modifications

A daily diet that promotes weight normalization, improves lipid levels, and reduces insulin resistance is essential. The following recommendations form the basis:

• 5 or more servings of fruits and vegetables daily, providing fiber, antioxidants, and phytonutrients

• 1–2 servings of legumes, fish, or lean meat to ensure protein and essential fatty acids

• Two handfuls of potatoes, wholegrain rice, or pasta for balanced carbohydrate intake and satiety

• One serving of low-fat milk for calcium and vitamin D

• Alcohol limited to a maximum of 14 units per week, as alcohol negatively affects insulin resistance and liver function

Physical Activity and Exercise Recommendations

Both prevention and treatment of metabolic syndrome require daily movement. WHO recommends at least 150 minutes of moderate activity per week – such as brisk walking, cycling, or gardening – or 75 minutes of vigorous activity. In addition, strength training should be performed at least two days per week.

Increasing everyday activity is an important strategy for people with low functional capacity, and even short walks can significantly improve insulin sensitivity and fat metabolism.

Smoking Cessation and Reduction of Other Risk Factors

Smoking increases central obesity, lowers HDL cholesterol, and contributes to insulin resistance. Quitting smoking is therefore a central part of the treatment plan – not only for the individual, but also for potential future children, as smoking during pregnancy is associated with unfavorable epigenetic programming.

Prevention: The Key to Reducing Disease Burden

Many Risk Factors Arise Early

Many risk factors for metabolic syndrome develop long before any clinical symptoms appear. For some, the risk begins with childhood obesity, while others carry a genetic vulnerability due to low birth weight or intrauterine growth restriction.

Early screening and risk assessment, for example in individuals with a family history of type 2 diabetes, heart attack, or obesity, give healthcare providers the opportunity to implement preventive measures before serious disease develops.

Low HDL cholesterol is the most common sign of metabolic syndrome in young adults and may be the first detectable marker in many cases. Identifying and addressing low HDL early can therefore have great public health importance⁶.

Weight Loss and Physical Activity Can Reverse the Syndrome

Regular exercise and moderate weight loss can not only prevent but also reverse all components of metabolic syndrome – including insulin resistance, dyslipidemia, hypertension, and abdominal obesity.

Physical activity has been shown to reduce the prevalence of both metabolic syndrome and type 2 diabetes, while also contributing to a significant reduction in the overall burden on healthcare systems.

Pharmacological Support and New Opportunities

In addition to lifestyle interventions, some high-risk individuals may benefit from medical support:

• Anti-obesity medications can aid weight control when lifestyle measures alone are insufficient

• PPARγ agonists may improve insulin sensitivity and lipid profile

• GLP-1 receptor agonists have shown benefits for weight, glucose control, and cardiovascular risk, and are now widely used in both diabetes and metabolic syndrome

These should only be considered after thorough medical evaluation, and always as a supplement to – not a replacement for – lifestyle changes.

The Role of Physiotherapy in Treating Metabolic Syndrome

Physiotherapists play a key role in both prevention and treatment. Integrating physical activity into the treatment plan has proven effects on all metabolic components, including:

• Improved insulin sensitivity

• Better lipid profile

• Reduced inflammatory response

• Enhanced cardiovascular health

• Positive epigenetic influence

Recent meta-analyses show that both aerobic exercise and strength training, alone or combined, produce significant improvements in individuals with metabolic syndrome. In many cases, a tailored exercise program can reduce risk factors to the point where patients no longer meet diagnostic criteria.

Examples of Effective Physiotherapy Interventions

• Treadmill walking or brisk walking 3–5 times per week

• Strength training targeting large muscle groups (2 times per week)

• Guidance on diet and health behaviors

• Functional testing and monitoring of progress

A central goal is to reduce the patient’s cardiometabolic risk while increasing function, quality of life, and self-management. This often requires interdisciplinary collaboration between physiotherapists, physicians, nutritionists, and psychologists.

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