Aldosterone-induced microvascular dysfunction as a cause of salt-sensitivity in obesity?

Recruitment & Eligibility

Status: Completed

Sex: Not specified

Target Recruitment: 40

Inclusion Criteria

Obese individuals
- Age 18-65 years
- Caucasian (because of ethnic differences in microvascular function and in the prevalence of cardiovascular disease and associated risk factors)
- Waist circumference > 102 cm (men)/> 88 cm (women) ;Lean individuals
- Age 18-65 years
- Caucasian (because of ethnic differences in microvascular function and in the prevalence of cardiovascular disease and associated risk factors)
- Waist circumference < 94 cm (men)/< 80 cm (women)

Exclusion Criteria

- Cardiovascular disease (stroke, coronary artery disease, peripheral vascular disease, congestive heart failure, cardiac shunts, cardiac surgery, pulmonary hypertension, cardiac arrhythmias, family history of cardiac arrhythmias or sudden cardiac death)
- Diabetes mellitus/impaired glucose metabolism (fasting glucose values > 6.1 mmol/L), because not only diabetes, but also intermediate hyperglycaemia has been associated with microvascular disease, which impedes the distinction between cause and consequence of disturbances in glucose metabolism in the concerning individuals
- Stage 3 hypertension (blood pressure > 180/110 mm Hg) in order not to expose these persons to unnecessary risks
- Unstable or severe pulmonary disease
- Unstable or severe thyroid disorders
- Inflammatory diseases
- Smoking (due to impairment of microvascular function)
- Alcohol use > 2 U/day (women)/> 3 U/day (men)
- Use of glucose-lowering medications, because of interference with microvascular function
- Use of corticosteroids (might cause hypertension and interfere with electrolyte homeostasis and glucose metabolism) and regular use (weekly or several times a week) of NSAIDs (might cause disturbance of microvascular function and electrolyte excretion)
- eGFR < 60 mL/min
- Impairment of hepatic function
- Pregnancy or lactation

Study & Design

Study Type: Interventional

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>Primary endpoints are skin capillary recruitment during reactive hyperemia,<br /><br>both basally and during hyperinsulinemia, skeletal muscle microvascular<br /><br>recruitment during hyperinsulinemia, aldosterone levels and salt-sensitivity.<br /><br>They will be compared between obese and lean individuals, under circumstances<br /><br>of low and high salt intake.</p><br>

Secondary Outcome Measures

Name	Time	Method
<p>Secondary endpoints are results of other microvascular measurements (baseline<br /><br>capillary density, skin vasomotion (basal and during local heating),<br /><br>endothelial glycocalyx thickness), both basally and during hyperinsulinemia,<br /><br>insulin sensitivity, blood pressure, other RAAS components, biomarkers<br /><br>representing endothelial activation and low-grade inflammation, and urinary<br /><br>excretion of albumin and products of NO metabolism. They will be compared as<br /><br>well between obese and lean individuals under circumstances of low and high<br /><br>salt intake. </p><br>