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Exercise as it relates to Disease/The impacts of TV viewing and physical activity, on metabolic syndrome in Australian Adults

Background to the ResearchEdit

Metabolic SyndromeEdit

Metabolic syndrome (MS) are factors which predispose diabetes and cardiovascular diseases, like abnormal glucose tolerance (diabetes, IGT, IFG), elevated blood pressure and insulin resistance [1].


The current studyEdit

Where is the research from?Edit

The data was collected by the Australian Diabetes, Obesity and Lifestyle study[2], which was designed to represent Australian’s ≥ 25, providing a benchmark of national data on the prevalence of diabetes, obesity, hypertension and kidney disease.

The study had numerous support with funding from:

  • The Commonwealth Department of Health and Aged Care
  • Abbott Australasia
  • The Australian Kidney Foundation
  • Diabetes Australia


What kind of research was this?Edit

This was a cross-sectional analysis of 6,241 Australian individuals aged over 35 to determine the strength of associations of TV viewing and physical activity with metabolic syndrome. It was a 5 year follow up from the original longitudinal population-based study in 1999-2000, which examined the history of diabetes, pre-diabetes, heart disease, and kidney disease.


What did the research involve?Edit

A number of self-reported, interview-based questionnaires and baseline measurements were conducted on 6,241 participants.

After a >8 hour fast, individuals were assessed on waist circumference, height, weight and blood pressure (BP). The participants were defined as having MS if they had:

Variable Measure
Fasting Insulin levels ≥ the upper quartile of the non-diabetic population
IGT Fasting plasma glucose <7.0 mmol/L and 2-h plasma glucose ≥7.8 mmol/L but <11.1mmol/L
Diabetes Fasting plasma glucose ≥7.0 mmol/L or 2-h plasma glucose ≥11.1 mmol/L
Obesity Waist-hip-ratio (men >0.9, women >0.85) or BMI (>30kg/m2)
Dyslipidaemia Serum triglycerides ≥1.7 mmol/L or HDL cholesterol <0.9 mmol/L for men or <1.0 mmol/L for women
Hypertension BP≥ 140/90 mmHg or antihypertensive medication
  • A family history of diabetes, smoking habits, and education were also assessed
  • Dietary intake was measured with a food frequency questionnaire, and nutrient intake was also calculated


Individuals self-reported total time spent watching TV used to create three categories:

Hours per week
0-7
7.01-14
≥14

The active Australia survey questionnaire was used to attain the frequency and duration of physical activity in the previous week.

Physical Activity Guidelines Hours Per week
Meeting the guidelines ≥2.5h moderate intensity (walking) or vigorous activity for ≥1h
NOT meeting the guidelines 0-2.49h of moderate intensity or ≤0.99h of vigorous activity


Limitations of the study

  • Large portion of self-reported questionnaires, which can be subject to bias like incorrect recall, distorting the relationship between TV viewing, physical activity and metabolic syndrome [3]
  • Only measures the effects of one sedentary behaviour, others include sitting at a desk, using electronic devices and traveling for long periods of time [4]
  • Measuring 2 types of physical activity (moderate and vigorous intensity-based activity). It is plausible that individuals participate in other activities in their day to day basis via jobs or household chores. [5]

Strengths of the study

  • Large sample size reducing statistical variance and provides stronger evidence to draw informed conclusions
  • The study notes one of its own limitations and how to improve future research

Future research suggestions

  • Sampling a population comparing a number of sedentary behaviours and using other physical activity monitors to track all day activities


What were the basic results?Edit

The results of this study show the following:

  • 25% of male and 14% of female participants were diagnosed with MS
  • MS was highly associated with those who were significantly less active and watched high levels of TV. With every increase in TV by 1 hour, there was a 12% increase in prevalence for MS in men and a 26% increase in women
  • Higher levels spent watching TV is associated with diabetes, IGT, IFG. Those who watched ≥ 14h each week were also more likely to develop insulin resistance, obesity, and dyslipidemia
  • MS is inversely related to physical activity, with every 30-minute increase in activity showed a decreased prevalence of 11% and 28% in males and females respectively


What conclusions can we take from this research?Edit

Prolonged TV viewing with insufficient physical activity time does significantly increase the prevalence of MS and several of its components. Individuals should increase their physical activity levels to meet the guidelines and reduce overall time spent watching TV per week.

These conclusions support numerous other studies which suggest sedentary activities should be replaced with more active behaviour like consistent physical activity to improve all risk factor components of metabolic syndrome. [6] [7]


Practical advice:Edit

Clinically, management of metabolic syndrome should focus on the underlying risk factors such as sedentary behaviours, physical inactivity, obesity/overweight, and diet.

Sedentary BehaviourEdit

Individuals should reduce sedentary behaviors by breaking up long periods of sitting as often as possible. The following strategies can be applied;

Strategies at work

  • Walking during lunch breaks instead of eating behind a desk
  • Consider standing desks to increase activity
  • Use the stairs instead of the elevator

Strategies at home

  • Listen to an audiobook and perform household activities rather than reading on the lounge
  • Change the channel physically rather than using a remote
  • Set a reminder on your smart device to move more often

Other strategies

  • Consider your mode of transport, walk to work rather than drive to decrease sitting time

Physical ActivityEdit

The Australian Government has provided the following guidelines [8]:

  • Accumulate 150-300 minutes of moderate intensity activity each week
  • Accumulate 75-150 minutes of vigorous activity each week
  • Perform at least 2 muscle-strengthening sessions a week


Further information/resourcesEdit

ReferencesEdit

  1. Dunstan D.W, Salmon O.N, Armstrong T, Zimmet P.Z, Welborn T.A, Cameron A.J, Dwyer D, Jolley J, Shaw J.E.; on behalf of the AusDiab Steering Committee. Associations of TV viewing and physical activity with the metabolic syndrome in Australian adults. Diabetologia. 2005;48(11):2254-61.
  2. Tanamas SK, Magliano DJ, Lynch B, Sethi P, Willenberg L, Polkinghorne KR, Chadban S, Dunstan D, Shaw JE. The Australian Diabetes, Obesity and Lifestyle Study. 2012:6-38.
  3. Celis-Morales C.A, Perez-Bravo F, Iban ̃ez L, Salas C, Bailey M E.S, Gill J M.R. Objective vs. Self-Reported Physical Activity and Sedentary Time: Effects of Measurement Method on Relationships with Risk Biomarkers. PLOS One. 2012;7(5):1-2.
  4. Tremblay M.S, Aubert S, Barnes J.D, Saunders T.J, Carson V, Latimer-Cheung A.E, Chastin S F.M, Altenburg T.M, Chinapaw M J.M; on behalf of SBRN Terminology Consensus Project Participants. Sedentary Behaviour Research Network (SBRN) - Terminology Consensus Project process and outcome. International Journal of Behavioral Nutrition and Physical Activity. 2017;14(75).
  5. Kumanyika S, Jeffery RW, Morabia A, Ritenbaugh C, Antipatis V.J. Obesity prevention: The Case for action. International Journal of Obesity. 2002;26:425-36.
  6. Eckel R.H, Grundy S.M, Zimmet P.Z. The Lancet. 2005;365:1415-28.
  7. Lakka TA, Laaksonen DE, Lakka HM, Männikkö N, Niskanen LK, Rauramaa R, Salonen JT. Sedentary Lifestyle, Poor Cardiorespiratory Fitness, and the Metabolic Syndrome. Medicine & Science in Sports & Exercise. 2003;35(8):1279-86.
  8. Australian Government- Department of Health. Australia's Physical Activity and Sedentary Behaviour Guidelines: Commonwealth of Australia; 2017