Metabolic syndrome is the fourth of Peter Attias’ Four ‘horseman’, the others being Cardiovascular disease, Cancer and Neurodegenerative Disease. Metabolic syndrome is a range of conditions that lead ultimately to diabetes. It plays a contributory part in the development of the three other ‘horsemen’.

Metabolic syndrome is defined by the presence of at least three of the following.

• High blood pressure defined as greater than 130/85
• Abdominal obesity defined as a waist greater than 40 inches in a man and 35 inches in a woman.
• Low HDL cholesterol defined as less than 2.2mmol/l.
• High triglycerides defined as greater than 8.3 mmol/l.
• Raised glucose defined as a fasting glucose of greater than 5.6 mmol/l.

About 100 million Americans are considered to have Metabolic Syndrome. About a quarter of those in the UK have the problem. Why should we be concerned about Metabolic Syndrome? Well, it is thought to increase:

• Risk of cardiovascular disease by 135%
• Stroke risk by 127%
• A 56% increase in age adjusted risk of cancer mortality.
  
  And what about the third horseman, neurodegenerative disease?

• It poses about a 24% higher risk of Parkinson’s disease.
• about a 10% increase in Alzheimer’s disease.

When you look at all forms of dementia, there is about a 37% increase in risk.

So, it is a very significant problem affecting 1 in 4 of us. So why am I telling you this? It certainly is not to depress you. The title of the blog is longevity. So, what can we all do to either avoid or reverse the problem? How can we recognise when someone has the problem?

Is Metabolic Syndrome Caused by Obesity?

As you can see from the definition, obesity is not essential for metabolic syndrome, about 22% of non-obese people have metabolic syndrome. What causes us to develop the five risk factors? It cannot just be overeating, or the non-obese people would be free of the problem.

It comes down to the way we manage fat and the resulting insulin resistance. Fat is an essential store of energy, and it was the ability to store fat that led to our ancestors being able to inhabit less hospitable environments. But what was an essential benefit, became a huge problem when food and particularly refined sugars became plentiful. We all have a different capacity to store fat and in those with less capacity or those who take up excess calories, fat starts to get stored in unhealthy places like the muscles, liver, around our organs and in the pancreas. These sites produce cytokines, chemicals that lead to inflammation and damage.

When infiltrated with fat, muscle develops resistance to insulin, meaning that glucose finds it harder to get taken up by muscle calls. It then gets stored as more fat, compounding the problem. Those with insulin resistance struggle to lose fat because the pathway to break fat down is interrupted. The problem then becomes self-perpetuating.

Fat in the pancreas causes inflammation that damages the cells that produce insulin. Fat in the liver causes inflammation and Non Alcoholic Fatty Liver Disease, NAFLD which can progress to cirrhosis and liver failure.

So clearly, it is not good news.

How do we diagnose Metabolic Syndrome before problems arise?

We can perform a number of screening tests in the surgery, these include.

• Uric acid ideally less than 270 nmol/l
• Homocysteine ideally less than 9
• Triglycerides/HDL-C ratio guidelines suggest less than 5:1 but ideally this should be less than 1.
• Fasting glucose/insulin, fasting insulin should be less than 20 according to guidelines but Peter targets 8 or ideally 6.
• Haemoglobin A1c ideally less than 36
• Liver function tests AST/ALT ideally less than 25
• Abdominal diameter Less than 40/35 inches in men/women
• Peter measures resting and fasting lactate, this can be measured with a metre, but tests must be performed with clean hands or it can produce errors.

There are a series of tests of function available to us, these include:

• Zone 2 output which can be measured using a lactate monitor or by measuring the output in watts on a bike or treadmill when you are exercising at a level that just allows you to speak.
• Cardiopulmonary exercise testing, a measurement of VO2 max, the ability of muscles to take up oxygen when exercising maximally. The University of Kent provide this test.
• Oral glucose tolerance test (OGTT): This test involves fasting overnight, drinking a glucose solution, and then having the blood glucose levels measured at intervals of 30 minutes for 2 hours. Measuring insulin levels on the same samples provides additional useful information.
• Continuous glucose monitoring (CGM): This is the device you may have seen on the arm of diabetics. It measures glucose levels in real-time throughout the day and night. It can help identify fluctuations and trends that might not be captured with traditional blood glucose monitoring. It can also help you understand the impact of various types of food and adjust dietary intake.

Imaging studies give us a visual measure of the problem:

• DEXA scans can be used for measuring:
  • Muscle mass
  • Fat mass
  • And probably most important for measuring Visceral adipose tissue. These scans are available in London, and I hope will become more available locally.
• Liver ultrasound to detect fatty liver disease.
  • One can use algorithms that combine liver ultrasound with blood tests to look at fibrosis scores. The Fib-4 score can be useful, the definitive test is a fibroscan that gives a measure of fibrosis.

How Do You Treat Metabolic Syndrome?

Once we have established a diagnosis, we can set about reducing the risk and reversing the process with:

Exercise

We need to improve zone 2 and VO2 max exercise levels. Any exercise is beneficial though if this is too difficult. Moving from no exercise to three hours a week reduces mortality by 50% in the following year. If you want to focus on zone 2 exercise, probably the most useful, try using a standing bike and measure the watts you produce at zone 2 level, the level at which you can continue to exercise and just complete sentences. With practice, the number of watts you can produce at level 2 will rise.

VO2 max is unpleasant to perform but perhaps once a year gives a measure of improvement.

Strength training increases muscle bulk and so increases the capacity to store fat without damage. Exercise also increases uptake of glucose from the blood reducing circulating levels that would otherwise be stored as damaging fat.

Reduction in visceral adipose tissue, the fat around your organs.

It is crucial to reduce visceral adipose tissue (the damaging form of fat). There are only four ways to do this.

• Caloric restriction (reducing calorie intake).
• Dietary restriction, removing an item of food from the diet, perhaps potato, rice and pasta.
• Time restriction, eating only for a limited number of hours, intermittent fasting.
• Increased energy expenditure leading to calorie deficit.

Sleep

Sleep is hugely underrated as a cause of insulin resistance. Studies have shown that having restricted sleep (4.5 vs 8.5 hours) for only four days increases insulin requirement by 16%.

Stress reduction

Stress increases cortisol levels, these can be measured too. It is harder to treat and affects sleep too.

For more in depth analysis of this subject you can delve into ‘The Drive’ podcast and Peter Attias’ outstanding book. ‘Outlive’.

Dr Allan Fox, Private GP Healthcare in Canterbury.