Hypertension and endstage renal disease

Evaluation of neopterin levels in patients undergoing hemodialysis

Neopterin is a diagnostic or a prognostic biomarker for several pathologies including renal diseases. However, the association between neopterin status and causative main reasons such as diabetes and hypertension for renal disease remains unclear. The aim of the study was to evaluate neopterin levels in diabetes and hypertension patients treated with/without hemodialysis. According to primary renal disorders, the patients undergoing hemodialysis were classified into 4 groups as diabetic nephropathy, hypertensive nephropathy, reflux nephropathy or interstitial nephritis, and others. The controls consisted of healthy subjects, hypertensive subjects, and diabetic individuals without any renal disorder. In the study, both urinary and serum neopterin levels were measured using high performance liquid chromatography and enzyme-linked immunosorbant assay in patients undergoing regular hemodialysis therapy (n=71). The effects of the duration of hemodialysis and treatment of erythropoietin and/or iron on neopterin levels were also evaluated. Neopterin levels were found to be higher in hemodialysis patients than in the healthy controls (P<0.05). A significant difference in neopterin levels was also found between diabetic control patients and diabetic nephropathy patients (P<0.05). A similar significant difference was detected in neopterin levels between hypertensive patients with/without nephropathy (P<0.05). Neopterin may be an early critical marker for progression of nephropathy in diabetic and hypertensive patients in early stages.

Racial differences in early-onset renal disease among young adults: the coronary artery risk development in young adults (CARDIA) study

Although 11 million people in the United States have chronic renal insufficiency, little is known about ethnic/racial disparities for early-onset renal impairment. This study sought to determine whether there is an independent association between race/ethnicity and early-onset renal impairment and to identify other risk factors that might account for observed disparities. All Coronary Artery Risk Development in Young Adults subjects in which serum creatinine was measured at the year 15 examination were identified (n = 3554), excluding those who were pregnant at year 15. Potential risk factors at study entry (ages 18 to 30 yr, 1985 to 1986) included age, weight, gender, race/ethnicity, glucose, uric acid, and systolic BP. Renal impairment was defined as creatinine > or =1.5 mg/dl for men and > or = 1.2 mg/dl for women at year 15 (ages 33 to 45 yr). Fifty-two (2.7%) women and 39 (2.4%) men had renal impairment at the year 15 examination. In bivariate analyses, the odds of renal impairment among black women was estimated to be 2.4-fold that of white women, and among black men, the odds of renal impairment were 9.0-fold that of white men. In multivariate analysis, the odds of an elevated creatinine among black women compared with white women reduced to a nonsignificant 1.5-fold, whereas among men, the odds of an elevated creatinine among blacks was 11.4-fold that of whites. Although adjustment for baseline glucose levels accounted for much of the association between ethnicity and elevated creatinine among women, adjustment for weight, systolic BP, uric acid, glucose, and socioeconomic status did not account for the association between ethnicity and renal impairment among men. The data suggest that there are ethnic differences in the development of early-onset renal dysfunction. Among women, these differences are modest and largely accounted for by differences in glucose levels early in adult life. Differences in race/ethnicity related risk of early-onset renal impairment are particularly large among men and are not accounted for by the metabolic or socioeconomic factors evaluated.

Dosing of antihypertensive medications in patients with renal insufficiency

The use of antihypertensive agents in patients with renal insufficiency necessitates careful consideration of dosages, titration, and monitoring. Renal function must be estimated to appropriately make dosage adjustments for antihypertensives that exhibit extensive renal elimination. Thiazide diuretics are useful in mild degrees of renal insufficiency but loop diuretics become necessary as renal function deteriorates further. With either class, low dosages should be used to prevent hypovolemia, hyponatremia, and hypokalemia which may worsen renal blood flow. Angiotensin-converting enzyme (ACE) inhibitors have become popular because they may have unique renal protective properties. All ACE inhibitors except fosinopril require reduced dosages and/or less frequent administration in patients with renal insufficiency. It is often necessary to use a diuretic with an ACE inhibitor and special dosing considerations are important. Due to demographic and physiologic characteristics of patients with renal insufficiency, beta blockers are often reserved for patients with other indications for beta blockers such as ischemic heart disease. Several beta blockers are eliminated primarily by the kidney and dosage reductions are necessary for these agents. Calcium antagonists may also have renal protective effects. Because calcium antagonists are metabolized extensively, significant dosage adjustments are not necessary. Data suggest that antihypertensives may slow the decline in renal insufficiency. The pharmacokinetics of several antihypertensives change with renal impairment because of reduced elimination. Therefore, dosage adjustments, slower titration, and less frequent administration are often necessary.