Uric Acid and Potassium Serum Levels Are Independent Predictors of Blood Pressure Non-Dipping in Overweight or Obese Subjects.

BACKGROUND

Obesity and sleeping blood pressure (BP) abnormalities are well recognized as some of the main risk factors for hypertension and cardiovascular diseases (CVDs). The primary objective of this study was to evaluate the prevalence of hypertension and non-dipping profile in overweight/obese subjects.

METHODS

A sample of 100 consecutive healthy overweight/obese subjects, aged 20-69 years and never treated with antihypertensive drugs was examined. Ambulatory 24 h BP monitoring was performed to diagnose hypertension and a non-dipping profile. Anthropometric, metabolic and routine hematochemical parameters were assessed. All subjects underwent ultrasound measurement of common carotid intima-media thickness.

RESULTS

Hypertension was demonstrated in 69% (n = 69) and 27% of the sample (n = 27) had a non-dipping profile. Among the hematochemical variables, estimated glomerular filtration rate (eGFR) (p = 0.02) and FT4 (p = 0.01) serum levels were higher in the hypertensive group than in the normotensive group. Lower potassium and uric acid serum levels (p = 0.05) were independent predictive factors of a non-dipping BP profile.

CONCLUSIONS

This study shows, for the first time, that 1) an unexpectedly high percentage (69%) of overweight/obese subjects is affected by hypertension; 2) early hypertensive subjects have an increased eGFR and higher FT4 serum levels; 3) lower potassium and uric acid levels are independent predictors of pathological nocturnal non-dipping.