Background Little is known about the prevalence of target organ damage in previously undiagnosed hypertension.

Design Cross-sectional population survey.

Methods We measured ankle–brachial index (ABI), estimated glomerular filtration rate (eGFR), electrocardiographically determined left ventricular hypertrophy (ECG-LVH), and cardiometabolic risk factors in subjects with previously undiagnosed hypertension (n = 138) and normotensive (n = 440) risk subjects, who had metabolic syndrome, glucose disorders, body mass index ≥30 kg/m² or a 10-year risk of cardiovascular disease death of 5% or more according to the Systematic Coronary Risk Evaluation (SCORE) system. None of the subjects had established cardiovascular or renal disease or previously diagnosed diabetes.

Results There was no difference (p = 0.68) among the studied age-groups in the prevalence of previously undiagnosed hypertension, and no interaction (p = 0.10) was found between sex and age groups. Evidence of subclinical organ damage defined as ECG-LVH, ABI ≤0.90, or eGFR <60 ml/min/1.73 m² were found in 22% of the subjects with previously undiagnosed hypertension, and 8% of the non-hypertensive risk persons (p  < 0.001). The prevalence of renal insufficiency did not differ between the study groups. Majority of the subjects with previously undiagnosed hypertension also have multiple cardiometabolic risk factors.

Conclusions Among subjects with previously undiagnosed hypertension, one in five patients had evidence of subclinical target organ damage, and three in four patients may be regarded as having high cardiovascular risk.