# Exercise as it relates to Disease/Exercise Prescription for the control of Metabolic Syndrome
## Brief Background

Metabolic Syndrome (MetS) or Syndrome X affects up to 1 in 3 Australians, being an interrelation of many distinct metabolic irregularities, especially the associated increase in Type 2 Diabetes and Cardiovascular Disease. There are a number of interventions/treatments, with exercise interventions reducing prevalence and negative outcomes.

### Prevalence

Australian prevalence (hard to define due to it’s varying symptoms and definitions) is ~ 29-33%, however numerous sources show increases in the prevalence of the overweight and obese (64.1% of women, 74.1% of men) and an increase in the diagnosis of Type 2 Diabetes. This translates directly into a high (increasing) prevalence of MetS, greater in men than women, steadily increasing from the age of 25, and progressively increasing as waist circumference increases.

### Causes and Symptoms

The disease state is also known as Insulin Resistance Syndrome, Metabolic Syndrome X, or simply Syndrome X due to the interrelation of the many key physiological factors, which can be seen in the following table:
| Defining Physiological Features | Range (highest definitions of the range included in brackets) |
| ↑ Abdominal Obesity (Waist Circumference) * Men * Women ↑ Triglyceride Level ↓HDL Cholesterol * Men * Women ↑ Blood Pressure ↑Fasting Glucose ↑ Urinary Albumin Excretion Ratio * or ↑ Albumin:Creatinine ratio | > 94 (102)cm > 80 (88) cm ≥ 1.7 (2.0)mMol/L (159 mg/dL) < 0.9 (1.04) mMol/L < 1.0 (1.30) mMol/L ≥ 130 (140) (Systolic)/≥ 85 (90)(Diastolic)mmHg ≥ 5.6 (6.1) mMol/L ≥ 20μg/min ≥ 30 mg/g |

### Focus of Intervention/Treatment

The primary focus for the treatment/prevention of MetS is manipulation of lifestyle (such as a change in diet, weight loss, quitting smoking, reduction in stress levels, pharmaceutical use and potentially surgery) and exercise levels; the primary concentration being treatment of obesity (due to the high correlation/direct relationship MetS has to central/visceral obesity), seconded by improvement of Insulin resistance.

## Current Methods
### Exercise

Up to 20% of Australians are classed as physically inactive, or insufficiently active (36%) and low aerobic exercise capacity appears to be the strongest predictor of mortality from MetS. Regular exercise leading to weight loss is key for positively altering insulin resistance, and glucose response, but also for influencing a number of other MetS features.

#### Aerobic Exercise

Aerobic exercise is optimal, due to its high correlation to a reduction in abdominal (or visceral) adiposity, and as aerobic physiological adaptations are highly beneficial specifically:
* As an anti-inflammatory reducing metabolic stress.
* ↓ In inflammatory cytokines (CRP, TNF-α, Adhesion molecules etc) via reductions in visceral fat/initiation of anti-inflammatory environment.
* ↓ Blood pressure (as much as 11mmHg systolic, 9mmHg Diastolic)
* ↓ Cardiovascular disease risk.
* ↓ Blood Glucose levels
* ↓ Psychosocial stress
* ↓ Plasma triglycerides
* ↓ Mean Arterial Pressure (MAP)
* ↑ Insulin sensitivity in muscle cells
* ↑ High Density Lipoprotein Cholesterol (↓LDL)
* ↑ Release of Adrenalin and Cortisol and ↓ in Pro-inflammatory monocytes
Type of aerobic activity varies, American College of Sports Medicine (ACSM) suggesting that sessions of continuous sub-maximal activity are best for controlling MetS, but other sources show that greater response is seen when a frequent change in intensity was introduced i.e. aerobic interval training.

#### Resistance Exercise

Abundant new evidence recommends resistance training should also be considered due to:
* Primarily its impact on skeletal muscle (and its role in the metabolism of triglycerides and glucose)
* general ↓ in fat mass,
* ↓ in systolic blood pressure,
* Improvement in glycaemic control,
* ↑ Insulin sensitivity (same mechanism as aerobic exercise).
Resistance training has much less of an effect on total cholesterol levels, HDL, LDL, triglyceride levels, and Diastolic BP. Increases in muscular strength may be imperative in the conservation of lean body mass (particular in the elderly) increasing the general activity level, and adding variety to exercise programs (facilitating adherence).

### Recommendations

All programs should be tailored to individual needs and capabilities, based on age, fitness level, and any considerable risk factors; see the following #Precautions and Further Resources. Program for continued, consistent energy expenditure. Whilst weight loss/<adiposity seems to be greater when observing aerobic capacity the positives of resistance training must be considered thus a combination may be best. Select a mode of exercise that:
* Uses large muscles/muscle groups (vary between upper and lower body modalities).
* Varies between non-weight bearing and weight bearing activities
* Can be graded to overload the cardio-respiratory system.
Frequency: 2 or more days per week (1-2 sets of 8-12 reps, with an intensity >60% of an individuals 1RM with 8-10 exercises per session). Aerobic exercise above 180 min/week has a “dose-response” effect i.e. ↑ Frequency = ↑ Physiological response. Resistance training is less dose-dependent and ↑ Frequency will not necessarily ↑ response. Three sessions ≥60min/week with an intensity ≥75% maximum heart rate yields best results for aerobic exercise.
Exercise should be predominantly aerobic based to maximise CV adaptations with additional resistance-training components for strength and functional capacity development. Ideally a combination of strength and aerobic, especially aerobic interspersed with regular increases to high intensity (interval training) for a minimum of 12 weeks.

