Author Interviews, Diabetes, Heart Disease, JAMA, Weight Research / 04.08.2016
Obesity Raises Risk of Diabetes But Not Heart Attacks in Twins
MedicalResearch.com Interview with:
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Prof. Peter Nordstrom[/caption]
Prof. Peter Nordström PhD
Department of Community Medicine and Rehabilitation
Geriatrics, Umeå University
Umeå, Sweden
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Numerous studies has shown an association between BMI, CVD and death. However, it is not known to what extent genetic factors influence this relationship. We used over 4000 monozygous twin pairs that had different BMI. This mean that the difference in BMI must be due to environmental factors since the genetic setup is similar in monozygous twins.
Since the fatter twin did not have a higher risk of myocardial infarction (MI) or death, environmental factors that increase BMI is very unlikely to increase the risk of myocardial infarction or death. By inference the strong association between BMI, MI and death must be explained by the fact that the same genes control both obesity, MI and death. By contrast, the fatter twin had a higher risk of diabetes.
Prof. Peter Nordstrom[/caption]
Prof. Peter Nordström PhD
Department of Community Medicine and Rehabilitation
Geriatrics, Umeå University
Umeå, Sweden
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Numerous studies has shown an association between BMI, CVD and death. However, it is not known to what extent genetic factors influence this relationship. We used over 4000 monozygous twin pairs that had different BMI. This mean that the difference in BMI must be due to environmental factors since the genetic setup is similar in monozygous twins.
Since the fatter twin did not have a higher risk of myocardial infarction (MI) or death, environmental factors that increase BMI is very unlikely to increase the risk of myocardial infarction or death. By inference the strong association between BMI, MI and death must be explained by the fact that the same genes control both obesity, MI and death. By contrast, the fatter twin had a higher risk of diabetes.





Dr. Annika Rosengren[/caption]
Annika Rosengren MD
Department of Molecular and Clinical Medicine, Institute of Medicine
Sahlgrenska Academy
University of Gothenburg,
Gothenburg, Sweden
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: In an earlier study we found that while hospitalizations for heart failure decreased among people aged 55 and older in Sweden 1987-2006, there was a clear increase among those younger than 45 years, particularly in young men. We thought that increasing body weight in the population might be a factor behind this.
We used anonymized data from more than 1.6 million Swedish men from the Swedish conscript registry aged on average 18 and followed them from adolescence onwards. Those who were overweight as teenagers were markedly more likely to develop heart failure in early middle age. The increased risk of heart failure was found already in men who were within the normal body weight range (a body mass index of 18.5 to 25) in adolescence, with an increased risk starting in those with a BMI of 20 and rising steeply to a nearly ten-fold increased risk in those who were very obese, with a BMI of 35 or over.
Among men with a BMI of 20 and over, the risk of heart failure increased by 16% with every BMI unit, after adjustments for factors that could affect the findings, such as age, year of enlistment into the Swedish armed forces, other diseases, parental education, blood pressure, IQ, muscle strength and fitness.
Dr. Mikhail Kolonin[/caption]
Mikhail Kolonin, PhD, Associate Professor
Director, Center for Metabolic and Degenerative Diseases
Harry E. Bovay, Jr. Distinguished University Chair in Metabolic Disease Research
The Brown Foundation Institute of Molecular Medicine
University of Texas Health Science Center at Houston
Houston, TX 77030
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Epidemiology studies have indicated that in obese patients progression of prostate, breast, colorectal, and other cancers is more aggressive. Adipose (fat) tissue, expanding and undergoing inflammation in obesity, directly fuels tumor growth. Adipose tissue is composed by adipocytes and stromal/vascular cells, which secrete tumor-trophic factors. Previous studies by our group have demonstrated that adipose stromal cells, which support blood vessels and serve as adipocyte progenitors, are recruited by tumors and contribute to cancer progression. Mechanisms underlying stromal cell trafficking from fat tissue to tumors have remained obscure. We discovered that in obesity a chemokine CXCL1, expressed by cancer cells, attracts adipose stromal cells to tumors.
