Table 4.
| Study | Year | Study type (Sample origin) | Demographics (AA cases)† | Sample Size Total (Detail) | Measures and outcomes |
|---|---|---|---|---|---|
| Dastgheib et al.[57] | 2014 | Case- control (Not described) | Sex: 16F Age: 26.63 ± 8.53 Country: Iran |
43 (16 AA cases and 27 sex- and age- matched healthy controls) | No difference in serum or hair iron levels in AA vs. healthy controls |
| Gonul et al. [72] | 2009 | Case- control (Not described) | Sex: 29M/14F Age: 29.1 ± 13.4 Country: Turkey |
79 (43 AA cases and 36 healthy sex and age-matched controls) | Low** ferritin levels detected in 4/43 patients; low** iron levels detected in 8/43 patients; No difference between AA and control groups for ferritin and iron levels |
| Tzellos et al. [73] | 2009 | Case-report | Sex: 1 M Age: 18 Country: Greece |
1 AA | Normal serum ferritin levels |
| Esfandiarpour et al. [74] | 2008 | Case- control (Not described) | Sex: 29M/23F Age: 23.52 ± 14.42 Country: Iran |
115 (52 AA cases and 63 age-matched healthy controls recruited from blood donors) | No difference in serum ferritin levels or serum iron levels in AA vs. controls |
| Kantor et al. [68] | 2003 | Case- control (Hospital- based) | Sex: 24F Age: AA: 34.9 (27.5, 42.3); AT/AU: 53.1 (39.6, 66.6) Country: USA |
35 (17 AA, 7 AT/AU cases and 11 controls having neither of the common mutations in the HFE-1 gene for hereditary hemochromatosis) | Serum ferritin levels in AA (24.9 ng/mL [95% CI: 17.2, 32.6]) vs. controls (59.5 ng/mL [40.8, 78.1]) (P < 0.05); No difference in serum ferritin in AT/AU vs. controls |
| White et al. [71] | 1994 | Case-series | Sex: 9M/21F Age: 31.36 ± 17.34 Country: Scotland |
30 AA | 14/21 females and 1/9 males were iron deficient*, 20/21 females and 2/9 males had serum ferritin ≤30 μg/L |
| Boffa et al. [70] | 1995 | Case-series | Sex: 11M/21F Age: 44.31 ± 14.71 Country: England |
32 AA | No evidence of iron deficiency* in male AA patients; prevalence of iron deficiency in AA females comparable to normal population |
| Mussalo- Rauhamaa et al. [58] | 1986 | Case- control (Not described) | Sex: 8M/19F Age: 29 ± 11 Country: Finland |
27 AA cases compared to normal Finnish population reference values | No difference in serum iron levels in AA vs. normal population |
AA alopecia areata, AT alopecia totalis, AU alopecia universalis
*
Iron deficiency defined as serum ferritin ≤ 15 μg/L
**
Threshold serum cut-offs not provided
†
Age given as mean ± standard deviation or mean (95% CI)