Table 1.
Effects of insulin resistance, ghrelin, and some adipokines on endocrine and metabolic functions in the pathogenesis of the MetS.
| General effects | Effects on sympathetic nervous system | In vitro/animal studies (references) | Human studies (references) | |
|---|---|---|---|---|
| Insulin resistance | Direct antinatriuretic action | (i) Its intracerebral administration increases sympathetic outflow (ii) Induces sympathetic overactivity (iii) Stimulates SNS to increase cardiac output |
[46–50] | [39, 49, 56–58] |
|
| ||||
| Leptin | (i) Levels correlate with adipose tissue mass (ii) Satiating factor decreases food intake (iii) Physiological regulation of feeding behavior trough hypothalamic receptors |
Vasocontractile effect related to SNS activation | [90, 92, 95, 97, 103, 104, 109, 110] | [90, 91, 99, 100, 102, 107, 111] |
|
| ||||
| NEFAs | Levels are increased in obesity and inversely correlated with insulin sensitivity | Induce a central activation of MNSA in lean subjects | [115–118] | [114, 119, 122] |
|
| ||||
| Adiponectin | (i) Levels are inversely related to obesity, DM, and insulin resistant states (ii) Ameliorates obesity-related hypertension |
[127, 128, 132, 133] | [129, 131] | |
|
| ||||
| Ghrelin | (i) Its infusion decreases blood pressure and HR (ii) Improves endothelial function (iii) Promotes weight gain and increases appetite |
Its infusion increases SNS activity | [136, 137, 141, 143] | [140, 142, 144] |