Relatively high levels of urinary albumin in healthy adults is associated with increased risk for hypertension, suggesting that lowering the norms for urinary albumin may help in the goal of preventing cardiovascular disease, according to a study published online June 25 by the Journal of the American Society of Nephrology.

The authors had hypothesized that high levels of urinary albumin could be an indicator of kidney damage. Albuminuria may also reflect dysfunction of endothelial cells throughout the body, which in turn may contribute to hypertension.

A variety of studies have shown that higher levels of urinary albumin excretion, even within the normal range, are associated with cardiovascular disease in individuals with diabetes or hypertension. However, less research has been done in low-risk populations.

In the current study, Dr. John Forman and colleagues at the Brigham and Women's Hospital in Boston, MA, looked at new-onset hypertension among 2,179 women without baseline hypertension or diabetes and with normal levels of urine albumin; all were enrolled in the Nurses' Health Studies, which are among the largest and longest running investigations of factors that influence women's health.

The researchers discovered that higher levels of urinary albumin excretion, even within the range considered normal, was associated with increased risk of developing hypertension.

Among older women (median, 65 years), those with the highest levels of albumin excretion were 76 percent more likely to develop hypertension than those with the lowest levels. For younger women (median, 44 years), the risk was 35 percent higher. The elevated risks held true when factors such body mass index, blood pressure, smoking, and family history of hypertension were taken into account.

The authors concluded that their results, in conjunction with the findings of various other studies, suggest that "it is time to re-evaluate our current concept of 'normal' albumin excretion."

Hypertension monitoring and treatment of individuals with higher urine albumin levels, even which are within the currently defined normal range, may be warranted.