Results of a 21 year study of the epidemiology of heart disease in Tibet found the frequencies of different types of heart disease radically different from those in China's interior.
The Tibet Research Institute of Medical. Sciences released the results of the investigation conducted between 1959 and 1980 among 2,627 patients of various nationalities and .ages, living at 2,500 metres to 4,500 metres above sea level.
Researchers found that hypertension accounts for 27.7 per cent; rheumatic heart disease, 19.03 per cent; altitude heart disease, 15 per cent; coronary heart disease, 13.65 per cent; pulmonary heart diseases, 9.63 per cent. But in China's interior, rheumatic heart disease is the most common, accounting for 30.4 to 67.36 per cent.
According to the study, men are slightly more susceptible to heart problems than women, and incidence among Han people who have come from elsewhere to work in Tibet is lower than native-born residents. Moreover, incidence increases with age for people above 12 years old, and winter is the season of highest occurrence and autumn the lowest.
The most common contributing factor of pulmonary heart disease is tuberculosis, as opposed to chronic bronchitis and asthma elsewhere.
Mortality rate from heart diseases on the Tibetan Plateau is 13.89 per cent, and the abovementioned five heart diseases account for more than 90 per cent of these deaths. Deaths due to heart disease are often accompanied by heart failure, respiratory tract infection, pulmonary edema and embolism.
The researchers are of the opinion that the causes of heart disease in Tibet are: shortage of oxygen at high altitudes, smoking, drinking, hereditary predisposition and excessively fatty diets.
Future research will focus on prevention and treatment of hypertension heart disease among adults and altitude-related heart problems among children, especially infants.
(This article appears on page 30, No. 49, 1982)