Dr. Kelly Glazer Baron[/caption]
Kelly Glazer Baron, PhD, MPH, C. B.S.M.
Diplomate, Academy of Cognitive Therapy
Northwestern University
Feinberg School of Medicine
Chicago, IL 60611
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: In contrast to several previous studies, being a late sleeper was not associated with higher BMI (good news for late sleepers!!) but it was associated with less healthy behaviors, more fast food, fewer vegetables, lower dairy. It may be possible that these late sleepers who are able to get enough sleep can compensate for their poor diet by controlling overall calories or it could possibly lead to weight gain over time if their habits continue over time.
Dr Siddharth Singh[/caption]
Siddharth Singh, MD, MS
Postdoctoral Fellow, NLM/NIH Clinical Informatics Fellowship
Division of Biomedical Informatics
Clinical Assistant Professor of Medicine, Division of Gastroenterology, Department of Internal Medicine,
University of California
San Diego, La Jolla
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Singh: Over the last 4 years, four new medications have been approved for long-term use for weight loss by the FDA. We sought to evaluate the comparative effectiveness and tolerability of these medications through a systematic review and network meta-analysis. Based on 28 trials in over 29,000 overweight or obese patients, we observed that magnitude of weight loss achieved with these agents is variable, ranging from 2.6kg with orlistat to 8.8kg with phentermine-topiramate. Over 44-75% of patients are estimated to lose at least 5% body weight, and 20-54% may lose more than 10% of body weight; phentermine-topiramate was the most efficacious, whereas lorcaserin was the best tolerated.
Dr. Katri Korpela[/caption]
Dr. Katri Korpela, PhD
University of Helsinki
Helsinki
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Korpela: Previous studies have shown that breastfeeding reduces the frequency of infections in the child and is associated with lower risk of childhood overweight. Conversely, antibiotic use in early life is associated with increased BMI. Both antibiotic use and breastfeeding are known to influence the infant's microbiota. However, these two factors have not been studied together and it was not known whether antibiotic use could modify the beneficial effects of breastfeeding. We collected data on lifetime antibiotic use, breastfeeding duration, and BMI in a group of daycare-attending children aged 2-6 years. We found that the beneficial effects on long breastfeeding, particularly as regards BMI development, were evident only in the children who did not get antibiotics in early life. Antibiotic use before or soon after weaning seemed to eliminate the protection against elevated BMI in preschool age and weaken the protection against infections after weaning.
Dr. Cynthia Ogden[/caption]
Cynthia L Ogden PhD, MRP
Public Health, Nutrition and Dietetics
CDC Atlanta
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Ogden: Monitoring trends in obesity prevalence is important because of the health risks associated with obesity and because obesity often tracks from childhood to adulthood. The most recent data before this point showed no increases overall in youth, men or women over the previous decade.
We used the most recent nationally representative data with measured weights and heights from the National Health and Nutrition Examination Survey to look at trends in obesity prevalence.
Dr. Ramon Estruch[/caption]
Dr Ramon Estruch, MD PhD
Senior Consultant in the Internal Medicine Department of the Hospital Clinic
Barcelona
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Estruch: Although weight stability requires a balance between calories consumed and calories expended, it seems that calories from vegetable fats have different effects that calories from animals on adiposity. Thus, an increase of dietary fat intake (mainly extra virgin olive oil or nuts) achieved naturally in the setting of Mediterranean diet does not promote weight gain or increase in adiposity parameters such as waist circumference.
Jimmy Celind[/caption]
Jimmy Celind
Postgraduate student
The Sahlgrenska Academy
University of Gothenburg
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: The background is that there is a widespread belief that birth weights are increasing, and that this at least partly is a product of the obesity epidemic (together with decreased smoking prevalence and higher maternal age). Several studies from countries such as Sweden, Norway, Denmark, USA, Scotland, Israel and Australia have shown a slight increase during the last decades of the 20th century. Our aim was to see when the increase started and how much it had increased.
Our main findings are that the trends of birth weight are stable during the study period of 65 years (1946-2011), regarding mean, distribution, and odds ratios for being born with a high birth weight (>4,5 kg) per birth year increment.
