Serum Albumin Although serum albumin is usuaUy included in the blood chemistry profile, it is not widely appreciated that low levels are associated with double the all-cause mortaUty of high levels. It is thus very important that patients with low serum albumin receive further workup to de termine the cause.
Serum Globulin Globulins are antibodies produced by the immune system. They help the body to fight off infections and maUgnancy. If you experience fre quent colds, sinusitis, diarrhea, or slow-healing infection of any type, you may have an immunoglobulin deficiency. If your total serum globulinsare low, you should be testedfor specific immunoglobulins, such as IgA, IgG,and IgM.In my experience, 10-20 percent of diabet ics have an inherited immunodeficiency disorder that may be treat able.
Cardiac Risk Factors This is a battery of tests that measuresubstances in the blood that may predispose you to arterial and heart disease.
It's worth noting that one of the hallmarks of high blood sugars is fatigue. However, diminished thyroid function can cause profound fatigue and coldness. If you're still "always tired" or "always cold" after normalizing blood sugars, talk to your physician about a thyroid profile. This test can be costly.
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Important note: Sometimes, months to years after a patient has experienced normal or near-normal blood sugars and resultant im provements inthecardiac risk profile, we might see deterioration inthe results of such tests as those for LDL, HDL,homocysteine, fibrinogen, andUpoprotein(a).
All toooften, thepatient orhis physician will blame our diet.Inevitably, however, wefindupon further testing that his thy roidactivity hasdeclined.
Hypothyroidism isan autoimmune disorder, like type 1 diabetes, and is frequently inherited by diabetics and their close relatives.
It can appear years before or after the development of diabetes and is not caused by high blood sugars.
In fact, hypothy roidism can cause a greater likelihood of abnormalities of the cardiac risk profile than can blood sugar elevation.
The treatment of a low thyroid condition is oral replacement of the deficient hormone(s) , usually 1 piU daily.
The best screening test is free T3 as measured by tracer dialysis.
If this is low, then a full thyroid test profile should be performed.
Correction of the thyroid deficiency inevitably corrects the abnormaUties of cardiac risk factors that it caused.
Lipid profile.
This profile measures fatty substances (lipids) in your blood and includes total cholesterol, HDL(high-density lipoprotein), triglycerides, and direct LDL (low-density Upoprotein).
Other cardiac risk factors (discussed below) include C-reactive protein, fibrinogen, lipoprotein(a), and homocysteine, and may be more predictive.
Ab normalities of these tests are frequently treatable and tend to improve with normalization of blood sugars.
These tests should be performed after you have fasted for at least 8 hours.
The easiest thing is to have them scheduled in the morning.
If you haven't fasted before the test, the results will be difficult to in terpret.
Maybeyou've heard of"good" cholesteroland "bad" cholesterol?
Well,this is why a reading for total cholesterol by itself won't neces sarily reflect cardiac risk.
Most of the cholesterol in our bodies, both good and bad, is made in the liver; it does not come from eating so- caUed "heart attack foods." If you'veeaten a meal that's high in choles terol, your Uver will adjust to make lessof the "bad" cholesterol, LDL.
Serum triglyceridelevels can vary dramatically after meals,with high- carbohydrate meals causing high triglyceride levels.
Some people , becausethey're obeseor havehigh blood sugarsor are genetically pre disposed , make more or dispose of less LDL than they should,
Tests:Baseline Measures 57
which can put them at a higher risk for cardiac problems.
High levels of LDL increase the risk of heart disease, which makes LDLthe "bad" cholesterol.
HDL, on the otherhand, is a Upid that reduces the riskof heart disease and is the "good" cholesterol.
So it is the ratio of total cholesterol to HDL (total cholesterol -s- HDL) that is significant.
You could have a high total cholesterol and yet, because of low LDL and high HDL, have a lowcardiac risk.
Conversely, a low totalcholesterol butwith a low HDL would signify increased risk.
Recently, asmorehas become known about cholesterol, research has shown that LDL occurs in at least two forms, smaU, dense LDL particles (the hazardous form) andlarge, buoyant LDL particles.
LDL particle size isnow being measured by commercial laboratories.
Larger particles, classified as size A, are considered benign, while smaller particles carry cardiac risk.
Associated with the test for particle size is apoUpoprotein B.
When theApo Btestresult islower than 120 mg/dl, or when LDL par ticle size is class A, even high LDL levels are considered benign and shouldnot be treatedwith statin drugs.
The only truly accurate measure of LDL is the direct LDL test.
The customary, calculated measure of LDL is estimated mathematicaUy and can result in values that are sometimes grossly in error.
The direct test,however, may cost more than the restof your Upid profile.
Also important to remember is that , as wewiU discuss in Chap ter 9 , fats and cholesterol in the diet do not cause high-risk Upid profiles in most people.
On the otherhand,diabetics tend to have Upid profiles that reflect increased cardiac risk, if their blood sugars have been elevated for several weeks or months.
Thrombotic risk profile.
