High sodium intake is associated with increased glucocorticoid production, insulin resistance and metabolic syndrome

ObjectiveHigh sodium (HS) diet is associated with hypertension (HT) and insulin resistance (IR). We evaluated whether HS diet was associated with a dysregulation of cortisol production and metabolic syndrome (MetS). Patients and measurementsWe recruited 370 adults (18-85years, BMI 29344kg/m(2), 70% women, 72% HT, 61% MetS). HS diet (urinary sodium >150mEq/day) was observed in 70% of subjects. We measured plasma hormones, lipid profile, urinary free cortisol (UFC) and cortisol tetrahydrometabolites (THM). ResultsUrinary sodium was correlated with UFC (r=+045, P<0001), cortisol THM (r=+041, P<0001) and inversely with adiponectin, HDL and aldosterone, after adjusting by age, gender and BMI. Subjects with high, compared with adequate sodium intake (50-149mEq/day) had higher UFC (P<0001), THM (P<0001), HOMA-IR (P=004), HT (81% vs 50%, P<0001), MetS (69% vs 41%, P<0001) and lower adiponectin (P=0003). A multivariate predictive model adjusted by confounders showed a high discriminative capacity for MetS (ROC curve 0878) using four clinical variables: HS intake [OR=56 (CI 23-153)], HOMA-IR [OR 17 (13-22)] cortisol THM [OR 12 (11-14)] and adiponectin [OR=09 (08-09)], the latter had a protective effect. ConclusionsHigh sodium diet was associated with increased urinary cortisol and its metabolites. Also, HS diet was associated with HT, insulin resistance, dyslipidaemia and hypoadiponectinaemia, even when adjusting by confounding variables. Further, we observed that high salt intake, IR and higher cortisol metabolites, alone or combined in a clinical simple model, accurately predicted MetS status, suggesting an additive mechanism in obesity-related metabolic disorders.