Mortality among Swedish reindeer breeding Lapps in 1961-85.

We analyzed the mortality pattern among Swedish reindeer breeding Lapps, a unique group with a carefully preserved culture and a lifestyle that differs considerably from that of the rest of the population. The cohort consisted of 2,034 Lapps who were recorded in the 1960 Population and Housing census as members of a household where someone were occupied in reindeer breeding. The cohort was followed-up in the Swedish Cause-of-Death Register from January 1, 1961 until death or December 31, 1985. The total mortality was similar to that of the entire population. Four hundred and twenty eight deaths occurred and the standardized mortality ratio (SMR) was 0.95. Ischemic heart disease was the most frequent cause-of-death and the mortality was the same as in the general population (SMR = 0.95). Significantly lower mortality than expected was observed for malignant tumors (SMR = 0.70), diseases of the circulatory system (SMR = 0.68 and for diseases of the digestive system (SMR = 0.42). Significantly increased SMR was found for external causes of injury (SMR = 1.83) and among female Lapps for cerebrovascular diseases (SMR = 1.70). Female Lapps had a significantly higher mortality of diseases of the circulatory system (SMR = 1.19) in relation to males (SMR = 0.48).