Historical demographic and epidemiological studies of aging in American Samoans

American Samoan mortality records, from 1920 through 1988, and epidemiological survey data from 1976 are used to examine demographic definitions of the elderly in different time periods and to examine the association of body habitus and blood pressure with mortality among middle-aged and older Samoans. In the 1920s, the average Samoan lived 24 years, but over 50% of deaths occurred prior to age 15. In the 1980s the average Samoan lived about 54 years and 50% of deaths occurred after age 58. The common definition for matua (an elder or true old one) was 50 years in 1962, an age to which only 17% of the population lived in the 1920s; this value increased to 60-65 years by 1976, when 53% of the population survived to age 50 years and 34% to age 65 years. These data suggest that quantitative demographic factors may have constrained Samoan cultural definitions of matua i.e., "elderliness" during the 20th century. Among middleaged and older Samoans who died between 1976 and 1980, body weight, body mass index (BMI), and systolic and diastolic blood pressure were differentially associated with cause-specific mortality by age and sex. None of these risk factors was associated with mortality in older men, but BMI and systolic pressure were significanlty lower among middle-aged men who died. In contrast, all four risk factors were associated positively with mortality in middle-aged women, but in older women only systolic pressure was.