Physiological characteristics and cardiac electrophysiology manifested in Minnesota coding of the "desert people" in Taklimakan Desert: study of 224 cases

Abstract

To study the physiological characteristics and cardiac electrophysiology of the "desert people" in Taklimakan Desert, an isolated population of Uygurs. Two hundred and twenty-four out of the 1030 "desert people", 133 males aged 37.8 +/- 17.5 (15-99) and 91 females aged 34.1 +/- 12.1 (27-85), underwent measurement of height, body weight, waist circumference, and blood pressure. Twelve-lead resting electrocardiogram was obtained and Minnesota coding was conducted. 150 Kariya Uygurs, 76 males aged 50.7 +/- 15.6 (27-85) and 75 females aged 46.6 +/- 11.7 (24-69) were used as controls. The abnormal Minnesota coding rate in the "desert people" as a whole was 46.0%, significantly higher than that of the controls (35.1%, P < 0.05). In the "desert people", the abnormal Minnesota coding rate was 54.9% in the males, significantly higher than that in the females (33.0%, P < 0.05). In the control group, the abnormal coding rate was 28.0% in the females and 42.1% in the males. The ECG high left R amplitude rate (code 3-1, 3-3) of the "desert people" as a whole was 32.6%, significantly higher than that of the controls (12.6%, P < 0.001). Within the "desert people" group, the ECG high left R amplitude rate of the females was 19.8%, significantly lower than that of the males (41.2%, P < 0.005). Within the control group, the ECG high left R amplitude rate of the females was 10.7%, not significantly different from that of the males (14.5%, P > 0.5). The hypertension rate of the "desert people" was 7.6%, significantly lower than that of the controls (36.4%, P < 0.005). The hypertension rate of the "desert people" coded as with left high R amplitude was 12.2%, significantly lower than that of the controls coded as with left high R amplitude (41.6%, P < 0.005). The overweight and obesity rate of the "desert people" was 9.6%, significantly lower than that of the controls (23%, P < 0.005). The arrhythmia (8-1 - 8-8) rate of the "desert people" was 8.92%, not significantly different from that of the controls (6.62%, P > 0.05). The incidence of conduction block (7-1 - 7-8) of the "desert people" was 3.12%, not significantly different from that of the controls (2.64%, P > 0.05). The higher incidence of ECG high left R amplitudes and low prevalence of hypertension in the "desert people" suggest that the high left R amplitude in "Desert people" may be related to their thin chest wall, low BMI, and physiological left ventricular hypertrophy. The "desert people" have more physical work, and less stress and pollution. They have low incidence of congenital heart disease, rheumatic heart disease and hypertension. All these may be associated with a low incidence of arrhythmia.