THE RELATIONSHIP OF SERUM FERRITIN WITH SEX AND EXERCISE IN CANADIANSOF ICELANDIC DESCENT - IMPLICATIONS FOR PREVENTION OF CORONARY-ARTERYDISEASE

OBJECTIVE: To investigate the relationship of serum ferritin with sex and exercise. DESIGN AND SETTING: A cross-sectional design study carri ed out in Winnipeg, Manitoba. SUBJECTS: Urban Canadians of Icelandic d escent, aged 21 to 60 years, took part in this investigation. Subjects were stratified by age, sex and menstrual status. INTERVENTIONS: Veno us blood samples from fasting subjects were drawn for serum ferritin, hemoglobin and hematocrit analyses. Various anthropomorphic measuremen ts were taken, and subjects underwent submaximal cycle ergometry testi ng. A health and lifestyles questionnaire and a four-day prospective f ood record were administered. MAIN RESULTS: Mean serum ferritin levels obtained were 187.93 and 47.84 mu g/L for males and females, respecti vely. Mean serum ferritin levels were 33.06 mu g/L and 71.14 mu g/L fa r premenopausal and postmenopausal females, respectively. The mean wee kly consumption of alcohol was 190 mL/week and 80 mL/week for males an d females, respectively. The mean dietary intake of iron was 27.3 and 18.9 mg/day for males and females, respectively. Males, but not female s, who exercised 45 mins or more per week had significantly lower leve ls of serum ferritin than their sedentary counterparts. In males, hemo globin, hematocrit and the consumption of alcohol were positively corr elated with serum ferritin, while exercise time was negatively correla ted with serum ferritin. A trend towards lower serum ferritin levels a t higher workloads was observed in males, but did not reach statistica l significance. In females, age and dietary intake of iron were found tobe positively correlated with serum ferritin, while history of anemi a, menstrual status and workload were negatively correlated with serum ferritin. CONCLUSIONS: These findings suggest that regular aerobic ex ercise may decrease iron stores in the body. This may be clinically si gnificant since high serum ferritin has been cited as a risk factor fo r coronary artery disease.