Metabolic Syndrome
The Rise of Metabolic Syndrome
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Defining Metabolic Syndrome
Metabolic Syndrome is the name for a group of risk factors that can raise a person’s risk of heart disease, diabetes and stroke (1). It may also be referred to as Dysmetabolic Syndrome, Insulin Resistance Syndrome, Obesity Syndrome or Syndrome X.
Risk factors for Metabolic Syndrome include:
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The clinical usefulness of the term, Metabolic Syndrome has been debated over the years. Some argue that making a diagnosis is no more useful than an assessment of the individual risk factors alone. However, others believe it can be a useful clinical tool to help identify people who may be at higher risk of cardiovascular disease and diabetes, and to encourage them to seek regular follow up and treatment.
Diagnosing Metabolic Syndrome - Criteria suggested by different international organisations (2)
WHO (1999) |
NCEP, ATP111 (2001) |
IDF (2006) |
Hyperglycaemia or insulin resistance, Plus two of: Obesity: Dyslipidemia: Hypertension: Microalbuminuria |
Three or more of: Central obesity: Waist > 102cm (M), 88cm (F) Fasting glucose ≥ 6.1mmol/L Hypertriglyceridemia: Hypertension: |
Central obesity: Waist (ethnic specific) Plus two of: Fasting glucose ≥ 5.6mmol/L Treated dyslipidemia: Treated hypertension: |
ATP= adult treatment panel; BMI = body mass index; F = female; HDL = high-density lipoprotein; IDF = International Diabetes Federation; LDL low-density lipoprotein; M = male; NCEP = National Cholesterol Education; W/H = waist/hip ratio; WHO = World Health Organisation |
Prevalence and causes
While the concept of Metabolic Syndrome has been around for decades, there has been much debate over its definition, making it difficult to gauge the true global prevalence. In 2012, it was predicted in many affluent and some developing countries, that approximately a quarter of all adults would fit the criteria for Metabolic Syndrome set by WHO and the NCEP, and a higher proportion if the criteria suggested by the International Diabetes Federation was used (2).
Since this time, Metabolic Syndrome has become more prevalent due to rising obesity rates. New Zealand and Australia currently rank in the top five most obese nations in the OECD , with obesity continuing to climb in both countries, increasing across all age groups and both genders in the last decade (3, 4). We can therefore expect that our countries are also disproportionately affected by Metabolic Syndrome (5).
Differences in diet, lifestyle, age, genetic background and level of physical activity can all influence the prevalence of Metabolic Syndrome. While some factors cannot be controlled, including age and genetics (family history and ethnicity), other factors such as excess body weight, lack of physical activity, insulin resistance and diet can be moderated through lifestyle intervention.
Investigations into specific dietary factors that may increase risk of Metabolic Syndrome continue. While research indicates that asides from sugar’s contribution to energy, there is no direct relationship between sugar intake and obesity. There is some evidence that in excess amounts during states of energy surplus, fructose in particular may be linked to other Metabolic Syndrome risk factors via raised uric acid concentrations (6, 7). In animal studies, it has been shown that lowering uric acid concentrations could largely prevent features of Metabolic Syndrome induced by fructose including weight gain, insulin resistance and hypertension (8). In humans however; despite being unable to consume the volumes of fructose prescribed in animal studies; the levels of fructose consumed may play a small role in obesity, insulin resistance, dyslipidemia and hypertension. However these conditions all have complex and multi-factorial origins and therefore more research is required to see conclusive results (6).
Treatment and prevention
There are two general approaches to managing Metabolic Syndrome. Treat Metabolic risk factors in isolation or target the root causes of the Syndrome, including high BMI, physical inactivity, and insulin resistance. While pharmacological modification of the associated risk factors has seen the most success in clinical practice, by far the greatest potential for both prevention and management of Metabolic Syndrome lies in reversing its root causes through lifestyle modification (9). Weight loss associated with increased physical activity and the appropriate dietary measures provides the only means of favourably influencing the broad range of abnormalities associated with the Syndrome (2). A weight loss of just 5-10% is often enough to make a difference. Adequate sleep and stress management may also play an important role in management (10-12).
NEXT: Glycemic index and glycemic load
Key References