Dr. Yann Klimentidis[/caption]
Dr. Yann C. Klimentidis PhD
Assistant Professor
Epidemiology and Biostatistics Department
The University of Arizona
Tucson, AZ 85724
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Klimentidis: There is a large gender disparity in obesity rates among African-Americans. African-American women have much higher rates of overweight and obesity as compared to African-American men. We hypothesized that genetic factors may partly explain this difference. So we tested whether the influence of West-African genetic ancestry on obesity differed among men and women. We found that greater West-African genetic ancestry was associated with protection against central obesity in men, but no such effect was observed in women.
Dr-Aurora-Perez-Cornago[/caption]
Aurora Perez-Cornago, PhD
Cancer Epidemiology Unit
Nuffield Department of Population Health
University of Oxford
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Excessive body size and adiposity have been proposed to influence
several metabolic and hormonal mechanisms that can promote cancer development.
We found that men who have greater adiposity have an elevated risk of
high grade prostate cancer, an aggressive form of the disease, and
prostate cancer death.
Dr. Markus Juonala[/caption]
Markus Juonala, MD, PhD
Murdoch Childrens Research Institute, Parkville
Victoria, Australia
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Juonala: This is an epidemiological follow-up study investigating whether childhood infections and socieconomic status are associated with cardiovasular risk factor and early chances in vasculature.
The main finding was that childhood infections were associated with obesity and impaired vascular function in adulthood among those individuals with low socioeconomic status.
Dr. Jennifer Kuk[/caption]
Jennifer L. Kuk, PhD
Associate Professor
York University
School of Kinesiology and Health Science
Toronto, Ontario
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Kuk: Artificial sweeteners are used to help individuals manage their weight, however, individuals who consume aspartame (a type of artificial sweeteners) have worse glucose metabolism than individuals with the same body weight but do not consume aspartame. This observation was only true for adults with obesity. Further, saccharin and natural sugars were not associated with differences in health after considering differences in obesity.
Dr. Brian Stansfield[/caption]
Dr. Brian Stansfield MD
Neonatologist
Children's Hospital of Georgia and the Medical College of Georgia
Augusta University
MedicalResearch.com: What is the background for this study?
Dr. Stansfield: Since the mid-20th century, we have experimental evidence in animal models and human data demonstrating the influence of maternal nutrition on the offspring - both in the short term and long term. Low birth weight has been connected with higher incidence of cardiometabolic diseases including insulin resistance, coronary artery disease, and hypertension. Interestingly, low birth weight infants grow up to be relatively thin adults compared to their normal or high birth weight counterparts. Conversely, high birth weight infants tend to become heavier adults and obesity is directly linked with the same adult outcomes. So the association of cardiac and metabolic diseases with low birth weight is not linked to adult obesity in general. Thus, speculation as to why extremes of birth weight lead to adult onset cardiometabolic disease suggests different mechanisms and modifying factors.
MedicalResearch.com: What are the main findings?
Dr. Stansfield: The findings of our study shed considerable light on the relationship between birth weight and risk factors for insulin resistance and visceral adiposity. Using magnetic resonance imaging (MRI) to achieve precise measurements of visceral adipose content and biomarkers for insulin resistance, we show that both low and high birth weight are associated with increased visceral adiposity and insulin resistance in a healthy population of adolescents aged 13-17 years. This association persists when we account for several recognized confounders including age, sex, race, activity level, and socioeconomic status. The most interesting finding of our study is that when you account for each adolescent’s current body mass index, a measure of obesity, the relationship between increased visceral fat and insulin resistance and low birth weight is strengthened suggesting that these adolescents had relatively high visceral adipose content despite obesity rates that were similar to their normal birth weight counterparts. On the other hand, correction for adolescent BMI (obesity) reduced the relationship between these metabolic markers and high birth weight infants. Thus, low birth weight infants may develop insulin resistance and increased visceral fat, both significant risk factors for cardiovascular disease and metabolic disease, despite having a relatively normal body shape in adolescents.
