Do low levels of circulating adiponectin represent a biomarker or just another risk factor for the metabolic syndrome?

Abstract

The metabolic syndrome is currently defined by various combinations of insulin resistance, obesity, dyslipidaemia and hypertension. The tendency for these risk factors to appear simultaneously suggests a single aetiologic basis. A low level of circulating adiponectin is associated with the appearance of each metabolic syndrome risk factor. The following review summarizes a large body of evidence that suggests a low level of circulating adiponectin represents an independent risk factor and a possible biomarker for the metabolic syndrome. An association between the metabolic syndrome and low adiponectin supports the view that the development of the metabolic syndrome may be triggered by a single underlying mechanism. Clinical studies in the future may show that a low level of circulating adiponectin is a primary biomarker for a specific cluster of metabolic syndrome risk factors rather than all the possible combinations of risk factors currently used to identify the metabolic syndrome. The significance of low circulating adiponectin in risk assessment models should ultimately be compared against insulin resistance, obesity, dyslipidaemia, hypertension and other metabolic syndrome risk factors presently under consideration. Adiponectin can be measured reliably in a clinical setting; circulating values of adiponectin do not fluctuate on a diurnal basis as much as insulin, glucose, triglycerides or cholesterol and only 2-4 microl of blood are currently needed for its measurement.

Effects of the traditional Mediterranean diet on adiponectin and leptin concentrations in men and premenopausal women: do sex differences exist?

“…2 These characteristics have been reported in a previous publication ( 14 ). 3 Analysis was performed on transformed values.…”

“…Of these adipose tissue-derived hormones, adiponectin and leptin have attracted much interest because of their significant impact on cardiovascular health. Adiponectin is known as having anti-inflammatory, antiatherogenic and insulin-sensitizing properties 1 and it has been previously demonstrated that a low concentration of this hormone is an independent predictor of the metabolic syndrome 2 , coronary heart disease 3 and type 2 diabetes 4 . In the case of leptin, mixed results have been obtained, some studies observed that a high leptin concentration is a predictor of coronary events and type 2 diabetes independently of adiposity 5,6 while others showed that the association between leptin concentrations and these major chronic diseases is largely explained by concomitant variations in body weight or BMI 7,8 .…”

Insulin resistance in young, lean male subjects with essential hypertension

“…Interestingly, our data indicate that in this 'lean range', the amount of SAT may be an important determinant of several metabolic cardiovascular risk factors, such as higher TG and lower high-density lipoprotein -cholesterol concentrations. Adiponectin, as a marker of metabolic syndrome, 40 and leptin, as an indicator of the amount of adipose tissue mass, 41 have been associated with insulin resistance and HT. 42 Patel et al 43 found inverse association of adiponectin with insulin resistance, visceral adiposity, and positive family history of coronary heart disease, HT and type 2 diabetes in young adults.…”

Adiponectin, but Not Leptin or High-Sensitivity C-Reactive Protein, Is Associated with Blood Pressure Independently of General and Abdominal Adiposity

“…Adipose tissue is a rich source of metabolically active molecules, including adiponectin and leptin (4). Adiponectin is considered a marker of metabolic syndrome (5), and leptin directly reflects the amount of adipose tissue mass (6). Obesity is also strongly associated with high-sensitivity C-reactive protein (hs-CRP), a marker of chronic systemic inflammation (7).…”