Metabolic syndrome is a group of health problems pertaining to diabetes, obesity (fat dysregulation) and high blood pressure. This article will aim to examine these three problems as a composite and then each problem individually. It will be in a Q&A form. Where 2 views exist, I have made my preferred view in bold.
What is metabolic syndrome?
Metabolic syndrome is defined by some health authorities to exist when one has 3 out of 5 factors. The factors are:
- Obesity: waist circumference more than 102 cm (males) and 88 cm (females)
- High triglycerides
- Low HDL
- High blood pressure
- High blood sugar which includes diabetes and prediabetes.
Why is metabolic syndrome important?
It has been shown that people with metabolic syndrome are at greater risk of heart attacks.
Does metabolic syndrome have a singular root cause?
The answer is controversial. Two views will be presented here.
No. Some other authorities doubt that metabolic syndrome exists as a disease entity and that each issue should be managed independently.
Yes. Statistical analysis have shown that people with one condition within the syndrome tend to have another.
It is always good to personalise treatment. Sometimes, theories such as aggressive exercise for weight loss may be too simplistic to be useful.
Does low salt diet help High blood pressure?
The answer here is controversial. The textbook answer would be yes. And there is good reason for that.
Yes. The diet studies (DASH and Premier, the names of the studies) showed reduction in mean blood pressures. In both studies the average reduction of blood pressure with aggressive limit on salt intake was from 4-11 mmHg.
No. If hypothetically one had a blood pressure of 150/90 mmHg. Aggressively cutting out the salt would lead to an average reduction of 8 mmHg for the systolic components. So we expect a new blood pressure of 142/85 mmHg.
Let us quantify the benefit. To do that we use the Framingham calculator. The Framingham calculator is based on a study of a group of people with various levels of blood pressure, cholesterol, of different ages. A model is made to estimate their chances of heart attacks. We can find the calculator online easily.
Let’s have a 55 year old male, non-smoker with a total cholesterol level of 4.8 mmol/L, HDL of 1.2 mmol/L, SBP 150mmHg.
Based on the Framingham calculator, he would have a risk of 7.5% heart attack of death in the next 10 years. With aggressive sodium restriction till the point of blandness of food, the risk is now 7.0%.
If 200 of such men limited their sodium intake, till the point that the food became unpalatable, only one of them will benefit from such an aggressive and (in my opinion) rather depressing intervention.
On this basis, whilst moderation and judicious sodium consumption is helpful, I feel if one has high blood pressure, it would make sense to start on blood pressure medications as the first line of intervention. The enjoyment of food is a very basic comfort.
Does diet help reduce LDL cholesterol meaningfully?
No. The argument will be build on 2 points. Firstly it is now NO LONGER recommended that patients fast before testing for their cholesterol. It has been shown that there is no major difference in the blood levels of random vs fasted cholesterol. On this basis, one might reason that there is no direct causal relationship between caloric intake and LDL cholesterol (or HDL) for that matter.
There are other biological reasons for this. But we may take it that this biological theory is valid as its findings are applied widely in blood tests.
MRFIT trial which included lifestyle interventions to reduce cholesterol also did not show any significant benefit in cardiovascular outcomes. Patients who did purported lifestyle changes had nearly the same rates of heart attacks as those who did not.
Why should I exercise then?
Exercise changes the body in complex ways. Even if exercise doesn’t really help significantly in weight loss for some individuals, exercise somehow modifies the body to be healthier. We do not fully understand why. But the evidence is overall consistent.
One extreme group of people to consider are the sumo wrestlers. By usual body measurements they are considered obese. Nonetheless they are amongst the healthiest group of people with extremely low rates of heart disease and diabetes. This is believed to be due to their aggressive exercise regime required at a professional sports level.
Hence even if one does not see tangible weight losses in exercise, exercise is a critical component of a healthy lifestyle.
Given that diet doesn’t seem to impact cholesterol and high blood pressure in meaningful ways, why watch our diet?
We now cover the last portion of the metabolic syndrome which is diabetes or sugar regulation.
We start first by tracing the outcomes of the calories. This is a simplistic framework but it can still be helpful.
We consume carbohydrates (sugars), protein and fats. Our liver then packages these and sends much of these to the rest of the body for use. Unfortunately, we have limited ability to store protein. So any excess protein that is not required by the body at that point of time is converted to sugar and urine.
Our body also has limited ability to store sugars. So any excess sugar that is unable to be stored as glycogen or used, will be converted to fat.
Our body seems to be able to store fat well. Hence, consuming calories will result in increased fat in our body, whether the calories come in the form of sugar, fat or protein.
Fat is a loose term. It refers to the chemical triglycerides (oil) as well as the cells (adipocytes) which manage the triglycerides. Adipocytes are hormonally active. They secrete hormones that cause diabetes. Hence the prevailing opinion of dieting and diabetes prevention.
What can help for weight loss?
Generally most of the weight loss therapy revolves around lifestyle modifications. Given the example of the Sumo wrestlers, exercise is amongst the first of the mainstay interventions. This is due to the positive effect of heart attack prevention and general well being. A caveat is that there might not be significant weight loss in spite of the profound health benefits.
There are physiologic studies to show this. Individuals who exercise regularly can be shown to have increased tolerance to various work loads and their bodies utilise energy more efficiently. This occurs even if there may not be any weight loss.
Some medications are used off label for weight control. These are usually diabetic medications. It would be best to discuss with a doctor about these.