QUICKI Calculator

Insulin sensitivity is the opposite of insulin resistance. Insulin sensitivity indicates how sensitive the body's cells are when they respond to insulin, where:

• High insulin sensitivity allows the cells of the body to use blood glucose more effectively and reduces blood sugar; and
• Low insulin sensitivity is associated with high blood sugar levels, as cells don't absorb the amount of glucose they should.

Insulin sensitivity may vary between people and can change depending on their lifestyle and dietary factors. Increasing insulin sensitivity can benefit people who have, or are, at risk of type 2 diabetes.

Insulin resistance occurs when the cells of the body don't properly respond to the hormone insulin. It is associated with low insulin sensitivity, which is characterized by human body producing more insulin than usual as a way to get the cells to respond correctly.

Initially, insulin resistance is does not present any symptoms, but over time, when the blood sugar levels go up, the following symptoms may occur:

• Tiredness;
• Hunger;
• Difficulty in concentrating;
• Weight gain;
• High blood pressure; and
• High cholesterol levels.

Insulin resistance, if untreated, develops into prediabetes or type 2 diabetes, which is associated with increased blood glucose levels and other symptoms.

Risk factors of low insulin sensitivity/insulin resistance include:

• Obesity;
• High calorie diet;
• Physical inactivity;
• Hormonal disorders (e.g. Cushing’s syndrome);
• Taking specific medication (e.g. steroids); and
• Chronic stress.

Now that you know what does insulin resistance mean, let's move to the QUICKI index (sorry force of habit) that was developed Katz et al. and described in the paper Quantitative Insulin Sensitivity Check Index: A Simple, Accurate Method for Assessing Insulin Sensitivity In Humans. It's a simple and accurate method that assesses insulin sensitivity. You can use it interchangeably with the more complicated "gold standard" methods: glucose clamp and minimal model analysis.

Katz defines the insulin sensitivity index (QUICKI index) as the inverse of the sum of the logarithms of fasting insulin and fasting glucose:

QUICKI = 1 / [log(FI) + log(FG)]

where:

• FI is the fasting insulin expressed in µU/ml;

• FG is the fasting glucose expressed in mg/dL; and

• log is the common logarithm with base 10.

So, when you have the QUICKI index in front of you, you'd probably like to know what the result means:

• QUICKI index ranges from 0.45 in healthy individuals to 0.30 in people with diabetes;
• Lower values indicate greater insulin resistance; and
• Values below 0.339 indicate insulin resistance which is associated with obesity and increased cardiovascular diseases - CVD risk.

To use QUICKI calculator you need only two values:

• Fasting glucose level (you can switch between mg/dL and mmol/L units); and
• Fasting insulin level (which is expressed in µU/ml).

Example:

Let's calculate the QUICKI index of a person with a fasting glucose level equal to 103 mg/dL and fasting insulin level of 15 µU/ml.

QUICKI = 1 / [log(FI) + log(FG)]

QUICKI = 1 / [log(15) + log(103)]

QUICKI = 1 / [1.176 + 2.013]

QUICKI = 1 / 3.189

QUICKI = 0.313

Which is less than 0.339. The result of QUICKI index indicates that this person has insulin resistance.