Similar factors were independently associated with walking less than 345 m in the 6MWT in multivariable stepwise logistic regression models: older age (56–65 years and > 65 years vs. < 55 years), elevated waist circumference, NT-pro BNP > 125 pg/mL, and anemia (p < 0.05 for all) Table 2. This evidence concerns the gene NPPB and anemia (phenotype).