Dr. Annette Schürmann[/caption]
Prof-Dr. Annette Schürmann
Department of Experimental Diabetology
German Institute of Human Nutrition Potsdam-Rehbruecke
Nuthetal, Germany
MedicalResearch.com: What is the background for this study?
Dr. Schürmann: The aim of our study was to clarify why genetically identical mice respond very different to a high fat diet. Some of the mice react with an elevated body weight, others not. We analyzed the expression pattern
of liver at two time points, at the age of 6 weeks, (the earliest time
point to distinguish between those that respond to the diet (responder
mice) and those that did not (non-responders)), and at the age of 20
weeks. One transcript that was significantly reduced in the liver of
responder mice at both time points was Igfbp2. The reason for the
reduced expression was an elevated DNA-methylation at a position that is
conserved in the mouse and human sequence. The elevated DNA-methylation
of this specific site in human was recently described to associate with
elevated fat storage (hepatosteatosis) and NASH. However, as 6 weeks old
mice did not show differences in liver fat content between responder and
non-responder mice we conclude that the alteration of Igfbp2 expression
and DNA methylation occurs before the development of fatty liver.
Our data furthermore showed that the epigenetic inhibition of Igfbp2
expression was associated with elevated blood glucose and insulin
resistance but not with fatty liver.
Dr. Gerda Pot[/caption]
Dr Gerda Pot
Lecturer in Nutritional Sciences
King’s College London | Faculty of Life Sciences & Medicine
Diabetes & Nutritional Sciences Division |
London UK
MedicalResearch.com: What is the background for this study?
Dr. Pot: Previous evidence suggested that the timing of food intake can have a significant impact on circadian rhythms (i.e. the body's internal clock) and therefore on metabolic processes within the body, potentially leading to an increased risk of being overweight or obese. However, the evidence from studies in children is very limited so we set out to establish whether this risk was also associated with the timing of children's evening meals.
MedicalResearch.com: What are the main findings?
Dr. Lori Hoepner[/caption]
Lori A. Hoepner, DrPH
Department of Environmental Health Sciences
Columbia University
New York, NY 10032
MedicalResearch.com: What is the background for this study?
Dr. Hoepner: The Columbia Center for Children’s Environmental Health was funded starting in 1998. Pregnant African American and Dominican mothers residing in Northern Manhattan and the South Bronx were enrolled from 1998 to 2006, and mothers and their children have been followed since this time. We collected urine samples from the pregnant mothers in their third trimester and from the children at ages 3 and 5. At ages 5 and 7 we measured the height and weight of the children, and at age 7 we also measured body fat and waist circumference.
MedicalResearch.com: What are the main findings?
Dr. Hoepner: We found a significant association between increased prenatal exposure to Bisphenol A (BPA) and increases in childhood body fat measures of waist circumference and percent body fat at age 7. Our research builds on earlier findings of an association between prenatal exposure to BPA and body fat in children up to age 4, and this is the first study to report an association at age 7.
Dr. Kapp[/caption]
Julie M. Kapp, MPH, PhD
Associate Professor
2014 Baldrige Executive Fellow
University of Missouri School of Medicine
Department of Health Management and Informatics
Columbia, MO 65212
MedicalResearch.com: What is the background for this study?
Dr. Kapp: For the past several decades the U.S. has had the highest obesity rate compared to high-income peer countries, and for many years people in the U.S. have had a shorter life expectancy. For female life expectancy at birth, the U.S. ranked second to last. At the same time, the U.S. has the third highest rate of mammography screening among peer countries, and the pink ribbon is one of the most widely recognized symbols in the U.S. While the death rate in females for coronary heart disease is significantly higher than that for breast cancer, at 1 in 7.2 deaths compared to 1 in 30, respectively, women have higher levels of worry for getting breast cancer.
Chloe Barrera MPH
ORISE Fellow
Centers for Disease Control and Prevention
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Previous studies have been inconsistent in whether introduction of solid foods to babies before 4 months may be associated with later obesity. In our analysis of more than a thousand babies followed through the first year of life and contacted again at 6 years, we did not find this association.