ADIPOQ and chronic obstructive pulmonary disease: Haplotypes AAAAACT and GGACCTC were associated with a reductive risk of COPD, while haplotypes AGAACTC, AGGCCTC, GGAACTC, GGACACT and GGGCCTC increased the risk of developing COPD, indicating the complexity of ADIPOQ gene in the development of COPD.