Missouri.edu - With the obesity rate rising for American adults and children, health concerns such as diabetes and cardiovascular disease are a frequent reality. Although obesity itself is a major risk factor for disease, most of the threat may be associated with a cluster of risk factors called the metabolic syndrome (MetS). Losing weight can improve health and reduce these risk factors, but many people have difficulty keeping the weight off. Now, University of Missouri researchers have found that exercising during weight regain can maintain improvements in metabolic health and disease risk.

In the NIH-funded study, individuals who didn’t exercise during weight regain experienced significant deterioration in metabolic health, while those who exercised maintained improvements in almost all areas. The MU study, led by Tom R. Thomas, professor in the Department of Nutrition and Exercise Physiology in the College of Human Environmental Sciences, is the first to examine the role of exercise in countering the negative effects of weight regain on metabolic syndrome and overall health status.

“Although many people are successful at losing weight through diet and exercise, the majority of them will relapse and regain the weight,” Thomas said. “The findings of this study indicate that regaining weight is very detrimental; however, exercise can counter those negative effects. The findings support the recommendation to continue exercising after weight loss, even if weight is regained.”

In the study, overweight men and women with measured characteristics of metabolic syndrome were given a diet plan and aerobic exercise plan that included supervised exercise five days a week, for 4-6 months. After losing weight, participants underwent programmed weight regain and were separated into two groups, one that exercised and one that didn’t. The non-exercise group experienced rapid deterioration in weight-loss induced benefits to metabolic health. The exercise group maintained improvements in almost all measures, including LDL and HDL cholesterol, oxygen consumption (VO2max), blood pressure and glucose. Exercise didn’t maintain blood cholesterol and abdominal fat loss.

“It’s clear that the message to lose weight isn’t working because so many people regain weight; a new message is to keep exercising and maintain your weight to reduce disease risk and improve overall health,” Thomas said. “Don’t worry so much about losing weight, but focus on exercising and maintaining your current weight.”

The abstract of the study is available online free here:

Exercise and the Metabolic Syndrome with Weight Regain

UTHSCSA.edu - Patients in severe heart failure who are too sick for transplantation have another lifesaving option these days — surgery to implant a new compact, lightweight ventricular assist device (VAD) - the FDA-approved second generation VAD called HeartMate II. The procedure is available in San Antonio from Jay D. Pal, M.D., Ph.D., a cardiothoracic surgeon recruited in 2009 to The University of Texas Health Science Center at San Antonio.

Dr. Pal is a member of UT Medicine San Antonio, the multispecialty practice of physicians in the Health Science Center’s School of Medicine. Dr. Pal specializes in heart and lung transplantation, VAD implantation, surgery for heart failure, coronary revascularization and valve surgery. With his arrival, San Antonio now has a specialty-trained heart transplant surgeon with extensive experience with mechanical circulatory support.

Ventricular assist devices have come a long way since the first model gained U.S. Food & Drug Administration (FDA) approval in 1994. VADs now are available to a wider range of patients, not only those who need a short-term bridge to transplant but also those for whom a VAD will be the sole means to provide improved, long-term cardiac function. The VAD is called “destination therapy” for these patients.

In January 2010 the FDA gave the green light for HeartMate II, a second-generation VAD, to be used in this acutely ill population. HeartMate II is a continuous-flow, left ventricular assist system that is implanted just below the heart to provide mechanical circulatory support, according to an FDA press release. The system is powered by an electrical cable that passes through the skin to a controller worn around the waist.

The FDA action came after a multicenter study found that HeartMate II significantly improved survival and decreased complication rates when compared to earlier-generation devices.

“The FDA approval of HeartMate II is significant for multiple reasons,” Dr. Pal said. “First, it confirms the safety and efficacy of this device in the treatment of advanced heart failure for extended periods in patients who are not eligible for heart transplantation. Second, it provides a proven treatment option for many patients who have significant limitations in quality of life due to heart failure. The new approval allows us to provide this lifesaving treatment to a new population of patients who were previously not candidates for mechanical circulatory support.”

For more information about this FDA-approved therapy, including patient eligibility, please call the cardiothoracic surgery group of UT Medicine San Antonio at (210) 358-8001.

HeartMate II is a registered trademark of Thoratec Corp. of Pleasanton, CA.

AHA - Three different weight-loss diets - a low-carbohydrate diet, a low-fat diet and the Mediterranean diet - were equally effective in helping overweight people to reverse atherosclerosis in the carotid arteries after losing moderate amounts of weight and improving their blood pressure, in a study reported in Circulation: Journal of the American Heart Association.

Researchers at Ben-Gurion University of the Negev, the Nuclear Research Center and Soroka Hospital in Israel investigated whether diet could reverse atherosclerosis, a slow, progressive condition in which the arteries thicken with plaque buildup, increasing risk of heart attacks and strokes. The research team compared the three diets among obese or overweight participants, mostly men, who were at high risk for atherosclerosis.

