What is the clinical evidence from this study?

Study design: Cohort. Population: Hypertension (n=1734). Intervention: Urinary albumin excretion ≥5 μg/min vs. Urinary albumin excretion <5 μg/min. Primary outcome: Incident coronary heart disease (RR 2.0, 95% CI 1.4 to 2.9, p=<0.001).

June 1, 2005

New Definition of Microalbuminuria in Hypertensive Subjects

Q: What are the key findings of this study?

Overnight urinary albumin excretion ≥5 μg/min in hypertensive individuals was associated with an increased risk of incident coronary heart disease (11% vs 5%; RR 2.0; 95% CI 1.4-2.9; P<0.001).

Key Result

Overnight urinary albumin excretion ≥5 μg/min in hypertensive individuals was associated with an increased risk of incident coronary heart disease (11% vs 5%; RR 2.0; 95% CI 1.4-2.9; P<0.001).

Study Design

Type

Cohort (n=1,734)

Structured PICO

Does urinary albumin excretion ≥5 microg/min predict coronary heart disease and death in hypertensive individuals?

Population

1,734 men and women aged 30 to 70 years with hypertension and no history of coronary heart disease, followed prospectively until 2000 for incident coronary heart disease and until 2004 for death.

Exposure

Urinary albumin excretion ≥5 microg/min

Comparator

Urinary albumin excretion <5 microg/min

Outcome

Incident coronary heart disease and deathhard clinical

An overnight urinary albumin excretion ≥5 microg/min is strongly predictive of coronary heart disease and death in hypertensive individuals, supporting a lower threshold for defining microalbuminuria.

Main Result

Relative Risk: 2 (95% CI 1.4–2.9)

Absolute Event Rate: 11% vs 5%

p-value: p=<0.001

Abstract

Microalbuminuria has so far been defined as urinary albumin excretion between 20 and 200 microg/min (or 15 to 150 microg/min overnight). In a recent report, an overnight urinary albumin excretion >5 microg/min was strongly predictive of coronary heart disease and death in the general population. The aim of the present study was to confirm this observation in a population of hypertensive individuals. In The Third Copenhagen City Heart Study in 1992 to 1994, 1734 men and women aged 30 to 70 years with hypertension, but no history of coronary heat disease, delivered a timed overnight urine sample. They were followed-up prospectively by registers until 2000 with respect to coronary heart disease, and until 2004 with respect to death. During follow-up, 123 incident cases of coronary heart disease and 308 deaths were traced. Incident coronary heart disease occurred in 11% of subjects with urinary albumin excretion > or =5 microg/min compared with 5% in subjects with urinary albumin excretion or =5 microg/min were 2.0 (1.4 to 2.9; P5 microg/min. In future risk assessment in hypertensive individuals, measurement of microalbuminuria has to be included.