ABSTRACT
To investigate the relationship between exposure to famine in fetus and infant period and the risks for hypertension in adulthood. A total of 5 960 participants born between 1956 and 1965 were included in the study and were divided into unexposed group (1963-1965), fetal exposed group (1959-1961), early- childhood exposed group (1956-1958) and transitional group (1962). Logistic regression model was used to explore the association between famine exposure in early life and the risk for hypertension in adulthood. Both the fetal exposure and the early-childhood exposure were the risk factors for hypertension in adulthood (=1.249, 95: 1.049-1.486 and =1.360, 95: 1.102-1.679). Meanwhile, in rural area, compared with unexposed group, the fetal exposure (=1.401, 95: 1.091-1.798) and the early-childhood exposure (=1.460, 95: 1.145-1.862) were also associated with a greater risk of hypertension in adulthood. In addition, fetal exposure and early-childhood exposure to famine in women were associated with 36.0 and 31.9 increased risks for hypertension (95: 7.8-71.7 and 95: 4.8-66.0) according to the stratified analysis. Fetal exposure to famine might increase the risk for hypertension in adulthood.
ABSTRACT
The objective of this study is to design and develop a programmable electrocardiogram (ECG) generator with frequency domain characteristics of heart rate variability (HRV) which can be used to test the efficiency of ECG algorithms and to calibrate and maintain ECG equipment. We simplified and modified the three coupled ordinary differential equations in McSharry's model to a single differential equation to obtain the ECG signal. This system not only allows the signal amplitude, heart rate, QRS-complex slopes, and P- and T-wave position parameters to be adjusted, but can also be used to adjust the very low frequency, low frequency, and high frequency components of HRV frequency domain characteristics. The system can be tuned to function with HRV or not. When the HRV function is on, the average heart rate can be set to a value ranging from 20 to 122 beats per minute (BPM) with an adjustable variation of 1 BPM. When the HRV function is off, the heart rate can be set to a value ranging from 20 to 139 BPM with an adjustable variation of 1 BPM. The amplitude of the ECG signal can be set from 0.0 to 330 mV at a resolution of 0.005 mV. These parameters can be adjusted either via input through a keyboard or through a graphical user interface (GUI) control panel that was developed using LABVIEW. The GUI control panel depicts a preview of the ECG signal such that the user can adjust the parameters to establish a desired ECG morphology. A complete set of parameters can be stored in the flash memory of the system via a USB 2.0 interface. Our system can generate three different types of synthetic ECG signals for testing the efficiency of an ECG algorithm or calibrating and maintaining ECG equipment.