This profile includes levels of fibrinogen, C-reactive protein, and Upoprotein(a).
These are also"acute phase re- actants," or substances that reflect ongoing infection and other in flammation.
These three substances are associated with increased tendency of blood to clot or form infarcts (blockages of arteries) in people who have had sustained high blood sugars.
In the casesof elevatedfibrinogen or Upoprotein(a), there is, addi- tionaUy, often an increased risk of kidney impairment or retinal dis ease.
Obesity, even without diabetes, can cause elevation of C-reactive protein.
In my experience,aU these tests are more potent indicators of impending heart attack than the Upid profile.
Treatmentsare available for elevations of each of these.
Bloodsugar normalization wiU tend to
58 BeforeYou Start
reverse most of theseelevations overthe long term.
Fibrinogen can be elevated by kidney disease, even in the absence of elevated blood sug ars.
It wiU tend to normalizeif kidneydisease reverses.
Lipoprotein(a) wiU also tend to normalize somewhat by blood sugar normalization, although your genetic makeup (and low estrogen levels in women) canplaya greater role thanbloodsugar.
AbnormaUy lowthyroidfunc tion is a common cause of low HDL and elevated LDL,homocysteine, and Upoprotein(a).
Although serum homocysteine is also a cardiac risk factor, it wasrecently discovered that the usualtreatment for ele vated values (vitamin B-12 and foUc acid supplements) actuaUy in creased mortaUty.
Serum transferrin saturation, ferritin, total iron binding ca pacity (TIBC).
These are aU measures of total body iron stores.
Iron isvital,but it is alsopotentially dangerous.
Levels that are too high can indicate a cardiac risk, cause insulin resistance, and are a risk factor for Uver cancer.
I wiU discuss insulin resistance at length in Chapter 6.
Higher iron levels are more likely in men than in premenopausal women because of blood (iron) loss during menstruation. (This is why I recommend iron-enhanced vitamin supplements onlyfor those with an established need.) Iron levelsthat are too low (iron deficiency anemia, which is more common in premenopausal women) can cause an uncontroUable urge to snack,which in turn can lead to uncontrol lable blood sugars.
Both high and low iron stores can be easily deter mined and readily treated.
Renal Risk Profile Chronic blood sugar elevation for many yearscan cause slow deterio ration of the kidneys.
If caught early, it may be reversible by blood sugar normalization, as it was in my own case.
Unless you think fre quent hospital visits for dialysis might be a nice way to meet people, it's wise to have periodic tests that reflect early kidney changes.
It is also wise to have aU these periodicaUy performed together, as the re sults of each can clarifythe interpretation of aU.
Several factors cause false positive results in some of these tests, so you should keep them in mind when your doctor schedulesthe tests.
You should avoid strenuous or prolonged lower-body exercise (which would include motorcycle or horseback riding) in the 48 hours pre ceding the tests.
AdditionaUy, if on the day the tests are to be per formed you are menstruating or have a fever, a urinary tract infection,
Tests:Baseline Measures 59
or active kidneystones, you shouldpostponethe tests until thesecon ditions have cleared. Abasic renal riskprofile should include the foUowing:
Urinary kappa light chains. Ifearly diabetic kidney disease ispres ent, this test reports "polyclonal kappa Ught chains present." This means that small amounts of tinyprotein molecules maybe entering the urine,due to leaky bloodvessels in thekidneys. Because thesemol ecules aresosmaU, theyarethefirst proteins to leak throughtinypores in the bloodvessels of the kidneys that mayhave been affected by dis ease.
This test requires a smaU amount of fresh urine. If the test report states "monoclonal Ught chains present," there is a possibiUty of treat able maUgnancies of certain white blood ceUs.
Microalbuminuria.
Thisless cosdy testcan nowbe performed qual itatively (by dipstick) in your doctor's office, or quantitatively at out side laboratories.
It, like the urinary kappa Ught chain test, can also reflect leaky vessels in the kidneys, but at a laterstage, sincealbumin is a sUghtly larger molecule.
A quantitative measurement requires a 24-hour urine specimen, which means you'U need to coUect aU the urine you produce in a 24- hour period in a big jug and deUver it to your physician or laboratory.
Given the potential embarrassment of carrying a jug fuU of urine around at work, you might want to schedule your test on a Monday and coUect the urine while at home on Sunday.
Many of my women patients report that it's easierto coUect urine initiaUy in a clean paper cup, and then pour it into the jug.
An easier screening test is the mea surement of the albumin-to-creatinine ratio in a first morning urine sample.
24-hour urinary protein. This test detectskidney damage at a later stage than the preceding two tests;it also requires a 24-hour urine col lection.Aswith the other tests, false positive resultscan occur foUow ing strenuous lower-body exercise, as previouslynoted.
Creatinine clearance. Creatinine is a chemicalby-product of mus cle metabolism, and is present in your bloodstream aU the time. Mea suring the clearance of creatinine from the body is a way of estimating the filteringcapacityof the kidneys. Test values are usuaUy higher than
60 BeforeYou Start