Impact of β-thalassemia trait carrier state on cardiovascular risk factors and metabolic profile in patients with newly diagnosed hypertension

Abstract

Thalassemia minor (Tm), the β-thalassemia carrier state, is followed by favorable lipidemic profile and seems to protect against myocardial infarction mainly in men. However, the cardiovascular risk factor (CRF) and metabolic profile of these subjects has not been thoroughly addressed, although it is not known whether gender differences are involved. We evaluated CRFs, metabolic parameters and risk-prediction equations along with renal function and selected echocardiographic indices in 23,680 consecutive subjects, that is, 11,192 women and 12,488 men, with newly diagnosed hypertension according to the presence or absence of Tm. Of 23,680 patients, 548 (2.3%) had Tm. Compared with patients without Tm, Tm cases had similar gender distribution, age, body mass index and blood pressure. Besides having a better lipidemic profile, Tm patients were less frequently smokers (25% vs. 32%, P<0.001), had a lower prevalence of metabolic syndrome (26% vs. 39%, P<0.001) and lower HeartSCORE and INTERHEART scores (P<0.001). Tm patients also had lower levels of fibrinogen and plasminogen activator inhibitor-1 (P<0.001), lower serum creatinine and higher estimated glomerular filtration rate (P<0.001), lower prevalence of left ventricular hypertrophy (35% vs. 48%, P<0.001) and higher total and mid-wall fractional shortening (P=0.03 and <0.001, respectively). Most of these differences were consistent in both genders, whereas the HeartSCORE and the echo indices were significantly better in Tm only in women. Among patients with newly diagnosed hypertension, those with Tm have a better overall CRF and metabolic profile, beyond the well-known differences in serum lipids. Compared with men, women seem to be at least equally protected.