If you don't want to read this page, the books I recommend or the references below, this single page from alt.support.diabetes is the most important thing you could ever read about maintaining your blood glucose: Jennifer's advice to the newly diagnosed
.I recommend either the Walgreens or Walmart store-brand monitors even though they don't have the bells-and-whistles of name-brand monitors because the generic Walgreens strips and Walmart strips are so cheap.
simplified view of carbohydrate digestion
The three simplest classifications of carbohydrate are monosaccharides (single sugars like glucose, fructose and galactose), disaccharides (double sugars such as sucrose and lactose) and polysaccharides (long chains of monosaccharides such as starches and fibers).
Carbohydrate digestion begins with enzymes in the mouth that break down starches, proceeds to the stomach where the high acid breaks down disaccharides and polysaccharides further, continues with pancreatic enzymes released to the small intestine which produce absorbable monosaccharides, and finally some additional digestion occurs by gut bacteria, which break down carbohydrates the body cannot.
After digestion to monosaccharides, they are absorbed from the small intestine into the bloodstream, raising blood glucose levels. This causes the pancreas to release the hormone insulin, which causes the liver and muscle cells to absorb excess glucose, storing it as glycogen for later use. Once glycogen stores are full, additional glucose is stored in adipose tissue as fat.
Later, when blood glucose is low, the pancreas secretes the hormone glucagon, which signals the liver to break down glycogen and release it as glucose into the blood and causes adipose to release fat into the bloodstream.
If glycogen stores are low and blood glucose remains low, cortisol is released by the adrenal glands to cause the liver to go into gluconeogenesis, the production of glucose from non-carbohydrate sources such as amino acids from protein, the glycerol portion of fat molecules, and lactate.
This is a simplified version of how blood glucose is maintained in a healthy person, ignoring other hormones such as amylin, leptin, adiponectin, resistin, IGFs, etc.
simplified view of carbohydrate metabolism
The purpose of maintaining blood glucose is because all the cells require glucose as their primary energy source for aerobic respiration.
Overall, respiration takes in glucose and oxygen and produces carbon dioxide, water and ATP, the primary fuel cells use for energy.
There are several steps involved in cellular respiration, glycolysis occurs in the cell cytosol and pyruvate decarboxylation, the Kreb's cycle and the electron transport chain occur in the mitochondria.
See references that follow for more details if you're interested in the biochemistry.
simplified explanation of diabetes
Diabetes is from the Greek and refers to an "excessive discharge of urine" and mellitus is from Latin and means "honey-sweet," referring to sweetness in the urine (as opposed to diabetes insipidus, which involves the high urine input, but no sugar issues). One way or another, all forms of diabetes mellitus are disorders of carbohydrate metabolism.
The three traditional forms of diabetes mellitus are T1, T2, and gestational diabetes. T1 diabetes is due to an insufficient production of insulin by the islet cells of the pancreas, T2 is caused by cells being insulin resistant and not responding to insulin, and gestational diabetes is a temporary version of T2 that occurs during pregnancy.
In general, type 1 was always considered an autoimmune disease, in that it was generally a rapid-onset disease occurring after an autoimmune event caused the body to destroy the islet cells, whereas type 2 (and gestational diabetes) was considered a metabolic disease caused by insulin resistance (IR) that begins in the liver and spreads to other cells over time.
These diseases are not exclusionary; there is nothing to prevent a Type 1 diabetic from developing IR and elevated bG from T2 destroys islet cells, thus some folks develop "double diabetes".
The classification of diabetes types has expanded in recent years. For example, T1 diabetes can be slow-onset as in Latent autoimmune diabetes (LADA). LADA and Type 2 can be combined to produce what is sometimes called Type 1.5 diabetes. Maturity onset diabetes of the young (MODY) types are caused by genetic defects that disrupt insulin production.
The thing that all these forms of diabetes have in common is that glucose is high in the blood, and thus does not enter cells properly, depriving them of their needed substrate to produce energy.
