Prevalence and distinguishing features of masked hypertension in type 2 diabetic patients

The prevalence and clinical features of masked hypertension (MH) in type 2 diabetes mellitus patients (T(2)DM) were investigated to define clinical indices which may aid diagnosis and treatment.

Clinical blood pressure (CBP) and ambulatory blood pressure (ABP) were measured in 856 T(2)DM patients to differentiate normotensive (NT), essential hypertensive (EH), and MH. Waist circumference (WC), abdominal circumference (AC), body mass index (BMI), waist to height ratio (WHtR), fasting blood glucose (FBG), and glycated hemoglobin levels were measured and compared between BP groups.

In total, 359 patients had normal CBP, of which 13.37% were diagnosed with MH based on established criteria. Males had significantly higher rates of MH (15.30%) than females (11.36%) (P=0.036). The MH detection rate increased with age and T(2)DM duration. There were no significant differences in BMI, WC or WHtR between total MH and EH groups. MH females, however, had lower BMIs than female EH females (P=0.023). Smoking, alcohol, and familial EH history were lower in MH than EH patients (smoking, P=0.029; alcohol ,P=0.001; and EH history, P=0.000), while BMI (male, P=0.037, female, P=0.015), WC (male, P=0.012, female, P=0.021), WHtR (P=0.011), smoking (P=0.016), and alcohol consumption (P=0.000) were higher in MH than NT patients. BMI, WHtR, 6-15 year disease course of diabetes, smoking and alcoholism were independent risk factors of T(2)DM complicated with MH. The dipper BP circadian pattern was significantly lower in MH than NT patients (P=0.001). The non-dipper pattern was lower in MH than EH (P=0.018) but higher than in NT (P=0.000).

A significant fraction of T(2)DM patients were diagnosed with MH. Clinical presentation also contrasted sharply from EH, MH is a specific blood pressure status that may severely damage target organs in T(2)DM.