Higher 24-hour urine Na/K and albumin-to-creatinine ratio are subclinical organ damage markers in hypertensive patients from Blida (Algeria)

Abstract

The aim of this study was to evaluate the relationship between ACR (albumin-to-creatinine ratio) and markers of TOD (target organ damage) in treated hypertensive patients. We enrolled 859 consecutive essential hypertensives (mean age 55 ± 10 years, 444 females) without known cardiovascular disease (CVD). LVMI was assessed by echocardiography by using the Devereux formula. eGFR was calculated by the MDRD equation. In a 24-hour urine collection, sodium/potassium ratio and ACR were measured. Valid 24-h ambulatory BP monitoring were analyzed. Participants were grouped in 4 groups: normotensives, isolated daytime hypertensives (IDHT), isolated nocturnal hypertensives (INHT), and both-hypertensives having both daytime and nocturnal hypertension. The 24-hour urine sodium (24HUNa) was 151.7 ± 71.4, 158.4 ± 69.3, 168.7 ± 68.8 and 177.1 ± 70.7 mmol/24 hour, respectively. The 24-hour urine potassium (24HUK) was 52.4 ± 17.8, 54.1 ± 16.2, 59.8 ± 20.7 and 62.1 ± 20.4 mmol/24 hour and the 24-hour urine sodium/potassium ratio (24HUNa/24HUK) were 3.1 ± 2.2, 3.3 ± 1.5, 3.2 ± 2.7 and 3.0 ± 2.3 respectively. Compared to NT group, INHT had higher 24HUNa ( P = 0.01), and both-HT had higher 24HUNa and 24HUNa/24HUK ( P < 0.01 and 0.01, respectively). There was no difference in 24HUNa, 24HUNK and 24HUNa/24HUK between INHT and both-HT. In multivariate analysis controlled with age, gender, body mass index, estimated glomerular filtration rate, INHT showed significantly higher 24HUNa/24HUK than NT ( P < 0.02). ACR exhibited significant association with LVMI (r = 0.312, P = 0.01) and eGFR ( r = –0.122, P = 0.01). In additional analysis, ACR was associated with TOD and decreased renal function (eGFR < 60 ml/min). Specifically, ACR exhibited a significant association with the number of TOD and this association was independent of age and gender ( P < 0.01). The results of present study suggest that high ratio of sodium/potassium may be a risk of isolated nocturnal hypertension and both-hypertension. Our findings support the close relationship between ACR and TOD in hypertension, as well as, the predictive value of ACR as a predictive of TOD.