Sodium intake affects urinary albumin excretion especially in overweight subjects

OBJECTIVES

To examine the relationship between sodium intake and urinary albumin excretion, being an established risk marker for later cardiovascular morbidity and mortality.

DESIGN

Cross-sectional cohort study using linear regression analysis. Setting. University hospital outpatient clinic.

SUBJECTS

A cohort drawn from the general population, consisting of 7850 subjects 28-75 years of age, all inhabitants of the city of Groningen, the Netherlands. The cohort is enriched for the presence of subjects with elevated urinary albumin concentration.

RESULTS

The results show a positive relationship between dietary sodium intake and urinary albumin excretion. The association was independent of other cardiovascular risk factors (such as sex, age, blood pressure, body mass index (BMI), waist-to-hip ratio, serum cholesterol, plasma glucose and smoking) and other food constituents (calcium, potassium and protein). The relationship between sodium intake and urinary albumin excretion was steeper in subjects with a higher BMI compared with a lower BMI.

CONCLUSIONS

Sodium intake is positively related to urinary albumin excretion. This relation is more pronounced in subjects with a higher BMI. These results suggest that high sodium intake may unfavourably influences cardiovascular prognosis especially in overweight and obese subjects.

Effect of dexamethasone on perioperative renal function impairment during cardiac surgery with cardiopulmonary bypass

BACKGROUND

In cardiac surgery with cardiopulmonary bypass (CPB), corticosteroids are administered to attenuate the physiological changes caused by the systemic inflammatory response. The effects of corticosteroids on CPB-associated renal damage have not been documented. The purpose of this study was to evaluate the effects of dexamethasone on perioperative renal dysfunction in patients undergoing cardiac surgery with CPB.

METHODS

Renal damage was prospectively studied in 20 patients without concomitant morbidity undergoing coronary artery surgery with CPB. Patients were randomized in a double-blind fashion to receive dexamethasone or placebo. Markers of glomerular function (creatinine clearance) and damage (microalbuminuria), and markers of tubular function (fractional excretion of sodium and free water clearance) and damage (N-acetyl-beta-D glucosaminidase (NAG)) were evaluated in addition to plasma and urinary glucose levels. Plasma and urinary specimens were obtained at the following time periods: (1) baseline, during the 12 h before surgery; (2) skin incision before heparinization; (3) from heparinization until the end of CPB; (4) during the 2 h following weaning from CPB; (5) in the intensive care unit from 2 to 6 h after weaning of CBP; (6) and from 36 to 60 h after weaning of CPB.

RESULTS

CPB was associated with an increase in markers in the placebo group, which returned to baseline during the second postoperative day, demonstrating a transient impairment of glomerular and tubular renal function. Similar patterns were observed in patients treated with dexamethasone. While postoperative glycosuria was significantly higher in the dexamethasone-treated group, no other differences between groups were observed.

CONCLUSION

Dexamethasone administration before CPB has no protective effect on perioperative renal dysfunction in low-risk cardiac surgical patients.

Tissue distribution of ACE2 protein, the functional receptor for SARS coronavirus. A first step in understanding SARS pathogenesis

Severe acute respiratory syndrome (SARS) is an acute infectious disease that spreads mainly via the respiratory route. A distinct coronavirus (SARS-CoV) has been identified as the aetiological agent of SARS. Recently, a metallopeptidase named angiotensin-converting enzyme 2 (ACE2) has been identified as the functional receptor for SARS-CoV. Although ACE2 mRNA is known to be present in virtually all organs, its protein expression is largely unknown. Since identifying the possible route of infection has major implications for understanding the pathogenesis and future treatment strategies for SARS, the present study investigated the localization of ACE2 protein in various human organs (oral and nasal mucosa, nasopharynx, lung, stomach, small intestine, colon, skin, lymph nodes, thymus, bone marrow, spleen, liver, kidney, and brain). The most remarkable finding was the surface expression of ACE2 protein on lung alveolar epithelial cells and enterocytes of the small intestine. Furthermore, ACE2 was present in arterial and venous endothelial cells and arterial smooth muscle cells in all organs studied. In conclusion, ACE2 is abundantly present in humans in the epithelia of the lung and small intestine, which might provide possible routes of entry for the SARS-CoV. This epithelial expression, together with the presence of ACE2 in vascular endothelium, also provides a first step in understanding the pathogenesis of the main SARS disease manifestations.