Risk factors for arterial hypertension in adults with initial optimal blood pressure: The Strong Heart Study
Whether metabolic factors and their change over time influence development of arterial hypertension in adults with initially optimal blood pressure (BP) is unknown. We analyzed associations of BP in the optimal range (<120/80 mm Hg), metabolic risk factors, and their changes over 4-year follow-up, with 8-year incident hypertension, in a cohort of American Indians with a high prevalence of obesity. At baseline, 967 participants with optimal BP and no prevalent cardiovascular disease (69.5% women; mean age, 54+/-7 years) were evaluated and reexamined after 4 (second examination) and 8 years to evaluate predictors of 8-year incident arterial hypertension. In participants with normal glucose tolerance, baseline BP and decrease in high-density lipoprotein cholesterol from baseline to the second examination were the most potent predictors of 8-year arterial hypertension (both P<0.0001), with additional effects of baseline waist circumference and its increase, increase in BP, and presence of diabetes at the second examination (all P<0.04). In participants with impaired glucose tolerance or diabetes, the most potent predictor of 8-year incident hypertension was diabetes at the second examination (P<0.0001) followed by a increase in BP and LDL cholesterol over the first 4 years (both P<0.001). Thus, incident arterial hypertension can be predicted by initial metabolic profile and unfavorable metabolic variations over time, in addition to initial BP. At optimal levels of initial BP, increasing abdominal obesity, and abnormal lipid profile are major predictors of development of arterial hypertension. Possible implications of these findings for primary cardiovascular prevention should be tested in prospective studies.