Teemu Koivistoinen

A new method for measuring the ballistocardiogram using EMFi sensors in a normal chair

Ballistocardiography is a non-invasive technique for the assessment of cardiac function. We built a measurement setup to measure the ballistocardiogram from a normal chair using EMFi sensors. The ballistocardiogram is recorded from a subject sitting on the chair. The measured signal is amplified by a specially-designed charge amplifier and digitized by a circulation monitor. A PC provides a user interface for the measurement devices, records the data and displays the results. Impedancecardiography and ECG serve as reference measurements for the ballistocardiography. To test the system, one healthy 24-year-old male and one healthy 22-year-old female were measured. It is concluded that the ballistocardiogram waveforms described in the literature can be recognized from the EMFi signal measured from a normal chair.

Lifetime Fruit and Vegetable Consumption and Arterial Pulse Wave Velocity in Adulthood The Cardiovascular Risk in Young Finns Study

Background— The relationships between childhood lifestyle risk factors and adulthood pulse wave velocity (PWV) have not been reported. We studied whether childhood and adulthood lifestyle risk factors are associated with PWV assessed in adulthood. Methods and Results— The study cohort comprised 1622 subjects of the Cardiovascular Risk in Young Finns Study followed up for 27 years since baseline (1980; aged 3 to 18 years) with lifestyle risk factor data available since childhood. Arterial PWV was measured in 2007 by whole-body impedance cardiography device. Vegetable consumption in childhood was inversely associated with adulthood PWV (&bgr;=−0.06, P=0.02), and this association remained significant (&bgr;=−0.07, P=0.004) when adjusted for traditional risk factors (high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, systolic blood pressure, body mass index, and smoking). Vegetable consumption was also an independent predictor of PWV in adulthood when adjusted for lifestyle or traditional risk factors (&bgr;=−0.08, P=0.002 and &bgr;=−0.07, P=0.0007, respectively). Persistently high consumption of both fruits and vegetables from childhood to adulthood was associated with lower PWV compared with persistently low consumption (P=0.03 for both). The number of lifestyle risk factors (the lowest quintile for vegetable consumption, fruit consumption, physical activity, and smoking) in childhood was directly associated with PWV in adulthood (P=0.001). This association remained significant when adjusted for the number of lifestyle risk factors in adulthood (P=0.003). Conclusions— These findings suggest that lifetime lifestyle risk factors, with low consumption of fruits and vegetables in particular, are related to arterial stiffness in young adulthood.

Arterial pulse wave velocity in relation to carotid intima-media thickness, brachial flow-mediated dilation and carotid artery distensibility: The Cardiovascular Risk in Young Finns Study and the Health 2000 Survey

OBJECTIVE Increased arterial pulse wave velocity (PWV) is a strong predictor of cardiovascular events and mortality. The data regarding the relationships between PWV and other indices of vascular damage is limited and partly controversial. We conducted the present study to examine PWV in relation to non-invasive measures of early atherosclerosis (brachial flow-mediated dilation [FMD], carotid intima-media thickness [IMT]) and local arterial stiffness (carotid artery distensibility [Cdist]). METHODS The study population consisted of 1754 young adults (aged 30-45 years, 45.5% males) participating in the Cardiovascular Risk in Young Finns Study (YFS), and of 336 older adults (aged 46-76 years, 43.2% males) participating in the Health 2000 Survey. FMD was measured only in the YFS cohort. FMD, IMT and Cdist were assessed by ultrasound, and PWV was measured using the whole-body impedance cardiography device. RESULTS In young adults, FMD and IMT were not associated with PWV independently of cardiovascular risk factors. Moreover, FMD status was not found to modulate the association between cardiovascular risk factors and PWV. In older adults, PWV and IMT were directly and independently associated (β=1.233, p=0.019). In both cohorts, PWV was inversely related with Cdist, and this relation remained significant (p<0.04) in models adjusted for cardiovascular risk factors. CONCLUSIONS The current findings suggest that PWV reflects a different aspect of vascular damage than FMD or IMT in young adults, whereas in older adults the information provided by PWV and IMT may be, to some extent, similar as regards subclinical vascular damage. The present observations also suggest that PWV and Cdist represent, at least in part, a similar adverse vascular wall process.

