Behind High Blood Sugar: Type 2 Diabetes in Your Pancreas, Liver, and Kidneys
What Causes High Blood Sugar Levels?
Contrary to popular belief, type 2 diabetes — which affects more than 29 million Americans — isn’t caused by an overload of sugar. In fact, there are many different factors that can increase a person’s risk for the disease, including genetics, body weight, fat distribution, physical activity levels, and race.
However, it is true that people with diabetes may have to limit their sugar intake. That’s because type 2 diabetes is characterized by an inability to properly use insulin, a hormone that helps usher sugar (in the form of glucose) out of the bloodstream and into the cells, where it’s used as energy. Eventually, the body is unable to produce enough insulin to keep your blood sugar levels stable.
You Say ‘Sugar,’ I Say ‘Glucose’
Is sugar in a doughnut the same as blood sugar? Let’s clear up the confusion: Sugar can have many different names, with different meanings.
When doctors and scientists talk about sugar in the blood, they often use the word “glucose.”?Glucose is a simple carbohydrate, also known as a “monosaccharide” (meaning, it’s made up of just one molecule). This can also be called blood sugar.
Unlike sucrose (table sugar) or fructose (the sweetener found in honey and fruit), you won’t be able to find glucose in the grocery store.
Related Health Problems
Over time, diabetes can harm almost every organ and system in the body. One reason: Chronically high blood sugar levels can cause high blood pressure and high cholesterol; it can also cause nerve damage, which hampers your ability to send and relay messages to different parts of the body.
Here are some of the most common complications of chronically high blood sugar levels and uncontrolled type 2 diabetes.
The Pancreas: Your Insulin Factory
When talking about high blood sugar, the first place to start is the pancreas. This pear-shaped organ sits inside the upper left part of the abdomen and is part of the digestive system. The pancreas has two main functions: The exocrine function is to manufacture digestive “juices” (enzymes) responsible for breaking down all kinds of nutrients — including fats, proteins, and carbohydrates. But the pancreas may be best known for the endocrine function — that is, making insulin and other hormones.
How Insulin Is Produced
When food enters the gut, cells in the intestines produce a peptide called GLP-1, which blocks the release of glucagon in the body and increases insulin secretion. (The reason: You don’t need glucagon to draw on your glucose reserves for energy while you’re consuming sugar from a meal.) This also kick-starts the production of insulin by B-cells in the pancreas.
Insulin Resistance: Understanding What Happens in Type 2 Diabetes
In type 2 diabetes, the body has become “insulin resistant,” meaning insulin is no longer able to effectively remove sugar from the blood. As a result, the pancreas ramps up its insulin production to try to keep up with the amount of carbohydrates you’re eating — a state of overproduction that can lead to B-cell fatigue.
When B-cells become fatigued (or fail), they can no longer make enough insulin to shuttle glucose out of your bloodstream. The end result: hyperglycemia, or high blood sugar.
Diabetes Medications That Work With the Pancreas
Most people who have type 2 diabetes need to take prescription medications, some of which act specifically on the pancreas to lower A1C.
Sulfonylureas and Meglitinides
How they work:?Lower blood sugar by encouraging the pancreas to produce more insulin
How they work:?Block the enzyme dipeptidyl peptidase 4, which increases the amount of GLP1 in the body
GLP-1 Receptor Agonists
How they work:?Mimic the effects of the hormone GLP-1, which triggers your pancreas to produce more insulin after you eat and decreases glucagon. These drugs also help you feel full after a meal and slow the rate at which the stomach empties, which may help you lose weight
The Liver: Your Body’s Sugar Warehouse
The liver is a big organ (it weighs about three pounds) with a big job: regulating chemical levels in the blood. Every system in the body depends on the liver for the high-quality fuel it needs to function. In addition to conditioning the blood and helping to remove waste products, the liver is your body’s sugar warehouse. When there’s too much sugar in the bloodstream, the body stashes the extra supply in the liver, where it’s stored for later use.
And when people become resistant to insulin, they can also develop nonalcoholic fatty liver disease. This further complicates type 2 diabetes because the buildup of fat in the liver can exacerbate insulin resistance as well, worsening type 2 diabetes and leading to high blood sugar. From there, the cycle continues.
Diabetes Medications That Work With the Liver
Most people who have type 2 diabetes need to take prescription medications, some of which act specifically on the liver to lower A1C.
How they work:?Prevent the liver from making glucose, increase insulin sensitivity, and limit the amount of sugar that gets absorbed by the intestines; metformin is often the first drug prescribed to treat type 2 diabetes
How they work:?Lower insulin resistance by decreasing the amount of fatty acids in circulation. This causes the body to use glucose as a source of fuel. Unfortunately, this treatment causes some people to gain weight
The Kidneys: Your Internal Waste Management System
The kidneys are two organs that rest on opposite sides of the spine. Think of them as the TSA of your bloodstream: They scan the blood for unwanted acids and excess minerals and usher the waste products out of the body through the urine. But they also play a surprising role in regulating blood sugar levels.
Specifically, the kidneys remove sugar from the blood and use it as their own source of energy, which provides the fuel they need to function.
What’s more, in partnership with the liver, the kidneys perform a process called gluconeogenesis, which produces sugar and releases it into the blood for the body to use as fuel.
Finally, kidneys’ responsibility to filter waste comes into play. The kidneys’ filters, called glomeruli, remove sugar from urine. Then, sodium-glucose cotransporters — often referred to as SGLTs — reabsorb the filtered sugar, moving it to the bloodstream. (This process is why one of the first signs of undiagnosed diabetes can be the need to urinate frequently!)
When these filters are forced to work too hard, they can become permanently damaged, leading to the development of diabetic kidney disease and, eventually, kidney failure.
Diabetes Medication That Works With the Kidneys
Most people who have type 2 diabetes need to take prescription medications, some of which act specifically on the kidneys to lower A1C.
Sodium-glucose cotransporter-2 (SGLT2) inhibitors
How they work:?By blocking SGLT2s, these drugs prevent glucose from being reabsorbed into the blood and help the kidneys remove sugar from the body through the urine
Treating Type 2 Diabetes: Know Your Numbers, Lower Your A1C
Less Than 5.7%
If your A1C level is less than 5.7%, your blood sugar levels fall in a normal range.
Between 5.7% and 6.4%
If your A1C level is between 5.7% and 6.4%, you have prediabetes.
6.5% or Higher
If your A1C level is 6.5% or higher, you have type 2 diabetes.
Finger prick tests can measure how high your sugar levels are at any specific moment, but an A1C test will help you find out whether your blood sugar is truly under control.
Because the A1C test looks at your blood-sugar levels over a two- to three-month period, the American Diabetes Association likens its reading to a batting average. An A1C reading of 6.5 percent or higher qualifies a diagnosis of diabetes.
You and your doctor will work together to adjust your treatment plan — including diet, exercise, and medications — to reach your target A1C.
Insulin Therapy to Lower AIC
If your A1C is high despite being on multiple diabetes medications, your doctor may prescribe injectable insulin, which mimics the action of insulin that is produced by the pancreas — meaning, it removes glucose from the blood and into cells where it’s used as energy.