The TNFA-308 A allele is significantly associated with HT risk in the log-additive (OR = 1.64, CI = 1.28–2.10, p-value = 8.2×10−5) and dominant models (OR = 1.82, CI = 1.37–2.43, p-value = 4.4×10−5). This evidence concerns the gene TNF and hematocrit.