(HealthDay News) — Post-meal surges in blood sugar can cut a man’s level of circulating testosterone by about a quarter, new research shows.

The finding might help doctors decide to test for testosterone levels while patients are fasting, the researchers said.

The study, slated for presentation Saturday at The Endocrine Society’s annual meeting in Washington, D.C., involved 74 men, including 42 with normal blood sugar, 23 with impaired blood sugar levels (”pre-diabetes”) and nine newly diagnosed with type 2 diabetes.

Each of the men drank a sugary solution (75 grams of pure glucose), which typically triggers a spike in blood sugar levels. They then had their testosterone levels tested.

The researchers found that, regardless of whether the men had diabetes or not, blood levels of testosterone dropped by as much as 25 percent after they drank the sugary drink. This trend continued for more than two hours after the glucose was ingested. In fact, 15 percent of the 66 men with normal testosterone levels before the test had low testosterone (”hypogonadism”) at some point during the test.

Changes in insulin levels didn’t seem to affect the results, nor did levels of other hormones, the team said.

Doctors need accurate testosterone testing to see whether men are hypogonadal and require testosterone supplementation, study co-author Dr. Frances Hayes, an endocrinologist at St. Vincent’s University Hospital in Dublin, Ireland, said in a news release from the Endocrine Society. Because testosterone now seems tied to blood-sugar levels, “this research supports the notion that men found to have low testosterone levels should be reevaluated in the fasting state,” said Hayes, who did the research while at Massachusetts General Hospital in Boston.

Michael O’Riordan

June 26, 2009 (Toyoake, Japan) — Vulnerable plaques identified visually by computed-tomography (CT) angiography are more likely to result in a subsequent acute coronary syndrome during follow-up, a new study has shown [1]. Identifying these unstable coronary plaques, which have areas of low attenuation and have undergone positive remodeling, could be used to aggressively treat patients who are at higher risk for future events, according to researchers.

“Our data suggest that once a patient is identified to be at risk of having an adverse event on the basis of traditional clinical, biochemical, and biomarker risk profiles, imaging may help identify those at greater risk of acute coronary events,” write lead investigator Dr Sadako Motoyama (Fujita Health University School of Medicine, Toyoake, Japan) and colleagues in the June 30, 2009 issue of the Journal of the American College of Cardiology.

Speaking with heartwire , Dr Renu Virmani (Cardiovascular Pathology Institute, Gaithersburg, MD), one of the study investigators, said the results show for the first time that high-risk, vulnerable lesions, characterized previously in pathologic studies, are able to identify patients with future symptoms, and this moves the field forward by a “big step.”

“This is just the beginning, but it is a good beginning,” she said. “It is the first study we have showing us that we can actually identify these lesions and that these are the lesions that are going to produce symptoms in patients. Before that, it’s all been a theory. We were able to say these are vulnerable plaques, and we should watch and worry about them, but we had no way of showing these were the ones that would go on to produce symptoms.”

More Than 1000 Patients Assessed by CTA

To determine whether the characteristics of atherosclerotic lesions were associated with future acute coronary syndromes, the researchers analyzed the lesions based on the presence of positive vessel remodeling and low-attenuation plaques. Virmani explained that these two characteristics, along with a necrotic core, are thought to be associated with subsequent plaque rupture.

Among the 1059 patients who underwent CT angiography, 45 patients had coronary plaques that had undergone positive remodeling and were classified as low attenuation. After more than two years of follow-up, 10 patients, 22.2%, with both characteristics of vulnerable plaque developed an acute coronary syndrome. On the other hand, just one of the 27 patients with only one feature, either low attenuation or positive remodeling, developed symptoms, while only 0.5% of the 820 patients without any features of vulnerable plaque developed an acute coronary syndrome.

In a multivariable regression analysis, the presence of low-attenuation plaque or positive remodeling was associated with a 23-fold increase in the risk of an acute coronary syndrome (hazard ratio 22.8; 95% CI 6.9-75.2; p<0.001).

Virmani told heartwire that it is not always easy to identify low-attenuation plaque and that there are those who doubt whether visualizing these softer plaques can be done reliably, although the technology is improving. On the horizon are better imaging modalities, including 320-detector-row CT scanners that improve resolution, as well as machines that limit the amount of radiation exposure.

Systemic vs Focal Disease

Commenting on the results of the study for heartwire , Dr Steven Nissen (Cleveland Clinic, OH) said he was skeptical of the results and the vulnerable-plaque hypothesis, in general. In a recent editorial in the Journal of the American College of Cardiology: Cardiovascular Imaging, Nissen said that many diagnostic techniques designed to detect vulnerable plaques, including thermography, virtual histology, and optical coherence tomography, among others, have promised much but delivered little [2].

