Is it necessary to consider obesity when constructing norms for hemoglobin or when screening for anemia using hemoglobin levels?

OBJECTIVE To assess the relationship of total adiposity and abdominal adiposity on hemoglobin levels in Saudi nonpregnant women. METHODS We carried out this cross-sectional study during winter of 2002 (from January to March) in and around Abha city, Kingdom of Saudi Arabia. Included in the study were 530 non-pregnant women between the age of 18-65 years. Body weight was measured using an Avery Beam weighing scale, while height was measured using a stadiometer and waist circumference using a fiberglass. Hemoglobin levels were estimated using cyanmethemoglobin method. Total obesity was defined as body mass index (BMI) >or=30 and abdominal obesity as WC >88 cm. RESULTS The mean and median hemoglobin levels were significantly higher in abdominally obese women compared with totally obese (p<0.04 versus <0.02) and non obese ones (p<0.04 versus <0.03). No significant differences in the mean and median hemoglobin levels were observed when abdominally obese women were compared with both abdominally and totally obese ones (p<0.7 for both). The mean and the median hemoglobin levels were virtually identical in non-obese and totally obese women. Statistical analysis showed that the mean hemoglobin level was positively and significantly associated with WC (p<0.005) and negatively and insignificantly associated with BMI (p<0.8). CONCLUSION In view of the positive and significant association between abdominal obesity and the mean hemoglobin level in this population, abdominal obesity should be considered when constructing norms for hemoglobin or when screening for anemia using hemoglobin levels.