After two years, researchers noted a significant 5 percent regression in average carotid artery vessel-wall volume and 1.1 percent decrease in carotid artery thickness.

Compared to participants who had increased carotid wall volume, those with decreases had other improvements:

* greater weight loss (11.7 pounds versus 7 pounds);
* decreased systolic blood pressure levels (6.8 mmHg versus 1.1 mmHg);
* improved homocysteine levels; and
* an increase in apolipoprotein A1 (Apo A1), the major component of “good” cholesterol.

The researchers said, beyond drug treatment, the data is some of the earliest showing the potential of diet as a lifestyle modification strategy to prevent atherosclerosis. The findings indicate that sustained, moderate weight loss - not the macronutrient content of the different diets - leads to improved cardiovascular health.

“Long-term adherence to weight-loss diets is effective for reversing carotid atherosclerosis as long as we stick to one of the current options of healthy diet strategy,” said Iris Shai, R.D., Ph.D., study lead author and a nutrition epidemiologist at Ben-Gurion University of the Negev in Beer-Sheva, Israel. “This effect is more pronounced among mildly obese persons who lose more than 5.5 kilograms (12.1 lbs) of body weight and whose systolic blood pressure decreases by more than 7 mmHg. An increase in ApoA1 (HDL cholesterol apolipoprotein) and a decrease in total homocysteine blood levels are further associated with subsequent success in reversing carotid atherosclerosis.”

Researchers studied 140 people (88 percent men, average age 51, average body mass index 30.4 kg/m2) from the Nuclear Research Center Negev who were randomly assigned to a low-carbohydrate, low-fat or Mediterranean diet as part of the Dietary Intervention Randomized Controlled Trial-Carotid (DIRECT-Carotid) study. Twenty-six percent of participants used lipid-lowering therapies, including 20 percent on statins, and nearly one-third of the group took blood pressure medication. They continued with their prescribed treatments throughout the study. Blood pressure was measured every three months, and blood samples to measure biomarkers such as homocysteine levels were collected after a 12-hour fast, at baseline, at six months and again at 24 months. Researchers used ultrasound to capture three-dimensional images of the carotid artery wall and to measure changes in arterial thickness at baseline and at the two-year follow-up.

Participants maintained food diaries and responded to diet questionnaires periodically throughout the study. While caloric deficits were similar among the three groups, intake of carbohydrates, fiber, dietary cholesterol and monounsaturated and saturated fats varied, depending on the type of diet. However, these variations in nutrient intake did not produce significant differences in the outcomes.

“The reduced caloric intake is probably the major determinant of weight loss, but the macronutrient content determines patients’ satisfaction with the diet and the metabolic changes associated with the weight loss,” said Yaakov Henkin, M.D., study co-author and a cardiologist at Soroka University Medical Center, Israel. “The importance of these results is in the understanding that over two years, changes in carotid atherosclerosis are more strongly predicted by diet-induced changes in blood pressure than by changes in lipoprotein levels, which are commonly believed more important for the coronary arteries.”

American Heart Association diet and lifestyle recommendations underscore the importance of balancing calories with physical activity to achieve and maintain a healthy body weight.

AASMNET.org - African–American and Hispanic young adults with too much sleep or too little sleep had greater increases in belly fat over a five-year period compared with those who reported sleeping six to seven hours a night, according to a new study in the March 1, 2010 issue of the journal SLEEP.

In individuals under 40, the NIH-funded study showed a clear association between averaging five hours or less of sleep each night and large increases in visceral fat, or fat around the organs. Of the study participants under 40, Hispanic men and black women were the largest groups to report getting such little sleep.

But sleeping the day away won’t do much to better one’s health, either. The researchers found that getting more than eight hours of sleep on average per night has a similar – though less pronounced – effect and is a problem most commonly seen in Hispanic women of all ages.

Surprisingly, the connection between extremes of sleep and accumulation of visceral fat was seen only in patients under 40, said Kristen G. Hairston, M.D., M.P.H., an assistant professor of endocrinology and metabolism and lead author on the study.

“We don’t really know yet why this wasn’t seen in participants over 40, but it was clear that, in individuals under 40, it is worse to get five or less hours of sleep on average each night than it is to get eight or more hours,” Hairston said. “However, both may be detrimental and, in general, people should aim for six to eight hours of sleep each night.”

Study details

Results show that in participants younger than 40 years of age, both short and long sleep durations were associated with significant increases in body mass index (BMI), as well as in subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) fat accumulation. Compared with people who reported a nightly sleep duration of six to seven hours, those with a self-reported sleep duration of five hours or less per night had an average BMI increase over a five-year period that was 1.8 kg/m2 higher, and greater accumulations of SAT (42 cm2) and VAT (13 cm2); and those who reported sleeping eight hours or more had a BMI increase that was 0.8 kg/m2 higher, as well as greater accumulations of SAT (20cm2) and VAT (6 cm2). No significant relationship existed between sleep duration and abdominal fat change in participants older than 40 years of age.