Last week, noted Nissen, a CT-angiography study, reported by heartwire , showed that the technology was unable to reliably identify the functional significance of coronary lesions in patients with stable angina and atypical chest pain. To now suggest that CT angiography can identify plaques at risk for rupture is “asking an awful lot from this technology.” Also, he said the investigators did not show that the lesion of the coronary artery identified by CT angiography as vulnerable is responsible for the acute coronary syndrome.

“They don’t close the loop,” said Nissen. “We don’t find out that the site that had positive remodeling and low attenuation is the site where the plaque ruptured. Without that, this becomes much more speculative.”

In general, Nissen said that he believes the vulnerable-plaque approach is the wrong approach because atherosclerosis is a systemic disease, and if anything is likely to predict outcomes, it’s a systemic, not focal, marker. Virmani, on the other hand, strenuously disagrees, telling heartwire that Nissen is “missing the boat” regarding these high-risk focal lesions because evidence shows that patients with coronary events have a focal thrombus formation.

“If you look at acute-myocardial-infarction patients, it occurs in one vessel, in the proximal areas,” said Virmani. “Why? Those are the most prone areas. That’s where we need to concentrate. His [Nissen's] idea of concentrating on systemic factors, such as LDL cholesterol, diabetes–yes, absolutely, but those are the patients that then have focal lesions. I don’t deny that you need hypercholesterolemia for a patient to have focal lesions, but in the patients that are high risk, they do develop them at focal spots.”

Did Anybody See My Stolen Horse?

In an editorial accompanying the published study, Dr Eugene Braunwald (Harvard Medical School, Boston, MA) adopts the middle road, hailing the study by Motoyama and colleagues as a landmark trial, while acknowledging the current limitations in the detection of vulnerable plaque [3].

Braunwald notes that widespread clinical application of CT angiography to characterize coronary lesions at risk for future rupture, which he aptly describes as “locking the barn before the horse is stolen,” will require more potent measures for the prevention of plaque rupture than are currently available. Dual antiplatelet therapy, possible stenting, or more potent anti-inflammatory drugs are just some of the possibilities, writes Braunwald.

“Nobody is saying we need to start treating these patients,” adds Virmani. “Start treating them systemically, just as Dr Braunwald points out in his editorial. Right now, we don’t know how to treat these patients. We might need to think of different therapies. Some patients might need anti-inflammatory drugs, or some might need stents, but we won’t know until we learn how these lesions behave prospectively.”

Dr Mario Garcia (Mount Sinai School of Medicine, New York) told heartwire that low-attenuation plaques with positive remodeling are features identified as characteristics of thin-cap, lipid-rich plaques in intravascular ultrasound (IVUS) correlative studies. He added that while the present study identifies a novel imaging biomarker as a powerful predictor of future ACS, there remain unanswered questions, particularly whether the predictive accuracy of CT is superior to established serum biomarkers such as high-sensitivity C-reactive protein (CRP) and whether the same predictive utility could be extrapolated to asymptomatic subjects at risk.

In addition, like Braunwald and Nissen, Garcia says trials are needed to determine the optimal treatment strategy to follow–for example, intensive medical therapy vs prophylactic PCI–once these “high-risk features” are identified in a patient.
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References

1. Motoyama S, Sarai M, Harigaya H, et al. Computed tomographic angiography characteristics of atherosclerotic plaques subsequently resulting in acute coronary syndrome. J Am Coll Cardiol 2009; 54: 49-57.
2. Nissen SE. The vulnerable plaque “hypothesis”: Promise, but little progress. J Am Coll Cardiol Cardiovasc Imaging 2009; 2:483-485.
3. Braunwald E. Noninvasive detection of vulnerable coronary plaques. J Am Coll Cardiol 2009; 54: 58-59.

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Authors and Disclosures
Journalist
Michael O’Riordan

Michael O’Riordan is a journalist for Medscape. Before becoming a journalist for theheart.org, now part of the WebMD Professional Network, he worked for WebMD Canada. Michael studied at Queen’s University in Kingston and the University of Toronto and has a master’s degree in journalism from the University of British Columbia, where he specialized in medical reporting. He can be contacted at MORiordan@webmd.net.

Heartwire © 2009 Medscape, LLC

In 2003, the Life Extension Foundation introduced a purified resveratrol supplement that was later documented to favorably alter some of the changes in gene expression that cause us to age.

On January 25, 2009, CBS News 60 Minutes featured an in-depth report on the multiple benefits resveratrol may confer in slowing and even reversing certain aspects of aging. You can view this entire 60 Minutes report on resveratrol by clicking here

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Research funded by Life Extension has shown that a combination of low-dose (20 mg) resveratrol plus grapeseed extract mimicked many of the favorable gene expression changes seen in calorie-restricted animals. Other studies, however, indicated that higher doses may be needed to obtain all of resveratrol’s positive benefits including:

* improved insulin sensitivity
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MRI scans can be used to diagnose Alzheimer’s disease, even before the onset of symptoms of dementia, say researchers.

