Correction: Hypertension and diabetes on cognitive impairment: a case–control study in China - Jing Wu; Xiangjun Yin; Weiqiang Ji; Yang Liu; Jing Tang; Han Zhang; Shige Qi; Jie Li; Li Lin; Xueqing Yang; Chengdong Xu; Qingfeng Du (Alzheimer’s Research & Therapy)