Patients with snoring and sleep apnea are commonly interpreted as obese or over weight. But this is not entirely true. In my clinical experience nearly one third patients coming for snoring and sleep disorder breathing are non obese. They have a low BMI or body mass index.
Problem snoring is more frequent in overweight/obese people and usually worsens with age. Snoring may be an indication of obstructed breathing and should not be taken lightly. The noisy sounds of snoring occur when there is an obstruction to the free flow of air through the passages at the back of the mouth and nose. This area is the collapsible part of the airway where the tongue and upper throat meet the soft palate and uvula. Snoring occurs when these structures strike each other and vibrate during breathing.
Snoring may be a sign of a more serious condition known as obstructive sleep apnea (OSA). OSA is characterized by multiple episodes of breathing pauses greater than 10 seconds at a time, due to upper airway narrowing or collapse. This results in lower amounts of oxygen in the blood, which causes the heart to work harder. It also causes disruption of the natural sleep cycle, which makes people feel poorly rested despite adequate time in bed. Apnea patients may experience 30 to 500 such events per night. Untreated obstructive sleep apnea increases the risk of developing heart attacks, strokes, diabetes, and many other medical problems.
Understanding BMI
It is better to understand the Body Mass Index formula and its significance in this context.
In simple words BMI is used to determine the percentage of fat in the body. The same formula is applicable to any gender, children and adults and irrespective of ethinicity.But it has some limitation as it shows wrong reading in athletic and muscular persons.
The BMI formula is calculated in the metric system or the English system of measurement.
Metric System
BMI = W / H2
If you’re using the metric system, the formula for BMI is:
Weight in kilograms divided by height in meters squared (weight (kg) / [height (m)2]).
An example of calculating BMI using the body mass index formula: Height = 165 cm (1.65 m), Weight = 68 kg
BMI Calculation: 68 ÷ (1.65)2 = 24.98
English System
If you’re using the English system, the BMI formula is:
Weight in pounds (lbs) divided by height in inches (in) squared and multiplied by a conversion factor of 703 (weight (lbs) / [height (in)2] x 703).
Therefore, to calculate BMI, take the weight (lbs) and divide it by height (in). Take the result of that calculation and divide it by height again. Then, multiply that number by 703. Round to the second decimal place.
An example of calculating body mass index using the BMI formula: Weight = 150 lbs, Height = 5’5″ (65 inches)
BMI Calculation: [150 ÷ (65)2] x 703 = 24.96
 Interpreting your BMI
Female – Male
Underweight (< 18.5) – (<19)
Acceptable (19 – 25)  – (20 – 25)
Overweight (25 – 30) – (25 – 30)
Obese (30 – 40) – (30 – 40)
Morbidly Obese (> 40) - (> 40)
Please note:
If your BMI is below 19, you are considered underweight.
If your BMI is 18.5 – 24.9, you are considered to be a normal weight.
If your BMI is 25.0 – 29.9, you are considered overweight.
If your BMI is above 30, you are considered obese.
Limitations of BMI
While the BMI tool is fairly reliable, it is only one tool that physicians use in evaluating a person’s health status. It is important to take other measures like blood pressure, cardiac health, physical inactivity and abdominal girth. Also keep in mind that BMI does not distinguish between muscles mass and fat mass. A particularly athletic person whose weight is higher due to muscle may have a BMI that indicates that they are overweight, when their weight is simply higher due to muscle mass.
Obesity and the Risks
If your BMI is 30 or over you are considered obese. Obesity has been linked to a number of serious health complications, some mentioned below;
and Snoring and Sleep apnea
Obesity has been found to be linked to snoring and sleep apnea. Also, weight reduction has been associated with comparable reductions in the severity of sleep apnea.
and Type 2 diabetes
One of the strongest risk factors for type 2 diabetes is obesity and this is also one of the most modifiable as it can be partially controlled through diet and exercise.
and Hypertension
There are multiple reasons why obesity causes hypertension, but it seems that excess adipose (fat) tissue secretes substances that are acted on by the kidneys, resulting in hypertension.
and Coronary heart disease
Obesity carries a penalty of an associated adverse cardiovascular risk profile. Largely as a consequence of this, it is associated with an excess occurrence of cardiovascular disease morbidity and mortality.
and High total cholesterol, high levels of triglycerides (Hyperlipidemia)
The primary dyslipidemia related to obesity is characterized by increased triglycerides, decreased HDL levels, and abnormal LDL composition.
and Respiratory and Brain _Corpulomnale and stroke are higher in obese patients.