Biochemical and Biometric Terms

A brief explanation of Biochemistry and Biometric data

What is Blood Glucose?

Blood Glucose is a measure of the amount of blood sugar at the time of the test. Glucose is a sugar that the body makes mainly from the starches and other sugars (carbohydrates) in your food. The blood carries glucose to all the cells in your body, where it is used to produce energy. But the cells cannot take the glucose out of the blood on their own. To do this, they need a hormone called insulin. Insulin is also carried in the blood. As the insulin lets the cells take glucose out of the blood, the amount of glucose left in the blood goes down. Exercise also reduces blood sugar levels.


What are Triglycerides?

Triglycerides are present in the blood and, along with cholesterol, form lipids in blood plasma. Triglycerides in the body come from fats in food, or fats made by the body from other energy sources such as carbohydrates. Calories in the food that we eat which are not used immediately are converted into triglycerides and transported to fat cells for storage. Hormones regulate the release of triglycerides from the fat tissue, so they can meet the body’s needs for energy between meals. Eating too many calories causes build-up of fat in the body and can lead to obesity.

You can have a blood test to measure increased levels of triglycerides, just as you can have a test for cholesterol. Triglyceride levels rise steeply after a meal, so, before a test, you are usually asked not to eat for a 12-hour period and to drink only clear fluids.


What is Blood Pressure?

Blood pressure is the pressure of blood in your blood vessels. The heart pumps blood around your body, through a network of arteries, by contracting and then relaxing. When the heart contracts the blood is forced through the arteries and your blood pressure goes up. This is when your blood pressure is highest and is called the systolic pressure. When your heart relaxes (between heart beats), your blood pressure goes down, this is when the pressure is lowest and is known as the diastolic pressure. These two pressures are written as numbers, one over the other like a fraction, for example, 140/85 mmHg. The top number is the systolic pressure and the bottom number is the diastolic pressure.


What is Body Mass Index?

The body mass index (BMI) is your weight/height ratio. It provides a good guide to your level of obesity. To calculate your BMI, divide your weight in kilograms by your height in metres squared. A healthy BMI is 20-25. 25-30 means you are overweight and above 30 indicates obesity, which is associated with high blood pressure and an increased risk of coronary heart disease. A BMI greater than 40 indicates extreme obesity.


What is Cholesterol?

Cholesterol is an essential fatty substance that is mainly made in the body. The liver makes it from the saturated fats in food. Very little cholesterol is found in foods, except for eggs, liver, kidney and seafood such as prawns, all of which contain some cholesterol. Although only a small proportion of the cholesterol in the body comes from cholesterol in food, cholesterol plays a vital role in how every cell wall works throughout the body. It is also the substance which the body uses to make other vital chemicals such as some hormones and vitamins. Too much cholesterol in the blood can increase your risk of getting heart disease.


What are LDL and HDL

LDL stands for Low Density Lipoprotein and HDL stands for High Density Lipoprotein. They are a combination of fat (lipid) and protein. Fat is less dense than protein and LDL has a greater fat to protein ratio than HDL and so is less dense than HDL. Both lipoproteins transport cholesterol around the body.

LDL carries cholesterol to cells around your body, but high levels of LDL can lead to a build-up of cholesterol in your arteries.

HDL helps to control the levels of cholesterol in your body by carrying it from other parts of your body to the liver where it can be removed.


 What is Creatinine?

Creatinine is formed from Creatine after exercise. Creatine is a protein which is involved in releasing energy in muscle tissue during intense exercise where it breaks down to form creatinine. Normal levels of creatinine differ depending on age, race, gender and body size but high levels of creatinine in the blood are often a sign of kidney damage and need to be monitored very carefully.


What is HbA1c?

Your blood contains a protein called haemoglobin which carries oxygen around your body. Haemoglobin also carries glucose (sugar) around your body. When haemoglobin is carrying glucose, it is called Glycated Haemoglobin or HbAc1. Measuring HbAc1 gives an indication of your average blood glucose level for the last few months. There is some debate as to how far back in time it goes, but it is likely to be about 2 or 3 months, with a bit more emphasis on the most recent month. HbAc1 goes up in people with diabetes. You can find out more about HbAc1 here.