RESUMO
BACKGROUND: Disorders of mineral metabolism occur in most patients with chronic kidney disease (CKD). The aim of this work was to correlate parathyroid hormone (PTH) levels with urinary magnesium excretion in patients with non-dialysis dependent CKD. METHODS: Cross-sectional study. Concentrations of creatinine, magnesium, calcium, phosphate, parathyroid hormone (PTH), 25-hydroxyvitamin D [25(OH)D] and alkaline phosphatase (ALP) were determined in blood samples. The assessment of urinary magnesium levels was performed by means of total daily excretion and by the excretion fraction (FEMg). RESULTS: The study evaluated 163 patients with a mean age of 60.7 ± 11.7 years and 51.0% were male. In the highest quartile of PTH (>89.5pg/mL), the mean levels of FEMg and ALP were higher (p<0.05). In the unadjusted regression analysis, the following variables were related to serum PTH levels: FEMg (odds ratio (OR) = 1.12; 95% confidence intervals (CI): 1.02-1.23), calcium (OR = 0.45; 95% CI: 0.22-0.90), ALP (OR = 1.02; 95% CI: 1.00-1.03) and eGFR (OR = 0.92; 95% CI: 1.00-1.03). After an adjusted analysis, only one FEMg and ALP will remain correlated with PTH. CONCLUSION: In patients with non-dialysis dependent CKD, FEMg and ALP were some variables that remained associated with PTH.
RESUMO
BACKGROUND: studies have shown an association between obesity and a reduction in estimated glomerular filtration rate (eGFR). However, little is known regarding whether this association is related to total fat or, more specifically, to central or visceral fat. OBJECTIVE: this study evaluated the correlations among the nutritional indices that measure total, central and visceral obesity with eGFR. METHODS: a cross-sectional study, involving 288 hypertensive patients. Kidney function was estimated by GFR, using the Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. Explanatory variables included body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), waist stature ratio (WSR), estimated visceral adipose tissue (eVAT) and body fat percentage (BF%). RESULTS: the mean BMI was 27.8 ± 4.7 kg/m². Most of the patients (68.1%) were in the normal range of BF%, but regarding WC and eVAT, they were at very high risk (58.3% and 64.6%, respectively). In men, there were no correlations between nutritional indices and eGFR. In women, only eVAT remained negatively correlated with eGFR, estimated by MDRD and CKD-EPI equations, independent of BMI, smoking, physical inactivity, blood pressure, glycated hemoglobin, LDL and HDL cholesterol, uric acid and microalbuminuria. CONCLUSIONS: the majority of obesity indices were not associated with eGFR. Only eVAT was negatively associated with eGFR by MDRD and CKDEPI equations in hypertensive women. In primary health care, visceral adipose tissue estimation could support the identification of hypertensive women at increased risk for developing chronic kidney disease.