Is obesity associated with iron status in the elderly? A case study from Sharpeville, South Africa

Objective To investigate the relationship between poor Fe status and overweight or obesity in elderly respondents in South Africa. Design Cross-sectional, observational baseline survey. Setting Sharpeville, South Africa. Subjects A sample size calculation determined a representative sample of 104 randomly selected elderly (60 years) respondents. Measurements included weight, height, biochemical and haematological parameters. Measured BMI was used to categorise the respondents into normal weight, overweight and obese groups. Results The majority of the women were overweight (284 %) or obese (546 %); 58 % of the respondents had normal Fe status, 15 % were classified as Fe depleted, 9 % as Fe deficient and 13 % as Fe-deficient anaemic. Ten per cent of the respondents had low Hb levels with no other low Fe status parameters, and were thus anaemic due to other causes. A significant correlation (r = 0318, P < 0001) existed between BMI and high-sensitivity C-reactive protein (hs-CRP). hs-CRP was negatively correlated to serum Fe levels (r = -0319, P < 0001). No significant relationships existed between BMI and Fe status parameters. Conclusions A coexistence of obesity and poor Fe status were observed in these elderly respondents. The positive relationship between hs-CRP and BMI indicated chronic inflammation in the higher BMI groups. The negative relationship between hs-CRP and serum Fe indicated that lower serum Fe levels were related to the inflammation linked with higher BMI. A relationship between obesity-related chronic, low-grade inflammation and poor Fe status has been found in adults, but the significance of the current study is that this relationship was also confirmed for elderly persons.