RECENT DEVELOPMENTS REGARDING RISK FACTORS FOR HEART DISEASE

[Guest guest]

RECENT DEVELOPMENTS REGARDING RISK

FACTORS FOR HEART DISEASE Part 2

http://www.diabetesincontrol.com/results.php?storyarticle=4866

 

Diabetics die from heart failure at a rate far exceeding that of people with

normal glucose tolerance. Heart failure involves a weakening of the cardiac

muscle so that it cannot pump enough blood. Most long term, poorly controlled

diabetics have a condition called cardiomyopathy. In diabetic cardiomyopathy,

the muscle tissue of the heart is slowly replaced by scar tissue over a period

of years. This weakens the muscle so that it eventually “fails.†There is no

evidence linking cardiomyopathy with dietary fat intake or serum lipids.

 

A fifteen-year study of 7,038 French policemen in Paris reported that “the

earliest marker of a higher risk of coronary heart disease mortality is an

elevation of serum insulin level.†A study of middle aged nondiabetic women at

the

University of Pittsburgh showed an increasing risk of heart disease as serum

insulin levels increased. Other studies in nondiabetics have shown strong

correlations between elevated serum insulin levels and other predictors of

cardiac

risk such as hypertension, elevated triglyceride, and low HDL. The importance

of elevated serum insulin levels (hyperinsulinemia) as a cause of heart

disease and hypertension has taken on such importance that a special symposium

on

this subject was held at the end of the 1990 annual meeting of the ADA. A report

in a subsequent issue of the journal Diabetes Care quite appropriately points

out that “there are few available methods of treating diabetes that do not

result in systemic hyperinsulinemia [unless the patient is following a

low-carbohydrate diet].†Furthermore, research published in the journal

Diabetes in

1990 demonstrated that elevated serum insulin levels cause excessive leakage of

protein from small blood vessels. This is a common factor in the etiology of

blindness (via macular edema) and kidney disease in diabetics.

 

Although the AHA and the ADA have been recommending lowfat, high-carbohydrate

diets for diabetics for many decades, no one had compared the effects on the

same patients of low- versus high carbohydrate diets until the late 1980s.

Independent studies performed in Texas and California demonstrated lower levels

of blood sugar and improved blood lipids when patients were put on

lower-carbohydrate, high-fat diets. It was also shown that, on average, for

every 1

percent increase in HgbA1C (the test for average blood sugar over the prior four

months), total serum cholesterol rose 2.2 percent and triglycerides increased 8

percent. A long-term study of 7,321 “nondiabetics†in 2006 showed that for

every 1 percent increase in HgbA1C above 4.5 percent, the incidence of coronary

artery disease increased 2.5-fold. The same study also showed that for every 1

percent increase in HgbA1C above 4.9 percent, mortality increased by 28

percent.

 

The National Health Examination Follow-Up Survey, which followed 4,710

people, reported in 1990 that “in the instance of total blood cholesterol, we

found

no evidence in any age-sex group of a risk associated with elevated values.â€

That’s right: they found no risk associated directly with elevated total

cholesterol. On the same page, this study lists diabetes as by far the single

most

important risk factor affecting mortality. In males aged 55–64, for example,

diabetes was associated with 60 percent greater mortality than smoking and

double the mortality associated with high blood pressure.

 

The evidence is now simply overwhelming that elevated blood sugar is the

major cause of the high serum lipid levels among diabetics and, more

significantly, the major factor in the high rates of various heart and vascular

diseases

associated with diabetes. Many diabetics were put on low-fat diets for so many

years, and yet these problems didn’t stop. It is only logical to look to

elevated blood sugar and hyperinsulinemia for the causes of what kills and

disables

so many of us.

 

My personal experience with diabetic patients is very simple. When we reduce

dietary carbohydrate, blood sugars improve dramatically. After several months

of improved blood sugars, we repeat our studies of lipid profiles and

thrombotic risk factors. In the great majority of cases, I see normalization or

improvement of abnormalities.* This parallels what happened to me more than

thirty-five years ago, when I abandoned the high-carbohydrate, low-fat diet that

I had

been following since 1946.

 

Sometimes, months to years after a patient has experienced normal or

near-normal blood sugars and improvements in the cardiac risk profile, we will

see

deterioration in the results of such tests as those for LDL, HDL, homocysteine,

and fibrinogen. All too often, the patient or his physician will blame our

diet. Inevitably, however, we find upon further testing that his thyroid

activity

has declined. Hypothyroidism is an 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, hypothyroidism 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 one pill daily. The best screening test is free T3, tested

by

tracer dialysis. If this is low, then a full thyroid risk profile should be

performed. Correction of the thyroid deficiency inevitably corrects the

abnormalities

of cardiac risk factors that it caused.

 

* If your physician finds all of this hard to believe, he or she might

benefit from reading the seventy articles and abstracts on this subject

contained in

the Proceedings of the Fifteenth International Diabetes Foundation Satellite

Symposium on “Diabetes and Macrovascular Complications,â€Diabetes 45,

Supplement

3, July 1996. Also worth reading is “Effects of Varying Carbohydrate Content

of Diet in Patients with Non-Insulin Dependent Diabetes Mellitus,†by Garg et

al., Jnl Amer Med Assoc 1994; 271:1421–1428. Many studies comparing

lowcarbohydrate and low-fat diets are presented each year at meetings of the

Metabolism

and Nutrition Society. The low-carbohydrate diets invariably have shown

reduced cardiac risk.

 

For Part 1: http://www.diabetesincontrol.com/results.php?storyarticle=4828