High-normal diastolic blood pressure is a risk for development of microalbuminuria in the general population: the...

Although hypertension is a well known risk factor for microalbuminuria, it is unclear whether blood pressure less than 140/90 mmHg could be a risk for microalbuminuria. We assessed the relationship between baseline blood pressure and the future onset of microalbuminuria in the general population.

We studied 2603 town inhabitants of Watari, located in the southeastern part of Miyagi prefecture, Japan. Demographic data, medical history, sitting blood pressure, fasting blood chemistry, and urinary albumin-creatinine ratio were measured at baseline and were followed annually during the next 3 years.

Among 2338 individuals who were normoalbuminuric at baseline (albumin-creatinine ratio <30 mg/g Cr), 161 developed microalbuminuria (albumin-creatinine ratio 30-299 mg/g Cr) during a mean follow-up period of 2.4 years. Incident microalbuminuria patients were older (63.7 ± 8.6 vs. 61.4 ± 10.5 years; P < 0.01), included fewer men (31.1 vs. 40.1%; P < 0.05), had a greater BMI (23.8 ± 3.6 vs. 23.1 ± 3.1 kg/m²; P < 0.01), higher blood pressures (133.5 ± 18.1/75.8 ± 11.9 vs. 127.6 ± 18.1/73.4 ± 11.0 mmHg; P < 0.01 for both systolic and diastolic), higher triglycerides (median 1.18 vs. 1.02 mmol/l; P < 0.01), higher fasting blood glucose (median 5.05 vs. 4.94 mmol/l; P < 0.01), higher urinary albumin excretion (median 13.0 vs. 5.9 mg/g Cr; P < 0.001), and lower serum creatinine concentrations (59.2 ± 12.8 vs. 61.4 ± 13.2 μmol/l; P < 0.05) compared to persistent normoalbuminuric individuals. Multivariate Cox proportional hazards analysis including all covariates revealed that only baseline urinary albumin excretion was an independent predictor for future microalbuminuria, whereas high-normal DBP, triglyceride, and fasting blood glucose concentrations were all significant predictors in the model excluding urinary albumin excretion.

High-normal DBP associated with metabolic disorders could initiate glomerular damage, leading to future microalbuminuria.