27 Apr Rotating Night Shift Work Linked to Increased Coronary Heart Disease Risk
Posted at 10:49h
in Author Interviews, Brigham & Women's - Harvard, Heart Disease, JAMA, Lifestyle & Health
MedicalResearch.com Interview with:
[caption id="attachment_23700" align="alignleft" width="138"]
Dr. Céline Vetter[/caption]
Dr. Céline Vetter, Dr.Phil.
Instructor in Medicine
Harvard Medical School
Associate Epidemiologist
Channing Division of Network Medicine
Brigham and Women's Hospital
Boston, MA, 02115
MedicalResearch.com: What is the background for this study?
Response: Heart Disease is still the leading cause of death in the US, with 1 in every 4 deaths being attributed to heart disease. On the other hand, it is estimated that approximately 15 millions Americans work evening shifts, night shift, rotating shifts or any other kind of irregular schedule that is arranged by the employer. The link between shift work and coronary heart disease has been studied for decades now, but because shift work can take so many forms, results have not been consistent. Another contributing factor to this inconsistency might be that few studies could actually track individuals over long periods of time, so that some studies might have missed when participants did actually develop coronary heart disease.
Our study was based on the Nurses' Health Studies I and II, where women about 189,000 registered female nurses completed every two years mailed questionnaires that comprise items about their health status, medical history, and known or suspected risk factors for cancer and heart disease. They also reported their lifetime history of rotating night shift work in 1988 and 1989, respectively. Across the 24 years of the study periods, we observed more than 10,000 cases of coronary heart disease (i.e. myocardial infarction, CHD death, angiogram-confirmed angina pectoris, and procedures related to coronary heart disease, i.e. angioplasty, coronary artery bypass graft surgery or stents).
Dr. Reddy[/caption]
E. Premkumar Reddy, Ph.D.
Professor, Department of Oncological Sciences
and Department of Structural and Chemical Biology
Director, Experimental Cancer Therapeutics
Mount Sinai School of Medicine
New York, NY 10029
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Reddy: It is now well established that cancer cells harbor mutations in their genome which are responsible for uncontrolled proliferation. Nearly 30 years ago, we as well as two other groups discovered that RAS genes are often mutated in human cancers. Later studies showed that nearly 25-30% of human cancers contain this mutation and these mutations can be caused by chemical carcinogens such as tobacco smoke. Since then there has been an intense effort to understand the biological functions of RAS and to develop drugs that block the activity of these mutant RAS genes. Although molecular oncologists have made significant headway in understanding these mutations and their impact on cellular signaling, little progress has been made towards developing drugs that systematically target the RAS oncogenes. This lack of progress has led many in the field to label RAS as “undruggable”. However, basic research conducted by scientists in this field has revealed that RAS proteins function as ON-OFF switches to signal cells to grow or not to grow because of their ability to bind to a large number of cellular proteins and transmit this signal to their binding partners. These findings also revealed that mutations in RAS genes leaves them in a permanent “ON” position which continues to transmit growth signals permanently. Since most efforts to develop drugs that bind to RAS proteins and reverse their activity failed, we took a different approach to block these signals. Since transmission of growth signals by RAS genes requires their interaction with cellular proteins, all of which contain a domain called “RAS-Binding Domain (RBD)” we created a drug named “Rigosertib” that binds to these RBDs and block their binding to RAS, thereby interrupting RAS signals. When Rigosertib was tested in animals, it could readily inhibit the growth of human tumors that contain RAS mutations. Our studies also show that Rigosertib is a very safe drug with minimal side-effects.
Dr. Maurice Ohayon[/caption]
Maurice M. Ohayon, MD, DSc, PhD
Chief of the Division of Public Mental Health and Population Sciences
Director of the Stanford Sleep Epidemiology Research Centre (SSERC)
John-Arrillaga PI & Professor of Psychiatry and Behavioral Sciences
School of Medicine, Stanford University
Palo Alto, CA 94303
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Ohayon: Artificial Lights at night are known to be powerful disruptors of the normal sleep/wake cycle. Light exposure at night acts on suppressing and delaying melatonin secretion and exciting the central nervous system.
