January 12, 2011

More Research of Note

Here's another quick round up of recently published research. Click on the link to see the journal article abstract.

1. Exercise does not change metabolic parameters associated with weight gain or insulin resistance. Birth weight has long been known to correlate with weight gain, and in the case of low birth weight, with increased insulin resistance. The European Youth Heart Study, a population-based study of 9 and 15 year olds (n = 1,254)
...did not find any evidence that physical activity or aerobic fitness can moderate the associations among higher birth weight and increased fat mass and greater waist circumference or between lower birth weight and insulin resistance in healthy children and adolescents.
2. More Evidence of the Desirability of an A1c under 5.7% and the dangers of one over 6.5%. Fourteen years of follow-up of 11,357 participants (773 with a history of diagnosed diabetes) from the Atherosclerosis Risk in Communities (ARIC) Study found that the risk for kidney disease and retinopathy rise significantly as A1c goes over 5.7% and dramatically increases when it is 6.5% or higher.

Compared to that of A1c of 5.7% or less, the risk of chronic kidney disease in this population was: 1.12 (0.94–1.34) at A1c 5.7-6.4%. and 1.39 (1.04–1.85) for A1c over ≥6.5%,

Compared to the A1c of 5.7 or less, the risk of End Stage Renal Disease (i.e. Kidney failure) was 1.51 (0.82–2.76)--about 50% higher to almost 3 times higher--for A1c 5.7-6.4%.and 1.98 (0.83–4.73)--twice to almost five times as high--for A1c of 6.5% or higher.

In the absence of diagnosed diabetes, A1c was cross associated with the presence of moderate/severe retinopathy (diabetic retinal damage leading to blindness), with adjusted odds ratios of 1.42 (0.69–2.92) for A1c between 5.8% and 6.4%--averaging about 60% higher but ranging to three times higher. But it was three to seven times as high--risk ratio of 2.91 (1.19–7.11)--3 to 7 times as high for A1c of 6.5% or higher.

3. Higher Levels of Cholesterol of ALL Types Correlates with LESS Likelihood of Alzheimers. It has long been known--though doctors have been brainwashed into ignoring it--that statins can cause permanent dementia, especially in older patients. Could it be because cholesterol is protective to the brain? This study would make you wonder.

It followed 1,130 adults 65 or older in New York City with no history of dementia or cognitive impairment.
Higher levels of HDL-C (>55 mg/dL) were associated with a decreased risk of both probable and possible A[lzheimers] D[isease] and probable AD compared with lower HDL-C levels (hazard ratio, 0.4; 95% confidence interval, 0.2-0.9; P = .03 and hazard ratio, 0.4; 95% confidence interval, 0.2-0.9; P = .03). In addition, higher levels of total and non–HDL-C were associated with a decreased risk of AD in analyses adjusting for age, sex, education, ethnic group, and APOE e4 genotype.

4. Educational Level Predicts Diagnosis of LADA vs. Type 2. This Norweigian study is titled "High Levels of Education Are Associated With an Increased Risk of Latent Autoimmune Diabetes in Adults", which makes it sound as if somehow the education is raising the risk of this late onset form of autoimmune Type 1 diabetes.

However, the result they found might also point to the likelihood that the college educated people, who they mention were also thinner, were more likely to get a correct diagnosis from their doctors because the doctors had more respect for them, and were more willing to put time into getting a correct diagnosis. When doctors see what they perceive as a lower class patient who is overweight, their prejudices (shared with society at large) may make them assume "Type 2" and fail to run the tests that would reveal LADA.

In fact, there are a significant number of overweight and obese people with LADA--all of the ones I've heard from report having a terribly tough time getting the tests that provide the correct diagnosis. Less educated people may be more cowed by doctors' authority and may never get that diagnosis.

5. Yet Another Study Finds Metformin Appears to Fight Cancer. If you've been putting off taking metformin out of fear of pharmaceutical drugs, get over it. The accumulating evidence about Metformin just keeps getting better and better. It's a cheap generic drug that is not making anyone rich, so the chances that this data have been skewed to sell the drug is low.

6. Byetta Slightly Reduces the Risk of Heart Attack, Stroke, and Stenting. Analyzing a large database of insurance claims and prescribing information, it was determined that people prescribed Byetta were sicker to start with--fatter and with pre-existing heart disease, high cholesterol, and high blood pressure, but they had fewer cardiovascular "events" than controls who didn't take Byetta.

7. The Diabetic Alelles of the TCF7L2 Gene--the One Most Strongly Associated with Diabetes in Western Europeans--Damage Insulin Production, But Have No Effect on Insulin Sensitivity. Other studies have already documented this, but this study in newly diagnosed people with Type 2 diabetes should drive home the message that the old saw that people with Type 2 produce lots of insulin is just plain not true.

That's it for now. I'll be doing further updates each month as the new journals come up.



LeonRover said...

Thanks for studies.

The Metformin story is not yet finished.

The genes report is also on point.

Rachael said...

Thank you!

A question: I was diagnosed "pre-diabetic" and hyperinsulinemic a while ago. I have made a number of diet changes, and lately I am doing pretty well even with fairly moderate carb levels (~100 grms a day) I am curious though, how damaging do you think the high insulin is? Mine was 90 at 1 hr. on a ogtt. I stopped taking Metformin because it didn't seem to make a difference in my readings, but I haven't followed up with another OGTT so I don't know if it changed my insulin levels.

One major change I made was I stopped taking 5HTP which I had taken for migraines for several years. Do you know of any research linking 5HTP to insulin resistance? All of the serotonergic drugs seem to cause diabetes in susceptible people, and I think 5HTP may have caused problems for me, though it did great things for my migraines.

Jenny said...

Rachel, Everything I've seen suggests it isn't the insulin that hurts people, it's the high blood sugars. High insulin may make it tough to lose weight, but otherwise no one has been able to prove it is harmful.

I don't know about the effect of 5HTP on insulin. The drug companies are so secretive and downright dishonest about SSRIs that it isn't clear what they do that messes up blood sugar and makes people gain weight. I have read both that they do and don't raise insulin.

Judi O said...

I always appreciate the new info. I have a question on seasonal change and I wonder does the onset of fall and winter sometimes cause a rise in fbg. Mine has gone up about 15-20 ml since October. I also read recently about cottage cheese, whey protein, and yogurt causing an insulin spike - would that make me more insulin resistant? I've increased my use of these over the past 4 months.

Jenny said...

Judi O,

Cottage cheese and some brands of whey protein and yogurt can be high in carbs. If so, they will raise blood sugar and that raises insulin levels in people who produce insulin. But I haven't heard anything about these foods making people insulin resistant.

Seasonal change should not cause a significant rise in fasting blood sugar like what you report. If you are seeing it repeatedly, even after opening a new container of test strips, I'd consider it real.

Judi O said...

Sigh...in August I was getting morning readings in the 90's and now they can range from 115 to 120. Eating the same stuff. I also think I may be getting a release of glucose in the late afternoon which makes my after dinner number higher as well. I am medication free right now but am thinking I may have to consider metformin. I keep under 140 and if I go higher I use exercise to bring it down. Am I missing anything obvious?

Jenny said...

Judi O, If your fasting blood sugar continues to rise with no changes in diet you need to be tested to see if you are producing normal amounts of insulin and to rule out slow onset autoimmune diabetes. Metformin is worth a try. If it doesn't have an impact, you need to see an endocrinologist.