Exercise as it relates to Disease/Occupation Sedentary Behaviour: Can Increased Standing Time Reduce Sedentary Associated Diabetes and Obesity?

/Occupational Sedentary Behaviour: Can Increased Standing Time Reduce Sedentary Associated Diabetes and Obesity?/
This wiki fact sheet analyses the research article "Workplace standing time and the incidence of obesity and type 2 diabetes" (http://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-015-1353-x). It will follow the outline of the article and briefly compare its findings to similar research articles. Statement: This has been created by [U3150604].

Background
Low-Energy-Expenditure Activities Sedentary behavior is classified as conducting activities between 1.0-1.5 metabolic equivalent units (METs) such as sitting and driving (excluding sleeping). Moderate to Vigorous activity such as completing household chores to running utilises appropriately 1.6-2.9 METs. Occupational minimal motion standing incurs approximately 1.2 METs although low, it activates a larger number of muscles and has positive effect on energy utilisation and blood pressure, ultimately resulting in lower disease states and an overall decrease in mortality.

Occupational sedentary behaviour is desk-based office work. We live in an age where most manual labour has been replaced by machinery, operated or regulated by people sitting for prolonged periods of time at computers. Theoretically it will only become more common. Awareness aimed at encouraging individuals with cardiovascular disease, obesity, diabetes and cancer to participate in more vigorous based exercise of a minimum of 150 min, has failed within approximately 40% of people globally and in 70% of individuals from high income countries. Marketing for standing office equipment is inferring its benefits are greater than evidence based research currently confirms. However there are results showing that breaking up prolonged sitting improves glucose and insulin levels as well as reducing fat accumulation around vital organs

Obesity is defined as a state of excess fat accumulation that may impede health. Risk factors include sedentary behaviour and overconsumption of foods high in fat and sugar. Some common obesity associated diseases are hypertension, cardiovascular disease, coronary heart disease, gallbladder disease and diabetes mellitus type 2. The most common initial diagnosis method for obesity is Body Mass Index (BMI) determined by dividing the patient's weight by their squared height. However this method is not entirely accurate as many factors are not incorporated. Equations to determine body fat % (BF%) are available to assist in including factors such as age and sex and can minimise error estimates.

Diabetes mellitus type 2 (T2D) is caused by an insulin resistance. Insulin is the hormone responsible for uptake of glucose by cells for immediate energy use and/or the storage of glucose as glycogen. Insulin signaling pathways and a decrease in receptors are seen in obese individuals, the exact mechanisms for these occurrences is uncertain however studies suggest it is most likely caused by toxic effects of lipid accumulation.

Research Funding and authors
The research carried out for the Quebec Family Study was conducted at the Physical Activity Sciences Laboratory, Laval University. Funding was provided by the Canadian government through grants approved by the Canadian Institute of Health Research. Dr Jean-Philippe Chaput designed and conducted the analysis of the study, he is currently Assistant professor at the Faculty of Medicine Pediatrics, Children's Hospital of Eastern Ontario. Dr Chaput has also been involved in 149 research publications relating to pediatrics and obesity. All authors declared they had no competing interests.

Research Methods
Research was conducted via a longitudinal study of 293 participants over a period of six years. Initially the research began in 1979 to investigate the genetics of fitness, body composition and cardiovascular risk factors, involving 1650 participants across 375 families of French descent in Canada. The participants were included irrespective of body weight. Phase two and three of the study conducted from 1989-1997 incorporated 100 families from the initial study along with an additional 123 families totaling 293 participants. All participants had a BMI greater than 32 kg/m2 and were aged between 18-65.

Participants were assessed at baseline and year 6 measuring BMI and performing oral glucose tolerance tests along with questionnaires relating to occupational standing time. BMI was conducted measuring height with a stadiometer to the nearest 0.1 cm and weight with digital scales to the nearest 0.1 kg. Overweight and Obesity were determined via a BMI ≥25 kg/m2. A 12 hour fasted 75 g oral glucose tolerance test was performed in the mornings along with blood samples Samples were taken at -15, 0, 15, 30, 45, 60, 90, 120, 150 and 180 min. Blood samples were analysed in EDTA and Trasylol tubes for enzyme-linked immunosorbent assays (ELISA) and fasting glucose concentrations were calculated as the mean of -15 and 0 min. T2D and Impaired Glucose Tolerance (IGT) were determined via the diagnosis criteria of the American Diabetes Association and World HealtH organisation.

Accounting for variables was analysed and measured through questionnaires comprising of age, sex, annual family income and smoking habits. These variables along with race, abnormal cholesterol and triglyceride levels, high blood pressure, polysistic ovary syndrome and gestational diabetes pose high risk factors for developing T2D. Three day food records to assess general daily energy intake along with cardiorespiratory fitness levels were also obtained. The food diaries recorded two weekdays and one weekend day which were shown to provide reliable data. Cardiorespiratory fitness levels were measured via a progressive exercise test conducted on a Monark cycle ergometer at a heart rate of 150 beats per min. Moderate cardiorespiratory fitness in obese men have shown to have similar rates of mortality when compared with highly fit normal-weight groups

Sixty percent of Canadians are either overweight or obese which can narrow the scope of this study ,. Questionnaires were also self reported which can cause error. However the analysis of the study was found to have proficient predictive performance and was not subject to over-fitting.

Comparative to similar studies the Quebec family study showed very similar method techniques and parameters. Several studies also mentioned the inaccuracy of self reported questionnaires. A meta analysis of 59 articles conducted the Loughborough University identified that obesity/overweight individuals may not necessarily have excessive fat accumulation around vital organs which is a leading cause of diabetes and obesity related disease through MRI.

Research Results
Findings At baseline there were 151 participants with a normal BMI and 33 with existing IGT/T2D. During the 6 year follow up 51 new cases of obesity/overweight were identified and 37 new cases of IGT/T2D. Occupational standing of the 293 participants were; 33% standing rarely or never, 23% half of the time and 19% most of the time. Significant association between decreased standing time and developing IGT/T2D and obesity/overweight was observed. However this association was no longer valid once the adjustment for other variables were included specifically family income and cardiorespiratory fitness.

The study results were slightly under emphasised due to the results. However the comparison to several other studies with validated data do suggest a correlation between the development of IGT/T2D and obesity/overweight with increased occupational sedentary time.

Conclusion
Can Increased Standing Time Reduce Sedentary Associated Diabetes and Obesity? Although the finding of this study do not provide further evidence to support that decreased occupational sedentary time reduces diabetes and obesity many other research results have shown a positive correlation. Targeting the population during work time to decrease extended periods of sitting appears to be the most practical method of reducing sedentary time. Although equipping offices with standing/seated workstations may initially seem far too costly, the overall investment will lower absentee days and increase productivity as well as delay mortality.

Further information of possible interest

 * * Calculate your BMI: https://heartfoundation.org.au/your-heart/know-your-risks/healthy-weight/bmi-calculator.
 * * Alternatively locate your nearest centre for a DEXA scan or Anthropometric measurements which will give you more accurate overall measurements.
 * * Further readings for national Diabetes statistics 2014 can be located at; http://www.cdc.gov/diabetes/data/statistics/2014statisticsreport.html
 * * This article explains 10 easy ways to be more active: http://www.lifehack.org/articles/communication/10-simple-ways-more-active.html.
 * Obesity prevention: https://www.hsph.harvard.edu/obesity-prevention-source/obesity-consequences/health-effects/

Please keep in mind if concerned you should seek medical advice.