Blood pressure and hypertension in type 1 diabetes mellitus patients with long duration

Abstract

Type 1 diabetes mellitus (T1DM) has significantly better prognosis which has led to increased cardio-vascular diseases (CVD) prevalence. The detection of CVD risk factors and their treatment become tasks of paramount importance. Among them, high blood pressure (BP) is a target of primary purpose. Aim: to explore the blood pressure values, the prevalence of hypertension (HTN) and its management in patients with T1DM with long duration and without overt CVD, in comparison to matched controls. Participants and methods: totally, 124 patients with T1DM were matched to 59 controls by sex, age and approximate body mass index (BMI). All participants filled in questionnaires with information on demographics, physical activity, life style, concomitant diseases, treatments, presence of complications, etc. Blood samples were taken for laboratory and biomarkers investigation. Blood pressure was measured by investigators twice and the mean of the two measurements was used. HTN was accepted using standard definitions. BP values were compared using t-test. Multiple linear regression models with dependent variable BP measures and age, sex, BMI, presence of T1DM, glycated hemoglobin levels, creatinine levels as independent variables were created. ANOVA method was used to test the interaction of sex and presence of T1DM. Results: The mean age of the participants was 43.47 ± 10.1 years, 54% were males. The mean duration of T1DM was 25.31 ± 8.2 years and the mean HbA1c was 8.42 ± 1.8% for diabetic patients. The mean blood pressure measures in T1DM groups were higher than in controls, both in males and females. The difference reached significance for SBP and pulse pressure (PP). The presence of T1DM independently affected the BP values, after adjusting for major confounders. The mean adjusted differences between T1DM and controls were 8.37 mm Hg for SBP, 4.92 mm Hg for DBP, and 5.19 mm Hg for PP (p < 0.001). HTN was significantly more frequent in T1DM patients than in controls – 54% vs. 27%, p = 0.0001, mainly due to already known hypertension. BP control was insufficient – in only 36% and 13% of the treated hypertensive participants, respectively, for BP < 140/90 and < 130/80 mm Hg. The majority of the patients with HTN were treated with combination therapy, mostly single-pill fixed dosage but 30% of the hypertensive patients with diabetes did not take antihypertensive medications. Inhibitors of the renin-angiotensin system were the preferred class of medications. Conclusions: SBP and PP were significantly higher in middle-aged patients with T1DM with long duration than their control counterparts. The presence of HTN was significantly more common in T1DM. Although treated according to the current recommendations, the control of BP was far from effective. These results show the need for constant screening of patients with T1DM for HTN and other risk factors and for more aggressive antihypertensive treatment to prevent future CVD events.