Information was obtained from 1,107 people in the IRAS Family Study, an extension of the Insulin Resistance Atherosclerosis Study (IRAS). Data were collected from 332 African-Americans and 775 Hispanics with a mean age of 41.7 years at baseline and an age range from 18 to 81 years. Sixty-two percent of participants were female. Mean sleep duration at baseline was 6.7 hours in response to the question, “On average, about how many hours of sleep do you get a night?” Seventeen percent of the sample reported sleeping five hours or less per night, 55 percent slept six to seven hours per night and 28 percent averaged eight or more hours of sleep per night.

Abdominal computed tomography (CT) scans and BMI were obtained at a five-year interval. Dietary intake was assessed using a short, retrospective, one-year, semi-quantitative food-frequency interview. An estimate of usual frequency of participation in vigorous activities also was obtained. Generalized estimating equations using linear regression models assessed the association between sleep duration and five-year fat accumulation with adjustment for age, race, gender, study site, baseline fat measure, physical activity, total calorie intake, smoking status and education.

In those younger than 40 years old, a short sleep duration of five hours or less was most frequently reported by Hispanic men (30 percent), and a long sleep duration of eight or more hours was most frequently reported by Hispanic women (53 percent). Participants reporting five hours of sleep or less consumed more total calories (2,224 kcal) than those reporting six to seven hours (1,920 kcal) or eight or more hours (2,199 kcal).

The authors proposed that short sleep may impact fat accumulation by promoting increased caloric intake via increased hunger, or by reducing energy expenditure via altered thermoregulation and increased fatigue. Both increased caloric intake and decreased vigorous activity were observed in the short sleep group.

The authors also suggested that it is just as important for doctors to encourage patients to get adequate sleep as it is for them to promote a healthy diet and physical activity. This is particularly relevant when young adults make transitions involving college, marriage and childbearing, because these life stages often are associated with sleep deprivation.

The abstract of the study is available free online here:

Sleep Duration and Five-Year Abdominal Fat Accumulation in a Minority Cohort

AASMNET.org - Frequent napping is associated with an increased prevalence of type 2 diabetes and impaired fasting glucose in an older Chinese population, according to a study in the March 1, 2010 issue of the journal Sleep.

Results show that the prevalence of type 2 diabetes was 36 percent higher (adjusted odds ratio = 1.36) in participants who reported napping four to six times a week and 28 percent higher (OR = 1.28) in those who napped daily. Similar associations were found between napping and impaired fasting glucose. The observed associations were unaltered in statistical analyses that removed participants with potential ill health and daytime sleepiness, suggesting it is less likely that diabetes leads to daytime sleepiness and raising the possibility that napping may increase the risk of diabetes.

According to the authors, napping in China is a social norm, which is practiced by all ages primarily as a habit started in childhood. In Western countries, napping is less common and is often unplanned and prompted by sleepiness likely caused by aging, deteriorating health status or nighttime complaints.

Lead author Neil Thomas, PhD, reader in epidemiology at the University of Birmingham, U.K., said that additional research is needed to determine if napping itself plays a causative role in the development of type 2 diabetes, or if other factors are involved.

“In many non-Mediterranean, Western countries a large proportion of those that nap are generally older or have other conditions that cause tiredness and create an urge to nap,” said Thomas. “The napping can therefore be a marker of disease.”

This cross-sectional study analyzed baseline data from the Guangzhou Biobank Cohort Study, a collaboration between the Guangzhou Number 12 People’s Hospital and the Universities of Birmingham and Hong Kong. The community-based study took place in Guangzhou, China, where 19,567 participants between the ages of 50 and 93 years were recruited from 2003 to 2004 and 2005 to 2006. The sample comprised 13,972 women with a mean age of 61.4 years and 5,595 men with an average age of 64.2 years.

Participants underwent a half-day assessment, which included a structured interview on lifestyle and medical history, and a physical examination. Self-reported frequency of napping was obtained by questionnaire, and type 2 diabetes was assessed by a fasting blood glucose sample and/or self-reports of physician diagnosis or treatment. Participants were asked to describe their napping habits and daytime sleepiness.

Type 2 diabetes was identified in 13.5 percent of the sample and was more prevalent in people who reported napping daily (15.1 percent) and in those who napped four to six times per week (14.7 percent). Logistic regression models were constructed to assess the relationship between napping and diabetes and impaired fasting glucose, adjusting for demographics, lifestyle, sleep habits, health status, body fat and metabolic markers.

