Does Pioglitazone Increase the Production of 15-EPI-Lipoxin A4?

Type-2 diabetes mellitus is a public health concern. Patients with type 2 diabetes mellitus are at high risk of developing cardiovascular complications. Diabetic patients are two to four-times more likely to develope cardiovascular disease. The mortality of diabetic patients with cardiovascular disease is much higher than in non-diabetic matched patients with cardiovascular disease. Recently, it has become apparent that not all anti-diabetic drugs have the same effect on the progression of atherosclerosis and on cardiovascular outcomes. There is a great need to understand the potential protective mechanisms of the various anti-diabetic drugs in order to decrease their risk for cardiovascular morbidity and mortality. In addition to increasing insulin sensitivity, Pioglitazone (PIO) has anti-inflammatory properties. However, the underlying mechanisms of these anti-inflammatory (and probably anti-atherosclerotic) effects of PIO are unknown. We have shown in the rat that 3-day pretreatment with PIO increases myocardial cyclooxygenase-2 (COX2) activity and levels of both 6-keto-PGF1a, the stable metabolite of prostacyclin (PGI2) and 15-epi-lipoxin A4, a lipid mediator with a strong anti-inflammatory properties. Prostacyclin inhibits platelet aggregation and causes vasodilatation. Increased levels of 6-keto-PGF1a and 15-epi-lipoxin A4 may thus be the explanation for the anti-inflammatory and anti-atherosclerosis effects of PIO. Several clinical studies have shown that COX2 inhibition is associated with increased cardiovascular events. Thus, augmenting COX2 activity and the production of prostacyclin and 15-epi-lipoxin A4 may have potential favorable effects. The purpose of the study is to test whether PIO therapy is associated with an increase in serum and/or urine levels of 6-keto-PGF1a and 15-epi-lipoxin A4 in patients with diabetes mellitus type 2.

Type-2 diabetes mellitus is a public health concern. According to the World health organization (WHO), diabetes mellitus affects more than 180 million people worldwide. Type 2 diabetes mellitus accounts for 80-95% of diabetes cases in developed countries and a higher proportion in developing countries (IDF 2006). Patients with type 2 diabetes mellitus are at high risk of developing cardiovascular complications. Diabetic patients are two to four-times more likely to develope cardiovascular disease. The mortality of diabetic patients with cardiovascular disease is much higher than in non-diabetic matched patients with cardiovascular disease. Recently, it has become apparent that not all anti-diabetic drugs have the same effect on the progression of atherosclerosis and on cardiovascular outcomes. There is a great need to understand the potential protective mechanisms of the various anti-diabetic drugs in order to decrease their risk for cardiovascular morbidity and mortality. In addition to increasing insulin sensitivity, Pioglitazone (PIO) has anti-inflammatory properties. Several studies have suggested that PIO decreases serum markers of inflammation including C-reactive protein (CRP). However, the underlying mechanisms of these anti-inflammatory (and probably anti-atherosclerotic) effects of PIO are unknown. We have shown in the rat that 3-day pretreatment with PIO increases myocardial cyclooxygenase-2 (COX2) activity and levels of both 6-keto-PGF1a, the stable metabolite of prostacyclin (PGI2) and 15-epi-lipoxin A4, a lipid mediator with a strong anti-inflammatory properties. Prostacyclin inhibits platelet aggregation and causes vasodilatation. Increased levels of 6-keto-PGF1a and 15-epi-lipoxin A4 may thus be the explanation for the anti-inflammatory and anti-atherosclerosis effects of PIO. Several clinical studies have shown that COX2 inhibition is associated with increased cardiovascular events. Thus, augmenting COX2 activity and the production of prostacyclin and 15-epi-lipoxin A4 may have potential favorable effects. The purpose of the study is to test whether PIO therapy is associated with an increase in serum and/or urine levels of 6-keto-PGF1a and 15-epi-lipoxin A4 in patients with diabetes mellitus type 2.

Eligibility Criteria:
Inclusion Criteria:

1. Men and women \> 21 years old with type 2 diabetes Mellitus and otherwise stable medical conditions

Exclusion Criteria:

1. Serum creatinine \>= 1.5 mg/dl and/or renal failure
2. NYHA class III or IV heart failure
3. Known intolerance to TZD
4. Current use of NSAID, COX-2 inhibitors, steroids (oral, topical and inhalation) or immunosuppressive therapy
5. Aspirin \> 162 mg/d
6. Recent myocardial infarction, ACS, or stroke \<=3 months)
7. Significant comorbid conditions such as: cancer (not cured), end stage renal disease, severe obstructive lung disease, cirrhosis, etc)
8. Recent (\<1 month) infection
9. Recent CABG or PCI (\<3 months)
10. Use of prostaglandin analogs (i.e., iloprost)
11. Active inflammatory disease
12. Current use of TZD
13. Pregnancy
14. Osteoporosis or high risk for bone fracture. Use of other antihyperglycemic agents is not an exclusion criterion. HbA1c and glucose levels will not restrict enrollment.