Blood Test May Predict Hypertension

Hypertension (high blood pressure) can often be overlooked, as blood pressure variability over time and the need to re-check it over multiple visits before making a definitive diagnosis can hamper efforts to treat it.  The standard troponin T test – which is considered the gold-standard screen for cardiac muscle damage from ongoing or recent heart attacks – is relatively inexpensive.  In the current study, Bill McEvoy, from Johns Hopkins University School of Medicine (Maryland, USA), and colleagues used a more sensitive version (high-sensitivity cardiac troponin T), which identifies molecular footprints of troponin T, a protein released by injured heart cells at a very low level.    The team analyzed blood samples collected on 5,479 people enrolled in the Atherosclerosis Risk in Communities Study, which followed participants for an average of 12 years. None of the participants had clinical diagnosis of hypertension at the beginning of the study although a small subgroup -- about 27% -- had high-normal blood pressures, a condition that often heralds the onset of full-blown hypertension later on.  Compared with people whose troponin levels were undetectable -- less than 5 nanograms per deciliter -- those with mild elevations -- 5 to 8 nanograms per deciliter -- had a 13% higher rate of hypertension during the follow-up. Those with notably elevated troponin levels -- 9 to 13 nanograms per deciliter -- were 24% more likely to have developed hypertension, and those with troponin levels above 13 nanograms per deciliter had a nearly 40% higher risk of hypertension. Similarly, compared with people whose troponin levels were undetectable on the high-sensitivity test, participants with slightly elevated troponin levels -- 5 to 8 nanograms per deciliter -- were twice as likely to develop heart muscle thickening within six years after the initial testing. Those with notably elevated troponin levels -- 9 to 13 nanograms per deciliter -- were three times more likely to have thickened heart muscle within six years, while participants with troponin above 13 nanograms per deciliter had a fivefold risk of such heart muscle abnormalities.  The study authors submit that: “In an ambulatory population with no history of cardiovascular disease, [high-sensitivity cardiac troponin T ] was associated with incident hypertension and risk of left ventricular hypertrophy."