Lifetime Fruit and Vegetable Consumption and Arterial Pulse Wave Velocity in Adulthood

Background— The relationships between childhood lifestyle risk factors and adulthood pulse wave velocity (PWV) have not been reported. We studied whether childhood and adulthood lifestyle risk factors are associated with PWV assessed in adulthood. Methods and Results— The study cohort comprised 1622 subjects of the Cardiovascular Risk in Young Finns Study followed up for 27 years since baseline (1980; aged 3 to 18 years) with lifestyle risk factor data available since childhood. Arterial PWV was measured in 2007 by whole-body impedance cardiography device. Vegetable consumption in childhood was inversely associated with adulthood PWV (&bgr;=−0.06, P=0.02), and this association remained significant (&bgr;=−0.07, P=0.004) when adjusted for traditional risk factors (high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, systolic blood pressure, body mass index, and smoking). Vegetable consumption was also an independent predictor of PWV in adulthood when adjusted for lifestyle or traditional risk factors (&bgr;=−0.08, P=0.002 and &bgr;=−0.07, P=0.0007, respectively). Persistently high consumption of both fruits and vegetables from childhood to adulthood was associated with lower PWV compared with persistently low consumption (P=0.03 for both). The number of lifestyle risk factors (the lowest quintile for vegetable consumption, fruit consumption, physical activity, and smoking) in childhood was directly associated with PWV in adulthood (P=0.001). This association remained significant when adjusted for the number of lifestyle risk factors in adulthood (P=0.003). Conclusions— These findings suggest that lifetime lifestyle risk factors, with low consumption of fruits and vegetables in particular, are related to arterial stiffness in young adulthood.

Pulse wave velocity reference values in healthy adults aged 26–75 years

The stiffening of arteries is associated with various cardiovascular diseases. Arterial stiffening can be studied utilizing arterial pulse wave velocity (PWV), but the absence of reliable reference values for PWV has limited its use in clinical practice. The aim of this study was to establish a range of reference values for PWV. PWV was examined by measuring the time difference of systolic pulse waves in arteries from the aortic arch to the popliteal artery using whole‐body impedance cardiography (ICG). The study population consisted of 799 individuals (age range 25–76 years), 283 of whom had no evidence of cardiovascular disease, and a low burden of risk factors was selected to represent an apparently healthy population. In healthy study population, PWV was higher in males (8·9 ± 1·8 m s−1) than females (8·1 ± 2·0 m s−1, P<0·001). Young males had lower PWV values than old males. Correspondingly, young females also had lower PWV values than old females. PWV was clearly associated with age, and PWV was higher in young and middle‐aged males than in females. There was no statistically significant difference between old males and females in PWV. In conclusion, whole‐body ICG provides a practical method for PWV measurement. Reference values can be useful in the clinical management of patients, especially in detecting early vascular disease or an increased risk of cardiovascular complications.

Prospective Relationship of Change in Ideal Cardiovascular Health Status and Arterial Stiffness: The Cardiovascular Risk in Young Finns Study

Background In 2010, the American Heart Association defined ideal cardiovascular health as the simultaneous presence of 4 favorable health behaviors (nonsmoking, ideal body mass index, physical activity at goal, and dietary pattern that promotes cardiovascular health) and 3 favorable health factors (ideal levels of total cholesterol, blood pressure, and fasting glucose). The association between a change in ideal cardiovascular health status and pulse wave velocity, a surrogate marker of cardiovascular disease, has not been reported. Methods and Results The study cohort consisted of 1143 white adults from the Cardiovascular Risk in Young Finns Study who were followed for 21 years since baseline (1986). This cohort was divided in 2 subgroups: 803 participants (aged 9 to 18 years at baseline) to study the health status change from childhood to adulthood and 340 participants (aged 21 to 24 years at baseline) to study health status change from young adulthood to middle age. The change in the ideal cardiovascular health index was inversely associated with pulse wave velocity (adjusted for age, sex, and heart rate), every 1‐point increase corresponded to a 0.09‐m/s (P<0.001) decrease in pulse wave velocity in both groups. This association remained significant in subgroups based on the ideal cardiovascular health index at baseline. Conclusions The change in ideal cardiovascular health status, both from childhood to adulthood and from young adulthood to middle age, was an independent predictor of adult pulse wave velocity. Our results support the concept of ideal cardiovascular health as a useful tool for primordial prevention of cardiovascular disease.

An EMFi-film sensor based ballistocardiographic chair: performance and cycle extraction method

New sensor technologies open possibilities for measuring traditional biosignals in new innovative ways. This, together with the development of signal processing systems and their computing power, can sometimes give new life to old measurement techniques. Ballistocardiogram is one such technique, originally promising but quickly replaced by the now very popular electrocardiogram. A ballistocardiograph chair, designed to look like a normal office chair, was built and fitted with pressure sensitive EMFi-films. The films are connected via a charge amplifier to a medical bioamplifier. The system was accepted for medical use in Tampere University Hospital and patient measurements have been performed. The system is presented and its performance evaluated. A wireless version of the system is needed to hide the cabling from the user. This makes the chair indistinguishable from a normal office chair. Overview of first wireless prototype is given. To analyze recorded BCG, individual BCG cycles must be extracted from the signal containing respiration and movement artifacts. A method for this and results of its application are presented. The developed system can be used for BCG measurements and it is able to automatically extract individual BCG cycles, but it has some limitations which are presented in the paper.

