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Lead Researcher:

Associate Professor Tony O’Sullivan

Significance

Obesity and the metabolic syndrome have a high and increasing prevalence in our society and carry increased risk of heart disease, diabetes (type II) and death.

A BMI of 35 (moderate-severe obesity) doubles the annual death rate of affected individuals while the morbidly obese (BMI > 40) have a 5 yr survival worse than that of many cancers. By 2010 more than 1.2M Australians will be diabetic and that a major risk for this soaring incidence is diet and obesity.

The risk of developing diabetes is 30-40 fold in someone carrying an 30 extra kilograms. A middle-aged person developing diabetes can expect to lose up to 15yrs of their predicted life expectancy.

Most significant advances or findings in past 10yrs

Through studies into body metabolism we have shown that oestrogen, the female sex hormone, reduces fat oxidation (burning) and this action may in part contribute to the higher fat mass seen in females compared with males. This biological action of oestrogen may also contribute to fat gain during pregnancy, which has advantages for fuel storage in the pregnant female. It is imperative that medical science understands the mechanisms by which the body regulates fat mass in order that effective strategies be developed to manage chronic and complex conditions such as diabetes and obesity.

Most important aspects of current work

We are planning to look into the hormonal changes in pregnancy in more detail to determine the mechanism whereby oestrogen may affect fat metabolism.

Recent publications

1. O’Sullivan AJ, Crampton, LJ, Freund J, Ho, KY. The route of estrogen replacement therapy confers divergent effects on substrate oxidation and body composition in postmenopausal women. J Clin Invest 1998;102:1035-1040.
2. Martin A, Brown MA, O’Sullivan AJ. Body Composition and Energy Metabolism in Pregnancy. Australian and New Zealand Journal of Obstetrics and Gynaecology 2001; 41: 216-222.
3. Martin A, O’Sullivan AJ, Brown MA. Body Composition and Energy Metabolism in Normal and Hypertensive Pregnancy. British Journal of Obstetrics and Gynaecology 2001; 108: 1263-1271.
4. O’Sullivan AJ, Martin A, Brown M. Efficient fat storage in premenopausal women and in early pregnancy: a role for estrogen. Journal of Clinical Endocrinology and Metabolism 2001; 86: 4951-4956.
5. Ho KKY, O'Sullivan AJ, Hoffman D, Leung K-C. Growth hormone action in man. In Bouillon R (ed). Targets for Growth Hormone and IGF-I action. 2001 Bioscientifica Ltd. Volume 5: 1-11.
6. O’Sullivan AJ, Lawson JA, Chan M, Kelly JJ. Body composition and energy metabolism in chronic renal insufficiency. American Journal of Kidney Diseases 2002; 39: 369-375. Editorial accompanied publication.
7. O’Sullivan AJ, Martin A, Brown M. Efficient fat storage in premenopausal women and in early pregnancy: a role for estrogen. In Mazzaferri E (ed). The Year Book of Endocrinology 2002. Mosby Inc, St. Louis, MO: 125-128.
8. Poynten AM, Gan SK, Kriketos AD, O’Sullivan AJ, Kelly JJ, Ellis B, Chisholm DJ, Campbell LV. Nicotinic acid induced insulin resistance is related to increased circulating fatty acids and fat oxidation but not muscle lipid content. Metabolism 2003; 52: 699-704.
9. Ho KKY, O'Sullivan AJ, Wolthers T, Leung K-C. Metabolic effects of oestrogens: impact of the route of administration. Annales d Endocrinologie 2003; 64: 170-77.
10. Ho K, Dinihan I, Cozzi P, O’Sullivan AJ. Consider von Hippel-Lindau Syndrome in young patients presenting with retinal angioma and phaeochromocytoma. Internal Medicine Journal 2005; 35: 498-499.
11. Cheema BSB, O’Sullivan AJ, Chan M, Patwardhan A, Kelly J, Gillin A, Fiatarone Singh MA. Progressive resistance training during hemodialysis: Rationale and method of a randomised-controlled trial. Hemodialysis International 2006; 10: 303-310.
12. O’Sullivan AJ, Lewis M, Diamond T. Amiodarone-induced thyrotoxicosis: left ventricular dysfunction is associated with increased mortality. European Journal of Endocrinology 2006; 154: 533-536.
13. O’Sullivan AJ, Kriketos AD, Martin A, Brown MA. Serum adiponectin levels in normal and hypertensive states of pregnancy. Hypertension in Pregnancy 2006; 25: 193-203.
14. O’Sullivan AJ, Kelly JJ. Insulin resistance and protein catabolism in non-diabetic hemodialysis patients. Kidney International 2007; 71: 98-100. Invited Editorial.
15. Cheema B, Abas H, Smith B, O’Sullivan AJ, Chan M, Patwardhan A, Kelly J, Gillin A, Pang G, Lloyd B, Fiatarone Singh M. Progressive exercise for anabolism in kidney disease (PEAK): A randomized controlled trial of resistance training during hemodialysis. Journal of the American Society of Nephrology 2007; 19: 1598-1601.
16. Cheema B, Abas H, Smith B, O’Sullivan AJ, Chan M, Patwardhan A, Kelly J, Gillin A, Pang G, Lloyd B, Fiatarone Singh M. A randomised controlled trial of intradialytic resistance training to target muscle wasting in end-stage renal disease: The PEAK Study. American Journal of Kidney Diseases 2007; 50: 574-584.
17. O’Sullivan AJ, Toohey SM. Assessment of Professionalism in Undergraduate Medical Students. Medical Teacher 2008; 30: 5-9.
18. Brillante DG, O’Sullivan AJ, Johnstone MT, Howes LG. Evidence for functional expression of vascular AT2 receptors in patients with insulin resistance. Diabetes, Obesity and Metabolism 2008; 10: 143-150.
19. Brillante DG, O’Sullivan AJ, Johnstone MT, Howes LG. Arterial stiffness and hemodynamic response to vasoactive medications in patients with insulin resistance syndrome compared with age- and sex-matched controls. Clinical Science 2008; 114: 139-147.