1 Introduction

According to the World Health Organization (WHO),hypertension is the primary cause of premature mortality. It is estimated that 7.5 million people die annually due to hypertension complications. In the Polish population, the prevalence of hypertension is 29%, and increases in patients aged 65 and over.[1]

The increase in blood pressure (BP) at older ages is due to age-related vascular stiffness caused by the accumulation of calcium, smooth muscle hyperplasia in the arterial media,and the quantitative and qualitative alterations in vascular wall collagen. The most important factor in hypertension treatment in elderly patients is personalization. Avoidance of polypharmacy is another key aspect. In accordance with the European Society of Cardiology/European Society of Hypertension (ESC/ESH) guidelines, hypertensive treatment should be preceded by an in-depth analysis of global cardiovascular risk, while non- pharmacological treatment guidelines for elderly patients are the same as for younger age groups.[2]

The Hypertension in the Very Elderly Trial (HYVET)showed that hypertensive treatment is safe and effective in patients above 80 years of age, and that hypertensive treatment in patients above 90 years of age should be continued if previously effective and well-tolerated.[3,4]

The appropriate lifestyle changes are fundamental for preventing hypertension. They should not justify delaying the start of pharmacological treatment in high-risk lifestyle modifications can have a hypertensive effect comparable to that seen with single-agent pharma-cological treatment.[5] The primary problem in non-pharmacological treatment is poor patient adherence in the longterm. The older population with hypertension has been reported to have poorer BP control than younger populations.[6] Appropriate lifestyle changes may reduce BP in patients who are already treated pharmaceutically, which in turn allows for reducing the dosage of hypertensive drugs.[7]

The results of the Trial of Non-pharmacologic Interventions in the Elderly (TONE) indicate that in compliant patients, including the elderly, weight loss and sodium restriction bring about satisfactory decreases in BP.[8,9] The BP drop in response to sodium-restricted diet is particularly marked in the elderly, in diabetic patients, and in patients with chronic kidney disease.[10,11]

Adherence to treatment and consistent medication-taking are key factors in treatment effectiveness, especially in elderly patients. Patient adherence is affected by their involvement in the treatment process, their understanding of its goals, and their overall wellbeing in the process. Approximately 55% of the elderly do not comply with the prescribed treatment.[12,13] Doses are often omitted due to the adverse effects of treatment, financial considerations, age,concurrent diseases, and physical and cognitive impairment affecting vision, hearing, and strength (frailty).[14]

In recent years, frailty syndrome in elderly patients has been widely discussed. It affects 15%–20% of patients older than 60, and 30% of patients older than 80.[15] Frailty and cognitive impairment have been implicated as a causative and prognostic factor in patients with cardiovascular disease(CVD). Frailty syndrome is associated with worse perceived health, more comorbidities, and social isolation of the patient.[15] A few studies investigated the role of the geriatric syndrome in adherence to treatment, and the available studies discussed chronic diseases other than hypertension.[16,17]There is a discussion in the literature regarding the impact of age on adherence.[18-22]

The study aimed at identifying the relationship between frailty syndrome and adherence to pharmacological and nonpharmacological treatment, and at distinguishing the sociodemographic and clinical variables that can affect adherence to hypertensive treatment.

2 Methods

2.1 Patients

The study was performed between January and April 2015, at the general practitioners’ clinic which belongs to the Department of Internal Medicine, Occupational Diseases,Hypertension and Oncology of the Wroclaw University Hospital in Wroc?aw, Poland. The study was based on anonymous surveys. Participation was voluntary, and each respondent provided informed written consent. All patients were informed about the purpose and course of the study and of their right to withdraw from the study at any time.

During the period of the study, 207 patients over 65 years were fulfilling the criteria. However, after meticulous verification 114 patients were qualified to the study: 14 patients were excluded from the study due to exacerbation of the concomitant diseases, 26 patients refused, and 53 patients were not able to fill out the questionnaires even with the assistance Mini Mental State Examination (MMSE) ＜ 27 points. Out of the group of 114 patients, 8 patients did not fill out their questionnaires properly, and 6 patients withdrew their informed consent. Finally, 100 patients were enrolled into the study. The study group included 100 patients (mean age 73.4 ± 7.5 years) diagnosed with hypertension, with a minimum time from diagnosis of five years, as recommended by the European Society of Hypertension(ESH) guidelines.[23] Another inclusion criterion was treatment with one or more hypertensive drugs. Exclusion criteria were: age under 65 years, severe cardiovascular complications or other severe comorbidities (hemodynamic instability, cancer, severe kidney failure, and dementia questionnaire MMSE result ＜ 27). Patients were selected by a panel consisting of a physician and a nurse–specialist in the field of cardiac nursing. The sample group was homogeneous and suitable for statistical analysis.