Abstract
The risk factors for ischemic heart disease (IHD) in 35 Tibetan highlanders were investigated and compared with those in 30 age-and sexmatched healthy Japanese controls. Although Tibetans had remarkably high hematocrit values, and a decrease of eicosapentaenoic acid in both serum total lipids and serum phospholipid (PL) possibly due to their diet, they were considered to have a low incidence of IHD from our door-to-door study. These positive risk factors are likely counteracted by other negative risk factors as follows; Tibetans rarely exhibited systolic hypertension, and had lower levels of serum cholesterol and serum apolipoprotein (apo) B, and apo B/apo A-I ratio. In addition, Tibetan highlanders showed a decreased level of palmitic acid and an increased level of linoleic acid in serum PL which may protect against atherosclerosis
