HYATTSVILLE, Md.—Prioritizing dietary interventions in patients with renal disease can be difficult because of the multitude of associated complications. Thus, it is important to choose the most appropriate intervention at a given time, reported Renal & Urology News. Sodium restriction is beneficial for reducing blood pressure (BP), and chronic kidney disease (CKD), frequently is associated with hypertension.
Controlling high BP can aid in slowing CKD progression, but the appropriate level of treatment is of concern in the wake of several studies showing that more conservative BP goals did not confer benefits in terms of cardiovascular outcomes and CKD progression.
Role of Albuminuria
A recent study published online ahead of print by Yan et al (PLoS One 2012;7:e37837) aimed to evaluate new data suggesting that individuals with higher levels of proteinuria may be better targets for intensive BP control. The study used data collected by the National Health and Nutrition Examination Survey (NHANES) from 1999-2006.
The study included 12,440 adults without diagnosed kidney disease, diabetes or cardiovascular disease. Researchers categorized subjects into four BP groups: normotension, prehypertension, undiagnosed hypertension and diagnosed hypertension.
Factors significantly and positively associated with hypertension included less than a high school education, an annual household income below $25,000, sedentary lifestyle, body mass index (BMI) less than 30 kg/m2, and albumin-creatinine ratio of 30 mg/g or greater. Factors significantly and negatively associated with hypertension included Mexican-American ethnicity, non-smoker status, non-drinker status, energy intake, and albumin/creatinine ratio below 30.
Stratifying the groups by estimated glomerular filration rate (eGFR), an overall eGFR below 60 mL/min/1.73m2 (specifically eGFR ranges of 45-59 and 30-44) was significantly and positively associated with hypertension status. Among subjects with an albumin/creatinine ratio of 30 or higher, the association between eGFR below 60 and hypertension status was much stronger.
In other words, those with renal impairment appear to be much more likely of having hypertension if albuminuria is present. This factor is important because it may offer new assessment criteria when considering whether intensive BP control regimens are necessary. The limitation of these data is that no factor can be clearly deemed causative.
Consequently, it is uncertain if the hypertension is inducing the renal impairment and albuminuria, if the renal impairment and albuminuria are inducing the hypertension, or whether the entire relationship is correlative in general.