High cholesterol in children

In adults, high blood cholesterol is diagnosed when blood cholesterol exceeds 200 milligrams per 0.1 litres (deciliter or dL) of blood. Low-density lipoprotein levels over 100 mg/dL, triglyceride levels over 150 mg/dL and high-density lipoprotein (good cholesterol) under 60 mg/dL are bad for the body, too.

In children, these values are slightly different. Here’s what the US National Cholesterol Education Program (NCEP) guidelines say about cholesterol levels in children aged 2-18:

HDL for children should ideally be over 45 mg/dL. Borderline low HDL is 40-45 mg/dL. Serum triglycerides in children should be less than 100 mg/dL up to nine years of age and under 130 mg/dL from 10-18 years.

Research shows that “Indians living in India” typically have lower total cholesterol and good cholesterol (HDL) than people living in the UK and US, but they have higher triglycerides. Low HDL and high triglycerides are risk factors for arterial diseases like atherosclerosis and blocked arteries.

Before we go further, let's take a look at the uses and benefits of cholesterol in the body, and when does cholesterol become bad:

We have all heard of blood cholesterol and triglycerides in the context of illness. The truth is that the body needs limited amounts of both cholesterol and triglycerides. We need cholesterol for making:

• Hormones like estrogen, progesterone, testosterone and cortisol among others
• Cell walls or membranes across the body
• Bile salts, which helps the body digest fats
• Vitamin D: our skin needs cholesterol to make vitamin D from sunlight

Triglycerides are used by the body for energy. Whatever is not used for energy, gets stored as fat.

Where do we get this cholesterol and triglycerides? Our liver makes about 1000 milligrams a day of cholesterol. We also get cholesterol from some foods. Triglycerides come from foods such as refined carbohydrates and fatty foods, but it is also made by the liver using excess calories, especially carbs, from food. Triglyceride levels are considered:

• Borderline high between 150 mg/dL and 199 mg/dL
• High: 200-499 mg/dL
• Very high: 500 mg/dL or more

Here's what happens to cholesterol in the body:

The liver makes lipoproteins—cholesterol and triglycerides (both fatty or fat-like substances)  wrapped in proteins—so that cholesterol and triglycerides can be transported to the cells that need them via the bloodstream.

Very low-density lipoproteins (VLDL) and high-density lipoproteins (HDL) are the two types of lipoproteins made in the liver.

VLDL have both triglycerides and cholesterol (a waxy substance) at their core. These lipoproteins travel through the blood to cells that need triglycerides for energy. Once the triglycerides are used up or stored as fat, what’s left behind is low-density lipoprotein (LDL) with cholesterol at its centre.

The body needs cholesterol for vital functions like making hormones and vitamin D. The LDL cholesterol can fulfil these needs. However, if there’s more cholesterol than the body needs, it starts getting deposited on the walls of blood vessels. This damages the blood vessels and makes it possible for plaque to build up there. This cholesterol plaque can make the blood vessels narrower, thus reducing blood flow. This condition is known as atherosclerosis.

If this condition affects the coronary artery that takes blood to the heart, it can lead to coronary artery disease and increase the risk of a heart attack. It can also increase stroke risk if it blocks an artery taking blood to the brain. A piece of plaque can also come away from the blood vessel walls and form a blood clot that can travel to other parts of the body—the blood clot may cause illnesses, including a cardiac event or stroke.

Indians are at high risk of high cholesterol, also known as hyperlipidemia because they naturally have lower HDL and more triglycerides. HDL helps the body get rid of excess cholesterol and cholesterol plaque by taking LDL back to the liver which removes the extra.

High cholesterol in children doesn’t show any clear symptoms until the problem has advanced quite a bit. Parents or doctors should ask if a test is necessary if the child:

• Is obese
• Has a parent or close relative with high cholesterol
• Eats lots of saturated fats and trans fats (found in many processed foods)
• Has one of the following health conditions: Kawasaki disease, juvenile idiopathic arthritis, liver disease, kidney disease
• Has hypertension, diabetes or hypothyroidism

You might have heard of coronary artery bypass surgery—it is one of the most common open-heart surgeries performed in India. The condition that necessitates it—advanced coronary artery disease—starts out with high cholesterol and high triglycerides, which get progressively worse over the years.

There are three main causes of high cholesterol in children:

• Family history and genes: Inherited conditions like familial hypercholesterolemia can start affecting children from birth.
  Familial hypercholesterolemia is a genetic condition in which the cells of the body are unable to take up LDL cholesterol properly even though they need it. This leaves a glut of LDL in the blood, which gets stored as plaque in the blood vessels. Children with this condition need to be put on statins from the age of eight or 10, to minimise the damage to their blood vessels and hearts.
  Experts say if either parent has dyslipidemia (literally, lipid problems), children should be tested for the same from a young age.
• Obesity and linked conditions: Research has shown that obesity and conditions linked with it can affect fat metabolism which in turn can lead to a build-up of excess cholesterol and triglycerides in the body.
• Lifestyle factors: A diet rich in fats and refined carbohydrates, consuming too many calories, low levels of exercise and smoking are linked with high cholesterol and high triglyceride levels in the blood.

The only way to diagnose high cholesterol—in children as well as in adults—by testing for it. The lipid profile test shows values for total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides.

Normal versus high cholesterol in children

Multiple research papers show that total blood cholesterol levels are low in newborns (51.4-96.8 mg/dL for full-term infants), with proportionately higher HDL and lower LDL than in grown-ups (22.1-44.9 mg/dl of HDL or good cholesterol and 22.0-44.9 mg/dL of bad cholesterol or LDL).

Children up to 19 years should have:

• Total cholesterol: Less than 170 mg/dL
• LDL: Less than 110 mg/dL
• HDL: More than 45 mg/dL
• Triglycerides:
  • 0-9 years: Less than 100 mg/dL
  • 10 and older: Less than 130 mg/dL

For people over 20, fasting lipoprotein profile (on an empty stomach for 9-12 hours) is recommended once in five years. In children who are not at risk of high cholesterol, it is still a good idea to have them tested to avoid complications.

Lifestyle management and treatment of underlying causes like hypothyroidism or diabetes is the first line of intervention. However, if diet control, exercise and weight management do not help, there are medicines that can help to keep cholesterol—and attendant problems like plaque deposits and premature hardening of blood vessels—at bay. Here are some interventions that your doctor may suggest if your child has high cholesterol: