Aldosterone production is associated with insulin resistance in obese and hypertensive subjects. However, its effect on insulin sensitivity in healthy subjects is not clear.
The objective of this study was to test the hypothesis that increased aldosterone production is associated with lower insulin sensitivity in healthy subjects.
This is an analysis of data previously collected during studies conducted as part of the International Hypertensive Pathotype Consortium. Participants and Interventions: Eighty-four subjects free of any medical or psychiatric illness were included in this study. They were studied after 7 d of a standardized high-sodium diet confirmed by 24-h urine sodium above 200 mEq. Insulin sensitivity index (ISI) was calculated after a 75-g oral glucose load with glucose and insulin measurements at 0, 30, 60, and 120 min. Serum aldosterone levels were measured after 45 min of angiotensin II (3 ng/kg/min) infusion.
There were significant negative correlations between ISI and age, body mass index (BMI), diastolic blood pressure, and angiotensin II-stimulated aldosterone level (P < 0.01). On multivariate regression analysis, stimulated aldosterone level was an independent predictor of ISI after adjusting for age, BMI, and diastolic blood pressure. Stimulated aldosterone level predicted 8% of the variance in ISI (P = 0.003) with age, BMI, and diastolic blood pressure together predicting 23% of the variance in ISI. Thus, the final regression model predicted 31% of the variance in ISI (P < 0.0001).
Aldosterone production is associated with insulin resistance in normotensive healthy subjects independent of traditional risk factors.
"Blockade of MR by spironolactone decreases local inflammation and vascular stiffness in rodent models of hypertension and insulin resistance (50, 52–54). The contribution of MR signaling to insulin resistance is also supported by insulin resistance in patients with primary hyperaldosteronism (55) and correlation of plasma aldosterone levels with BMI and insulin resistance in normotensive subjects (56). "
[Show abstract][Hide abstract] ABSTRACT: Epidemiological studies support the notion that arterial stiffness is an independent predictor of adverse cardiovascular events contributing significantly to systolic hypertension, impaired ventricular-arterial coupling and diastolic dysfunction, impairment in myocardial oxygen supply and demand, and progression of kidney disease. Although arterial stiffness is associated with aging, it is accelerated in the presence of obesity and diabetes. The prevalence of arterial stiffness parallels the increase of obesity that is occurring in epidemic proportions and is partly driven by a sedentary life style and consumption of a high fructose, high salt, and high fat western diet. Although the underlying mechanisms and mediators of arterial stiffness are not well understood, accumulating evidence supports the role of insulin resistance and endothelial dysfunction. The local tissue renin-angiotensin-aldosterone system (RAAS) in the vascular tissue and immune cells and perivascular adipose tissue is recognized as an important element involved in endothelial dysfunction which contributes significantly to arterial stiffness. Activation of vascular RAAS is seen in humans and animal models of obesity and diabetes, and associated with enhanced oxidative stress and inflammation in the vascular tissue. The cross talk between angiotensin and aldosterone underscores the importance of mineralocorticoid receptors in modulation of insulin resistance, decreased bioavailability of nitric oxide, endothelial dysfunction, and arterial stiffness. In addition, both innate and adaptive immunity are involved in this local tissue activation of RAAS. In this review we will attempt to present a unifying mechanism of how environmental and immunological factors are involved in this local tissue RAAS activation, and the role of this process in the development of endothelial dysfunction and arterial stiffness and targeting tissue RAAS activation.
Frontiers in Endocrinology 10/2013; 4:161. DOI:10.3389/fendo.2013.00161
[Show abstract][Hide abstract] ABSTRACT: In this paper we present a controller design and implementation on a mini-rotorcraft having four rotors. A Lagrangian model of the helicopter was used for the controller synthesis. The proposed controller is based on Lyapunov analysis. Experimental results show that the controller is able to perform autonomously the tasks of taking-off, hovering and landing.
Intelligent Robots and Systems, 2004. (IROS 2004). Proceedings. 2004 IEEE/RSJ International Conference on; 10/2002
[Show abstract][Hide abstract] ABSTRACT: Key components of the metabolic syndrome (MetS), ie, obesity and insulin resistance, are associated with increased aldosterone production and mineralocorticoid receptor (MR) activation. Both MetS and hyperaldosteronism are proinflammatory and pro-oxidative states associated with cardiovascular disease. This review discusses emerging data that MR activation may contribute to abnormalities seen in MetS. In view of these data, MR antagonists may be beneficial in MetS, not only by controlling hypertension but also by reversing inflammation, oxidative stress, and defective insulin signaling at the cellular-molecular level. Clinical trials have demonstrated benefits of MR antagonists in heart failure, hypertension, and diabetic nephropathy, but additional trials are needed to demonstrate the clinical significance of MR blockade in MetS.
Current Hypertension Reports 08/2010; 12(4):252-7. DOI:10.1007/s11906-010-0126-2 · 3.44 Impact Factor
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