Alzheimer’s disease is currently diagnosed by a process of elimination as many other diseases cause similar symptoms, furthermore a diagnosis of Alzheimer’s disease cannot be confirmed until after the patient has died by autopsy. However, results of a study by Ranjan Duara and colleagues at the Florida Alzheimer’s Disease Research Center (ADRC) has added to a growing body of evidence which suggests that MRI scans of the brain can be used to diagnose the neurodegenerative disease.

The researchers used a visual rating system to evaluate the extent of atrophy, or shrinkage, present on MRI scans in three parts of the medial temporal lobe of the brain which are vital for conscious memory. They then compared the MRI brain scans of 260 people, which included people with probable Alzheimer’s disease, people with varying degrees of mild cognitive impairment (MCI), and a control group of normal elderly with no symptoms of memory loss. Results showed that by using the rating system they could accurately distinguish those with probable Alzheimer’s disease from those with MCI, and from those in the control group. Furthermore, the scans even enabled the researchers to identify brain atrophy in some participants who did not have symptoms of memory loss at the start of the study, but who went on to develop memory problems several years later. Thus suggesting that MRI scans could enable doctors to identify those who will get Alzheimer’s long before they become symptomatic.

“This study demonstrates that MRI brain scans are accurate enough to be clinically useful, both in diagnosing Alzheimer’s disease itself at an early stage and in identifying people at risk of developing Alzheimer’s,” said Huntington Potter, PhD director of the Florida ADRC.

News release: MRI brain scans accurate in early diagnosis of Alzheimer’s disease. University of South Florida Health. December 18th 2008.

Body composition appears to be of key importance when it comes to surviving cancer, as researchers have found that cancer patients with more lean muscle mass live longer.

The study of 250 obese cancer patients revealed that patients with depleted muscle mass – a recently recognized condition known as sarcopenic obesity – lived, on average, for 10 months less than obese patients with more muscle mass. Participants with sarcopenic obesity were also more likely to be bedridden. Study leader Professor Vickie Baracos says muscle mass could even effect how patients respond to chemotherapy.

The authors concluded: “This study provides evidence of the great variability of body composition in patients with cancer and links body composition, especially sarcopenic obesity, to clinical implications such as functional status, survival, and potentially, chemotherapy toxicity.”

Prado CMM, Lieffers JR, McCargar LJ, et al. Prevalence and clinical implications of sarcopenic obesity in patients with solid tumours of the respiratory and gastrointestinal tracts: a population-based study. The Lancet Oncology. 2008;9:629-635.

New York Heart Association (NYHA) Class IV congestive heart failure patients are often unable to reach adequate plasma CoQ10 levels even after consuming up to 900 mg per day of standard CoQ10 (ubiquinone) supplements. These patients often have plasma total CoQ10 levels of less than 2.5 μg/ml and have limited clinical improvement. Researchers believe these low levels are the result of the intestinal edema that occurs in these patients, which may impair CoQ10 absorption.

In the current study, researchers investigated seven patients with advanced congestive heart failure (mean ejection fraction 22 percent) with sub-therapeutic plasma CoQ10 levels (mean level of 1.6 μg/ml on an average dose of 450 mg of ubiquinone daily). Ejection fraction refers to the fraction of blood pumped out of a ventricle with each heartbeat. All seven of these patients were switched to an average of 580 mg per day of CoQ10-H2 (450–900 mg/day) with follow-up plasma CoQ10 levels, clinical status, and ejection fraction measurements by echocardiography.

After the subjects were switched to the CoQ10-H2, mean plasma CoQ10 levels increased from 1.6 μg/ml (0.9–2.0 μg/ml) up to 6.5 μg/ml (2.6–9.3 μg/ml). Mean ejection fraction improved from 22 percent (10–35%) up to 39 percent (10–60 percent). Clinical improvement in the CoQ10-H2 group was what the researchers termed as “remarkable” with the NYHA class improving from a mean of IV to a mean of II. The prognosis for patients with NYHA class IV heart failure is very poor with mortality as high as 74 percent at 6 months and 94 percent at 12 months, but six of the seven patients receiving CoQ10-H2 survived longer than expected and remained stable throughout the 12-month study. The one patient in this study that did not survive stopped taking the CoQ10-H2 after three months, even after experiencing an improvement in heart function.

The study authors concluded, “Ubiquinol has dramatically improved absorption in patients with severe heart failure and the improvement in plasma CoQ10 levels is correlated with both clinical improvement and improvement in measurement of left ventricular function.”

The results are interesting in light of an earlier study by another group of researchers, which found that in 236 patients with chronic heart failure, plasma CoQ10 concentration was an independent predictor of mortality.

