HEALTH NEWS

Metabolic Syndrome, Diabetes, and Obesity Affects Hearing Status

By Dr. Linda J. Dobberstein, DC, Board Certified in Clinical Nutrition

June 29, 2020

Hearing loss is the most common loss of the five special senses in the human population. Nearly one out of four Americans 12 years or older has some type of hearing loss. Your spouse or kids may have to shout at you or stand directly in front of you so you can hear and understand what is being said. Perhaps you notice that certain sounds are harder to hear as you strain to make out specific words. Hearing loss commonly happens with age, but it correlates with many factors including metabolic syndrome and obesity. This relationship to obesity and metabolic syndrome occurs at any age and impacts young and old alike. It knows no boundaries.

Hearing is gift that we often take for granted until it starts slipping away. If you want to hear the sound of your loved ones voices, birds singing, warning sirens and other sounds of life, it is vital to keep a healthy weight and metabolism. Here some recent findings on hearing loss related to metabolic syndrome, diabetes, adiponectin, and childhood obesity.

Metabolic Syndrome and Hearing Loss

Metabolic syndrome is group of conditions that increase the risk of heart disease, stroke, obesity, and even cancer. It is also considered a substantial risk factor for hearing loss. There are five components that identify the presence of metabolic syndrome – increased blood pressure, high blood sugar, belly fat or excess body fat around the waist, and elevated cholesterol or triglycerides. The diagnosis is made if three or more components are present.

• Obesity: Waist Circumference: Men: > 40 inches. Women: >35 inches

• Elevated Blood Sugar: Fasting glucose greater or equal to 100 mg/dl or more with or without prescription.

• Triglycerides: Greater than 150 mg/dl with or without prescription.

• HDL cholesterol: Men: less than 40 mg/dl. Women: less than 50 mg/dl with or without prescription.

• High blood pressure: systolic (top number) greater than 130, diastolic (bottom number) greater than 85 with or without prescription.

Limited research suggests that the greatest association with hearing loss and metabolic syndrome is linked primarily with low HDL levels. Noise trauma worsens the risk of hearing loss in people with metabolic syndrome.

Diabetes and Hearing Loss

Individuals with elevated blood sugar without metabolic syndrome are also at high risk for hearing loss. A 2019 study with the Association of Otolaryngologists (ear-throat physicians) of India compared 50 diabetic patients to 50 non-diabetic patients.

Of the 50 diabetic patients, profound hearing loss was more common in those with a fasting blood sugar greater than 200. If random blood sugars were greater than 300, severe and profound hearing loss was evident. Those who had a longer history of diabetes had greater hearing loss. Almost half of the diabetic patients tested had moderate to severe hearing loss, whereas only 26 percent of the diabetics had normal hearing.

Low Adiponectin

Adiponectin, a hormone produced and secreted by your fat cells, regulates the metabolism of glucose and fats. Adiponectin helps with insulin sensitization and anti-inflammatory effects. It also positively affects the inside lining of your blood vessels. It has a teeter-totter effect with the hormone leptin.

In obesity and metabolic syndrome, leptin levels are high, whereas adiponectin is low. This imbalance creates chronic inflammation that adversely impacts blood vessels along with the manifestations of metabolic syndrome. This affects blood flow and causes inflammation throughout the body including the inner ear, nerves and brain. Preliminary research shows that low adiponectin levels play an important role in contributing to age-related hearing loss.

Children, Obesity, Low Adiponectin, and Chronic Inflammation

Various studies have found that childhood obesity is an independent risk factor for hearing loss. Research from 2013 identified a 1.85 fold increase of hearing loss in obese adolescents compared to others with normal body weight.

A 2018 research study confirmed similar findings. Scientists evaluated several factors including body mass index, (BMI) hemoglobin A1C, HDL, and triglycerides, etc in adolescents 12-19 years old. Compared to normal body weight adolescents (5-85th percentile), the obese adolescents (=/> than 95th percentile) had 21.5 percent rate or 1.73 fold increase of hearing loss compared to the 13.44 percent in normal weight adolescent.

An estimated 41 million children UNDER five years of age are obese or overweight worldwide and are affected by imbalanced leptin-adiponectin levels. Like adults, obese children with leptin resistance and insufficient adiponectin experience chronic inflammation. This is believed to contribute to sensorineural hearing loss and a number of other ear, nose, and throat disorders linked with obesity. Childhood obesity that continues on for a decade or longer has been found to contribute to hearing loss later in middle age.

Studies on a blood test called glycoprotein A or GlycA reflects chronic inflammation linked with diminished hearing in childhood. The GlyA pro-inflammatory marker is considered a strong marker of chronic inflammation and even reduced life expectancy.

Chronic inflammation related to metabolic syndrome and obesity renders ongoing oxidative stress to the delicate inner ear and hearing mechanisms that affects the nerves, cell membranes, hairs, and mitochondria of your inner ear. This inflammation added to other factors, like noise trauma, cause stress to your ears and impact hearing.

Your daily lifestyle and dietary choices that increase the risk of metabolic syndrome, obesity, and type 2 diabetes are up to you. As a parent, you must teach and model healthy behaviors for your children. Hopefully, this information provides some additional insight into the “I didn’t hear you” for you or your kids.