Metabolic syndrome in childhood and increased arterial stiffness in adulthood: the Cardiovascular Risk In Young Finns Study.

Abstract Objective. We conducted the present study to examine the associations of two different paediatric metabolic syndrome (MetS) definitions and recovery from childhood MetS with arterial pulse wave velocity (PWV), an index of arterial stiffness, measured in adulthood. Methods. A total of 945 subjects participated in the base-line study in 1986 (then aged 9–18 years) and the adult follow-up in 2007 (then aged 30–39 years). Cardiovascular risk factor data were available at both base-line and follow-up. In the follow-up study, arterial PWV was measured using a whole-body impedance cardiography device. Results. Subjects suffering from MetS in childhood (prevalence 11.1%–14.1%) had higher arterial PWV after 21-year follow-up when compared with those not afflicted by the syndrome in childhood (P < 0.007). An increasing number of the MetS components in childhood were associated with increased PWV in adulthood (P for trend = 0.005). Subjects who recovered from the MetS during the 21-year follow-up period had lower PWV than those with persistent MetS (P < 0.001). Conclusion. MetS in childhood predicted increased arterial stiffness in adulthood, and recovery from childhood MetS was associated with decreased arterial PWV in adulthood. The current results emphasize the importance of the prevention and controlling of MetS risk factors both in childhood and adulthood.

Association of Physical Activity in Childhood and Early Adulthood With Carotid Artery Elasticity 21 Years Later: The Cardiovascular Risk in Young Finns Study

Background Decreased arterial elasticity is a risk factor for several cardiovascular outcomes. Longitudinal data on the effect of physical activity in youth on adult arterial elasticity are limited. The aim of this study was to determine the long‐term effects of physical activity in children and young adults on carotid artery elasticity after 21 years of follow‐up. Methods and Results Participants were 1417 children (aged 9 to 15 years) and 999 young adults (aged 18 to 24 years) from the prospective Cardiovascular Risk in Young Finns Study. Participants had questionnaire measures of leisure‐time physical activity available from 1986 and ultrasound‐derived indices of carotid artery elasticity measured in 2007. Carotid artery elasticity indices were distensibility (%/10 mm Hg), Youngs elastic modulus (kPa), and stiffness index (unitless). Physical activity at age 18 to 24 years was directly associated with distensibility (β=0.068, P=0.014) and inversely with Youngs elastic modulus (β=−0.057, P=0.0037) and indirectly with stiffness index (β=−0.050, P=0.0028) 21 years later in males and females. The associations remained after adjustment for age, sex, body mass index, smoking, systolic blood pressure, serum lipids and insulin, and 21‐year change in physical activity. At age 9 to 15 years, the favorable association, remaining after adjustment, was found in males (distensibility [β=0.097, P=0.010], Youngs elastic modulus [β=−0.060, P=0.028], and stiffness index [β=−0.062, P=0.007]) but not in females (P=0.70, P=0.85, and P=0.91, respectively). Conclusions Leisure‐time physical activity in boys and young adults is associated with carotid artery elasticity later in life, suggesting that higher levels of physical activity in youth may benefit future cardiovascular health.

Metabolic syndrome and carotid intima media thickness in the Health 2000 Survey

BACKGROUND AND PURPOSE Metabolic syndrome has been associated with increased carotid intima-media thickness (CIMT) and cardiovascular disease (CVD). The objective of this study was to examine metabolic syndrome as a determinant of CIMT in men and women and to compare the Framingham risk score (FRS) and metabolic syndrome as risk factors for increased carotid atherosclerosis. METHODS The study population consisted of 1353 Finnish men and women aged 45 years and above who participated in Finnish population-based Health 2000 Survey. CIMT was used as a marker of subclinical atherosclerosis. The National Cholesterol Education Program Adult Treatment Panel III criterion was used to define the presence of metabolic syndrome. RESULTS In multivariable models, metabolic syndrome was an independent determinant of CIMT in both sexes (p</=0.001 for both). When metabolic syndrome was included in the regression models along with its components, it was an independent determinant of CIMT in women but not in men. After dividing the population into risk categories according to FRS and the presence of metabolic syndrome, FRS predominantly determined CIMT regardless of the presence of metabolic syndrome in men. In women, however, CIMT was significantly higher in subjects with metabolic syndrome than in those without it, independently of the FRS. CONCLUSIONS Metabolic syndrome is an independent determinant of CIMT in both sexes. In women but not in men, metabolic syndrome is associated with CIMT independently of its components. Metabolic syndrome provides additional information on a persons risk for early atherosclerosis beyond FRS in women but not in men.