Body iron stores and mortality due to cancer and ischaemic heart disease: a 17-year follow-up study of elderly men and women.
BACKGROUND
Increased body iron stores have been suggested as a risk factor for cancer and ischaemic heart disease (IHD). However, all studies carried out to date have focused on relatively young populations although the elderly may also be at increased risk.


METHODS
We investigated the association between body iron stores and mortality due to cancer and IHD in a 17-year follow-up study of 260 non-institutionalized elderly people aged 64-87 years. Iron status was assessed in 1971 by means of the haemoglobin level, transferrin saturation and total iron binding capacity (TIBC). Information about the vital status and causes of death was obtained in 1988.


RESULTS
Among women mortality due to cancer was inversely related to TIBC; the relative risk for the highest tertile of TIBC, adjusted for age, smoking and alcohol intake was 0.05 (95% confidence interval (CI): 0.007-0.39). The risk of mortality due to all-causes was also inversely associated with TIBC. Among men, no association between body iron stores and mortality due to cancer was observed. Mortality due to IHD was not clearly associated with body iron status. Among men, the adjusted relative risk decreased slightly per tertile of transferrin saturation, but this trend was only of borderline significance (P = 0.10).


CONCLUSIONS
These results suggest that body iron stores are a risk factor for mortality due to cancer in postmenopausal women. This may be due to accumulation of stored iron among women after menopause. No clear associations with mortality due to IHD were observed in either elderly men or elderly women.
Department of Chronic Diseases and Environmental Epidemiology, National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands.
I A
IA
van Asperen
E J
EJ
Feskens
C H
CH
Bowles
D
D
Kromhout
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007501:Iron / Q000378:metabolism*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000378:metabolism / Q000401:mortality*; D009369:Neoplasms / Q000378:metabolism / Q000401:mortality*; D009426:Netherlands / Q000453:epidemiology; D012307:Risk Factors; D014168:Transferrin / Q000378:metabolism
D006454:Hemoglobins; D014168:Transferrin; D007501:Iron