Wednesday, May 14, 2014

Low Vitamin D is directly linked with low glucose, fasting insulin and more.

Vitamin D Cut Point Linked to Normal Glucose Metabolism

Marlene Busko
April 21, 2014
"Vitamin D was inversely related to fasting glucose, fasting insulin, 2-hour insulin, insulin resistance, visceral abdominal fat, percentage fat, PTH, and triglycerides."
"... the cut point for sufficient vitamin D is the same for black and white women."
"Dr. Peterson agrees with the authors that "the Institute of Medicine values [for vitamin-D sufficiency or insufficiency] are probably myopic. They really honed in on bone health without looking beyond bone-health measure outcomes."
A 25-hydroxyvitamin D (vitamin D) level of about 26 ng/mL is needed for normal glucose metabolism in both black and white obese, postmenopausal women, a new observational study suggests. Women with a blood vitamin-D concentration at or above this threshold had lower body fat and blood glucose, insulin, and triglyceride levels than women with lower levels of vitamin D.
The cutoff is below the minimal vitamin-D level recommended by the Endocrine Society (30 ng/mL) but above that recommended by the Institute of Medicine (20 ng/mL); however, both guidelines are based on studies of bone health. The current study implies that "if you want to think about defining cut points for vitamin D, you need to think about things other than bone," lead author John D. Sorkin, MD, from the University of Maryland, in Baltimore, told Medscape Medical News.
"Our results...suggest that the [Institute of Medicine recommendation] of 20 ng/mL is probably too low." Importantly, the data also indicate that the cut point for sufficient vitamin D is the same for black and white women, he said.
However, this was a retrospective, observational study with inherent limitations. "A large, prospective interventional study in black and white women will be needed to confirm that increasing 25(OH)D concentration above [around 26 ng/mL] improves glucose homeostasis and insulin sensitivity with little improvement above this value," Sorkin and colleagues caution. They also call for further research to determine whether their findings hold true for other racial and ethnic groups, men, and younger, older, or nonobese individuals.
The study is published in the May 2014 issue of the Journal of Nutrition.
Vitamin D Beyond Bone
The definition of normal vitamin-D levels remains controversial, and guidelines largely base their recommendations on studies of bone metabolism, the researchers explain. However, low levels of vitamin D have been recently linked with glucose intolerance, type 2 diabetes, insulin resistance, hypertension, hyperlipidemia, and cardiovascular disease.
The researchers aimed to study the effect of vitamin D on glucose tolerance, insulin resistance, and other cardiovascular risk factors. The study population included obese individuals and blacks, who are more likely to have a vitamin-D deficiency, Dr. Sorkin explained.
They performed a cross-sectional study of 83 black and 156 white overweight or obese, sedentary, postmenopausal women without diabetes who had participated in studies at their center between June 1995 and July 2009 and had a fasting blood glucose and 2-hour oral glucose tolerance test. Other assessments included insulin resistance, insulinlike growth factor 1, parathyroid hormone (PTH), aerobic fitness, body composition (using dual X-ray absorptiometry), subcutaneous abdominal and visceral fat, and blood pressure.
Vitamin D was inversely related to fasting glucose, fasting insulin, 2-hour insulin, insulin resistance, visceral abdominal fat, percentage fat, PTH, and triglycerides. There was no relationship between vitamin D and blood pressure, lipids (other than triglycerides), or fitness.
Adds to Evidence, Has Some Limitations
Asked to comment, Catherine A. Peterson, PhD, from the University of Missouri in Columbia, said that "this is another little piece of evidence suggesting that vitamin-D status does matter in terms of glucose control." She previously published results from a randomized controlled trial that showed correcting vitamin-D insufficiency improved insulin sensitivity in obese adolescents.
The article has several limitations, she noted. It uses inconsistent measures for vitamin D (as opposed to just using to the standard unit, ng/mL) and describes how vitamin-D levels "cause outcomes," which cannot be established, because it was an observational study. Although Sorkin and colleagues explain that frozen samples of vitamin D have been shown to be stable for 6 to 24 years, there still might be some degradation of the 4- to 18-year-old samples in the current study, which could preclude being able to establish a precise vitamin-D threshold.
However, Dr. Peterson agrees with the authors that "the Institute of Medicine values [for vitamin-D sufficiency or insufficiency] are probably myopic. They really honed in on bone health without looking beyond bone-health measure outcomes."
The study was supported by the Baltimore Veterans Affairs Medical Center Geriatrics Research, Education, and Clinical Center and grants from the National Institute on Aging, National Institute of Diabetes and Digestive and Kidney Diseases, and National Institutes of Health. The authors declared no conflicts of interest.
J Nutr. 2014;144. Full text

Saturday, January 18, 2014

Sunlight creates NO (Nitric Oxide) and lowers blood pressure.

