Subclinical renal insufficiency range of estimated glomerular filtration rate and microalbuminuria are independently associated with increased arterial stiffness in never treated hypertensives

Background and objectives: Microalbuminuria (MAU) and decreased estimated glomerular filtration rate (eGFR) are risk factors for cardiovascular disease (CVD) in patients with hypertension. However, in hypertensive patients with normal or minimally reduced eGFR (≥60 mL/min/1.73 m(2)) and with normo- or MAU, the value of combined estimation of eGFR and urine microalbumin for the risk assessment has not been widely reported. We evaluated the association between arterial stiffness and the combined estimation of eGFR and urine microalbumin.

Subjects and methods: Subjects with never treated hypertension and normal or minimally reduced eGFR were evaluated (n=491, 50.1±10.4 years). eGFR was calculated by the simplified Modification of Diet in Renal Disease formula. Urinary albumin-to-creatinine ratio (UACR) was assessed with spot urine. Arterial stiffness was assessed with heart-femoral pulse wave velocity (hfPWV). All subjects were divided into four groups; group 1, eGFR ≥90 mL/min/1.73 m(2) (normal eGFR) and normo-albuminuria (NAU); group 2, eGFR 89.9-60 mL/min/1.73 m(2) (minimally reduced eGFR) and NAU; group 3, normal eGFR and MAU; group 4, minimally reduced eGFR and MAU.

Results: Group 1 had the lowest hfPWV (964.6±145.4; group 2, 1013.5±168.9; group 3, 1058.2±238.0; group 4, 1065.8±162.9 cm/sec). Analysis adjusting age, sex, body mass index, heart rate and mean arterial pressure showed significantly lower hfPWV of group 1 compared to group 2 (p=0.032) and 3 (p=0.007). Multiple regression analysis showed a significant association of hfPWV with logUACR {beta=0.096, 95% confidence interval (CI) 8.974-60.610, p=0.008} and eGFR (beta=-0.069, 95% CI -1.194 - -0.005, p=0.048).

Conclusion: Minimally reduced eGFR or MAU is independently associated with increased arterial stiffness, indicating greater CVD risk.