Table 2. Proportion of the sample classified with diabetes and prediabetes by HbA1c only, FBG only, both HbA1c and FBG, or neither according to categories of iron deficiency and/or anemia status, Chinese adults aged 18–75 years, 2009 China Health and Nutrition Survey.
| Diabetes classification |
Nondiabetica |
DiabetesHbA1ca |
DiabetesFBGa |
DiabetesHbA1c+FBGa |
P-valueb | ||||
|---|---|---|---|---|---|---|---|---|---|
| Percent | Standard error | Percent | Standard error | Percent | Standard error | Percent | Standard error | ||
| Men | N=3027 | N=86 | N=81 | N=211 | 0.04 | ||||
| Normal iron/hemoglobinc | 80.1% | 0.7% | 81.4% | 4.2% | 75.3% | 4.8% | 70.1% | 3.2% | |
| Anemia alonec | 4.5% | 0.4% | 5.8% | 2.5% | 4.9% | 2.4% | 5.7% | 1.6% | |
| Iron deficiency alonec | 12.3% | 0.6% | 9.3% | 3.2% | 18.5% | 4.3% | 18.5% | 2.7% | |
| Iron-deficiency anemiac | 3.1% | 0.3% | 3.5% | 2% | 1.2% | 1.2% | 5.7% | 1.6% | |
| Women | N=3542 | N=117 | N=53 | N=189 | 0.008 | ||||
| Normal iron/hemoglobinc | 59.7% | 0.8% | 75.2% | 4% | 54.7% | 6.9% | 59.8% | 3.6% | |
| Anemia alonec | 7.9% | 0.5% | 6.8% | 2.3% | 11.3% | 4.4% | 12.7% | 2.4% | |
| Iron deficiency alonec | 22.3% | 0.7% | 11.1% | 2.9% | 26.4% | 6.1% | 21.7% | 3% | |
| Iron-deficiency anemiac | 10.1% | 0.5% | 6.8% | 2.3% | 7.5% | 3.7% | 5.8% | 1.7% | |
| Prediabetes classification |
Normoglycemiaa |
PrediabetesHbA1ca |
PrediabetesFBGa |
PrediabetesHbA1c+FBGa |
P-valueb | ||||
|---|---|---|---|---|---|---|---|---|---|
| Percent | Standard error | Percent | Standard error | Percent | Standard error | Percent | Standard error | ||
| Men | N=1952 | N=480 | N=364 | N=231 | <0.001 | ||||
| Normal iron/hemoglobinc | 78.8% | 0.9% | 78.8% | 1.9% | 82.7% | 2% | 90.5% | 1.9% | |
| Anemia alonec | 4.1% | 0.4% | 7.7% | 1.2% | 2.7% | 0.9% | 3.9% | 1.3% | |
| Iron deficiency alonec | 13.7% | 0.8% | 10.0% | 1.4% | 12.4% | 1.7% | 4.8% | 1.4% | |
| Iron-deficiency anemiac | 3.4% | 0.4% | 3.5% | 0.8% | 2.2% | 0.8% | 0.9% | 0.6% | |
| Women | N=2320 | N=572 | N=391 | N=259 | <0.001 | ||||
| Normal iron/hemoglobinc | 57.6% | 1% | 66.6% | 2% | 58.1% | 2.5% | 65.3% | 3% | |
| Anemia alonec | 7.9% | 0.6% | 8.0% | 1.1% | 9.0% | 1.4% | 5.8% | 1.5% | |
| Iron deficiency alonec | 23.5% | 0.9% | 15.2% | 1.5% | 25.1% | 2.2% | 22.8% | 2.6% | |
| Iron-deficiency anemiac | 10.9% | 0.6% | 10.1% | 1.3% | 7.9% | 1.4% | 6.2% | 1.5% | |
Abbreviations: FBG, fasting blood glucose; HbA1c, hemoglobin A1c.
Diabetes was classified as nondiabetic (FBG <126 mg dl−1 and HbA1c <6.5% (48 mmol mol−1)), diabetesHbA1c (HbA1c ⩾6.5% (48 mmol mol−1) and FBG <126 mg dl−1), diabetesFBG (FBG ⩾126 mg dl−1 and HbA1c <6.5% (48 mmol mol−1)) or diabetesHbA1c+FBG (FBG ⩾126 mg dl−1 and HbA1c ⩾6.5% (48 mmol mol−1), doctor diagnosis or reported diabetes medication use). Prediabetes classification excluded N=737 individuals with diabetes according to FBG, HbA1c, doctor diagnosis or reported diabetes medication use. Prediabetes was classified as normoglylcemia (FBG <100 mg dl−1 and HbA1c <5.7% (39 mmol mol−1)), prediabetesHbA1c (HbA1c=5.7–6.5% (39–48 mmol mol−1) and FBG <100 mg dl−1), prediabetesFBG (FBG=100–126 mg dl−1 and HbA1c <5.7% (39 mmol mol−1)) or prediabetesHbA1c+FBG (FBG =100–126 mg dl−1 and HbA1c=5.7–6.5% (39–48 mmol mol−1)). Column percents may not add up to 100% due to rounding.
P-value for χ2 test for differences diabetes or prediabetes classification according to categories of iron deficiency and/or anemia.
Iron/anemia status was categorized as normal iron and hemoglobin (hemoglobin ⩾12 g dl−1 (women) or ⩾13 g dl−1 (men), ferritin ⩾15 μg l−1, soluble transferrin receptor <1.76 mg l−1), anemia alone (as hemoglobin <12 g dl−1 (women) or <13 g dl−1 (men) without iron deficiency), iron deficiency alone (ferritin <15 μg l−1 or transferrin receptor ⩾1.76 mg l−1 without anemia) and iron-deficiency anemia (anemia: hemoglobin <12 g dl−1 (women) or <13 g dl−1 (men), as well as iron-deficiency ferritin <15 μg l−1 or transferrin receptor ⩾1.76 mg l−1).