Obesity, a Major Risk Factor for Diabetes and Other Ills, Targeted by Study

Waistlines are expanding at such an alarming rate across the globe that, if trends hold, almost 58 percent of the world’s population will be overweight or obese by 2030, according to researchers at the Tulane School of Public Health and Tropical Medicine.

Epidemiologic studies indicate that obesity and being overweight are important risk factors for diabetes, cardiovascular disease, cancer and premature death, according to Dr. Jiang He, the Joseph S. Copes Chair and Professor of Epidemiology and Medicine at Tulane.

Almost one-third of the world is already considered overweight or obese, according the Tulane team in “Global Burden of Obesity in 2005 and Projections to 2030,” published in the International Journal of Obesity (published online on July 8, 2008).

These alarming global results highlight the urgent need for the World Health Organization and governments to support programs that target maintaining a healthy weight, says He.

For more information on the spreading obesity epidemic and its link to diabetes and other chronic diseases, see: https:// tulane.edu/news/newwave/071408_obesity.cfm?RenderForPrint=1

Consumption of green leafy vegetables and fruit was associated with a lower hazard of type 2 diabetes mellitus (DM), whereas consumption of fruit juices may be associated with an increased hazard of diabetes among women, according to the results of a study reported in the April 4 Online First issue of Diabetes Care.

“Fruit and vegetable consumption has been associated with decreased incidence of and mortality from a variety of health outcomes including obesity, hypertension, and cardiovascular diseases in epidemiologic studies,” write Lydia A. Bazzano, MD, PhD, from Tulane University School of Public Health and Tropical Medicine in New Orleans, Louisiana, and colleagues. “However, few prospective studies have examined the relationship between fruit and vegetable intake and risk of DM, and their results are not entirely consistent.”

The goal of this study was to determine the association between intake of fruits, vegetables, and fruit juices and the development of type 2 DM in a cohort of 71,346 female nurses, aged 38 to 63 years, who were free of cardiovascular disease, cancer, and DM in 1984.

During follow-up for 18 years in the Nurses’ Health Study, a semiquantitative food frequency questionnaire (FFQ) was administered every 4 years, and diagnosis of DM was self-reported.

The prevalence of diabetes is increasing worldwide. Insulin resistance and diabetes mellitus are major predictors of cardiovascular ischaemic disease. Other risk factors for cardiovascular death including hypertension, dyslipidaemia, smoking and visceral obesity are especially lethal in diabetics. C-reactive protein, plasminogen activator inhibitor-1, matrix metalloproteinases and other emerging risk factors and their roles are continually being researched and discovered.

Treatment of this syndrome must be aimed at lifestyle modification, glycaemic control and management of concomitant risk factors. Diet and exercise play a vital role in the treatment of diabetes and the metabolic syndrome. Weight reduction and increased physical activity will improve insulin resistance, hyperglycaemia, hypertension and dyslipidaemia. Hypertension management has been shown to be especially important in diabetics to prevent cardiovascular events. Likewise, multiple clinical trials show that reduction of cholesterol is even more vital in diabetics than the general population for risk reduction of coronary disease.

There is a great deal of evidence that tight control of glycaemia is essential to treatment of this condition. There are a variety of available pharmacological agents available including metformin, insulin secretagogues, alpha-glucosidase inhibitors, thiazolidinediones and insulin. The mechanisms and side effects of these medications are discussed. As macrovascular disease is the major cause of morbidity and mortality, an early, aggressive, multi-factorial approach to treatment of the metabolic syndrome and diabetes is vital to prevent adverse cardiac outcomes.

 

A team from the University of Newcastle upon Tyne, UK, studied 412 men and women and found that fatter adults were more likely to have increased insulin resistance, a risk marker for Type 2 diabetes.

Childhood factors, such as birth weight and nutrition, were found to have limited impact, whereas they were previously thought to be significant. The study is published in the academic journal, Diabetes/Metabolism Research and Reviews.

Diabetes is a global health problem that is presenting a major medical challenge worldwide. It increases the risk of ill health and shortens life. In the UK alone, diabetes has been said to account for nine per cent of the annual NHS budget – approximately £5.2 billion a year.

There are two kinds of diabetes – Type 1 and Type 2. All diabetes is characterized by raised blood sugar (glucose). In Type 1 diabetes there is an absolute lack of insulin. In Type 2 diabetes, insulin is produced, but the body’s tissues are resistant to its action, leaving too much glucose in the blood.

Type 2 diabetes is strongly related to overweight and lack of physical activity, and accounts for 90% of all diabetes. It usually occurs in middle to older aged adults. The World Health Organisation predicts that the number of people with type 2 diabetes will more than double over the next 25 years.

The Newcastle University study measured participants’ percentage body fat and waist-hip ratio, along with other lifestyle elements. Men and women with a higher body fat and higher waist-hip ratio were more likely to demonstrate increased insulin resistance.

The data was collected as part of the Thousand Families Study, a Newcastle University project which has examined the health of children born in Newcastle in May and June 1947 throughout their lives. The study was funded by the Wellcome Trust, the Minnie Henderson Trust, the Sir John Knott Trust and the Special Trustees of the Newcastle Hospitals.

Study leader Dr Mark Pearce, who is also director of the Thousand Families Study, said promotion of healthier lifestyles throughout life would be the public health interventions most likely to reduce insulin resistance in later life.

He said: “Previous studies have suggested that risk of poor health in later life is programmed by impaired development in the womb, and that poor growth in fetal and infant life is associated with impaired insulin secretion and sensitivity. However, not all of these studies have not had access to complete data on later life.

“Our study, which has examined people from birth to adulthood, suggests that the life you lead as an adult has the biggest influence on your health, in terms of diabetes risk, in later life.

Dr Pearce, of Newcastle University’s School of Clinical Medical Sciences, added: “It’s never too late to start living a healthy lifestyle – and even though our study shows that childhood experience had limited impact on insulin resistance in adulthood, parents still have a role to play in introducing their children to eating a healthy diet and physical exercise, so they can develop good habits that will hopefully last throughout adulthood and old age.”

Amanda Vezey, care advisor at Diabetes UK, said, “We already know that lifestyle factors play a large part in the development of Type 2 diabetes. This study further emphasises the importance of eating a healthy, balanced diet and taking part in regular physical activity.

“To reduce the risks of developing Type 2 diabetes in earlier years, it’s essential to start leading a healthy lifestyle as early as possible.”

Source: Tulane University
University of Newcastle upon Tyne, via EurekAlert!

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