Study: Exposing skin to sunlight may help lower blood pressure

Published on January 17, 2014 at 7:21 AM · No Comments

Friday, January 10, 2014

New blood test measures endothelial cells 'could accurately predict heart attack risk'

Test identifies endothelial cells in blood to predict heart attacks
According to The Heart Foundation, more than 920,000 Americans will suffer a heart attack this year, and many of these will occur without warning. But researchers from The Scripps Research Institute in California say they have created a blood test which may be able to predict whether patients are at high risk of heart attack.

The research team, led by Prof. Pete Kuhn, says that at present there is no test available that can predict the occurrence of aheart attack with good accuracy.
But they say their novel test, details of which have been recently published in the journal Physical Biology, has so far proved successful in identifying which patients are undergoing treatment for a recent heart attack and which patients are healthy.
The new test uses a "fluid biopsy" technique. It works by identifying the presence of endothelial cells - which line the artery walls - in the bloodstream.
According to the researchers, endothelial cells that circulate in the bloodstream have been associated with ongoing heart attacks.
Lady suffering chest pain
Researchers say the HD-CEC test can accurately detect circulating endothelial cells in patients, meaning the test could be used to predict heart attack risk.
They believe that endothelial cells enter the bloodstream as a result of diseased plaque building up, rupturing and ulcerating in the arteries, which triggers inflammation.
They add that this damage to the arteries can lead to the formation of blood clots. This stops the blood flowing through the arteries, which in turn can cause a heart attack.
Using a newly-created procedure called the High-Definition Circulating Endothelial Cell (HD-CEC) assay, the researchers were able to identify and differentiate endothelial cells in blood samples of 79 patients, all of whom had already suffered a heart attack when their samples were taken.
The researchers also used the HD-CEC assay on two groups of patients as a control measure. One group was made up of seven patients who were receiving treatment for cardiovascular disease, while the other group consisted of 25 healthy patients. 

Blood test successfully identified Heart Attack Patients
The research team found that the HD-CEC assay was able to detect circulating endothelial cells in the blood of the patients through the cells' "morphological features and their reactions with specific antibodies."

Patients who suffered a heart attack had much higher levels of circulating endothelial cells in their blood, compared with healthy patients. And the researchers note that the cells were identified with "high sensitivity and high specificity."
To further confirm the accuracy of the HD-CEC assay, the researchers compared it with CellSearch - a test that has been approved by the US Food and Drug Administration (FDA) to identify circulating tumor cells in patients with cancer.
From this, the investigators found that the HD-CEC test was able to detect circulating endothelial cells more accurately than the CellSearch test.
The researchers say this is because the HD-CEC test "used a direct analysis method and was free of bias from an enrichment stage."
"Our assay effectively analyzes millions of cells, which is more work but guarantees that you are analyzing all of the potential cells," says Prof. Kuhn.
The investigators believe the technique is now ready to be tested on patients who show symptoms of increased risk of heart attack, but have not yet suffered one.
Prof. Kuhn adds:
"The goal of this paper was to establish evidence that these circulating endothelial cells can be detected reliably in patients following a heart attack and do not exist in healthy controls - which we have achieved.
Our results were so significant relative to the healthy controls that the obvious next step is to assess the usefulness of the test in identifying patients during the early stages of a heart attack."
This is not the only research to look at the possibility of predicting heart attack risk. In November last year,Medical News Today reported on a study from researchers at the University of Edinburgh in the UK, which detailed a new imaging technique that can light up dangerous fatty plaques in the arteries that are in danger of rupturing - therefore identifying heart attack risk.
Written by Honor Whiteman