In an effort to better understand the relationship existing between lipoprotein pattern and longevity, we studied the lipid and lipoprotein distribution of 94 men over age 80 who lived in a nursing home, and assessed the role of selective mortality, body mass and sex hormone secretion in determining these distributions. High density lipoprotein subfraction and serum testosterone measurements were obtained on subsamples. The main findings were: (a) Presence of a lipoprotein pattern characterized by low LDL (total serum cholesterol: 179.6 +/- 36.0 mg/dl; LDL cholesterol: 106.3 +/- 31.2 mg/dl) and high HDL2 cholesterol (18.5 +/- 10.2 mg/dl) levels. (b) Occurrence of a positive association between LDL and HDL3 (r = 0.51, P less than 0.01), resulting in an overall high HDL2/HDL3 ratio. Mortality over a 6-month period was directly related to LDL level and possibly inversely related to HDL2 level, suggesting that selective mortality played a major role in determining the pattern observed. Body mass and serum testosterone concentration, which tended to be low, were independently correlated with lipoprotein level; a particularly strong correlation (positive) existed between free testosterone and triglyceride (r = 0.68, P less than 0.01). The latter results suggest that changes related to senescence also influenced lipid and lipoprotein levels.