John C. Merritt, MD Prevention for the People, Inc.
September 9, 2013
Don’t take your kidneys for granted! Talk to anyone on dialysis. It is strikingly true that high blood pressure and/or diabetes will gradually destroy your kidney tissues, especially its nephrons. These cellular work horses implement the ‘heavy lifting’ for kidney health. It is now clear that the status of your kidney (especially the amount of protein in urine) predicts future (and recurrent) cardiovascular and stroke events in our rural North Carolina Stroke Belt. Preventive measures to reduce chronic kidney failure emphasize the importance of identifying small amounts of albumin (protein similar to egg whites) in your urine; hence the term urinary albumin excretion.
The REGARDS study (Reasons for Geographic and Racial Differences in Stroke) determined stroke incidence (frequency of commonality) in a population-based in adults (black and white) >45 y/o. The relationship of the urinary albumin to creatinine ratio (ACR) became the exposure-of-interest in REGARDS. The subjects resided in the US states termed the Stroke Belt: Alabama, Arkansas, Georgia, Louisiana, Mississippi, North Carolina, South Carolina and Tennessee. (GA, SC, NC considered its “Stroke Buckle”). The study was conducted between 2003 and 2007 with follow up through Dec. 31, 2009. Fasting blood and urine samples were collected during in-house study visit.
Their final report describes 23,273 participants (9747 black, 3526 white); mean follow up was 4.4 years. There were 4934 participants that had experienced previous heart health issues. Their results suggested:
1- Higher levels of albumin in urine was associated with a greater risk of recurrent (a second cardiac event) coronary heart disease in both blacks and whites; there was no statistically significant difference between them.
2- There was a two-fold higher risk of incident (new) coronary heart disease in blacks than in whites.
3- Blacks develop end stage kidney 10-15 years earlier than whites thereby presenting to kidney dialysis centers with more severe disease.
4- Having even small amounts of protein in your urine (microalbuminuria) should get your attention: check yourself for life-behavioral patterns that may lead either a stroke (remember you live in the Stroke Belt of NC) or a cardiovascular event- these two health culprits are first cousins in Sampson County NC.
Gutierrez OM, Khodneva YA, Muntner P, Rizk DV et al. Association between urinary albumin excretion and coronary heart disease in black and white adults. JAMA. 2013;310(7):706-713 doi:10.1001/jama.2013.8777