In this study we focused on the effects of the outdoor lights at night, (such as street lights and lights, outdoor light fixtures and advertising boards) as measured at nighttime by satellite observations.
We analyzed the sleep habits of a representative sample of the American general population that had been interviewed with the artificial intelligence system Sleep-EVAL.
We found that individuals living in areas at high level of radiance, such as can be found in the downtowns of metropolitan areas, have a delayed bedtime, delayed wake up time and, overall, shorter sleep duration, than people living in areas with low nighttime radiance.
Dr. Haidong Zhu[/caption]
Haidong Zhu, MD, PhD
Associate Professor of Pediatrics
Georgia Prevention Institute
Medical College of Georgia
Augusta University
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Zhu: Vitamin D plays an important role in a wide range of body functions beyond bone health. Vitamin D deficiency is associated with increased risk of cancer and cardiovascular disease. Vitamin D deficiency is common among darker skin individuals, particularly African-Americans, which could contribute to health disparity. We want to understand underlying molecular mechanism (i.e. global DNA methylation) for how vitamin D deficiency causes cancer, cardiovascular disease and impaired immune function. DNA methylation, a chemical modification to our genome, is one of the ways that our body adapts to the environment. Low rate of global DNA methylation is a common event in cancer, which may lead to disturbances in the genome, make the genome more vulnerable to environmental damage and increase disease risk.
Our study shows that majority of black teens are vitamin D deficient and have a lower rate of global DNA methylation than white teens. We further demonstrate that vitamin D3 supplementation for 16 weeks increases global DNA methylation in black teens and young adults. Our study provides an important piece of evidence that vitamin D plays a role in epigenetic regulation in humans, which could be an underlying mechanism for vitamin D-deficiency related disease risk and health disparity.
Dr. Nelly Tan[/caption]
Dr. Nelly Tan MD
David Geffen School of Medicine
Department of Radiology
UCLA
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Tan: Standard of care for prostate cancer diagnosis has been to perform ultrasound guided random (non-targeted) prostate biopsy (TRUS) which is neither sensitive or specific. The main limitation had been our inability to detect and localize prostate cancer through imaging.
Over the past 10 years, MRI has taken center stage for detection and localization of prostate cancer and has shown to improve prostate cancer diagnosis, risk stratification, and staging of the disease. Over the past few years, MRI guided biopsy techniques (in the form of Ultrasound-MRI (US-MRI) fusion and in-bore direct MRI guided biopsy) have been reported. We reported our performance of direct in-bore MRI guided biopsy at UCLA. Our study showed a prostate cancer diagnosis of 59% in all patients and 80% of patients with prostate cancer had clinically significant cancer.
Dr. Rivera Hernandez[/caption]
Maricruz Rivera-Hernandez, PhD
Investigator
Department of Health Services, Policy & Practice
Center for Gerontology and Health Care Research
Brown University, Providence, RI
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Rivera-Hernandez: Over three-quarters of Medicare-eligible residents in Puerto Rico enroll in Medicare Advantage plans, making them the primary source of health care coverage for the island’s seniors. Puerto Rican Medicare Advantage plans have a long history of receiving lower payments than Medicare Advantage plans located in the United States.
The study’s purpose was to compare the quality of care provided to Medicare Advantage enrollees in Puerto Rico with that delivered to Medicare Advantage enrollees in the 50 states and the District of Columbia.
We found significantly worse quality for Puerto Rican Medicare Advantage enrollees compared to their US counterparts for 15 of the 17 quality indicators. These indicators measured whether patients received the recommended treatment and achieved desired outcomes in diabetes care, cardiovascular disease, and cancer screening and whether they received any inappropriate medications in 2011.
Dr. Joan Luby[/caption]