## Precautions and Further Resources

Before engaging in any exercise or exercise prescription (especially "at risk" populations/individuals), it is recommended to get checked by a health professional, as well as undertaking specific Pre-Exercise screening tools (such as the ESSA Screening system). ESSA Screening Tool and Information
ESSA - Metabolic syndrome and Exercise fact sheet
International Diabetes Foundation Metabolic Syndrome
ACSM Factsheet - Lifestyle and Metabolic Syndrome
Nutrition Australia - Metabolic Syndrome
see also these previous metabolic syndrome focused wikibooks: Short Duration Exercise, Aerobic Exercise.

## Reference list

* 1 2 3 4 Janus, E. D., Laatikainen, T., Dunbar, J. A., Kilkkinen, A., Bunker, S. J., Philpot, B., Heistaro, S. (2007). Overweight, obesity and metabolic syndrome in rural southeastern Australia. Medical Journal of Australia, 187(3), 147.
* 1 2 3 Tanamas, S., Magliano, D. J., Lynch, B., Sethi, P., Willenberg, L., Polkinghorne, K., Shaw, J. (2013). The Australian Diabetes, Obesity and Lifestyle Study (AusDiab 2012) Melbourne: Baker IDI Heart and Diabetes Institute.
* ↑ Grundy, Scott M., et al. "Definition of metabolic syndrome report of the National Heart, Lung, and Blood Institute/American Heart Association Conference on scientific issues related to definition." Circulation 109.3 (2004): 433-438.
* 1 2 3 4 5 Cornier, M., Dabelea, D., Hernandez, T. L., Lindstrom, R. C., Steig, A. J., Stob, N. R., Eckel, R. H. (2008). The Metabolic Syndrome. Endocrine Reviews, 29(7), 777-822. doi: 10.1210/er.2008-0024 Retrieved from http://edrv.endojournals.org/content/29/7/777.abstract
* ↑ Anagnostis, P., Athyros, V. G., Tziomalos, K., Karagiannis, A., & Mikhailidis, D. P. (2009). The pathogenetic role of cortisol in the metabolic syndrome: a hypothesis. Journal of Clinical Endocrinology & Metabolism, 94(8), 2692-2701.
* 1 2 3 4 5 Brandon, J. B. (2013). ACSM Factsheet: Lifestyle and Paediatric Metabolic Syndrome .http://www.acsm.org/docs/current-comments/metabolicsyndrometemp.pdf
* ↑ Australian Bureau of Statistics. (2011). Sports and Physical Recreation: A Statistical Overview. (4156.0). Canberra, Australia: Australian Government.
* ↑ Tjønna, A. E., Lee, S. J., Rognmo, Ø., Stølen, T. O., Bye, A., Haram, P. M., Wisløff, U. (2008). Aerobic Interval Training Versus Continuous Moderate Exercise as a Treatment for the Metabolic Syndrome: A Pilot Study. In (pp. 346-354) doi: 10.1161/CIRCULATIONAHA.108.772822. Retrieved from http://circ.ahajournals.org/content/118/4/346.abstract
* 1 2 Ross, R., Dagnone, D., Jones, P. J., Smith, H., Paddags, A., Hudson, R., & Janssen, I. (2000). Reduction in obesity and related comorbid conditions after diet-induced weight loss or exercise-induced weight loss in men. A randomized, controlled trial. Annals of Internal Medicine, 133(2), 92-103.
* 1 2 Goodpaster, B. H., Kelley, D. E., Wing, R. R., Meier, A., & Thaete, F. L. (1999). Effects of weight loss on regional fat distribution and insulin sensitivity in obesity. Diabetes, 48(4), 839-847.
* 1 2 3 Lee, S., Bacha, F., Hannon, T., Kuk, J. L., Boesch, C., & Arslanian, S. (2012). Effects of Aerobic Versus Resistance Exercise Without Caloric Restriction on Abdominal Fat, Intrahepatic Lipid, and Insulin Sensitivity in Obese Adolescent Boys: A Randomized, Controlled Trial. Diabetes, 61(11), 2787-2795. doi: 10.2337/db12-0214 Retrieved from http://diabetes.diabetesjournals.org/content/61/11/2787.abstract
* 1 2 Gleeson, M., Bishop, N. C., Stensel, D. J., Lindley, M. R., Mastana, S. S., & Nimmo, M. A. (2011). The anti-inflammatory effects of exercise: mechanisms and implications for the prevention and treatment of disease. Nature Reviews Immunology, 11(9), 607-615.
* 1 2 Stensvold, D., Tjønna, A. E., Skaug, E., Aspenes, S., Stølen, T., Wisløff, U., & Slørdahl, S. A. (2010). Strength training versus aerobic interval training to modify risk factors of metabolic syndrome. Journal of Applied Physiology, 108(4), 804-810.
* 1 2 Escalante, Y., Saavedra, J. M., García-Hermoso, A., & Domínguez, A. M. (2012). Improvement of the lipid profile with exercise in obese children: A systematic review. Preventive Medicine, 54(5), 293-301. doi: http://dx.doi.org.ezproxy1.canberra.edu.au/10.1016/j.ypmed.2012.02.006
* 1 2 Strasser, B., Siebert, U., & Schobersberger, W. (2010). Resistance training in the treatment of the metabolic syndrome. Sports Medicine, 40(5), 397-415.
* ↑ Williams, M.A., Haskell, W.L., Ades, P. A., Amsterdam, E. A., Bittner, V., Franklin, B.A., Stewart, K. J. (2007). Resistance exercise in individuals with and without cardiovascular disease: 2007 update, a scientific statement from the American Heart Association Council on Clinical Cardiology and Council on Nutrition, Physical Activity, and Metabolism. Circulation, 116(5), 572-584.