What's new?

This is the first study based on the latest and largest Polish epidemiological WOBASZ II surbey regarding the prevalence of hypercholesterolemia and hypertension in the Polish population, the prevalence of hypercholesterolemia in patients with hypertension, control of blood pressure and cholesterol levels, and factors affecting this control.

Introduction

In the Polish population, according to the WOBASZ II (Multicenter National Population Health Examination Survey; Polish, Wieloośrodkowe Ogólnopolskie Badanie Stanu Zdrowia Ludności), the prevalence of hypertension in adults above 20 years of age is 46% and 40% and the prevalence of dyslipidemia is 70% and 64.3% in men and women, respectively.^1,2

In the 2011 Polish NATPOL (Arterial hypertension and other CVD risk factors in Poland; Polish, Nadciśnienie Tętnicze oraz inne czynniki ryzyka chorób serca i naczyń w Polsce) study, in the general population aged 18 to 79 years, the prevalence of hypercholesterolemia was estimated at 61.1% and the efficacy of treatment (achieving total cholesterol [TC] <4.9 mmol/l) at 10.9%.³ In POLFOKUS, another Polish study, elevated level of low‑density lipoprotein cholesterol (LDL‑C) was observed in 49.2%, 61.6%, and 61.5% patients with controlled, uncontrolled, and resistant hypertension, respectively.⁴ The prevalence of other modifiable risk factors for cardiovascular disease in the WOBASZ II study population was described elsewhere.^5-8

The Framingham study showed that the incidence of CVD increases 2- to 3‑fold in patients with hypertension—with the highest risk of stroke, heart failure, and all forms of coronary heart disease (CHD): angina pectoris, myocardial infarction, sudden cardiac death. In patients aged 40 to 69 years, mortality due to stroke or CHD doubled with each increase in systolic blood pressure (SBP) of 20 mm Hg and diastolic blood pressure (DBP) of 10 mm Hg.⁹ A relationship with CVD risk was seen in a wide range of TC and LDL‑C concentrations. This applies to men and women, both with and without diagnosed CVD.¹⁰ It has been proved that changes in SBP in the range of 110 to 170 mm Hg are associated with an approximately 6‑fold increase in CHD risk. Similarly, an increase in TC level in the range of 4.0 to 8.0 mmol/l results in an approximately 8‑fold increase in the risk of CHD. And an increase in the range of 110 to 170 mm Hg SBD and 70 to 105 mm Hg DBP also increases the risk of stroke nearly 8‑fold.¹¹ The implementation of antihypertensive treatment reduces the risk of CHD by approximately 25%.¹² The inclusion of lipid‑lowering treatment in patients with hypertension reduces the residual risk of CHD by more than 35%,¹³ as confirmed by the AFCAPS/TexCAPS (Air Force/Texas Coronary Atherosclerosis Prevention Study)¹⁴ and the ASCOTLLA (AngloScandinavian Cardiac Outcomes Trial‑Lipid Lowering Arm) study.¹⁵

Patients with multiple CVD risk factors are at higher risk of incident CVD than persons exposed to only 1 risk factor. The CVD risk resulting from concomitant hypertension and hypercholesterolemia is typically greater than the sum of risk from individual exposure to hypertension or hypercholesterolemia alone.^16,17 It was found that in patients with hypertension and concomitant hyperlipidemia, the risk of CVD doubles, and in patients with normal cholesterol levels, the coexistence of hypertension results in a 3‑fold increase in the risk of CVD.¹⁴ In people with SBP of 195 mm Hg and TC level of 8.5 mmol/l, the risk of CVD increases as much as 9‑fold.¹⁸ Data on men aged 35 to 64 years from the POL‑MONICA (Polish part of the Monitoring of Trends and Determinants in Cardiovascular Disease) study showed that the coexistence of hypertension and hypercholesterolemia increases the risk of death caused by CHD over 4.5‑fold.¹⁹The assessment of the overall cardiac risk can be made using the Systematic Coronary Risk Evaluation (SCORE) tables. For example, in the Polish population, a nonsmoking 70‑year‑old man with SBP of 180 mm Hg and TC of 8 mmol/l has a 50% risk of cardiovascular death within 10 years, and, respectively, with SBP of 120 mm Hg and TC of 4 mmol/l, only 10%.²⁰

Results of the analyses in the Polish population published so far do not indicate to what extent exposure to hypertension and hypercholesterolemia occurs in the same person.

The objectives of the study were: 1) to assess the prevalence of comorbid hypertension and hypercholesterolemia in participants of the nationwide WOBASZ II study; 2) to assess the prevalence of hypercholesterolemia in the Polish hypertensive population; 3) to evaluate the control of blood pressure and cholesterol levels in patients with hypertension and hypercholesterolemia; and 4) to assess the factors related to the control.

