Statin Therapy Does Not Significantly Alter Microvascular Function in Uncomplicated Hypertension

Abstract

Objective Young patients with uncomplicated hypertension are frequently exempt from statin therapy as they generally fall below current treatment thresholds. This study examined whether there may be evidence of improved microvascular function in young patients with grade 1 hypertension after 12 weeks of statin therapy. Methods This was a randomized double-blind placebo-controlled crossover study in which 42 statin-naïve participants with grade 1 hypertension (mean systolic/diastolic blood pressure 142/92 mmHg) were randomized to receive either simvastatin 40 mg or a placebo for 12 weeks, followed by a 4-week washout period, after which the arms crossed for a further 12 weeks. Measures of vascular function were recorded at the beginning and end of each study period equating to four measures in total. The brachial artery was studied by flow-mediated dilatation (FMD) together with the resistive and pulsatility indices and mean velocity of flow. Results Statin therapy did not significantly alter the change in FMD seen in the brachial artery [standardized differential mean = 0.02 (0.23), confidence interval (CI) = −0.45 to 0.48, p = 0.932]. No significant changes were seen in the brachial artery mean velocity (CI = −9.68 to 11.51, p = 0.861), resistive index (CI = −0.11 to 0.12, p = 0.903), or pulsatility index (CI = −5.82 to 4.91, p = 0.864). Conclusion This study did not demonstrate any significant changes in established measures of microvascular function after treatment with a statin in a young hypertensive population with no antecedent cardiovascular disease. This may indicate that either the intervention was insufficiently vasoactive to produce a clinically detectable improvement in vascular function, or that the means used to assess the microvasculature were insufficiently sensitive to detect what may have been quite minor changes.