At least one nap per week was reported by 67.2 percent of participants, more commonly in males (76.4 percent) than in females (63.6 percent). About 59.4 percent of these people reported napping daily. Total sleep duration was longer and daytime sleepiness was reported less often in more frequent nappers than in people who never napped.

In a sub-sample of 3,822 participants who were re-contacted for additional information about sleep habits, there was a statistically significant trend of increasing risk of diabetes with longer nap duration. Compared with people who never took naps, the risk of diabetes was 41 percent higher (OR = 1.41) for people who took naps that lasted longer than 30 minutes and 35 percent higher (OR = 1.35) for people whose naps lasted 30 minutes or less.

The authors noted that the association between napping and diabetes was observed despite the fact that nappers had higher levels of physical activity, which has been shown to reduce the risk of diabetes. This suggests that the relationship between napping and diabetes might have been stronger had it not been offset by the protective effects of physical activity. The authors added that there will be profound public health implications in China if the relationship between napping and increased risk of type 2 diabetes is confirmed in longitudinal studies, as the nation is currently affected by an emerging diabetes epidemic.

The abstract of the article is available free online here:

Napping linked to higher risk of type 2 diabetes

AHA - More Americans now drink sugar-sweetened sodas, sport drinks and fruit drinks daily, and this increase in consumption has led to more diabetes and heart disease over the past decade, researchers reported at the American Heart Association’s 50th Annual Conference on Cardiovascular Disease Epidemiology and Prevention (Abstract P365).

Using the Coronary Heart Disease (CHD) Policy Model, a well-established computer simulation model of the national population age 35 and older, researchers estimate that the increased consumption of sugar-sweetened beverages between 1990 and 2000 contributed to 130,000 new cases of diabetes, 14,000 new cases of coronary heart disease (CHD), and 50,000 additional life-years burdened by coronary heart disease over the past decade.

Sugar-sweetened soda, sport and fruit drinks (not 100 percent fruit juice) contain equivalent calories, ranging from 120 to 200 per drink, and thus play a role in the nation’s rising tide of obesity, researchers said. Previous research has linked daily consumption of these sugary beverages to an increased risk of diabetes, even apart from excessive weight gain.

“The CHD model allows us to incorporate data from other studies that demonstrate an association between daily consumption of sugared beverages and diabetes risk; we can then translate this information into estimates of the current diabetes and cardiovascular disease that can be attributed to the rise in consumption of these drinks,” said Litsa Lambrakos, M.D., study lead investigator and internal medicine resident at the University of California–San Francisco.

The prospective simulation model draws on data from major epidemiological studies, including the Framingham Heart Study, The Nurses Health Study and the National Health and Nutrition Examination Survey (NHANES).

Through the model, the researchers estimate the additional disease caused by the drinks has increased coronary heart disease healthcare costs by 300-550 million U.S. dollars between 2000-2010. This figure likely underestimates the true costs because it does not account for the increased costs associated with the treatment and care of patients with diabetes alone. Over the last decade, at least 6,000 excess deaths from any cause and 21,000 life-years lost can be attributed to the increase in sugar-sweetened drinks.

Health policy experts suggest curbing the consumption of sugared drinks through an excise tax of 1 cent per ounce of beverage, which would be expected to decrease consumption by 10 percent.

“If such a tax could curb the consumption of these drinks, the health benefits could be dramatic,” said Kirsten Bibbins-Domingo, M.D., Ph.D., senior author of the study and associate professor of medicine at the University of California, San Francisco.

The authors are currently examining the impact of various approaches to reducing consumption of sugary beverages. “We want to make the general public more aware of the adverse health outcomes of consuming these drinks over time,” Lambrakos said. “We want to help support disease prevention and curb consumption of these drinks that lead to poor health outcomes and increased healthcare costs for the average American.”

“The American Heart Association recommends a dietary pattern that is rich in fruit, vegetables, low-fat or fat free dairy products, high-fiber whole grains, lean meat, poultry and fish,” said Robert H. Eckel, M.D., past president of the American Heart Association, and professor of medicine at the Anschutz Medical Campus of the University of Colorado Denver. “Always consider overall diet in the context of energy balance and make sure foods and drinks high in added sugars are not taking the place of foods with essential nutrients.”

The American Heart Association recommends an upper limit of half of the discretionary calorie allowance from added sugars, which for most American women is no more than 100 calories per day and for most American men is no more than 150 calories per day from added sugars. Sugar-sweetened beverages should be limited to 450 calories or less per week (36oz), based on a 2000 calorie per day diet.

Study highlights:

* More than 100,000 cases of diabetes over the last decade were likely caused by the rise in consumption of sugar-sweetened beverages, sports drinks, and fruit drinks since 2000.
* This rise in diabetes from consumption of sugary beverages has led to more cases of heart disease and higher healthcare costs.