Patients and methods

The WOBASZ II study was a cross‑sectional survey conducted from 2013 to 2014 in 6170 people (3410 women and 2760 men) from all 16 voivodships (108 communes) in Poland. The reporting rate was 45.5%. The sampling method used a 3‑stage scheme, stratified by voivodship, commune category, and sex. The study was approved by the Ethics Committee at the Institute of Cardiology in Warsaw, Poland (no. 1344). Each respondent was informed in writing about the purpose of the study and the range of activities (including blood pressure measurements and blood collection for laboratory tests). All participants signed informed consent form. The study methods have been presented in detail elsewhere.²¹ Blood pressure was measured 3 times in 1 visit in a sitting position in accordance with the 2013 European Society of Cardiology/European Society of Hypertension guidelines²² and the 2015 Polish Society of Hypertension²³ guidelines. An UA631(AND Co., Tokyo, Japan) automatic device was used. The mean of the second and third measurements was used for analysis. Clinical chemistry tests were performed at the Central Laboratory “Diagnostyka” at the Institute of Cardiology in Warsaw, which has been certified by the Centre for Disease Control – Lipid Standardization Program in Atlanta, United States, and has the European quality certificate, Random International Quality Assessment Scheme. The sequence of procedures was as follows: first, blood pressure measurements were performed, then the survey was taken, and finally, blood was collected for laboratory tests. Details of the methodology for measuring blood pressure, blood collection, and clinical chemistry tests have been described elsewhere.^1,2

Hypertension was defined as SBP of 140 mm Hg or higher, or DBP of 90 mm Hg or higher, or use of blood pressure‑lowering medication (regularly for the last 2 weeks). Hypercholesterolemia was diagnosed if TC levels were 5 mmol/l or higher, or LDL‑C levels were 3 mmol/l or higher, or the participant was taking a lipid‑lowering medication (regularly for the last 2 weeks). Treated hypertension was defined as patients with hypertension who reported taking medication for high BP (affirmative response to the question, “Have you taken these medicines regularly during the last 2 weeks?”). Treated hypercholesterolemia was defined as patients who reported taking medication for high cholesterol level (affirmative response to the question, “Have you taken these medicines regularly during the last 2 weeks?”). Controlled hypercholesterolemia was defined as patients with hypercholesterolemia who had TC of less than 5 mmol/l and LDL‑C of less than 3 mmol/l for people with intermediate or low cardiovascular risk; LDL‑C of less than 2.5 mmol/l for people with high CVD risk; LDL‑C of less than 1.8 mmol/l for people with very high CVD risk. The target treatment thresholds have been adopted according to risk categories based on the 2016 European guidelines for CVD prevention in clinical practice.²⁴ Controlled hypertension was defined as patients with hypertension who had SBP of less than 140 mm Hg and DBP of less than 90 mm Hg. CVD risk was assessed according to the SCORE risk charts as follows: less than 1%, low risk; from 1% up to 5%, intermediate risk; from 5% up to 10%, high score; 10% and higher, very high risk. Diabetes was defined as patients who gave an affirmative response to the question, “Have you ever been diagnosed with diabetes?” or those taking a hypoglycemic medication (regularly for the last 2 weeks). Smoking was defined as at least 1 cigarette per day. Comorbid CVD was defined as previously diagnosed coronary artery disease, past myocardial infarction, myocardial revascularization, previous stroke, peripheral atherosclerosis. Physical activity was defined as at least 30 minutes of uninterrupted activity, for example, a walk, gymnastic exercises at least 4 d/wk. Alcohol drinkers were defined as patients who gave an affirmative response to the question, “Have you drunk any vodka, wine or beer in the last 12 months at least once?” High education was defined as more than vocational education. Obesity was defined as body mass index (BMI) of 30 kg/m² or higher; overweight, as BMI of 25 to 30 kg/m²; and normal weight, as BMI of less than 25 kg/m². High income income per person in the household of more than 1000 PLN (>250 EUR).

Results

The analysis included 5939 participants aged 19 to 99 years (2647 men and 3292 women). A total of 231 people with no measurements of blood pressure or cholesterol levels were excluded from the analysis. Mean (SD) age was 49.5 (16.3) years (men, 48.9 [16.3] years; women, 50.0 [16.3] years).

In the whole WOBASZ II population, hypertension was found in 2784 (crude data 46.9%) persons (1365 men and 1419 women). Mean (SD) age was 58.4 (13.9) years (men, 55.8 [14.4] years; women, 60.9 [13.0]).

Comorbid hypertension and hypercholesterolemia was found in 2037 patients (982 men and 1055 women). Mean age was 58.8 (12.9) years (men, 56.1 [13.4] years; women, 60.5 [11.8] years). Descriptive statistics of the study group are summarized in Tables 1 and 2.