Targeting components of the stress system as potential therapies for the metabolic syndrome - The peroxisome-proliferator-activated receptors

The three peroxisome-proliferator-activated receptor (PPAR) subtypes PPAR-alpha, PPAR-gamma, and PPAR-delta are ligand-activated transcription factors of the nuclear receptor family. PPARs form obligate heterodimers with the retinoid X receptor, which bind to peroxisome-proliferator-response elements (PPREs). PPAR-alpha is expressed mainly in liver, brown fat, kidney, heart, and skeletal muscle; PPAR-gamma in intestine and adipose tissue; PPAR-alpha and PPAR-gamma are both expressed in vascular endothelium, smooth muscle cells, macrophages, and foam cells; PPAR-delta in skeletal muscle, human embryonic kidney, intestine, heart, adipose tissue, developing brain, and keratinocytes. Intense interest in the development of drugs with new mechanisms of action for the metabolic syndrome has focused attention on nuclear receptors, such as PPARs that function as regulators of energy homeostasis. Agonists of PPAR-a and PPAR-gamma are currently used to treat diabetic dyslipidemia and type 2 diabetes. Dual PPAR-alpha/gamma agonists and PPAR-alpha/gamma/delta pan-agonists are under investigation for treatment of cardiovascular disease and the metabolic syndrome. Selective PPAR modulators (SPPARMs) are PPAR ligands that possess desirable efficacy and improved tolerance. Efforts are being made to identify novel partial agonists or antagonists for PPAR-gamma in order to combine their antidiabetic and antiobesity effects. Glucocorticoids are major mediators of the stress response and could be the link between stress and PPAR activator signaling and thus may affect the downstream metabolic pathways involved in fuel homeostasis

Prevalence of obesity in Turkey

Obesity and overweight are increasing in Turkey according to the field surveys that were carried out a decade apart (TEKHARF 1990 and 2000). The overall prevalence of obesity in adults was 18.6% in the year 1990. Ten years later in 2000, the prevalence was 21.9%, which shows a relative increase rate of 17.7%. As it is true for most of the countries, overweight is more common in men and obesity is more prevalent among women in Turkey

Prevalence of Overweight and Obesity in Turkey

The objectives of this study were to determine the prevalence of overweight and obesity in Turkey, and to investigate their association with age, gender, and blood pressure. A cross-sectional population-based study was performed. A total of 20,119 inhabitants (4975 women and 15,144 men, age > 20 years) from 11 Anatolian cities in four geographic regions were screened for body weight, height, and systolic and diastolic blood pressure between the years 1999 and 2000. The overall prevalence rate of overweight was 25.0% and of obesity was 19.4%. The prevalence of overweight among women was 24.3% and obesity 24.6%; 25.9% of men were overweight, and 14.4% were obese. Mean body mass index (BMI) of the studied population was 27.59 +/- 4.61 kg/m(2). Mean systolic and diastolic blood pressure for women were 131.0 +/- 41.0 and 80.2 +/- 16.3 mm Hg, and for men 135.0 +/- 27.3 and 83.2 +/- 16.0 mm Hg. There was a positive linear correlation between BMI and blood pressure, and between age and blood pressure in men and women. Obesity and overweight are highly prevalant in Turkey, and they constitute independent risk factors for hypertension