References:

Langsjoen PH, Langsjoen AM. Supplemental ubiquinol in patients with advanced congestive heart failure. BioFactors. December 2008;32:119-128.

Molyneux SL, Florkowski CM, George PM, Pilbrow AP, Frampton CM, Lever M, Richards AM. Coenzyme Q10: an independent predictor of mortality in chronic heart failure. J Am Coll Cardiol. 2008 Oct 28;52(18):1435-41.

The finding was presented at the Seventh Annual American Association for Cancer Research International Conference on Frontiers in Cancer Prevention Research, held in Washington, DC. The study results suggest that the risk of developing lung cancer was reduced by 22% to 50% among smokers who consumed at least 4.5 servings of raw cruciferous vegetables a month, compared with those who consumed less than 2.5 servings per month.

The researchers also observed that the significant inverse association between consumption of cruciferous vegetables and lung cancer was only seen for squamous or small cell carcinoma, which are the 2 subtypes most strongly associated with heavy smoking.

Our study was initiated by strong evidence that there is an inverse association between cruciferous vegetable intake and lung cancer risk, said lead author Li Tang, PhD, a post-doctoral fellow at Roswell Park Cancer Institute, in Buffalo, New York.

Researchers from Roswell Park previously demonstrated that the intake of raw cruciferous vegetables, including broccoli, broccoli sprouts, cabbage, and cauliflower, was associated with a reduced risk for bladder cancer. (Cancer Epidemiol Biomarkers Prev. 2008;17:938-944). The inverse association was significant among current and heavy smokers who consumed 3 or more servings per month of raw cruciferous vegetables. The protective action of cruciferous vegetables is derived at least in part from isothiocyanates, a group of carcinogen-modulating phytochemicals found in these vegetables.

But although the consumption of cruciferous vegetables has previously been shown to be associated with a lower risk for lung cancer, findings stratified by smoking status have remained inconsistent.

In the current study, Dr. Tang and colleagues conducted a hospital-based case–control study that examined 948 patients diagnosed with primary lung cancer between 1982 and 1998, and 1743 healthy controls. Study participants completed questionnaires that detailed their intake of total fruits and vegetables, as well as cruciferous vegetables, along with risk factors for lung cancer, such as cigarette smoking.

“To control for the compounding factors of smoking, we matched case and control for smoking status and further adjusted the data for smoking duration and smoking intensity,” said Dr. Tang during a press briefing. “Unlike previous studies, we also took into account whether the vegetables were cooked or raw because we know that cooking can substantially decrease the amount of isothiocyanates,” he continued.

After controlling the data for smoking status and other known risk factors, the researchers observed strong linear inverse associations between intakes of fruit, total vegetables, and cruciferous vegetables, and risk for lung cancer (odds ratio range, 0.53 – 0.70; P for trend < .05). An intake of fruits and total vegetables showed a relatively stronger association among never smokers, whereas significant inverse associations with cruciferous vegetable consumption were only observed among smokers and former smokers.

They also noted that, of the 4 histologic subtypes of lung cancer, the risk reduction was only seen for small cell carcinoma and squamous cell carcinoma.

Previous research has found that fruit and vegetables can be protective against lung cancer, but this study provides new information about smoking status and the nature of the fruits and vegetables, commented Elizabeth A. Platz, ScD, MPH, associate professor at Johns Hopkins Bloomberg School of Public Health, in Baltimore, Maryland. “They looked at which vegetables might be the most helpful in preventing lung cancer, and also looked at the histologic types of lung cancer.”

The researchers also looked at the relation between fruit and vegetable intake and never smokers. This is important, explained Dr. Platz, “because there are people diagnosed with lung cancer who have never smoked.”

Cedric Louvet, Ph.D., from the University of California San Francisco, and colleagues tested the effectiveness of various tyrosine kinase inhibitors to treat type 1 diabetes, an autoimmune disease, in a mouse model of the disease (the non-obese diabetic mouse).

The researchers found that treatment with imatinib (Gleevec) or sunitinib (Sutent), which inhibit multiple protein kinases, prevented and reversed type 1 diabetes. In contrast, the tyrosine kinase inhibitor PLX647 or an anti-c-Kit antibody were largely ineffective, whereas a soluble form of platelet-derived growth factor receptor rapidly reversed diabetes. In addition, discontinuation of imatinib treatment at 10 weeks led to long-term remission in most mice.

“Thus, long-term efficacy and tolerance is likely to depend on inhibiting a combination of tyrosine kinases supporting the use of selective kinase inhibitors as a new, potentially very attractive approach for the treatment of type 1 diabetes,” Louvet and colleagues conclude.

One of the study authors is an employee of Plexxikon in Berkeley, Calif.