Elevated blood glucose directly causes organ damage and thus a number of diabetic complications including:
- skin infections - styes, boils, carbuncles and infected hair follicles
- eye problems - glaucoma, cataracts, retinopathy and potential blindness
- neuropathy (nerve damage) - feeling "pins and needles", slow-healing ulcers and infections of the feet (can result in amputation), bladder paralysis, erectile dysfunction, gastroparesis (delayed gastric emptying)
- arteriosclerosis (arterial plaques) - edema and high blood pressure, heart attack, stroke, and transient ischemic attack
- kidney disease - requiring dialysis or transplant
- diabetic ketoacidosis - when bG is very high and ketones are present in the urine, this condition can lead to coma or even death
- in those using insulin or insulin-increasing drugs, hypoglycemia may occur, which also can result in coma or death
diabetes treatment
Treatment depends on the type of diabetes.
Insulin insufficiency is treated in a rather straightforward manner by providing insulin, via syringe, pen or an insulin pump.
For insulin resistance, three types of treatment are commonly used.
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Because IR correlates with obesity and a sedentary lifestyle, diet and exercise are the first recommendations for treating T2 and related forms of diabetes.
Because an inability to handle carbohydrate properly is the problem with all forms of diabetes, Dr. Richard K. Bernstein proposed the surprisingly controversial notion that diabetics ought to eat little carbohydrate as treatment to assist in control of their blood glucose. His proposed diet is extremely low-carb but has been successful for many in avoiding diabetic complications.
In my opinion, a more realistic view of restricted carbohydrate intake, including treatment to control bG while cheating, is provided by Jenny Ruhl in her Blood Sugar 101: What They Don't Tell You About Diabetes, the book I most highly recommend to all diabetics. - Insulin resistance may be treated with medications that work in one of four ways:
- drugs that increase insulin production and decrease glucagon production
- sulfonylurea drugs, nonsulfonylurea secretagogues, incretins, glucagon-like peptide analogs and amylin analogs
- drugs that increase sensitivity to insulin
- biguanides and thiazolidinediones
- drugs that slow absorption of carbohydrate from the digestive tract
- alpha-glucosidase inhibitors
- insulin sufficient to overcome IR
- Finally, weight loss surgery has been shown to reduce IR independently from the weight lost itself.
about using insulin
Insulin comes in two basic types, long-acting insulins (basal) and fast-acting insulins (bolus).
The first type of insulin use is called multiple daily injections (MDI). This uses a basal insulin once or twice a day to keep the bG level while fasting and bolus insulin before meals and snacks to lower bG resulting from food intake. Most diabetics must calculate their boluses based on the carbohydrate content of their food; some (mostly T1s) must also account for protein intake.
In insulin pump therapy, the diabetic wears a pump for 5-10 days avoiding the multiple injections, and only one type of insulin is used. The pump trickles a small amount of bolus insulin at all times to act as a basal insulin and the user programs the appropriate amounts for bolus insulin for food intake.
There are continuous glucose monitors that work similarly to the insulin pump in that they are worn for several days and monitor glucose continually.
Testing is underway for products connecting continuous glucose monitors with insulin pumps via computers, which may eventually result in an artifical pancreas.
I learned most of what I know about dosing insulin from John Walsh's Using Insulin.
references
- Jennifer's advice to the newly diagnosed from alt.support.diabetes
- diabetes mellitus @ Wikipedia
- carbohydrate digestion @ Wikipedia
- pancreas @ Wikipedia
- Islet cells @ Wikipedia
- liver @ Wikipedia
- insulin resistance @ Wikipedia
- carbohydrate metabolism @ Wikipedia
- insulin @ Wikipedia
- glucagon @ Wikipedia
- cortisol @ Wikipedia
- gluconeogenesis @ Wikipedia
- amylin @ Wikipedia
- leptin @ Wikipedia
- adiponectin @ Wikipedia
- resistin @ Wikipedia
- insulin-like growth factors @ Wikipedia
- cellular respiration @ Wikipedia
- adenosine triphosphate @ Wikipedia
- glycolysis @ Wikipedia
- pyruvate decarboxylation @ Wikipedia
- Kreb's cycle @ Wikipedia
- electron transport chain @ Wikipedia
- mitochondria @ Wikipedia
- type 2 diabetes @ Wikipedia
- diabetes medications @ Wikipedia
- multiple daily injection therapy @ Wikipedia
- insulin pump therapy @ Wikipedia
- blood glucose monitors @ Wikipedia
- artifical pancreas @ Wikipedia
- Dr. Bernstein's web site
- Jenny Ruhl's web site