Age-Related Changes in Clinical and Analytical Variables in Chronic Hemodialyzed Patients.

Worldwide, the number of elderly individuals receiving chronic hemodialysis is rising. The aim of our study was to evaluate several clinical and analytical biomarkers in chronically dialyzed patients and analyze how they change with age. A cross-sectional study was performed by evaluating 289 end-stage renal disease patients undergoing dialysis. We evaluated the hemogram, adipokines, the lipid profile, and several markers related to inflammation, endothelial function/fibrinolysis, nutrition, iron metabolism, and cardiac and renal fibrosis. Clinical data and dialysis efficacy parameters were obtained from all patients. The relationships between studied biomarkers and age were assessed by a statistical comparison between younger (adults with age < 65 years) and older (age ≥ 65 years) patients and by performing regression analysis. Participants presented a mean age of 68.7 years (±13.6), with 66.8% (n = 193) being classified as older. Compared to younger patients, older patients presented the following: (a) significantly lower values of diastolic blood pressure (DBP) and ultrafiltration volume; (b) lower levels of phosphorus, uric acid, creatinine, and albumin; and (c) higher circulating concentrations of tissue-type plasminogen activator (tPA), D-dimer, interleukin-6, leptin, N-terminal pro B-type natriuretic peptide, and tissue inhibitor of metalloproteinase-1. In the multiple linear regression analysis, DBP values, tPA, phosphorus, and D-dimer levels were independently associated with the age of patients (standardized betas: -0.407, 0.272, -0.230, and 0.197, respectively; p < 0.001 for all), demonstrating relevant changes in biomarkers with increasing age at cardiovascular and nutritional levels. These findings seem to result from crosstalk mechanisms between aging and chronic kidney disease.

Troponin I, but not BNP, is associated with phosphorus, calcium and vitamin D in stable coronary artery disease.

BACKGROUND: Elevated plasma cardiac troponin, elevated plasma phosphorus and decreased plasma vitamin D have been shown to be associated with negative outcomes. METHODS AND RESULTS: Troponin I, calcium, phosphorus and 25-OH vitamin D were studied in a cohort of 60 patients with stable coronary heart disease and preserved left ventricular function. Using a cut-off value of 0.012 ng/mL for plasma troponin I, patients with higher values (18 patients), when compared to the other patients (n=42), had higher mean values for plasma phosphorus (3.42+0.45 mg/dL vs 3.17+0.45 mg/dL, p= 0.041) and calcium (5.08+0.23 mEq/L vs 4.92+0.18 mEq/L, p= 0.016) and lower values for 25-OH vitamin D (14.2+5.6 ng/mL vs 19.4+8.8 ng/mL, p= 0.032). Binary logistic regression analysis showed that troponin I > 0.012 ng/ml is associated with increased phosphorus, increased calcium and decreased 25-OH vitamin D concentrations. A similar analysis using BNP >100 pg/mL failed to show signifcant associations with phosphorus, calcium and 25-OH vitamin D concentrations. CONCLUSIONS: In patients with stable coronary artery disease and preserved left ventricular function, those having cardiac troponin I > 0.012 ng/ml, but not those having BNP >100 pg/mL, had higher plasma phosphorus, higher plasma calcium and lower plasma 25-OH vitamin D concentrations than those having cardiac troponin I ≤ 0.012 ng/ml (or BNP ≤ 100 pg/mL).

Systemic correlates of angiographic coronary artery disease.

Coronary angiography allows a direct evaluation of coronary anatomy. The aim of the present investigation was to search for correlations between the magnitude of coronary artery disease, as assessed by angiography, and a number of systemic parameters. A group of 116 patients (80 male, 36 female) with coronary heart disease diagnosed by angiography, aged 62.0+/-10.5 years, was the subject of an observational study. Correlation and linear regression analysis using coronary artery disease burden (CADB - sum of the percentage of the luminal stenosis encountered in all the lesions of the coronary arterial trees) as dependent variable, and age, sex, plasma calcium, phosphorus, magnesium, glucose, HDL cholesterol, LDL cholesterol, triglycerides, uric acid, estimated glomerular filtration rate and body mass index as independent variables, were carried out. Significant correlation values versus CADB were seen with age (r 0.19, p 0.04), uric acid (r 0.18, p 0.048) and fasting plasma glucose (r 0.33, p<0.001). Linear regression analysis, yielding a global significance level of 0.002, showed a significant value for glucose (p 0.018) and for sex (0.008). In conclusion, among several systemic parameters studied, plasma glucose was found to be correlated to coronary artery atherosclerosis lesions.

The case for dietary calcium restriction in patients with atherosclerosis.

An increasingly vast set of data is linking the process of vascular calcification to the metabolism of calcium and phosphorus. This phenomenon is already relatively well understood in renal failure patients. A similar phenomenon, however, could be taking place in the general population. This may indicate a need for a reassessment of calcium supplementation, including the ingestion of milk, not only in dialysis patients, but also in patients with preserved renal function. Given the fact that no clear prospective randomized evidence exists to show what may be the impact on prognosis of patients with atherosclerosis, caused by the ingestion of milk and milk derivatives, containing calcium and lactose, as is currently recommended to prevent bone disease in the general population, a case could be made to recommend restriction of such dietary products in atherosclerosis patients, until precise data have been obtained, in controlled, prospective studies, and especially so in patients with no evidence of osteoporosis. Such a case would not be a strong one at the present stage, but neither would be the opposite view. The recommendation that could be made at this stage would be that patients with significant atherosclerotic disease should be informed that the ingestion of milk, and calcium supplementation in general, has neither been conclusively proven to be safe, nor the opposite.